
Shaanxi Normal University
UniversityXi'an, China
Research output, citation impact, and the most-cited recent papers from Shaanxi Normal University (China). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Shaanxi Normal University
Abstract. High-spatial-resolution and long-term climate data are highly desirable for understanding climate-related natural processes. China covers a large area with a low density of weather stations in some (e.g., mountainous) regions. This study describes a 0.5′ (∼ 1 km) dataset of monthly air temperatures at 2 m (minimum, maximum, and mean proxy monthly temperatures, TMPs) and precipitation (PRE) for China in the period of 1901–2017. The dataset was spatially downscaled from the 30′ Climatic Research Unit (CRU) time series dataset with the climatology dataset of WorldClim using delta spatial downscaling and evaluated using observations collected in 1951–2016 by 496 weather stations across China. Prior to downscaling, we evaluated the performances of the WorldClim data with different spatial resolutions and the 30′ original CRU dataset using the observations, revealing that their qualities were overall satisfactory. Specifically, WorldClim data exhibited better performance at higher spatial resolution, while the 30′ original CRU dataset had low biases and high performances. Bicubic, bilinear, and nearest-neighbor interpolation methods employed in downscaling processes were compared, and bilinear interpolation was found to exhibit the best performance to generate the downscaled dataset. Compared with the evaluations of the 30′ original CRU dataset, the mean absolute error of the new dataset (i.e., of the 0.5′ dataset downscaled by bilinear interpolation) decreased by 35.4 %–48.7 % for TMPs and by 25.7 % for PRE. The root-mean-square error decreased by 32.4 %–44.9 % for TMPs and by 25.8 % for PRE. The Nash–Sutcliffe efficiency coefficients increased by 9.6 %–13.8 % for TMPs and by 31.6 % for PRE, and correlation coefficients increased by 0.2 %–0.4 % for TMPs and by 5.0 % for PRE. The new dataset could provide detailed climatology data and annual trends of all climatic variables across China, and the results could be evaluated well using observations at the station. Although the new dataset was not evaluated before 1950 owing to data unavailability, the quality of the new dataset in the period of 1901–2017 depended on the quality of the original CRU and WorldClim datasets. Therefore, the new dataset was reliable, as the downscaling procedure further improved the quality and spatial resolution of the CRU dataset and was concluded to be useful for investigations related to climate change across China. The dataset presented in this article has been published in the Network Common Data Form (NetCDF) at https://doi.org/10.5281/zenodo.3114194 for precipitation (Peng, 2019a) and https://doi.org/10.5281/zenodo.3185722 for air temperatures at 2 m (Peng, 2019b) and includes 156 NetCDF files compressed in zip format and one user guidance text file.
Since the emergence of the first cases in Wuhan, China, the novel coronavirus (2019-nCoV) infection has been quickly spreading out to other provinces and neighboring countries. Estimation of the basic reproduction number by means of mathematical modeling can be helpful for determining the potential and severity of an outbreak and providing critical information for identifying the type of disease interventions and intensity. A deterministic compartmental model was devised based on the clinical progression of the disease, epidemiological status of the individuals, and intervention measures. The estimations based on likelihood and model analysis show that the control reproduction number may be as high as 6.47 (95% CI 5.71-7.23). Sensitivity analyses show that interventions, such as intensive contact tracing followed by quarantine and isolation, can effectively reduce the control reproduction number and transmission risk, with the effect of travel restriction adopted by Wuhan on 2019-nCoV infection in Beijing being almost equivalent to increasing quarantine by a 100 thousand baseline value. It is essential to assess how the expensive, resource-intensive measures implemented by the Chinese authorities can contribute to the prevention and control of the 2019-nCoV infection, and how long they should be maintained. Under the most restrictive measures, the outbreak is expected to peak within two weeks (since 23 January 2020) with a significant low peak value. With travel restriction (no imported exposed individuals to Beijing), the number of infected individuals in seven days will decrease by 91.14% in Beijing, compared with the scenario of no travel restriction.
