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| 1 | A semi-spring and semi-edge combined contact model in CDEM and its application to analysis of Jiweishan landslide显示文摘Continuum-based discrete element method(CDEM)is an explicit numerical method used for simulation of progressive failure of geological body.To improve the efficiency of contact detection and simplify the calculation steps for contact forces,semi-spring and semi-edge are introduced in calculation.Semispring is derived from block vertex,and formed by indenting the block vertex into each face(24semisprings for a hexahedral element).The formation process of semi-edge is the same as that of semi-spring(24semi-edges for a hexahedral element).Based on the semi-springs and semi-edges,a new type of combined contact model is presented.According to this model,six contact types could be reduced to two,i.e.the semi-spring target face contact and semi-edge target edge contact.By the combined model,the contact force could be calculated directly(the information of contact type is not necessary),and the failure judgment could be executed in a straightforward way(each semi-spring and semi-edge own their characteristic areas).The algorithm has been successfully programmed in C++program.Some simple numerical cases are presented to show the validity and accuracy of this model.Finally,the failure mode,sliding distance and critical friction angle of Jiweishan landslide are studied with the combined model. | Chun Feng Shihai Li Xiaoyu Liu Yanan Zhang | 2014 | Journal of Rock Mechanics and Geotechnical Engineering2014，6，1： | 34 |
| 2 | Novel metabolic and physiological functions of branched chain amino acids: a review显示文摘It is widely known that branched chain amino acids(BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA(isoleucine, leucine and valine) regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including:(1) Insufficient or excessive levels of BCAA in the diet enhances lipolysis.(2) BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.(3)Supplementation of leucine in the diet enhances meat quality in finishing pigs.(4) BCAA are beneficial for mammary health, milk quality and embryo growth.(5) BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.(6) BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood(decreased BCAA catabolism) are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA. | Shihai Zhang Xiangfang Zeng Man Ren Xiangbing Mao Shiyan Qiao | 2017 | Journal of Animal Science and Biotechnology2017，8，3： | 28 |
| 3 | BP-PSO-based intelligent case retrieval method for high-rise structural form selection显示文摘Modern architectures are developing in the direction of tall buildings and complex structures,and the theoretical analysis and the design experience have seriously lagged behind the construction of super high-rise structures.Structural form selection,especially the case based reasoning (CBR) based structural form selection,is a promising tool for the construction of high-rise structures.In view of the limit of cognitive ability of domain experts,a BP (back propagation)-PSO (particle swarm optimization)-based intelligence case retrieval method for high-rise structural form selection is proposed.The CBR-based case retrieval method and the construction of the BP-PSO neutral network are introduced.And then the BP-PSO-based case retrieval method is validated by some engineering cases.The results of training and prediction indicate that the proposed method has good ability to retrieve the cases of high-rise structures. | ZHANG ShiHai OU JinPing | 2013 | Science China(Technological Sciences)2013，56，4： | 9 |
| 4 | A fundamental theorem for eco-environmental surface modelling and its applications显示文摘We propose a fundamental theorem for eco-environmental surface modelling(FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth’s surface system modeling(FTESM). The Beijing-Tianjin-Hebei(BTH) region is taken as a case area to conduct empirical studies of algorithms for spatial upscaling, spatial downscaling, spatial interpolation, data fusion and model-data assimilation, which are based on high accuracy surface modelling(HASM), corresponding with corollaries of FTEEM. The case studies demonstrate how eco-environmental surface modelling is substantially improved when both extrinsic and intrinsic information are used along with an appropriate method of HASM. Compared with classic algorithms, the HASM-based algorithm for spatial upscaling reduced the root-meansquare error of the BTH elevation surface by 9 m. The HASM-based algorithm for spatial downscaling reduced the relative error of future scenarios of annual mean temperature by 16%. The