High-quality coherent ghost imaging of a transmission target.

When the test detector of ghost imaging (GI) is a point-like detector and the detector's transverse size is smaller than the transverse coherence length of the light field at the detection plane, this case is corresponding to coherent GI (CGI) and the imaging result recovered by traditional GI (TGI) reconstruction algorithm is usually bad for a transmission target. Here a CGI scheme of a transmission target is proposed and a corresponding CGI reconstruction algorithm is developed to stably recover the target's image. The validity of the proposed method is verified by both simulation and experiments. Both the simulation and experimental results demonstrate that the target's transmission function can be perfectly reconstructed by CGI. We also show that the imaging quality of CGI with a point-like detector is better than that of TGI with a bucket detector if detection noise exists in the sampling process. Performance comparisons between CGI reconstruction and TGI reconstruction are also discussed.

Acidification-Induced Micronano Mechanical Properties and Microscopic Permeability Enhancement Mechanism of Coal.

An acid solution improves the pore-plugging problem in hydraulic fracturing, which in turn improves the permeability of the coal seam. The study aimed to investigate the effect of mixed acid on the micronano mechanical properties and permeability of the coal seam. The surface morphology of acidified coal was analyzed from the micronano scale using atomic force microscopy (AFM) and scanning electron microscopy. Additionally, the micronano scale mechanical characteristics of acidified coal were examined using the mechanical mode in an atomic force microscope. Furthermore, the complexity and connectivity of the micronano pores of samples were investigated using the low-temperature nitrogen adsorption and mercury intrusion porosimetry methods and the fractal theory. The results indicated that the surface minerals of acidified coal were dissolved, loosening the coal and increasing the complexity of the pore structure. Mineral deformation and pore deformation weakened the mechanical properties of coal at the micronano scale, and the mean elastic modulus of acidified coal (B# and E#) decreased by 28.78 and 25.66% compared to that of raw coal. The acid solution effectively enlarged the pore diameter, transitioning from micropores to mesopores and macropores, and the total pore volume of acidified coal increased by 1.88 times and 1.25 times, Kn increased from 0.064 to 0.581 and 0.37, respectively. The type of methane diffusion in the diffusion pores changed from Knudsen diffusion to transition-type diffusion. The tortuosity of the pore structure of acidified coal decreased, the fractal dimension of the tortuosity of the pore structure decreased, and the permeability increased by nearly three times. The research results indicate that the mechanical properties of coal decrease after acidification and that the microstructural changes can promote methane migration (diffusion-seepage), which can provide theoretical guidance for coalbed methane extraction in low-permeability coal reservoirs.

Finer Particle Size Distribution and Potential Higher Toxicity of Elemental Carbon and Polycyclic Aromatic Hydrocarbons Emitted by Ships after Fuel Oil Quality Improvement.

Ship emissions are a significant source of air pollution, and the primary policy to control is fuel oil quality improvement. However, the impact of this policy on particle size distribution and composition characteristics remains unclear. Measurements were conducted on nine different vessels (ocean-going vessels, coastal cargo ships, and inland cargo ships) to determine the impact of fuel upgrading (S < 0.1% m/m marine gas oil (MGO) vs S < 0.5% m/m heavy fuel oil (HFO)) on elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) emitted by ships. (1) Fuel improvement significantly reduced EC and PAH emission, by 31 ± 25 and 45 ± 38%, respectively. However, particle size distributions showed a trend toward finer particles, with the peak size decreasing from DP = 0.38-0.60 µm (HFO) to DP = 0.15-0.25 µm (MGO), and the emission factor of DP < 100 nm increased. (2) Changes in emission characteristics led to an increase in the toxicity of ultrafine particulate matter. (3) Ship types and engine conditions affected the EC and PAH particle size distributions. Inland ships have a more concentrated particle size distribution. Higher loads result in higher emissions. (4) The composition and engine conditions of fuel oils jointly affected pollutant formation mechanisms. MGO and HFO exhibited opposite EC emissions when emitting the same level of PAHs.

N-N-Bridged Polynuclear POM-Based Coordination Polymers Based on a V-Type Ligand: Proton Conduction and Magnetism.

