Fast, intelligent and high-precision adaptive null interferometry for optical freeform surfaces by backpropagation.

In the past 10 years, adaptive wavefront interferometry (AWI) has been employed for measuring freeform surface profiles. However, existing AWI techniques relying on stepwise and model-free stochastic optimizations have resulted in inefficient tests. To address these issues, deterministic adaptive wavefront interferometry (DAWI) is firstly introduced in this paper based on backpropagation (BP), which employs a loss function to simultaneously reconstruct and sparsify initial incomplete interferometric fringes until they are nulled. Each iteration of BP requires two phase shifts. Through simulations, we have verified that freeform wavefront error with a peak-to-valley (PV) of up to 168 λ can be fully compensated in tens of iterations using a 1024 × 1024 pixel area of a liquid-crystal spatial light modulator. In experiments, we accomplished a null test of a freeform surface with 80% missing interference fringes in 39 iterations, resulting in a surface profile error PV of 66.22 λ and measurement error better than λ/4. The DAWI has at least 20 times fewer iterations in fringe reconstruction than the 3-step AWI methods, and nearly an order of magnitude fewer iterations in the whole process, paving the way for significantly enhanced efficiency, generality and precision in freeform surface adaptive interferometry.

Differences and common ground in the frameworks of health-related quality of life in traditional Chinese medicine and modern medicine: a systematic review.

PURPOSE: This systematic review aims to explore the conceptualization of health-related quality of life (HRQoL) in China. With HRQoL influenced by both modern medicine (MM) and traditional Chinese medicine (TCM), the study seeks to identify differences and common ground between the frameworks of MM and TCM as defined in the literature. METHOD: A systematic literature search was conducted across three Chinese databases and four English databases. The data was extracted including title, author(s), publication year, region, aim, method, category, and result. When sorting data, we broke down the HRQoL frameworks into concepts, domains and facets, with a focus on overlapped facets between the frameworks of MM and TCM. RESULTS: A total of 31 studies were included. In the perspective of TCM, HRQoL is centered around three key 'concepts': (1) 'xingshentongyi' (unity of body and spirit), (2) 'tianrenheyi' (harmony between man and nature), and (3) 'qiqing' (seven emotional forms). In contrast, the MM framework comprises 'physical,' 'mental,' 'social,' and 'environment' domains. Out of the 59 unique facets identified, 28 are common to both TCM and MM, 9 specific to TCM, and 22 specific to MM. 'Appetite,' 'sleep,' and 'energy' are the most frequently mentioned facets in both frameworks. CONCLUSION: The concept of HRQoL in China encompasses frameworks rooted in both TCM and MM. While TCM and MM have distinct healthcare approaches, they share overlapping domains when measuring HRQoL through questionnaires. Furthermore, TCM and MM demonstrate considerable convergence in terms of HRQoL facets, showing the potential for utilizing HRQoL instruments across different cultural settings.

266 nm ultraviolet communication under unknown interference using UVC micro-LED.

Ultraviolet C (UVC) micro light-emitting diode (LED) can achieve symbol communication rate up to 100Msps at distance 40 meters without transmitter-side lens to guarantee certain communication mobility. We consider what we believe to be a new scenario where high speed UV communciation is realized under unknown low-rate interference. The signal amplitude properties are characterized, and the interference intensity is categorized into three cases, namely weak, medium and high interference intensity. The achievable transmission rates for the three cases are derived, where the achievable transmission rate for medium interference intensity can approach those in weak interference intensity and strong interference intensity cases. We provide Gaussian approximation and related log-likelihood ratio (LLR) calculation, which are fed into the subsequent message-passing decoder. In the experiment, the data is transmitted with symbol rate 20 Msps under unknown interference with symbol rate 1 Msps, received by one photomultiplier tube (PMT). Experimental results show that the proposed interference symbol estimation approach shows negligibly higher bit error rate (BER) compared with those with perfect knowledge on the interference symbols.

Ultraviolet communication with a large scattering angle via artificial agglomerate fog.