HASM-based algorithm for spatial interpolation reduced the relative error of change trend of annual mean precipitation by 0.2%. The HASM-based algorithm for data fusion reduced the relative error of change trend of annual mean temperature by 70%. The HASM-based algorithm for model-data assimilation reduced the relative error of carbon stocks by 40%. We propose five theoretical challenges and three application problems of HASM that need to be addressed to improve FTEEM. | Tianxiang YUE Na ZHAO Yu LIU Yifu WANG Bin ZHANG Zhengping DU Zemeng FAN Wenjiao SHI Chuanfa CHEN Mingwei ZHAO Dunjiang SONG Shihai WANG Yinjun SONG Changqing YAN Qiquan LI Xiaofang SUN Lili ZHANG Yongzhong TIAN Wei WANG Ying’an WANG Shengnan MA Hongsheng HUANG Yimin LU Qing WANG Chenliang WANG Yuzhu WANG Ming LU Wei ZHOU Yi LIU Xiaozhe YIN Zong WANG Zhengyi BAO Miaomiao ZHAO Yapeng ZHAO Yimeng JIAO Ufra NASEER Bin FAN Saibo LI Yang YANG John PWILSON | 2020 | Science China Earth Sciences2020，63，8： | 7 |
| 5 | Effects of Nd^(3+)on the microstructure and magnetic properties of Ni-Zn ferrites显示文摘Ni0.4Zn0.6Fe2 ? 铁酸盐与 Nd2O3 的不同数量做了的 xNdxO4 (x = 0-0.07 ) 用标准陶器的技术被准备。样品单轴地被压并且在 1250D 的 | FAN Xiufeng REN Huiping ZHANG Yanghuan GUO Shihai WANG Xinlin | 2008 | Rare Metals2008，27，3： | 7 |
| 6 | Safety evaluation of Dagangshan arch dam resisting strong earthquakes with a rate-dependency anisotropic damage model显示文摘This paper presents a model to simulate the safe behavior of Dagangshan arch dam with a rate-dependency anisotropic damage model. This model considers the damage of asymmetry and anisotropy under cyclic loading of tension and compression, and it is used in the compiled finite element code. The material parameters used in the model can be identified from uniaxial static and dynamic experiments. Thereafter, it is used for analyzing damage and failure patterns of the dam subjected to water pressure and strong earthquakes. The numerical results show that it is necessary to consider both asymmetry between tension and compression and anisotropy of damage. Severe damage regions of the dam reveal brittle and risky positions clearly. Meanwhile damage patterns show the failure trend and safety behaviors of the dam. These results match well with that of the experiments carried out in DUT. The proposed model may be used to predict the damage patterns and potential failure modes of concrete structures like the dam. And the aseismic performance of the dam can be figured out. | DU RongQiang ZHANG Qing CHEN ShiHai LIN Gao | 2011 | Science China(Technological Sciences)2011，54，3： | 6 |
| 7 | Optical observations of LIGO source GW 170817 by the Antarctic Survey Telescopes at Dome A,Antarctica显示文摘The LIGO detection of gravitational waves(GW) from merging black holes in 2015 marked the beginning of a new era in observational astronomy. The detection of an electromagnetic signal from a GW source is the critical next step to explore in detail the physics involved. The Antarctic Survey Telescopes(AST3),located at Dome A, Antarctica, is uniquely situated for rapid response time-domain astronomy with its continuous night-time coverage during the austral winter. We report optical observations of the GW source(GW 170817) in the nearby galaxy NGC 4993 using AST3. The data show a rapidly fading transient at around 1 day after the GW trigger, with the i-band magnitude declining from 17:23 ± 0:13 magnitude to 17:72 ± 0:09 magnitude in ~1:8 h. The brightness and time evolution of the optical transient associated with GW 170817 are broadly consistent with the predictions of models involving merging binary neutron stars. We infer from our data that the merging process ejected about ~10^(-2) solar mass of radioactive material at a speed of up to 30% the speed of light. | lei hu xuefeng wu igor andreoni michael c.b.ashley jeff cooke xiangqun cui fujia du zigao dai bozhong gu yi hu haiping lu xiaoyan li zhengyang li ensi liang liangduan liu bin ma zhaohui shang tianrui sun n.b.suntzeff charling tao syed a.uddin lifan wang xiaofeng wang haikun wen di xiao jin xu ji yang shihai yang xiangyan yuan hongyan zhou hui zhang jilin zhou zonghong zhu | 2017 | Science Bulletin2017，62，21： | 6 |