The construction of polyoxometalate (POM)-based coordination polymers, in the presence of a nitrogen heterocyclic ligand, is intriguing due to the potential for obtaining diverse structures. These structures exhibit extensive application possibilities in the fields of proton conductivity and magnetism. Herein, four new POM-based polynuclear coordination polymers with the formulas of {[Fe2(btb)3(H2O)2(SiW12O40)]·3H2O}n (1), {[Cd2(btb)2(H2O)6(HPMoVI10MoV2O40)]·2H2O}n (2), {[Co3(OH)2(btb)2(H2O)5(HPMoVI10MoV2O40)]·7H2O}n (3), and {[Cu3(OH)(btb)2(H2O)(HP2Mo5O23)]·6H2O}n (4) have been prepared using the V-type 1,3-bis(4H-1,2,4-triazole-4-yl)benzene (btb) ligand. Compounds 1 and 2 feature similar two-dimensional (2D) structures, derived from the binuclear Fe2N6 and Cd2N4 subunits connected by tridentate btb ligands. Meanwhile, in compound 3, hexanuclear Co6(OH)4 units are bound by quadridentate btb ligands forming a 2D layer with the same 4-c sql topology simplification as compounds 1 and 2. In compound 1, Keggin-type polyoxoanions are monodentate-coordinated to metal ions and suspended on the 2D structure, while, in compounds 2 and 3, they act as discrete counterions residing in the interstitial spaces between two adjacent layers, thereby extending the 2D structures into 3D structures through hydrogen bonding interactions. In compound 4, trinuclear Cu3(OH) subunits are further constructed into a 3D framework through cooperation with four tridentate and quadridentate btb ligands as well as Strandberg-type anions. Furthermore, the proton conduction of the four compounds has been investigated. They display high proton conductivities at 358 K and 98% RH with powdered samples, which are 1.26 × 10-3, 1.24 × 10-3, 3.24 × 10-4, and 2.57 × 10-4 S cm-1, respectively. Interestingly, by mixing with Nafion, the composite membranes of compounds 2 and 4 exhibit enhanced proton conductivities, measuring at 4.87 × 10-2 and 1.28 × 10-2 S cm-1, respectively, at 358 K and 98% RH, which suggests excellent potential for applications. In addition, compounds 1, 3, and 4 display antiferromagnetic behaviors due to similar magnetic interactions. This work can provide research insights into the assembly of 2D POM-based coordination polymers with nitrogen heterocyclic ligands and Keggin-type POMs and further promote their research progress in proton conduction.

Aqueous-Phase Reactions of Anthropogenic Emissions Lead to the High Chemodiversity of Atmospheric Nitrogen-Containing Compounds during the Haze Event.

Nitrogen-containing organic compounds (NOCs), a type of important reactive-nitrogen species, are abundant in organic aerosols in haze events observed in Northern China. However, due to the complex nature of NOCs, the sources, formation, and influencing factors are still ambiguous. Here, the molecular composition of organic matters (OMs) in hourly PM2.5 samples collected during a haze event in Northern China was characterized using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We found that CHON compounds (formulas containing C, H, O, and N atoms) dominated the OM fractions during the haze and showed high chemodiversity and transformability. Relying on the newly developed revised-workflow and oxidation-hydrolyzation knowledge for CHON compounds, 64% of the major aromatic CHON compounds (>80%) could be derived from the oxidization or hydrolyzation processes. Results from FT-ICR MS data analysis further showed that the aerosol liquid water (ALW)-involved aqueous-phase reactions are important for the molecular distribution of aromatic-CHON compounds besides the coal combustion, and the ALW-involved aromatic-CHON compound formation during daytime and nighttime was different. Our results improve the understanding of molecular composition, sources, and potential formation of CHON compounds, which can help to advance the understanding for the formation, evolution, and control of haze.

Emission Characteristics and Formation Mechanism of Carbonyl Compounds from Residential Solid Fuel Combustion Based on Real-World Measurements and Tube-Furnace Experiments.