Considering strong signal attenuation of the large-angle non-line-of-sight (NLOS) link achieved due to the ultraviolet (UV) scattering properties, we propose to increase the UV communication link gain under a large scattering angle via generating agglomerate fog within a certain range as a secondary light source. In this study, a channel model with locally strong scatterers from agglomerate fog is proposed based on Monte Carlo ray-tracing approaches. Mie theory is adopted to calculate the atmospheric channel parameters, to further evaluate the link gain of a channel under non-uniform atmosphere. The performance of scattering system in the presence of fog conditions depends on the relative positions of the light source to the fog and to the receiver. The link gain results reveal the transmission capabilities for different scattering channel geometries, and give the optimal spray point location within a 10 m communication range. We further establish a foggy NLOS system using an agglomerate fog generator to verify our research in the real environment. The results show that the received signal strength of the NLOS link can be effectively enhanced by constructing scatterers in the atmospheric channel, which significantly decreases the bit-error rate (BER).

Visible-light-driven Oxygen Vacancy and Carbon Doping of C@TiO2-x Photocatalyst for Enhanced Pollutants Degradation Performance.

Oxygen Vacancy (OVs) and carbon doping of the photocatalyst body will significantly enhance the photocatalytic efficiency. However, synchronous regulation of these two aspects is challenging. In this paper, a novel C@TiO2-x photocatalyst was designed by coupling the surface defect and doping engineering of titania, which can effectively remove rhodamine B (RhB) and has a relatively high performance with wide pH range, high photocatalytic activity and good stability. Within 90 minutes, the photocatalytic degradation rate of RhB by C@TiO2-x (94.1 % at 20 mg/L) is 28 times higher than that of pure TiO2 . Free radical trapping experiments and electron spin resonance techniques reveal that superoxide radicals (⋅O2- ) and photogenerated holes (h+ ) play key roles in the photocatalytic degradation of RhB. This study demonstrates the possibility of regulating photocatalysts to degrade pollutants in wastewater based on an integrated strategy.

Driving factors for decoupling water resources ecological footprint and economic growth in water-deficient cities dominated by agriculture.

To explore the key factors and specific thresholds of water resources limiting economic development, and to provide technical support for water resources management in cities dominated by agriculture similar to Zhangjiakou. We used the Tapio elastic decoupling method to quantitatively evaluate the decoupling relationship between the water resources ecological footprint (WEF) and economic growth. Then the logarithmic mean Divisia index (LMDI) and mathematical statistics are used to identify the key factors and threshold effects. The results show a significant decreasing trend in the WEF and obvious spatial differences in Zhangjiakou between 2006 and 2015, with agricultural ecological footprint dominating all districts and counties (77.54 ± 14.35%). The changes in technological effect are a contributing factor to the decoupling between the WEF and the economy in Zhangjiakou, while the economic effect is the main restricting factor. In particular, there is a high correlation between the WEF and the number of water-saving irrigation machines and the total power of agricultural machinery. According to the findings, for water-scarce cities such as Zhangjiakou, where agriculture is the primary focus, it is suggested that increasing the number of agricultural machinery can effectively alleviate the problem of water scarcity constraining economic development.

Thebaine induces anaphylactic reactions via the MRGPRX2 receptor pathway on mast cells.

Morphine derivatives are clinically important anesthetic and sedative drugs, which often show anaphylactic side effects. Mas-related G-protein coupled receptor member X2 (MRGPRX2) triggers mast cell degranulation, which is important process in anaphylactic reactions. MRGPRX2-HEK293 and LAD2 cell membrane chromatographic (CMC) models were used to screen morphine derivatives binding to MRGPRX2. Furthermore, most morphine derivatives significantly enhanced Ca2+ mobilization. More importantly, thebaine was found to effectively promote histamine release. Thebaine induced the increased release of ß-hexosaminidase and high secretion level of cytokines, confirming that thebaine could further trigger anaphylactic reactions and promote subsequent inflammatory reactions. Moreover, the ability of thebaine inducing degranulation and the release of allergenic mediators in mast cells was significantly decreased after MRGPRX2 knockdown, which proved that MRGPRX2 is the key media for thebaine-induced anaphylactic reactions. Significant hind paw swelling and hypothermia in mice after injecting thebaine suggested that thebaine could trigger anaphylactic reactions in vivo.