Abstract Even though the mesoporous-type perovskite solar cell (PSC) is known for high efficiency, its planar-type counterpart exhibits lower efficiency and hysteretic response. Herein, we report success in suppressing hysteresis and record efficiency for planar-type devices using EDTA-complexed tin oxide (SnO 2 ) electron-transport layer. The Fermi level of EDTA-complexed SnO 2 is better matched with the conduction band of perovskite, leading to high open-circuit voltage. Its electron mobility is about three times larger than that of the SnO 2 . The record power conversion efficiency of planar-type PSCs with EDTA-complexed SnO 2 increases to 21.60% (certified at 21.52% by Newport) with negligible hysteresis. Meanwhile, the low-temperature processed EDTA-complexed SnO 2 enables 18.28% efficiency for a flexible device. Moreover, the unsealed PSCs with EDTA-complexed SnO 2 degrade only by 8% exposed in an ambient atmosphere after 2880 h, and only by 14% after 120 h under irradiation at 100 mW cm −2 .
Studies in neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and Amyotrophic lateral sclerosis, Huntington's disease, and so on, have suggested that inflammation is not only a result of neurodegeneration but also a crucial player in this process. Protein aggregates which are very common pathological phenomenon in neurodegeneration can induce neuroinflammation which further aggravates protein aggregation and neurodegeneration. Actually, inflammation even happens earlier than protein aggregation. Neuroinflammation induced by genetic variations in CNS cells or by peripheral immune cells may induce protein deposition in some susceptible population. Numerous signaling pathways and a range of CNS cells have been suggested to be involved in the pathogenesis of neurodegeneration, although they are still far from being completely understood. Due to the limited success of traditional treatment methods, blocking or enhancing inflammatory signaling pathways involved in neurodegeneration are considered to be promising strategies for the therapy of neurodegenerative diseases, and many of them have got exciting results in animal models or clinical trials. Some of them, although very few, have been approved by FDA for clinical usage. Here we comprehensively review the factors affecting neuroinflammation and the major inflammatory signaling pathways involved in the pathogenicity of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Amyotrophic lateral sclerosis. We also summarize the current strategies, both in animal models and in the clinic, for the treatment of neurodegenerative diseases.
INTRODUCTION Our understanding of the pathophysiology of psychiatric disorders, including autism spectrum disorder (ASD), schizophrenia (SCZ), and bipolar disorder (BD), lags behind other fields of medicine. The diagnosis and study of these disorders currently depend on behavioral, symptomatic characterization. Defining genetic contributions to disease risk allows for biological, mechanistic understanding but is challenged by genetic complexity, polygenicity, and the lack of a cohesive neurobiological model to interpret findings. RATIONALE The transcriptome represents a quantitative phenotype that provides biological context for understanding the molecular pathways disrupted in major psychiatric disorders. RNA sequencing (RNA-seq) in a large cohort of cases and controls can advance our knowledge of the biology disrupted in each disorder and provide a foundational resource for integration with genomic and genetic data. RESULTS Analysis across multiple levels of transcriptomic organization—gene expression, local splicing, transcript isoform expression, and coexpression networks for both protein-coding and noncoding genes—provides an in-depth view of ASD, SCZ, and BD molecular pathology. More than 25% of the transcriptome exhibits differential splicing or expression in at least one disorder, including hundreds of noncoding RNAs (ncRNAs), most of which have unexplored functions but collectively exhibit patterns of selective constraint. Changes at the isoform level, as opposed to the gene level, show the largest effect sizes and genetic enrichment and the greatest disease specificity. We identified coexpression modules associated with each disorder, many with enrichment for cell type–specific markers, and several modules significantly dysregulated across all three disorders. These enabled parsing of down-regulated neuronal and synaptic components into a variety of cell type– and disease-specific signals, including multiple excitatory neuron and distinct interneuron modules with differential patterns of disease association, as well as common and rare genetic risk variant enrichment. The glial-immune signal demonstrates shared disruption of the blood-brain barrier and up-regulation of NFkB-associated genes, as well as disease-specific alterations in microglial-, astrocyte-, and interferon-response modules. A coexpression module associated with psychiatric medication exposure in SCZ and BD was enriched for activity-dependent immediate early gene pathways. To identify causal drivers, we integrated polygenic risk scores and performed a transcriptome-wide association study and summary-data–based Mendelian randomization. Candidate risk genes—5 in ASD, 11 in BD, and 64 in SCZ, including shared genes between SCZ and BD—are supported by multiple methods. These analyses begin to define a mechanistic basis for the composite activity of genetic risk variants. CONCLUSION Integration of RNA-seq and genetic data from ASD, SCZ, and BD provides a quantitative, genome-wide resource for mechanistic insight and therapeutic development at Resource.PsychENCODE.org. These data inform the molecular pathways and cell types involved, emphasizing the importance of splicing and isoform-level gene regulatory mechanisms in defining cell type and disease specificity, and, when integrated with genome-wide association studies, permit the discovery of candidate risk genes. The PsychENCODE cross-disorder transcriptomic resource. Human brain RNA-seq was integrated with genotypes across individuals with ASD, SCZ, BD, and controls, identifying pervasive dysregulation, including protein-coding, noncoding, splicing, and isoform-level changes. Systems-level and integrative genomic analyses prioritize previously unknown neurogenetic mechanisms and provide insight into the molecular neuropathology of these disorders.