This study updated carbonyl compound (CC) emission factors (EFs) and composition for residential solid fuel combustion based on real-world measurements of 124 fuel/stove combinations in China and explored the CC formation mechanism using tube-furnace experiments with 19 fuels and low/high temperatures to explain the impact of fuel and stove on CC emission characteristics. The average EFCC values for straw, wood, and coal were 1.94 ± 1.57, 1.50 ± 0.88, and 0.40 ± 0.54 g/kg, respectively. Formaldehyde and acetaldehyde were the most abundant species, accounting for 40-60% of CCs, followed by acetone (∼20%), aromatic aldehydes (∼10%), and unsaturated aldehydes (∼5%). Different from formaldehyde and acetaldehyde, other species showed significant variation among fuel types. All these characteristics could be explained by the difference in the volatile content and chemical structure of fuel, such as aromatic in coal versus lignin in biomass. The improvement in stove technology reduced CC emissions by 30.4-69.7% (mainly formaldehyde and acetaldehyde) among fuels but increased the proportion of aromatic aldehydes by 24.3-89.4%. Various CC species showed different formation mechanisms related to fuel property and burning temperature. The volatile matter derived from thermal pyrolysis of fuel polymers determined CC composition, while higher temperature preferentially degraded formaldehyde and acetaldehyde but promoted the formation of acetone and aromatic aldehydes. This study not only revealed emission characteristic of CCs from RSFC but also contributed to the improvement of clean combustion technology.

Rapid FRET-based homogeneous immunoassay of procalcitonin using matched carbon dots labels.

A novel method for the detection of procalcitonin in a homogeneous system by matched carbon dots (CDs) labeled immunoprobes was proposed based on the principle of FRET and double antibody sandwich method. Blue-emitting carbon dots with a strong fluorescence emission range of 400-550 nm and red-emitting carbon dots with the best excitation range of 410-550 nm were prepared before they reacted with procalcitonin protoclone antibody pairs to form immunoprobes. According to the principles of FRET, blue-emitting carbon dots were selected as the energy donor and red-emitting carbon dots as the energy receptor. The external light source excitation (310 nm) could only cause weak luminescence of CDs. However, once procalcitonin was added, procalcitonin and antibodies would be combined with each other quickly (≤20 min). Here, blue-emitting carbon dots acquired energy could be transferred to red-emitting carbon dots efficiently, causing the emitted fluorescence enhancement of red-emitting carbon dots. The fluorescence detection results in PBS buffer solution and diluted rabbit blood serum showed that the fluorescence intensity variation was linear with the concentration of procalcitonin. There was a good linear relationship betweenF/F0 and procalcitonin concentrations in PBS buffer solution that ranged from 0 to 100 ng ml-1, and the linear equation wasF/F0 = 0.004 *Cpct + 0.98359. Detection in the diluted rabbit serum led to the results that were linear in two concentration ranges, including 0-40 ng ml-1and 40-100 ng ml-1, and the detection limit based on 3σK-1was 0.52 ng ml-1. It is likely that this matched CDs labeled immunoprobes system can provide a new mode for rapid homogeneous detection of disease markers.

A novel hierarchical machine learning model for hospital-acquired venous thromboembolism risk assessment among multiple-departments.

Venous thromboembolism (VTE) is a common vascular disease and potentially fatal complication during hospitalization, and so the early identification of VTE risk is of significant importance. Compared with traditional scale assessments, machine learning methods provide new opportunities for precise early warning of VTE from clinical medical records. This research aimed to propose a two-stage hierarchical machine learning model for VTE risk prediction in patients from multiple departments. First, we built a machine learning prediction model that covered the entire hospital, based on all cohorts and common risk factors. Then, we took the prediction output of the first stage as an initial assessment score and then built specific models for each department. Over the duration of the study, a total of 9213 inpatients, including 1165 VTE-positive samples, were collected from four departments, which were split into developing and test datasets. The proposed model achieved an AUC of 0.879 in the department of oncology, which outperformed the first-stage model (0.730) and the department model (0.787). This was attributed to the fully usage of both the large sample size at the hospital level and variable abundance at the department level. Experimental results show that our model could effectively improve the prediction of hospital-acquired VTE risk before image diagnosis and provide decision support for further nursing and medical intervention.

Intrinsic signal optical imaging of visual brain activity: Tracking of fast cortical dynamics.

