A sentiment analysis approach for travel-related Chinese online review content.

Using technology for sentiment analysis in the travel industry can extract valuable insights from customer reviews. It can assist businesses in gaining a deeper understanding of their consumers' emotional tendencies and enhance their services' caliber. However, travel-related online reviews are rife with colloquialisms, sparse feature dimensions, metaphors, and sarcasm. As a result, traditional semantic representations of word vectors are inaccurate, and single neural network models do not take into account multiple associative features. To address the above issues, we introduce a dual-channel algorithm that integrates convolutional neural networks (CNN) and bi-directional long and short-term memory (BiLSTM) with an attention mechanism (DC-CBLA). First, the model utilizes the pre-trained BERT, a transformer-based model, to extract a dynamic vector representation for each word that corresponds to the current contextual representation. This process enhances the accuracy of the vector semantic representation. Then, BiLSTM is used to capture the global contextual sequence features of the travel text, while CNN is used to capture the richer local semantic information. A hybrid feature network combining CNN and BiLSTM can improve the model's representation ability. Additionally, the BiLSTM output is feature-weighted using the attention mechanism to enhance the learning of its fundamental features and lessen the influence of noise features on the outcomes. Finally, the Softmax function is used to classify the dual-channel fused features. We conducted an experimental evaluation of two data sets: tourist attractions and tourist hotels. The accuracy of the DC-CBLA model is 95.23% and 89.46%, and that of the F1-score is 97.05% and 93.86%, respectively. The experimental results demonstrate that our proposed DC-CBLA model outperforms other baseline models.

A hybrid GA-PSO strategy for computing task offloading towards MES scenarios.

As a new type of computing paradigm closer to service terminals, mobile edge computing (MEC), can meet the requirements of computing-intensive and delay-sensitive applications. In addition, it can also reduce the burden on mobile terminals by offloading computing. Due to cost issues, results in the deployment density of mobile edge servers (MES) is restricted in real scenario, whereas the suitable MES should be chosen for better performance. Therefore, this article proposes a task offloading strategy under the sparse MES density deployment scenario. Commonly, mobile terminals may reach MES through varied access points (AP) based on multi-hop transmitting mode. The transmission delay and processing delay caused by the selection of AP and MES will affect the performance of MEC. For the purpose of reducing the transmission delay due to system load balancing and superfluous multi-hop, we formulated the multi-objective optimization problem. The optimization goals are the workload balancing of edge servers and the completion delay of all task offloading. We express the formulated system as an undirected and unweighted graph, and we propose a hybrid genetic particle swarm algorithm based on two-dimensional genes (GA-PSO). Simulation results show that the hybrid GA-PSO algorithm does not outperform state-of-the-art GA and NSA algorithms in obtaining all task offloading delays. However, the workload by standard deviation approach is about 90% lower than that of the GA and NSA algorithms, which effectively optimizes the performance of load balancing and verifies the effectiveness of the proposed algorithm.

Research into the correlation between positional skull deformation and motor performance of infants aged under 4 months.

OBJECTIVE: To investigate the correlation between positional skull deformation (PD) and motor performance of infants under 4 months of age. METHODS: Infants aged under 4 months were enrolled in the children's healthcare and the premature infants follow-up Clinic of the Second Affiliated Hospital of Army Military Medical University. The cranial vault asymmetry (CVA) and cephalic index (CI) were calculated in all infants, and the infant motor performance test (TIMP) was used to evaluate the infant motor performance. The motor performances of infants with different types and degrees of PD were compared, so were the incidences of PD in infants with different motor performance levels. RESULTS: Overall, 2118 infants were recruited and divided according to the types of PD and TIMP scores. The comparison of TIMP scores within different types of PD at different months of age showed that, regardless of the types of PD, TIMP scores of infants with PD were lower than those of normal infants. In particular, the difference in TIMP scores was statistically significant (P < 0.05) in infants with dolichocephaly, plagiocephaly,dolicho-plagiocephaly and brachy-plagiocephy. In addition, the comparison of CVA values of infants with different TIMP score levels at different months of age showed that the CVA values of the extremely low-level group were significantly higher than those of the medium-level and high-level group, especially in the 3-month-old and 4-month-old groups, which showed significant statistical differences (P < 0.05). CONCLUSIONS: PD and motor performance of infants aged under 4 months seem to interact and influenc each other. The more serious the severity of PD were,the worse the motor performance of infants. Conversely, the incidence of PD increased in infants with poor motor performance.