The fields of theoretical and computational chemistry have come a long way since their inception in the mid-20th century. Fifty years ago, only rudimentary approximations for very simple molecules could be performed. Thanks in part to the ongoing development of very fast computers, and the efforts of theoretical chemists in developing fast and accurate quantum mechanical (QM) methods for calculating electronic energies of atoms and molecules, theoretical and computational chemistry can now give reliable geometries, energies, reactivities, and electronic properties for molecules. Such information has become indispensable in understanding and explaining experimental results that would be otherwise difficult to interpret.
Globally increasing energy demands and environmental concerns related to the use of fossil fuels have stimulated extensive research to identify new energy systems and economies that are sustainable, clean, low cost, and environmentally benign. Hydrogen generation from solar-driven water splitting is a promising strategy to store solar energy in chemical bonds. The subsequent combustion of hydrogen in fuel cells produces electric energy, and the only exhaust is water. These two reactions compose an ideal process to provide clean and sustainable energy. In such a process, a hydrogen evolution reaction (HER), an oxygen evolution reaction (OER) during water splitting, and an oxygen reduction reaction (ORR) as a fuel cell cathodic reaction are key steps that affect the efficiency of the overall energy conversion. Catalysts play key roles in this process by improving the kinetics of these reactions. Porphyrin-based and corrole-based systems are versatile and can efficiently catalyze the ORR, OER, and HER. Because of the significance of energy-related small molecule activation, this review covers recent progress in hydrogen evolution, oxygen evolution, and oxygen reduction reactions catalyzed by porphyrins and corroles.
Two-inch-sized perovskite crystals, CH3NH3PbX3 (X=I, Br, Cl), with high crystalline quality are prepared by a solution-grown strategy. The availability of large perovskite crystals is expected to transform its broad applications in photovoltaics, optoelectronics, lasers, photodetectors, LEDs, etc., just as crystalline silicon has done in revolutionizing the modern electronics and photovoltaic industries. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
The efficiency of planar CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> perovskite solar cells has been improved up to 19.62% using an ionic liquid to modify the TiO<sub>2</sub> electron transport layer, and the <italic>J</italic>–<italic>V</italic> hysteresis is completely eliminated.
Positively-charged gold nanoparticles possess intrinsic peroxidase-like activity, and can catalyze oxidation of the peroxidase substrate 3,3,5,5-tetramethylbenzidine (TMB) by H(2)O(2) to develop a blue color in aqueous solution, thus providing a simple approach to colorimetric detection of H(2)O(2) and glucose.