Hemodynamic-based brain imaging techniques are typically incapable of monitoring brain activity with both high spatial and high temporal resolutions. In this study, we have used intrinsic signal optical imaging (ISOI), a relatively high spatial resolution imaging technique, to examine the temporal resolution of the hemodynamic signal. We imaged V1 responses in anesthetized monkey to a moving light spot. Movies of cortical responses clearly revealed a focus of hemodynamic response traveling across the cortical surface. Importantly, at different locations along the cortical trajectory, response timecourses maintained a similar tri-phasic shape and shifted sequentially across cortex with a predictable delay. We calculated the time between distinguishable timecourses and found that the temporal resolution of the signal at which two events can be reliably distinguished is about 80 milliseconds. These results suggest that hemodynamic-based imaging is suitable for detecting ongoing cortical events at high spatial resolution and with temporal resolution relevant for behavioral studies.

Tubular-like Nanocomposites with Embedded Cu9S5-MoSx Crystalline-Amorphous Heterostructure in N-Doped Carbon as Li-Ion Batteries Anode toward Ultralong Cycling Stability.

Transition metal sulfides (TMSs) show the potential to be competitive candidates as next-generation anode materials for Li-ion batteries (LIBs) due to their high theoretical specific capacity. However, sluggish ionic/electronic transportation and huge volume change upon lithiation/delithiation remain major challenges in developing practical TMS anodes. We rationally combine structural design and interface engineering to fabricate a tubular-like nanocomposite with embedded crystalline Cu9S5 nanoparticles and amorphous MoSx in a carbon matrix (C/Cu9S5-MoSx NTs). On the one hand, the hybrid integrated the advantages of 1D hollow nanostructures and carbonaceous materials, whose high surface-to-volume ratios, inner void, flexibility, and high electronic conductivity not only enhance ion/electron transfer kinetics but also effectively buffer the volume changes of metal sulfides during charge/discharge. On the other hand, the formation of crystalline-amorphous heterostructures between Cu9S5 and MoSx could further boost charge transfer due to an induced built-in electric field at the interface and the presence of a long-range disorder phase. In addition, amorphous MoSx offers an extra elastic buffer layer to release the fracture risk of Cu9S5 crystalline nanoparticles during repetitive electrochemical reactions. Benefiting from the above synergistic effect, the C/Cu9S5-MoSx electrode as an LIB anode in an ether-based electrolyte achieves a high-rate capability (445 mAh g-1 at 6 A g-1) and superior ultralong-term cycling stability, which delivers an initial discharge capacity of 561 mAh g-1 at 2 A g-1 and its retention capacity after 3600 cycles (376 mAh g-1) remains higher than that of commercial graphite (372 mAh g-1).

Tailored chitosan/glycerol micropatterned composite dressings by 3D printing for improved wound healing.

Wound infection control is a primary clinical concern nowadays. Various innovative solutions have been developed to fabricate adaptable wound dressings with better control of infected wound healing. This work presents a facile approach by leveraging 3D printing to fabricate chitosan/glycerol into composite dressings with tailored micropatterns to improve wound healing. The bioinks of chitosan/glycerol were investigated as suitable for 3D printing. Then, three tailored micropatterns (i.e., sheet, strip, and mesh) with precise geometry control were 3D printed onto a commercial dressing to fabricate the micropatterned composite dressings. In vitro and in vivo studies indicate that these micropatterned dressings could speed up wound healing due to their increased water uptake capacity (up to ca. 16-fold@2 min), benign cytotoxicity (76.7 % to 90.4 % of cell viability), minor hemolytic activity (<1 %), faster blood coagulation effects (within 76.3 s), low blood coagulation index (14.5 % to 18.7 % @ 6 min), enhanced antibacterial properties (81.0 % to 86.1 % against S. aureus, 83.7 % to 96.5 % against E. coli), and effective inhibition of wound inflammation factors of IL-1ß and TNF-α. Such tailored micropatterned composite dressing is facile to obtain, highly reproducible, and cost-efficient, making it a promising implication for improved and personalized contaminated wound healing.

Enhanced coalbed methane well production prediction framework utilizing the CNN-BL-MHA approach.