Electron and Ion Transport in Lithium and Lithium-Ion Battery Negative and Positive Composite Electrodes.

Electrochemical energy storage systems, specifically lithium and lithium-ion batteries, are ubiquitous in contemporary society with the widespread deployment of portable electronic devices. Emerging storage applications such as integration of renewable energy generation and expanded adoption of electric vehicles present an array of functional demands. Critical to battery function are electron and ion transport as they determine the energy output of the battery under application conditions and what portion of the total energy contained in the battery can be utilized. This review considers electron and ion transport processes for active materials as well as positive and negative composite electrodes. Length and time scales over many orders of magnitude are relevant ranging from atomic arrangements of materials and short times for electron conduction to large format batteries and many years of operation. Characterization over this diversity of scales demands multiple methods to obtain a complete view of the transport processes involved. In addition, we offer a perspective on strategies for enabling rational design of electrodes, the role of continuum modeling, and the fundamental science needed for continued advancement of electrochemical energy storage systems with improved energy density, power, and lifetime.

Design principles for heterointerfacial alloying kinetics at metallic anodes in rechargeable batteries.

How surface chemistry influences reactions occurring thereupon has been a long-standing question of broad scientific and technological interest. Here, we consider the relation between the surface chemistry at interfaces and the reversibility of electrochemical transformations at rechargeable battery electrodes. Using Zn as a model system, we report that a moderate strength of chemical interaction between the deposit and the substrate-neither too weak nor too strong-enables highest reversibility and stability of the plating/stripping redox processes. Focused ion beam and electron microscopy were used to directly probe the morphology, chemistry, and crystallography of heterointerfaces of distinct natures. Analogous to the empirical Sabatier principle for chemical heterogeneous catalysis, our findings arise from competing interfacial processes. Using full batteries with stringent negative electrode-to-positive electrode capacity (N:P) ratios, we show that such knowledge provides a powerful tool for designing key materials in highly reversible battery systems based on Earth-abundant, low-cost metals such as Zn and Na.

Multimodal electrochemistry coupled microcalorimetric and X-ray probing of the capacity fade mechanisms of Nickel rich NMC - progress and outlook.

Lithium nickel manganese cobalt oxide (NMC) is a commercially successful Li-ion battery cathode due to its high energy density; however, its delivered capacity must be intentionally limited to achieve capacity retention over extended cycling. To design next-generation NMC batteries with longer life and higher capacity the origins of high potential capacity fade must be understood. Operando hard X-ray characterization techniques are critical for this endeavor as they allow the acquisition of information about the evolution of structure, oxidation state, and coordination environment of NMC as the material (de)lithiates in a functional battery. This perspective outlines recent developments in the elucidation of capacity fade mechanisms in NMC through hard X-ray probes, surface sensitive soft X-ray characterization, and isothermal microcalorimetry. A case study on the effect of charging potential on NMC811 over extended cycling is presented to illustrate the benefits of these approaches. The results showed that charging to 4.7 V leads to higher delivered capacity, but much greater fade as compared to charging to 4.3 V. Operando XRD and SEM results indicated that particle fracture from increased structural distortions at >4.3 V was a contributor to capacity fade. Operando hard XAS revealed significant Ni and Co redox during cycling as well as a Jahn-Teller distortion at the discharged state (Ni3+); however, minimal differences were observed between the cells charged to 4.3 and 4.7 V. Additional XAS analyses using soft X-rays revealed significant surface reconstruction after cycling to 4.7 V, revealing another contribution to fade. Operando isothermal microcalorimetry (IMC) indicated that the high voltage charge to 4.7 V resulted in a doubling of the heat dissipation when compared to charging to 4.3 V. A lowered chemical-to-electrical energy conversion efficiency due to thermal energy waste was observed, providing a complementary characterization of electrochemical degradation. The work demonstrates the utility of multi-modal X-ray and microcalorimetric approaches to understand the causes of capacity fade in lithium-ion batteries with Ni-rich NMC.

Interfacial Reactivity of Silicon Electrodes: Impact of Electrolyte Solvent and Presence of Conductive Carbon.

