Vegetation cover change and the driving factors over northwest China

In this paper the spatio-temporal variation of vegetation cover in northwest China during the period of 1982-2006 and its driving factors were analyzed using GIMMS/NDVI data. The annual average NDVI was increased with a rate of 0.0005/a in northwest China and there was an obvious difference between regions. The trend line slopes of NDVI were higher than 0.0005 in the Tianshan Moutains and Altay Mountains of Xinjiang, the Qilian Mountains of Gansu and the eastern part of Qinghai, which indicated the vegetation cover was significantly increased in these areas. The trend line slopes of NDVI were lower than -0.0005 in the southern region of Qinghai, the border regions of Shaanxi and Ningxia, the parts of Gansu and Tarim Basin, Turpan and Tuoli in Xinjiang, which indicated the vegetation cover was declined in these areas. The NDVI of woodland, grassland and cultivated land had an ascending tendency during the study period. The study shows that the vegetation cover change was caused by both natural factors and human activities in northwest China. The natural vegetation change, such as forests was influenced by climate change, while human activities were the main reason to the change of planting vegetation. The changes of vegetation covers for different elevations, slopes and slope aspects were quite different. When the eleva- tion is exceeded to 4,000 m, the NDVI increasing trend was very low; the NDVI at the slope of less than 25~ was increased by the ecological construction; the variation of NDVI on sunny slope was stronger than that on shady slope. The temperature rose significantly in recent 25 years in northwest China by an average rate of 0.67^-C/10a, and precipitation increased by an average rate of 8.15 mm/10a after 1986. There was positive correlation between vegetation cover and temperature and annual precipitation changes. Rising temperature increased the evaporation and drought of soils, which is not conducive to plant growth, and the irrigation in agricultural areas reduced the correlation between agricultural vegetation NDVI and precipita- tion. The improvement of agricultural production level and the projects of ecological construction are very important causes for the NDVI increase in northwest China, and the ecological effect of large-scale ecological construction projects has appeared.

The Solar Upper Transition Region Imager(SUTRI)Onboard the SATech-01 Satellite

The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.

Effect of sub-cloud evaporation on the δ^18O of precipitation in Qilian Mountains and Hexi Corridor, China

The sub-cloud evaporation effect refers to the evaporation process for raindrops that fall from the cloud base to the ground, which is usually accompanied by depleted light isotopes and enriched heavy isotopes in the precipitation. Based on 461 event-based precipitation samples collected from 12 weather stations in the Qilian Mountains and the Hexi Corridor from May to August of 2013, our results indicated that sub-cloud evaporation has a great influence on the δ^18O of precipitation, especially in small-amount precipitation events. In May, June, July, and August the δ18O composition was enriched by 35%, 26%, 39%, and 41%, respectively, from the cloud base to the ground. This influence clearly strengthened with temperature rise, from the Qilian Mountains to the Hexi Corridor. When falling raindrops are evaporated by 1.0% in the Qilian Mountains and the Hexi Corridor, the composition of δ18O would be enriched by 1.2% and 2.6%, respectively. Temperature dominated the sub-cloud evaporation in the Qilian Mountains, whereas relative humidity controlled it in the Hexi Corridor. These results provide new proofs of the evolutional process of stable isotopes in precipitation in arid regions.

Discovery of natural products capable of inducing porcine host defense peptide gene expression using cell-based high throughput screening

Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.

The high catalytic activity and strong stability of 3%Fe/AC catalysts for catalytic wet peroxide oxidation of m-cresol: The role of surface functional groups and FeO_(x) particles

FeO;supported on activated carbon(AC) has been shown to be an ideal catalyst for catalytic wet peroxide oxidation(CWPO) due to its high CWPO reaction activity and stability. Although there have been some studies on the mechanism of Fe/AC catalysis in CWPO, the specific contribution of each component(surface oxygen groups and FeOxon AC) inside an Fe/AC catalyst and their corresponding reaction mechanism remain unclear, and the reaction stability of CWPO catalysts has rarely been discussed. Then the optimal CWPO catalyst in our laboratory, 3%Fe/AC, was selected.(1) By removing certain components on the AC through heat treatment, its contribution to the reaction and the corresponding reaction mechanism were investigated. With the aid of temperature-programmed desorption–mass spectrometry(TPD–MS) and the CWPO reaction, the normalized catalytic contributions of components were shown to be: 37.3%(carboxylic groups), 5.3%(anhydride), 19.3%(ether/hydroxyl),-71.4%(carbonyl groups) and 100%(FeOx),respectively. DFT calculation and EPR analysis confirmed that carboxylic groups and Fe_(2)O_(3) are able to activate the H_(2)O_(2) to generate·OH.(2) The catalysts at were characterized at different reaction times(0 h, 450 h, 900 h, 1350 h, and 1800 h) by TPD–MS and M?ssbauer spectroscopy. Results suggested that the number of carboxylic goups gradually increased and the size of paramagnetic Fe_(2)O_(3) particle crystallites gradually increased as the reactions progressed. The occurrence of strong interactions between metal oxides and AC was also confirmed. Due to these effects, the strong stability of 3%Fe/AC was further improved. Therefore, the reasons for the high activity and strong stability of 3%Fe/AC in CWPO were clearly shown. We believe that this work provides an idea of the removal of cresols from wastewater into the introduction to show the potential applications of CWPO.