As the mechanization of the CBM extraction process advances and geological conditions continuously evolve, the production data from CBM wells is deviating increasingly from linearity, thereby presenting a significant challenge in accurately predicting future gas production from these wells. When it comes to predicting the production of CBM, a single deep-learning model can face several drawbacks such as overfitting, gradient explosion, and gradient disappearance. These issues can ultimately result in insufficient prediction accuracy, making it important to carefully consider the limitations of any given model. It's impressive to see how advanced technology can enhance the prediction accuracy of CBM. In this paper, the use of a CNN model to extract features from CBM well data and combine it with Bi-LSTM and a Multi-Head Attention mechanism to construct a production prediction model for CBM wells-the CNN-BL-MHA model-is fascinating. It is even more exciting that predictions of gas production for experimental wells can be conducted using production data from Wells W1 and W2 as the model's database. We compared and analyzed the prediction results obtained from the CNN-BL-MHA model we constructed with those from single models like ARIMA, LSTM, MLP, and GRU. The results show that the CNN-BL-MHA model proposed in the study has shown promising results in improving the accuracy of gas production prediction for CBM wells. It's also impressive that this model demonstrated super stability, which is essential for reliable predictions. Compared to the single deep learning model used in this study, its prediction accuracy can be improved up to 35%, and the prediction results match the actual yield data with lower error.

Study on the mechanism of methane "solid-liquid-gas" conversion controlled by the evolution of coal micro- and nanopore structure.

Currently, the utilization of coalbed methane resources in the Guizhou region faces challenges such as complex reservoir structure, high gas content, and microporous development. Based on these, the pore structure and adsorption capacity of Guizhou tectonic deformed coals (TDCs) were evaluated using a suite of integrated diagnostic techniques including low-temperature nitrogen adsorption (LT-N2A), mercury intrusion porosimetry (MIP), methane isothermal adsorption. Through the above methods, the pore structure and adsorption characteristics of the samples were characterized; The samples were divided into the range of joint pores by combining the results of MIP and LT-N2A; Using the molecular simulation software, the 2 nm, 4 nm, 10 nm pores affecting the methane endowment state were investigated respectively, and from the perspective of the heat of adsorption and energy, the concept of the three-phase transition of methane was proposed, and explore the change of the pore spacing affecting the endowment state of methane from the solid state pore to the gas state pore. The results provide new ideas for the in-depth study of gas storage in tectonic coal reservoirs in Guizhou Province.

Experimental research on the influence of acid on the chemical and pore structure evolution characteristics of Wenjiaba tectonic coal.

The chemical and pore structures of coal play a crucial role in determining the content of free gas in coal reservoirs. This study focuses on investigating the impact of acidification transformation on the micro-physical and chemical structure characteristics of coal samples collected from Wenjiaba No. 1 Mine in Guizhou. The research involves a semi-quantitative analysis of the chemical structure parameters and crystal structure of coal samples before and after acidification using Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) experiments. Additionally, the evolution characteristics of the pore structure are characterized through high-pressure mercury injection (HP-MIP), low-temperature nitrogen adsorption (LT-N2A), and scanning electron microscopy (SEM). The experimental findings reveal that the acid solution modifies the structural features of coal samples, weakening certain vibrational structures and altering the chemical composition. Specifically, the asymmetric vibration structure of aliphatic CH2, the asymmetric vibration of aliphatic CH3, and the symmetric vibration of CH2 are affected. This leads to a decrease in the contents of -OH and -NH functional groups while increasing aromatic structures. The crystal structure of coal samples primarily dissolves transversely after acidification, affecting intergranular spacing and average height. Acid treatment corrodes mineral particles within coal sample cracks, augmenting porosity, average pore diameter, and the ratio of macro-pores to transitional pores. Moreover, acidification increases fracture width and texture, enhancing the connectivity of the fracture structure in coal samples. These findings provide theoretical insights for optimizing coalbed methane (CBM) extraction and gas control strategies.

Pharmacological activity and clinical application analysis of traditional Chinese medicine ginger from the perspective of one source and multiple substances.