Photocatalytic hydrogen production from water offers an abundant, clean fuel source, but it is challenging to produce photocatalysts that use the solar spectrum effectively. Many hydrogen-evolving photocatalysts are active in the ultraviolet range, but ultraviolet light accounts for only 3% of the energy available in the solar spectrum at ground level. Solid-state crystalline photocatalysts have light absorption profiles that are a discrete function of their crystalline phase and that are not always tunable. Here, we prepare a series of amorphous, microporous organic polymers with exquisite synthetic control over the optical gap in the range 1.94-2.95 eV. Specific monomer compositions give polymers that are robust and effective photocatalysts for the evolution of hydrogen from water in the presence of a sacrificial electron donor, without the apparent need for an added metal cocatalyst. Remarkably, unlike other organic systems, the best performing polymer is only photoactive under visible rather than ultraviolet irradiation.
The basic reproduction number of an infectious agent is the average number of infections one case can generate over the course of the infectious period, in a naïve, uninfected population. It is well-known that the estimation of this number may vary due to several methodological issues, including different assumptions and choice of parameters, utilized models, used datasets and estimation period. With the spreading of the novel coronavirus (2019-nCoV) infection, the reproduction number has been found to vary, reflecting the dynamics of transmission of the coronavirus outbreak as well as the case reporting rate. Due to significant variations in the control strategies, which have been changing over time, and thanks to the introduction of detection technologies that have been rapidly improved, enabling to shorten the time from infection/symptoms onset to diagnosis, leading to faster confirmation of the new coronavirus cases, our previous estimations on the transmission risk of the 2019-nCoV need to be revised. By using time-dependent contact and diagnose rates, we refit our previously proposed dynamics transmission model to the data available until January 29th, 2020 and re-estimated the effective daily reproduction ratio that better quantifies the evolution of the interventions. We estimated when the effective daily reproduction ratio has fallen below 1 and when the epidemics will peak. Our updated findings suggest that the best measure is persistent and strict self-isolation. The epidemics will continue to grow, and can peak soon with the peak time depending highly on the public health interventions practically implemented.
The trap states at grain boundaries (GBs) within polycrystalline perovskite films deteriorate their optoelectronic properties, making GB engineering particularly important for stable high-performance optoelectronic devices. It is demonstrated that trap states within bulk films can be effectively passivated by semiconducting molecules with Lewis acid or base functional groups. The perovskite crystallization kinetics are studied using in situ synchrotron-based grazing-incidence X-ray scattering to explore the film formation mechanism. A model of the passivation mechanism is proposed to understand how the molecules simultaneously passivate the Pb-I antisite defects and vacancies created by under-coordinated Pb atoms. In addition, it also explains how the energy offset between the semiconducting molecules and the perovskite influences trap states and intergrain carrier transport. The superior optoelectronic properties are attained by optimizing the molecular passivation treatments. These benefits are translated into significant enhancements of the power conversion efficiencies to 19.3%, as well as improved environmental and thermal stability of solar cells. The passivated devices without encapsulation degrade only by ≈13% after 40 d of exposure in 50% relative humidity at room temperature, and only ≈10% after 24 h at 80 °C in controlled environment.
We report a low-cost water-in-salt electrolyte, of 30 m ZnCl2, which enables a dendrite-free Zn metal anode to possess a high coulombic efficiency (CE). In asymmetric Zn‖Zn cells with a limited mass of plated Zn as the working electrode, the ZnCl2 WiSE improves the average CE of the Zn anode to 95.4% from 73.2% in 5 m ZnCl2.
This paper presents a comprehensive survey of ChatGPT-related (GPT-3.5 and GPT-4) research, state-of-the-art large language models (LLM) from the GPT series, and their prospective applications across diverse domains. Indeed, key innovations such as large-scale pre-training that captures knowledge across the entire world wide web, instruction fine-tuning and Reinforcement Learning from Human Feedback (RLHF) have played significant roles in enhancing LLMs’ adaptability and performance. We performed an in-depth analysis of 194 relevant papers on arXiv, encompassing trend analysis, word cloud representation, and distribution analysis across various application domains. The findings reveal a significant and increasing interest in ChatGPT-related research, predominantly centered on direct natural language processing applications, while also demonstrating considerable potential in areas ranging from education and history to mathematics, medicine, and physics. This study endeavors to furnish insights into ChatGPT’s capabilities, potential implications, ethical concerns, and offer direction for future advancements in this field.