Control Chaos in System with Fractional Order

In this paper, by utilizing the fractional calculus theory and computer simulations, dynamics of the fractional order system is studied. Further, we have extended the nonlinear feedback control in ODE systems to fractional order systems, in order to eliminate the chaotic behavior. The results are proved analytically by stability condition for fractional order system. Moreover numerical simulations are shown to verify the effectiveness of the proposed control scheme.

Vehicle Type Recognition Based on Deep Convolution Neural Network

The systems based on image processing for vehicle type recognition is becoming more and fiercer. It plays an important role in traffic safety. In order to improve the problems that traditional Convolutional Neural Network has low accuracy of feature extraction from the low-resolution image, a novel model based on Deep Convolutional Neural Network (DCNN) was proposed. In this paper, our work mainly contains two aspects both extraction of feature dimension and recognition of vehicle image. Firstly, the learning way was introduced,and the raw image of vehicle subsampled with several different sizes was operated with the filter corresponding each channel in a way of convolution to extract the feature dimension of image. Secondly, the features dimension obtained from every channel were merged by a full connected layer. Eventually,features used to recognize the type of vehicle is got. The experiment shows that the architecture of DCNN model has a efficient performance on the recognition of vehicle image. Compared with the traditional algorithm of CNN, the results of experiment show that the mode of DCNN can achieve 97.6% accuracy and a higher precision is got.

A thermo-responsive rewritable plasmonic bio-memory by regulating single core-satellite gold nanocluster dissociation

A thermo-responsive rewritable plasmonic bio-memory chip has been successfully fabricated on an indium tin oxide(ITO)glass slide by assembling core-satellite gold nanoclusters with different size of gold nanoparticles(AuNPs)using double-strand DNA(dsDNA)linker.And the prepared 70@DNA20@13 gold nanoclusters(AuNCs)exhibited more stable and greater photothermal conversion ability.With short time irradiation by 633 nm microbeam laser,every individual AuNCs could be excited and remove the satellite AuNPs on its surface.Especially,in the dissociation process of AuNCs with 3−5 satellite,its color would change from yellow to green,which showed more significant reduction in the red channel of the dark-field microscopy(DFM)images and could be defined to state“0”and“1”respectively.Besides,this plasmonic nano bio-memory could transform cyclically its state between 0 and 1 which exhibited excellent rewritable ability.

Protection of Omicron Sub-Lineage Infection Against Reinfection with Another Omicron Sub-Lineage:Systematic Review,Meta-Analysis,and Meta-Regression-Worldwide,2022-2023

Summary What is already known about this topic?Both the decline in immunity over time and the evolution of the virus play a role in the level of protection offered by a prior infection.What is added by this report?Point estimates indicated variations in protection levels based on the initial infecting variant and the reinfecting variant.There was a consistent correlation between real-world protection,antigenic distance,and humoral immunity levels.Specifically,shorter antigenic distances and higher humoral immunity levels corresponded to enhanced real-world protection.What are the implications for public health practice?Our findings suggest that virological and immunological studies could help identify and assess the epidemic risk posed by new variants before they become dominant.Prompt incorporation of the latest variants into the antigen components of the coronavirus disease 2019(COVID-19)vaccines can significantly contribute to effective epidemic prevention and control measures.

Recent techniques on analyses and characterizations of shale gas and oil reservoir

This article offers a comprehensive review focused on the analysis and characterization of shale reservoirs,unconventional hydrocarbon resources that uniquely serve as both the source reservoir for gas and oil,and the rock.To analyze and characterize shale reservoirs,pore structure,rock components and rock mechanical properties are three main factors to analyze.These three main factors are necessary for successful field operations in shale reservoirs.Until now,there are various techniques utilized to characterize these three properties.Therefore,this study delves into the intricacies of shale reservoir's pore structure,rock components and mechanical properties under varying geological conditions,summarizing various techniques utilized to characterize these properties in previous studies.The study also discusses the role of analytical techniques in understanding the complex interactions between kerogen and the surrounding mineral matrix.By providing a summary of various techniques operated on the mentioned three main factors,this paper supplies the effective and optimal technique on analyzing different properties of shale reservoirs.Furthermore,the paper aims to contribute to more effective resource assessment and production optimization in shale reservoirs,offering insights that have significant implications for the future of unconventional hydrocarbon extraction.