All types of ginger have common fundamental components, although they possess distinct strengths and inclinations when it comes to effectiveness and medicinal applications. Fresh ginger possesses the ability to effectively stimulate movement within the body, alleviate the act of vomiting, induce sweating, and provide relief for external syndromes. Dried ginger possesses both defensive and stimulant characteristics, which effectively raise the internal temperature and enhance the Yang energy. Fresh ginger is more hydrating than dried ginger, highly skilled at heating the Middle-jiao, alleviating pain, halting bleeding, and managing diarrhea. Dried ginger possesses the ability to alleviate coldness when consumed in a heated form, as well as to alleviate diarrhea when consumed in a heated form. It thrives in warm conditions and has a tendency to revert back to its warm nature. The moisture content of baked ginger is inferior to that of dried ginger, but it is highly effective in alleviating pain, bleeding, and diarrhea by warming the Middle-jiao. Ginger charcoal and stir-fried charcoal, produced through carbonization, have excellent heat retention properties and are effective in warming meridians and stopping bleeding. The potency and ability to spread of roasted ginger is less intense compared to fresh ginger, and its moisture content is not as low as that of dried ginger. The medicinal characteristics of this substance are gentle, making it beneficial for alleviating vomiting in patients who are physically frail. Its primary mode of action is on the Middle-jiao. Nevertheless, the main chemical compositions of various traditional Chinese medicines are nearly identical due to their shared base element. Ginger, in particular, possesses a range of pharmacological activities including antioxidant, anti-inflammatory, anti-tumor, anti-bacterial, and anticoagulant properties. However, modern pharmacological research has not fully acknowledged the clinical medicinal value of ginger and consequently, fails to provide accurate guidance for clinical medication. This situation has a negative impact on the contemporary advancement of traditional Chinese medicine (TCM). The research on modernizing ginger is conducted by analyzing and considering the prospects. It is based on Traditional Chinese Medicine (TCM) theory and incorporates the comprehensive perspective of TCM philosophy. In order to modernize ginger, it is essential to have a proper knowledge of the concepts of "recognizing nature by efficacy, homology, and mutual expression of nature and efficacy" and "rationally utilizing modern drug research technology". By applying these principles, we can construct a bridge towards the advancement of ginger.

Intraoperative Intraocular Lens Waste: Incidence, Cost and Reasons.

PURPOSE: To evaluate the incidence and cost of intraocular lens(IOL) waste during IOL implantation, as well as the reasons for it. METHODS: A retrospective analysis was conducted on the data of 485 patients from the IOL waste registers of a single tertiary eye hospital in China during 2016-2020. The primary outcomes were the incidence, cost, and reasons for different IOL properties. Cases were examined to ascertain IOL material, design, procedural details, and causes of waste. RESULTS: IOL waste occurred in 485 (6.62‰) of the 73,246 IOL implantations during the study period. The total cost of IOL waste was 429, 850.26 Chinese Yuan (CNY) related to waste with an average cost of 2, 442.33 CNY per procedure during the study period. Comparisons between IOL properties showed that polymethyl methacrylate (PMMA) material (39, 2.05%), three-piece design (142, 1.49%), and secondary IOL implantation (26, 2.16%) were associated with IOL wastage, and the difference was statistically significant. The causes of IOL waste were damage (107, 60.80%), patient reasons (37, 21.26%), aseptic errors (22, 12.50%), IOL quality problems (8, 4.55%), and loss (2, 1.14%). CONCLUSIONS: The incidence of IOL waste is low, but still leads to a significant cost burden due to a large number of cataract surgeries. PMMA material, three-piece design, and secondary implantation were identified as factors increasing IOL waste. Damage emerged as the primary reason for waste, largely attributed to human error. Therefore, the development of strategies to mitigate IOL waste is imperative.

Comparative investigation of the performances of hematite nanoplates and nanograins in lithium-ion batteries.

In this work, we selectively prepared two samples with quite different nanocrystal shapes, i.e. nanoplates and nanograins but with almost identical surface areas to make a clear comparison of nanocrystal shapes on electrochemical performance. The electrochemical results indicate that the thinner hexagonal α-Fe2O3 nanoplates considerably enclosed by two larger (0001) basal surfaces exhibit higher capacity and stability than thicker α-Fe2O3 nanograins enclosed by a variety of crystal facets. During the conversion reaction, an orientated growth of porous nanostructure with orientated nanowalls as a stable framework is observed for the nanoplate, readily supplying a pathway for long and easy lithiation-delithiation cycling. The improved electrochemical performance of α-Fe2O3 nanoplates is surely related to the nanostructure with significantly stacked (0001) lattice planes along [0001] direction for orientated growth of γ-Fe2O3 nanodomains along one [111] direction.

Evolution of fissures and pressure discharge of gas caused by mining of the upper protective layer of a coal seam.