Silicon (Si) is a promising high-capacity material for lithium-ion batteries; however, its limited reversibility hinders commercial adoption. Approaches such as particle and crystallite size reduction, introduction of conductive carbon, and use of different electrolyte solvents have been explored to overcome these electrochemical limitations. Herein, operando isothermal microcalorimetry (IMC) is used to probe the influence of silicon particle size, electrode composition, and electrolyte additives fluoroethylene carbonate and vinylene carbonate on the heat flow during silicon lithiation. The IMC data are complemented by X-ray photoelectron and Raman spectroscopies to elucidate differences in solid electrolyte interphase (SEI) composition. Nanosized (∼50 nm, n-Si) and micrometer-sized (∼4 µm, µ-Si) silicon electrodes are formulated with and without amorphous carbon and electrochemically lithiated in ethylene carbonate (EC), fluoroethylene carbonate (FEC), or vinylene carbonate (VC) based electrolytes. Notably, n-Si electrodes generate 53-61% more normalized heat relative to their µ-Si counterparts, consistent with increased surface area and electrode/electrolyte reactivity. Introduction of amorphous carbon significantly alters the heat flow profile where multiple exothermic peaks and increased normalized heat dissipation are observed for all electrolyte types. Notably, the VC-containing electrolyte demonstrates the greatest normalized heat dissipation of the electrode compositions tested showing as much as a 50% increase compared to the EC or FEC counterparts. The results are relevant to the understanding of silicon negative electrode function in the presence of electrolyte additives and provide insight relative to silicon containing cell reactivity and safety.

Probing the Physicochemical Behavior of Variously Doped Li4Ti5O12 Nanoflowers.

This study thoroughly investigated the synthesis of not only 4 triply-doped metal oxides but also 5 singly-doped analogues of Li4Ti5O12 for electrochemical applications. In terms of synthetic novelty, the triply-doped materials were fabricated using a relatively facile hydrothermal method for the first-time, involving the simultaneous substitution of Ca for the Li site, Ln (i.e., Dy, Y, or Gd) for the Ti site, and Cl for the O site. Based on XRD, SEM, and HRTEM-EDS measurements, the resulting materials, incorporating a relatively homogeneous and uniform dispersion of both the single and triple dopants, exhibited a micron-scale flower-like morphology that remained apparently undamaged by the doping process. Crucially, the surface chemistry of all of the samples was probed using XPS in order to analyze any nuanced changes associated with either the various different lanthanide dopants or the identity of the metal precursor types involved. In the latter case, it was observed that the use of a nitrate salt precursor versus that of a chloride salt enabled not only a higher lanthanide incorporation but also the potential for favorable N-doping, all of which promoted a concomitant increase in conductivity due to a perceptible increase in Ti3+ content. In terms of the choice of lanthanide system, it was observed via CV analysis that dopant incorporation generally (albeit with some notable exceptions, especially with Y-based materials) led to the formation of higher amounts of Ti3+ species within both the singly and triply-doped materials, which consequentially led to the potential for increased diffusivity and higher mobility of Li+ species with the possibility for enabling greater capacity within these classes of metal oxides.

Analysis of cranial type characteristics in term infants: a multi-center study.

BACKGROUND: Positional head deformity (PHD) is defined as a change in the shape of an infant's skull due to an external force. In certain cases, it can lead to cosmetic deformities or even neurological issues due to its impact on the developing nervous system. Therefore, we conducted this study to investigate the incidence and characteristics of PHD in term infants in China and preliminarily establish a localized diagnostic reference standard. METHODS: Overall, 4456 term infants from three medical institutions in Chongqing were and divided and analyzed according to their age. Cranial vault asymmetry (CVA) and cephalic index (CI) were calculated in all infants. The current international diagnostic criteria were used to understand PHD incidence and analyze the CVA and CI distribution. RESULTS: According to the current international standards, the total detection rate of PHD in Chongqing's term infants was 81.5%, with brachycephaly alone being the most frequent (39.4%), followed by brachycephaly with plagiocephaly (34.8%) and plagiocephaly alone (6.2%). The detection rates of dolichocephaly were low: alone, 0.9% and combined with plagiocephaly, 0.2%. According to age, plagiocephaly (44.5%) and brachycephaly (82.0%) were the most frequent in the 2-3-month group. The 75th/90th/97th and 3rd/10th/25th/75th/90th/97th percentiles of CVA and CIs were 0.4/0.7/1.0 and 76.4/78.8/82.3/91.1/94.6/99.2%, respectively. CONCLUSIONS: According to the current international standards, the PHD detection rate among term infants in Chongqing was high. Therefore, a new diagnostic standard for Chinese infants was proposed where CVA ≥ 0.4 cm indicates plagiocephaly, CI ≥ 91% indicates brachycephaly, and CI ≤ 82% indicates dolichocephaly.