面向智能时代的人机合作心理模型

最近10年,人工智能和人机交互研究突飞猛进,在学术界和产业界都掀起了热潮.不管是突破人工智能的瓶颈,还是实现和谐、自然的人机交互,都迫切需要符合人类认知机理和心理规律的人机交互心理模型.建构面向智能时代的人机合作心理模型,不但可以解释、模拟和预测人类的行为,而且可以指导相应的智能系统和人机交互设计.本文回顾和总结了以往的人机交互模型和认知计算模型,基于最近10年的实验证据和研究发现,试图拓展和深化已有的认知模型,建构面向智能时代的人机合作心理模型,为智能时代的人机交互研究提供理论基础.

Immunogenicity of 23-Valent Pneumococcal Polysaccharide Vaccine in Patients with Chronic Obstructive Pulmonary Disease—Hebei Province,China,September−December,2019

Summary What is already known on this topic?The global burden of chronic obstructive pulmonary disease(COPD)is serious.Pneumococcal infection is associated with acute exacerbations of COPD(AECOPD).The 23-valent pneumococcal polysaccharide vaccine(PPSV23)is recommended for COPD patients to decrease AECOPD due to pneumococcus,but evidence on the immunogenicity of PPSV23 in COPD patients is limited.What is added by this report?

A short note on the horizontal and vertical movements of a whale shark, Rhincodon typus, tracked by satellite telemetry in the South China Sea

Whale sharks,a global migratory species,are often reported entangled in fishing nets in coastal areas of Chi-na.The effectiveness of conservation measures has been constrained by very limited knowledge on their move-ments and preferred habitats in the coastal areas of China.For the first time,we tracked the movements of 2 whale sharks by satellite telemetry in China' Mainland.The tracking results of 1 whale shark revealed that it travelled in the South China Sea in a south-eastern direction,parallel to the eastern coast of Vietnam.Total dis-tance travelled was 1018 km,in approximately 74 days,with a mean speed of 14 km per day.It appeared to head towards the cool upwelling zones in southern Vietnam at the time of the tag’s detachment.In our study,it was observed that this whale shark was a surface dweller and spent approximately 45%of its time above 10 m water depth and 90%of its time above 50 m depth.It also tended to stay in water temperatures between 27 and 30°C,and was rarely recorded in water below 20°C.This preliminary study indicates the importance of shal-low waters as the foraging habitat for whale sharks,and has implications for their management and conserva-tion.

Impact of Influenza and Pneumococcal Polysaccharide Vaccination on Economic Burden from Acute Exacerbations of Chronic Obstructive Pulmonary Disease-Hebei Province,China,November 2018 to November 2020

Summary What is already known on this topic?Chronic obstructive pulmonary disease(COPD)exacerbations increase household economic burden,but there is limited evidence from prospective cohort studies in China about the impact of vaccination on economic burden.What is added by this report?This study demonstrated the economic burden of COPD exacerbations,pneumonia,and hospitalization in COPD patients in China is substantial.Influenza vaccine and 23-valent pneumococcal polysaccharide vaccine(PPSV23),separately or together,were significantly associated with decreased economic burden.What are the implications for public health practice?Our study supports evidence on recommendations that COPD patients in China are offered both influenza vaccine and PPSV23.

Survey on Immunization Services for Children with Medical Conditions-China, 2022

Summary What is already known about this topic?Children with medical conditions frequently experience under-immunization.Ensuring high-quality immunization services is crucial for enhancing vaccination coverage levels;nevertheless,the state of immunization service provision for children with medical conditions in China remains unclear.What is added by this report?Immunization support for children with medical conditions in China demonstrates considerable variability and may be inadequate.Primary obstacles to the provision of immunization services include an absence of comprehensive vaccination recommendations and assessment guidelines for specific medical conditions,as well as inconsistencies among vaccine recommendations,package inserts,and expert consensus statements pertaining to the vaccination of children with medical conditions.What are the implications for public health practice?The examination of provincial practices in providing immunization services for children with medical conditions,as well as understanding the barriers faced by National Immunization Program providers in administering vaccinations,can contribute to the improvement of immunization services for this population in China.

国际汉语教师教学自主性特征的关键差异:一项判别分析的发现

"后方法时代"语言教学观反思传统方法概念,倡导对教师教学自主性和创造性的回归.教学自主性对教师自身专业发展和获得教学实效具有至关重要的意义.本项研究以北京地区90名新手、熟手和专家汉语教师为样本,从教学自主性的八个维度即自发性、目的 性、责任性、独立性、胜任性、自省性、自控性和跨文化适应性出发,判别分析结果得出:(1)独立性是判断不同专业发展水平教师教学自主性差异的共享预测指标;(2)自主意识层面的自发性、目的 性和自主能力层面的自控性是新手教师与熟手教师的关键差异特征,而胜任性和跨文化适应性是熟手教师与专家教师的关键差异特征,主要集中在自主能力层面.基于以上发现,本文认为应该加强汉语教师群体教学自主性的培养,提升不同专业发展阶段教师的实践智慧,引领新手教师走向熟手教师、专家教师.