Weak signal detection for visible light communication in the pulse and transition regimes of an operational PMT detector via an SVM-based learning method.

Photo-multiplier tube can be adopted for optical signal detection under weak signal and ambient light intensity, where the signals can be classified into three regimes, discrete-pulse regime, continuous waveform regime and the transition regime between the discrete-photon and continuous waveform regimes. While Poisson and Gaussian distributions can well characterize the discrete-photon and continuous waveform regimes, respectively, a statistical characterization and the related signal detection in the transition regime are difficult. In this work, we resort to a learning approach for the signal characterization and detection under pulse and transition regimes. We propose a support vector machine (SVM)-based approach for signal detection, which extracts eight key features on the received signal. We optimize the hyper-parameters to improve the SVM detection performance. The proposed SVM-based approach is experimentally evaluated under different symbol and sampling rates, and outperforms that of various statistics-based comparison benchmarks.

Several factors influencing energy-loss near-edge structure calculations using Wien2k.

Electron energy-loss spectroscopy (EELS) is widely applied combining with transmission electron microscopes with high spatial resolution, but its interpretation is a challenging task. One of the reasons is that the factors affecting EELS are very complicated. In this paper, we focus on the several factors involved in density functional theory (DFT) calculations. The sensitivity of calculated energy-loss near-edge structure (ELNES) to spin order, pressure and on-site Coulomb energy U has been discussed. Since EELS technique detects the local environment of atoms, the influence of spin order cannot be ignored. The chemical shifts and peak intensity of ELNES are also closely related to corresponding pressure. The correlation effects are very important for transition metal compounds and play a key role in EELS simulations. An overview of the effects of these factors on the ELNES is presented with the help of Wien2k code. The antiferromagnetic order results in the decreasing of intensities of related peaks and the moving of the peaks to high energy loss. The decreasing of lattice parameters causes the ELNES peaks to shift to high energy loss, and the peak shifts at the higher energy loss are more significant. The increase of correlation effect leads to the ELNES peaks to shift to high energy loss accompanied by the increase of the relative intensity of the peaks which locate at higher energy loss. Our work helps to understand how these factors affect EELS and to explain and predict the experimental EELS spectra. Through the discussion of these factors, we propose that some factors could not be ignored in EELS simulations.

VIS-NIR superachromatic triplet design with five-color correction for a broadband interferometer.

In general, k lenses with different materials can achieve at most (k+1) color correction (k≥2). A superachromat containing three lenses is designed to achieve five-color correction in the 600-1600 nm waveband, where the maximum chromatic focal shift is controlled within 1/100,000 of the focal length, achieving an almost unprecedented result. Conditions for lens power combination of three thin lenses in contact are first derived based on the Buchdahl dispersion equation; then a metric is introduced to verify the five-color correction, and a correction method is proposed to improve the refractive index fitting accuracy of the Buchdahl model from ∼10-3 to ∼10-7. By traversing 197 ecofriendly glass materials in the CDGM glass library iteratively, 113 initial structures are obtained in only 61.75 s, from which the structure with the minimum chromatic focal shift is selected to be optimized with Opticstudio. By setting up required operands, the final structure being within the diffraction limit in a field of view of ±0.05∘ is obtained within only 6 s, where the maximum longitudinal chromatic aberration is close to the maximum chromatic focal shift. We provide a complete theoretical basis and important guidance for designing broadband superachromats with (k+2) color correction using only k lenses and the smallest chromatic focal shift, and based on the theories, we have developed a broadband interferometer.

Regulation of High Miscibility for Efficient Charge-Transport in n-Doped Conjugated Polymers.