The Relationship Between Resilience and Posttraumatic Growth Among the Primary Caregivers of Children With Developmental Disabilities: The Mediating Role of Positive Coping Style and Self-Efficacy.

This study was conducted to investigate the relationship between posttraumatic growth (PTG), resilience, positive coping style, and self-efficacy among the primary caregivers of children with developmental disorders in Chongqing, China. A total of 198 primary caregivers (parents and grandparents) aged from 22 to 66 years old (M = 35.55, SD = 9.16), including 155 females (78.3%) and 43 males (21.7%), were enrolled. The Posttraumatic Growth Inventory, Connor-Davidson Resilience Scale-10, Simplified Coping Style Questionnaire, and General Self-Efficacy Scale were used for data collection. The results found that PTG could be positively predicted by resilience. Positive coping style and self-efficacy mediated the relationship between resilience and PTG. The different levels of PTG were determined by the resident location, monthly income and education of the primary caregivers. The results suggest that it is critical to improve the mental health of the primary caregivers (parents and grandparents) of children with developmental disabilities. Our results also provide a scientific basis for future research.

A comparative study between traditional head measurement and structured light three-dimensional scanning when measuring infant head shape.

BACKGROUND: This study aimed to evaluate the correlation and consistency between traditional head measurement and structured light three-dimensional (3D) scanning parameters when measuring infant skull shape. METHODS: A total of 76 infants aged 3 months to 2.5 years old were included in the study. Head circumference (HC) was measured with a tape measure. The transverse, anteroposterior, and oblique diameters were measured using a spreading caliper, and the cranial vault asymmetry index (CVAI) and a cranial index (CI) of symmetry were calculated; 76 cases were measured successfully. The above indexes were measured using a structured light 3D scanning system (71 cases were measured with success). Thus, in the end, the valid data of 71 cases were analyzed, and the measurements of the two approaches were compared. RESULTS: The 95% confidence interval of traditional head measurement and structured light 3D scanning was between 0.633 and 0.988. Pearson's correlation coefficient indicated a high correlation between the two methods (r=0.793-0.980). The correlation coefficients of the transverse diameter, anteroposterior diameter, and HC, and the CI of symmetry were higher than 0.9. The lowest correlation coefficient for the CVAI was 0.793. The P values of the above measurement data were all <0.001, which indicated that they were closely related. A Bland-Altman plot indicated reasonable consistency between the two methods. CONCLUSIONS: Both traditional head measurement and structured light 3D scanning are suitable for the measurement of infant head shape. However, while traditional head measurement using a spreading caliper is economical and simple, making it suitable for general screening at a basic level, structured light 3D scanning can deliver additional parameters, which is useful for infants with an abnormal head shape. The latter is also convenient for designing a customized helmet for skull correction when needed.

Insights into Reactivity of Silicon Negative Electrodes: Analysis Using Isothermal Microcalorimetry.

Silicon offers high theoretical capacity as a negative electrode material for lithium-ion batteries; however, high irreversible capacity upon initial cycling and poor cycle life have limited commercial adoption. Herein, we report an operando isothermal microcalorimetry (IMC) study of a model system containing lithium metal and silicon composite film electrodes during the first two cycles of (de)lithiation. The total heat flow data are analyzed in terms of polarization, entropic, and parasitic heat flow contributions to quantify and determine the onset of parasitic reactions. These parasitic reactions, which include solid-electrolyte interphase formation, contribute to electrochemical irreversibility. Cycle 1 lithiation demonstrates the highest thermal energy output at 1509 mWh/g, compared to cycle 1 delithiation and cycle 2. To complement the calorimetry, operando X-ray diffraction is used to track the phase evolution of silicon. During cycle 1 lithiation, crystalline Si undergoes transformation to amorphous lithiated silicon and ultimately to crystalline Li15Si4. The solid-state amorphization process is correlated to a decrease in entropic heat flow, suggesting that heat associated with the amorphization contributes significantly to the entropic heat flow term. This study effectively uses IMC to probe the parasitic reactions that occur during lithiation of a silicon electrode, demonstrating an approach that can be broadly applied to quantify parasitic reactions in other complex systems.

Prevalence of positional skull deformities in 530 premature infants with a corrected age of up to 6 months: a multicenter study.