The evolution of fissures and permeability associated with mining of the upper protective layer of the coal seam is crucial for pressure relief gas drainage of the underlying seam. To understand the influence of mining the upper protective layer on gas drainage within the underlying coal seam, this study utilized the M16 and M18 seams in the Qinglong Coal Mine in Guizhou. Theoretical analysis, discrete element numerical simulation, and field tests were used to characterize the evolution of fractures associated with mining of the upper protective layer and the effects of pressure relief gas drainage within the protected coal seam. The results show that mining-related stress changes controlled the development of fractures, altering the permeability values of coals. An analysis of the crack development in the coal mass caused by mining of the upper protective layer shows that during the initial stage of mining, the produced cracks exhibited a butterfly shape network. Yet, with further development of the mining, these cracks and the stress changes gradually produced an inverted butterfly shape network. According to simulations, the areas of maximum deformation via expansion in the protected coal seam were located near the open cut and the mining end line of the working face. The maximum deformation values were 29.06 and 26.68 mm, respectively, and the corresponding deformation rates were 9.37‰ and 8.61‰, which are greater than the required 3‰. The findings of this study provide a new reference for gas control in pressure relief coal seams under similar working conditions.

Decomposition and Reconstruction of Human Palm Movements.

OBJECTIVE: The human hand is known to have excellent manipulation ability compared to other primate hands. Without the palm movements, the human hand would lose more than 40% of its functions. However, uncovering the constitution of palm movements is still a challenging problem involving kinesiology, physiology, and engineering science. METHODS: By recording the palm joint angles during common grasping, gesturing, and manipulation tasks, we built a palm kinematic dataset. Then, a method for extracting the eigen-movements to characterize the common motion correlation relationships of palm joints was proposed to explore the palm movement constitution. RESULTS: This study revealed a palm kinematic characteristic that we named the joint motion grouping coupling characteristic. During natural palm movements, there are several joint groups with a high degree of motor independence, while the movements of joints within each joint group are interdependent. Based on these characteristics, the palm movements can be decomposed into seven eigen-movements. The linear combinations of these eigen-movements can reconstruct more than 90% of palm movement ability. Moreover, combined with the palm musculoskeletal structures, we found that the revealed eigen-movements are associated with joint groups that are defined by muscular functions, which provided a meaningful context for palm movement decomposition. CONCLUSION: This paper suggests that some invariable characteristics underlie the variable palm motor behaviors and can be used to simplify palm movement generation. SIGNIFICANCE: This paper provides important insights into palm kinematics, and helps facilitate motor function assessment and the development of better artificial hands.

Interspecific competitive effects and annual differences in predation of Empoasca onukii (Hemiptera: Cicadellidae) by wandering spiders.

Empoasca onukii Matsuda is an important pest widely distributed in tea areas in China, which greatly affects tea production and quality. The long-term use of chemical control measures will cause environmental pollution. To better utilize wandering spiders that have strong competitive effects on the predation of E. onukii, we conducted a path analysis between the populations of E. onukii and wandering spiders in 3 tea plantations in 2020 and 2021. The wandering spider species that had the greatest direct and indirect effects on the population of E. onukii were analyzed by the magnitude of the path coefficient. Then, a gray system analysis was conducted to determine the closeness of the populations of different wandering spiders to E. onukii by the magnitude of gray correlation coefficient. Finally, the competition coefficients were calculated to determine the competitiveness of wandering spiders. In addition, considering the influence of the number of E. onukii on the interspecific competition of wandering spiders, the gray correlation coefficient and competition coefficient were combined to derive the competition intensity index, which was used to analyze the competitiveness of wandering spiders in a comprehensive manner. The highest competition coefficients in 2020 and 2021 were found for Ebrechtella tricuspidata Fabricius (Araneae: Thomisidae) (X2, 0.5329) and Clubiona reichlini Fabricius (Araneae: Clubionidae) (X4, 0.8475), respectively. The magnitude of the competition intensity index showed that the most competitive wandering spider in 2020 and 2021 was E. tricuspidata (X2, 0.5692) and C. reichlini (X4, 0.8892), respectively. The least competitive spider in both years was Plexippus setipes Karsch (Araneae: Salticidae) (X7). The more competitive the wandering spider is, the closer it is to E. onukii in terms of numbers, and the more dominant it is in feeding on E. onukii. By reasonably protecting and utilizing the competitive E. tricuspidata (X2) and C. reichlini (X4), we can achieve sustainable and effective control of E. onukii.