Strong interchain interactions of conjugated polymers usually result in poor miscibility with molecular dopants, limiting the doping efficiency because of uncontrolled phase separation. We have developed a strategy to achieve efficient charge-transport and high doping miscibility in n-doped conjugated polymers. We solve the miscibility issue through disorder side-chains containing dopants better. Systemic structural characterization reveals a farther side-chain branching point will lead to higher disorders, which provides appropriate sites to accommodate extrinsic molecular dopants without harming original chain packings and charge-transport channels. Therefore, better sustainability of solid-state microstructure is obtained, yielding a stable conductivity even when overloading massive dopants. This work highlights the importance of realizing high host-dopant miscibility in molecular doping of conjugated polymers.

FLOURY ENDOSPERM11-2 encodes plastid HSP70-2 involved with the temperature-dependent chalkiness of rice (Oryza sativa L.) grains.

The frequent occurrence of chalky rice (Oryza sativa L.) grains becomes a serious problem as a result of climate change. The molecular mechanism underlying chalkiness is largely unknown, however. In this study, the temperature-sensitive floury endosperm11-2 (flo11-2) mutant was isolated from ion beam-irradiated rice of 1116 lines. The flo11-2 mutant showed significantly higher chalkiness than the wild type grown under a mean temperature of 28°C, but similar levels of chalkiness to the wild type grown under a mean temperature of 24°C. Whole-exome sequencing of the flo11-2 mutant showed three causal gene candidates, including Os12g0244100, which encodes the plastid-localized 70-kDa heat shock protein 2 (cpHSP70-2). The cpHSP70-2 of the flo11-2 mutant has an amino acid substitution on the 259th aspartic acid with valine (D259V) in the conserved Motif 5 of the ATPase domain. Transgenic flo11-2 mutants that express the wild-type cpHSP70-2 showed significantly lower chalkiness than the flo11-2 mutant. Moreover, the accumulation level of cpHSP70-2 was negatively correlated with the chalky ratio, indicating that cpHSP70-2 is a causal gene for the chalkiness of the flo11-2 mutant. The intrinsic ATPase activity of recombinant cpHSP70-2 was lower by 23% at Vmax for the flo11-2 mutant than for the wild type. The growth of DnaK-defective Escherichia coli cells complemented with DnaK with the D201V mutation (equivalent to the D259V mutation) was severely reduced at 37°C, but not in the wild-type DnaK. The results indicate that the lowered cpHSP70-2 function is involved with the chalkiness of the flo11-2 mutant.

Phosphorus recovery and recycling from model animal wastewaters using materials prepared from rice straw and corn cobs.

Anthropogenic loss of phosphorus to surface waters not only causes environmental problems but depletes valuable phosphorus reserves. In this study, magnesium amended biochars and magnesium silicate, synthesized from corn cobs and rice straw, respectively, were evaluated for phosphorus uptake including the effects of pH and alkalinity. The overall goal was to close the phosphorus loop by recovering phosphorus from animal waste and reusing it as fertilizer. After phosphorus uptake, spent materials were tested for phosphorus release using modified soil tests representing different soil pH and alkalinity conditions. In experiments using model animal wastewaters containing both ammonia and bicarbonate alkalinity, dissolved phosphorus was removed by struvite (MgNH4PO4·6H2O) formation, whereas in deionized water, dissolved phosphorus was removed by adsorption. Alkalinity in the model animal wastewaters competed with phosphate for dissolved or solid-associated magnesium, thereby reducing phosphorus uptake. Spent materials released significant phosphorus in waters with bicarbonate alkalinity. This work shows that abundant agricultural wastes can be used to synthesize solids for phosphorus uptake, with the spent materials having potential application as fertilizers.

Identifying the Evolution of Selenium-Vacancy-Modulated MoSe2 Precatalyst in Lithium-Sulfur Chemistry.