BACKGROUND: Positional deformities (PD) are common during early infancy. Severe cases may result in facial abnormalities and be associated with delayed neurological development in infants. The earlier the detection of PD, the better the intervention effect and the lower the cost of treatment. Currently, there are many studies on PD in Europe and the United States. However, in China, there is little data on the basic metrics and incidence of PD. Premature infants have a high risk of PD. However, there are few studies on PD in premature infants globally, and none in Asia. This study aimed to investigate PD and its characteristics inpremature infants to help its early detection and intervention and thus improve the quality of life for premature infants. METHODS: We analyzed 530 preterm infants who visited the outpatient departments at Xinqiao Hospital of Army Medical University and Maternal and Child Health Care Hospitals of Wanzhou and Yongchuan Districts in Chongqing from September 1, 2016, to August 31, 2017. The head shape data measured by a simple manual method were recorded. The diagonal difference (DD) between the transcranial diagonals and the cranial index (CI) was calculated. PD and its incidences indifferent gestational ages and corrected age groups were analyzed. RESULTS: According to previously defined international diagnostic criteria, the incidence of plagiocephaly, brachycephaly, and dolichocephaly were 51.1, 85.1, and 3.0% respectively, and those of right and left plagiocephalywere69.4 and 30.6%, respectively. The incidence of PD was highest among infants with a gestational age of < 32 weeks and decreased as the gestational age increased. As the corrected age (CA) increased, the incidence of plagiocephaly and dolichocephaly decreased, and the incidence of brachycephaly increased. CONCLUSIONS: PD incidence is high among preterm infants. As gestational age decreased, PD incidence and severity increased. Therefore, healthcare providers should implement early PD detection and intervention to prevent the adverse outcomes. The extremely high incidence of brachycephaly and extremely low incidence of dolichocephaly in this study are likely to be due to the variance of cranial metrics caused by cultural differences. The Chinese standards for infant cranial measurements must be established.

A novel de novo mutation in the TSC2 gene in a Chinese patient with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC), a multisystem genetic syndrome, often affects the central nervous system. The age of onset of TSC ranges from 0 to 15 years. The clinical features manifest as a combination of seizures, mental retardation, facial angiofibroma, renal angiomyolipoma, and cardiac rhabdomyoma. Most cases of TSC are caused by mutations of the TSC1 or TSC2 genes. We characterized a Chinese patient with a novel de novo mutation in the TSC2 gene associated with the TSC detected by next-generation sequencing.

A reconstruction method based on AL0FGD for compressed sensing in border monitoring WSN system.

In this paper, to monitor the border in real-time with high efficiency and accuracy, we applied the compressed sensing (CS) technology on the border monitoring wireless sensor network (WSN) system and proposed a reconstruction method based on approximately l0 norm and fast gradient descent (AL0FGD) for CS. In the frontend of the system, the measurement matrix was used to sense the border information in a compressed manner, and then the proposed reconstruction method was applied to recover the border information at the monitoring terminal. To evaluate the performance of the proposed method, the helicopter sound signal was used as an example in the experimental simulation, and three other typical reconstruction algorithms 1)split Bregman algorithm, 2)iterative shrinkage algorithm, and 3)smoothed approximate l0 norm (SL0), were employed for comparison. The experimental results showed that the proposed method has a better performance in recovering the helicopter sound signal in most cases, which could be used as a basis for further study of the border monitoring WSN system.

Arrayed narrow linewidth erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss silicon-nitride platform.

We demonstrate an array of erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss Si(3)N(4) platform. Sidewall gratings providing the lasing feedback are defined in the silicon-nitride layer using 248 nm stepper lithography, while the gain is provided by a reactive co-sputtered erbium-doped aluminum-oxide layer. We observe lasing output over a 12 nm wavelength range (1531-1543 nm) from the array of five separate lasers. Output powers of 8 µW and lasing linewidths of 501 kHz are obtained. Single-mode operation is confirmed, with side-mode suppression ratios over 35 dB for all designs.

Second-order bandpass terahertz filter achieved by multilayer complementary metamaterial structures.

We propose a multilayer complementary metamaterial structure fabricated on a crystal quartz substrate measuring between 100 and 700 GHz. The concept of a second-order terahertz bandpass filter is realized by this structure, and it offers a superior quality factor, steepness of skirts, and out-of-band rejection. Physical limitations on the quality factor and insertion loss have also been studied, including the skin depth of the metal and the optical phonon resonance in quartz. Based on these factors, a series of higher frequency filters has been designed, and simulation results are presented.