The search for a low-cost, ultrastable, and highly efficient non-precious metal catalyst substitute for Pt in the oxygen reduction reaction (ORR) is extremely urgent, especially in acidic media. Herein, we develop a template-assisted pyrolysis (TAP) method to obtain a unique Co catalyst with isolated single atomic sites anchored on hollow N-doped carbon spheres (ISAS-Co/HNCS). Both the single sites and the hollow substrate endow the catalyst with excellent ORR performance. The half-wave potential in acidic media approaches that of Pt/C. Experiments and density functional theory have verified that isolated Co sites are the source for the high ORR activity because they significantly increase the hydrogenation of OH* species. This TAP method is also demonstrated to be effective in preparing a series of ISAS-M/HNCS, which provides opportunities for discovering new catalysts.
Cs<sup>+</sup>doping into 2D (BA)<sub>2</sub>(MA)<sub>3</sub>Pb<sub>4</sub>I<sub>13</sub>perovskites boosts power conversion efficiency (PCE) to 13.7% and yields superior humidity and thermal stability.
Abstract Artificial photosynthesis provides a blueprint to harvest solar energy to sustain the future energy demands. Solar‐driven water splitting, converting solar energy into hydrogen energy, is the prototype of photosynthesis. Various systems have been designed and evaluated to understand the reaction pathways and/or to meet the requirements of potential applications. In solar‐to‐hydrogen conversion, electrocatalytic hydrogen and oxygen evolution reactions are key research areas that are meaningful both theoretically and practically. To utilize hydrogen energy, fuel cell technology has been extensively investigated because of its high efficiency in releasing chemical energy. In this review, general concepts of the photosynthesis in green plants are discussed, different strategies for the light‐driven water splitting proposed in laboratories are introduced, the progress of electrocatalytic hydrogen and oxygen evolution reactions are reviewed, and finally, the reactions in hydrogen fuel cells are briefly discussed. Overall, the mass and energy circulation in the solar‐hydrogen‐electricity circle are delineated. The authors conclude that attention from scientists and engineers of relevant research areas is still highly needed to eliminate the wide disparity between the aspirations and realities of artificial photosynthesis.
Abstract Recently, lead halide‐based perovskites have become one of the hottest topics in photovoltaic research because of their excellent optoelectronic properties. Among them, organic‐inorganic hybrid perovskite solar cells (PSCs) have made very rapid progress with their power conversion efficiency (PCE) now at 23.7 %. However, the intrinsically unstable nature of these materials, particularly to moisture and heat, may be a problem for their long‐term stability. Replacing the fragile organic group with more robust inorganic Cs + cations forms the cesium lead halide system (CsPbX 3 , X is halide) as all‐inorganic perovskites which are much more thermally stable and often more stable to other factors. From the first report in 2015 to now, the PCE of CsPbX 3 ‐based PSCs has abruptly increased from 2.9 % to 17.1 % with much enhanced stability. In this Review, we summarize the field up to now, propose solutions in terms of development bottlenecks, and attempt to boost further research in CsPbX 3 PSCs.
Proton exchange membrane water electrolyzers (PEMWEs) are an attractive technology for renewable energy conversion and storage. By using green electricity generated from renewable sources like wind or solar, high-purity hydrogen gas can be produced in PEMWE systems, which can be used in fuel cells and other industrial sectors. To date, significant advances have been achieved in improving the efficiency of PEMWEs through the design of stack components; however, challenges remain for their large-scale and long-term application due to high cost and durability issues in acidic conditions. In this review, we examine the latest developments in engineering PEMWE systems and assess the gap that still needs to be filled for their practical applications. We provide a comprehensive summary of the reaction mechanisms, the correlation among structure-composition-performance, manufacturing methods, system design strategies, and operation protocols of advanced PEMWEs. We also highlight the discrepancies between the critical parameters required for practical PEMWEs and those reported in the literature. Finally, we propose the potential solution to bridge the gap and enable the appreciable applications of PEMWEs. This review may provide valuable insights for research communities and industry practitioners working in these fields and facilitate the development of more cost-effective and durable PEMWE systems for a sustainable energy future.