Witnessing compositional evolution and identifying the catalytically active moiety of electrocatalysts is of paramount importance in Li-S chemistry. Nevertheless, this field remains elusive. We report the scalable salt-templated synthesis of Se-vacancy-incorporated MoSe2 architecture (SeVs-MoSe2 ) and reveal the phase evolution of the defective precatalyst in working Li-S batteries. The interaction between lithium polysulfides and SeVs-MoSe2 is probed to induce the transformation from SeVs-MoSe2 to MoSeS. Furthermore, operando Raman spectroscopy and ex situ X-ray diffraction measurements in combination with theoretical simulations verify that the effectual MoSeS catalyst could help promote conversion of Li2 S2 to Li2 S, thereby boosting the capacity performance. The Li-S battery accordingly exhibits a satisfactory rate and cycling capability even with and elevated sulfur loading and lean electrolyte conditions (7.67 mg cm-2 ; 4.0 µL mg-1 S ). This work elucidates the design strategies and catalytic mechanisms of efficient electrocatalysts bearing defects.

Thermally Activated n-Doping of Organic Semiconductors Achieved by N-Heterocyclic Carbene Based Dopant.

Molecular doping plays an important role in the modification of carrier density of organic semiconductors thus enhancing their optoelectronic performance. However, efficient n-doping remains challenging, especially owing to the lack of strongly reducing and air-stable n-dopants. Herein, an N-heterocyclic carbene (NHC) precursor, DMImC, is developed as a thermally activated n-dopant with the excellent stability in air. Its thermolysis in situ regenerates free NHC and subsequently dopes typical organic semiconductors. In sequentially doped FBDPPV films, DMImC does not disturb the π-π packing of the polymer and achieves good miscibility with the polymer. As a result, a high electrical conductivity of up to 8.4 S cm-1 is obtained. Additionally, the thermally activated doping and the excellent air stability permit DMImC to be noninteractively co-processed with polymers in air. Our results reveal that DMImC can be served as an efficient n-dopant suitable for various organic semiconductors.

The Critical Role of Dopant Cations in Electrical Conductivity and Thermoelectric Performance of n-Doped Polymers.

The low n-doping efficiency of conjugated polymers with the molecular dopants limits their availability in electrical conductivity, thermoelectrics, and other electric applications. Recently, considerable efforts have focused on improving the ionization of dopants by modifying the structures of host polymers or n-dopants; however, the effect of ionized dopants on the electrical conductivity and thermoelectric performance of the polymers is still a puzzle. Herein, we try to reveal the role of molecular dopant cations on carrier transport through the systematic comparison of two n-dopants, TAM and N-DMBI-H. These two n-dopants exhibit various doping features with the polymer due to their different chemical structure characteristics. For instance, while doping, TAM negligibly perturbs the polymer backbone conformation and microstructural ordering; then after ionization, TAM cations possess weak π-backbone affinity but strong intrinsic affinity with side chains, which enables the doped system to screen the Coulomb potential spatially. Such doping features lead to high carrierization capabilities for TAM-doped polymers and further result in an excellent conductivity of up to 22 ± 2.5 S cm-1 and a power factor of over 80 µW m-1 K-2, which are significantly higher than the state of the art values of the common n-dopant N-DMBI-H. More importantly, this strategy has also proven to be widely applicable in other doped polymers. Our investigations indicate the vital role of dopant counterions in high electrical and thermoelectric performance polymers and also suggest that, without sacrificing Seebeck coefficients, high conductivities can be realized with precise regulation of the interaction between the cations and the host.

Aptamer Display on Diverse DNA Polyhedron Supports.

DNA aptamers are important tools for molecular recognition, particularly for a new generation of tools for biomedicine based on nucleic acid nanostructures. Here, we investigated the relative abilities of different shapes and sizes of DNA polyhedra to display an aptamer which binds to the malaria biomarker Plasmodium falciparum lactate dehydrogenase (PfLDH). The aptamer was shown to perform an Aptamer-Tethered Enzyme Capture (APTEC) assay with the hypothesis that the display of the aptamer above the surface through the use of a polyhedron may lead to better sensitivity than use of the aptamer alone. We compared different numbers of points of contact, different shapes, including tetrahedron, square, and pentagon-based pyramids, as well as prisms. We also investigated the optimal height of display of the structure. Our results demonstrated that the display of an aptamer on an optimized nanostructure improved sensitivity up to 6-fold relative to the aptamer alone in the APTEC assay. Other important factors included multiple basal points of contact with the surface, a tetrahedron proved superior to the more complex shaped structures, and height above the surface only made minor differences to efficacy. The display of an aptamer on a nanostructure may be beneficial for higher sensitivity aptamer-mediated malaria diagnosis. Aptamer displays using DNA nanostructure polyhedron supports could be a useful approach in a variety of applications.

Fine-Tuning of Crystal Packing and Charge Transport Properties of BDOPV Derivatives through Fluorine Substitution.

Molecular packing in organic single crystals greatly influences their charge transport properties but can hardly be predicted and designed because of the complex intermolecular interactions. In this work, we have realized systematic fine-tuning of the single-crystal molecular packing of five benzodifurandione-based oligo(p-phenylenevinylene) (BDOPV)-based small molecules through incorporation of electronegative fluorine atoms on the BDOPV backbone. While these molecules all exhibit similar column stacking configurations in their single crystals, the intermolecular displacements and distances can be substantially modified by tuning of the amounts and/or the positions of the substituent fluorine atoms. Density functional theory calculations showed that the subtle differences in charge distribution or electrostatic potential induced by different fluorine substitutions play an important role in regulating the molecular packing of the BDOPV compounds. Consequently, the electronic couplings for electron transfer can vary from 71 meV in a slipped stack to 201 meV in a nearly cofacial antiparallel stack, leading to an increase in the electron mobility of the BDOPV derivatives from 2.6 to 12.6 cm(2) V(-1) s(-1). The electron mobility of the five molecules did not show a good correlation with the LUMO levels, indicating that the distinct difference in charge transport properties is a result of the molecular packing. Our work not only provides a series of high-electron-mobility organic semiconductors but also demonstrates that fluorination is an effective approach for fine-tuning of single-crystal packing modes beyond simply lowering the molecular energy levels.

Urban-Water Harmony model to evaluate the urban water management.

Water resources in many urban areas are under enormous stress due to large-scale urban expansion and population explosion. The decision-makers are often faced with the dilemma of either maintaining high economic growth or protecting water resources and the environment. Simple criteria of water supply and drainage do not reflect the requirement of integrated urban water management. The Urban-Water Harmony (UWH) model is based on the concept of harmony and offers a more integrated approach to urban water management. This model calculates four dimensions, namely urban development, urban water services, water-society coordination, and water environment coordination. And the Analytic Hierarchy Process has been used to determine the indices weights. We applied the UWH model to Beijing, China for an 11-year assessment. Our findings show that, despite the severe stress inherent in rapid development and water shortage, the urban water relationship of Beijing is generally evolving in a positive way. The social-economic factors such as the water recycling technologies contribute a lot to this change. The UWH evaluation can provide a reasonable analysis approach to combine various urban and water indices to produce an integrated and comparable evaluation index. This, in turn, enables more effective water management in decision-making processes.

Termites can learn.

It is generally believed that termites can't learn and are not "intelligent". This study aimed to test whether termites could have any form of memory. A Y-shaped test device with one release chamber and two identical test chambers was designed and constructed by 3D printing. A colony of damp wood termites was harvested from the wild. Worker termites were randomly selected for experiment. Repellent odors that could mimic the alarm pheromone for termites were first identified. Among all substances tested, a tea tree oil and lemon juice were found to contain repellent odors for the tested termites, as they significantly reduced the time that termites spent in the chamber treated with these substances. As control, a trail pheromone was found to be attractive. Subsequently, a second cohort of termites were operant conditioned by punishment using both tea tree oil and lemon juice, and then tested for their ability to remember the path that could lead to the repellant odors. The test device was thoroughly cleaned between trials. It was found that conditioned termites displayed a reduced tendency to choose the path that led to expectant punishment as compared with naïve termites. Thus, it is concluded that damp wood termites are capable of learning and forming "fear memory", indicative of "intelligence" in termites. This result challenges established presumption about termites' intelligence.