| 8 | Phase transformation,thermodynamics and kinetics property of Mg90Ce5RE5(RE=La,Ce,Nd)hydrogen storage alloys显示文摘The Mg90Ce5 RE5(RE=La,Ce,Nd)alloys were prepared by a vacuum induction furnace and their micro structure,phase transformation,thermodynamics and kinetics property were systematically studied by XRD,SEM,TEM,and PCT characterization methods.The result shows that the activated alloys are composed of Mg/MgH2 and corresponding REH2+x with nanoscale.The REH2+x grain with Ce and La or Nd functional group have lower nucleation potential barriers than CeH2+x grains as the nucleation location,thus improve the hydrogen absorption kinetics of these alloys among which the Mg90Ce5Nd5 alloy can absorb 90%of the hydrogen within 2 min at 320℃.In addition,the Mg90Ce10 alloy has the lowest activation energy with 103.2 kJ mol-1 and the fastest desorption kinetics,which can release 5 wt%of the hydrogen within 20 min at 320℃.This is a correlation with grain size and the in-suit formed CeH2.73/CeO2 interface.Moreover,the co-doping Ce and La or Nd can effectively disorganize the thermodynamic stability of Mg-based hydrogen storage alloys to a certain degree,but the dehydrogenation kinetics of that still is restricted by the recombination energy of hydrogen ions on the surface. | Hui Yong Shihai Guo Zeming Yuan Yan Qi Dongliang Zhao Yanghuan Zhang | 2020 | Journal of Materials Science & Technology2020，47，16： | 5 |
| 9 | Self-mixed self-interference analog cancellation in full-duplex communications显示文摘Rather than using existing self-interference cancellation methods, which essentially consist of reconstruction and subtraction, this paper proposes a novel approach, based on multiplication, to cancel selfinterference in the analog domain in full-duplex communications. This approach is called self-mixed selfinterference analog cancellation(SM-SIAC). Moreover, rather than using an individual analog cancellation circuit in existing self-interference cancellation methods, SM-SIAC can merge the analog cancellation circuit and the receiver. SM-SIAC is configured with three auto-tuning loops, consisting of one delay loop and two gain loops. SM-SIAC is further simplified with the Gaussian minimum shift keying(GMSK) self-interference signal.When these loops converge, the paper analyzes the cancellation capacity and derives a closed-form expression for the quadrature amplitude modulation self-interference signal and the GMSK self-interference signal. Simulation results illustrate the convergence of the gain loops and the cancellation capacity in the presence of engineering errors. | Hongtao LU Shihai SHAO Kai DENG Youxi TANG | 2016 | Science China(Information Sciences)2016，59，4： | 5 |
| 10 | Deformation Measurement of Glass Structure Using FBG Sensor显示文摘Glass has been widely used as an important component in structures such as reflection glass curtainwalls,high speed trains,and landscape glass bridges with advantages of transparent and easy to clean,which are exposed to extreme weather conditions and external loads.Over time,these factors can lead to a damage of glass.So the health status of glass structure is critical,which should be routinely monitored to improve safety and provide reliable maintenance strategy.In this paper,fiber Bragg grating(FBG)sensors are used to monitor glass damage based on the fact that the main components of both the optical fiber and the glass are silica,which hints that both optical fiber and glass have the similar mechanical properties.Furthermore,the diameter of FBG installed on the glass structure is small,which has little effect on the beauty of glass.In order to validate the feasibility of the damage monitoring method,one common glass panel model with two-side fixations is loaded impact and static loads respectively,on the upper and lower surfaces of which four FBG sensors and two resistance strain gages are installed.A comparison study among the measured strains from the FBG sensors,those from the resistance strain gages,and those calculated from finite element model(FEM)analysis is conducted and the result obtained with experiments agrees with the element result.Test results show that the FBG sensors can effectively measure the glass deformation or damage under the impact and static load. | Bin LIU Shihai ZHANG Jianping HE | 2019 | Photonic Sensors2019，9，4： | 5 |
| 11 | A two-scale contact model for collisions between blocks in CDEM显示文摘Contact detection between interacting blocks is of great importance to discontinuity-based numerical methods, such as DDA, DEM, and NMM. A rigorous contact theory is a prerequisite to describing the interactions of multiple blocks. Currently, the penalty method, in which mathematical springs with high stiffness values are employed, is always used to calculate the contact forces. High stiffness values may cause numerical oscillations and limit the time step. Furthermore, their values are difficult to identify. The intention of this study is to present a two-scale contact model for the calculation of forces between colliding blocks. In this new model, a calculation step taken from the moment of contact will be divided into two time stages: the free motion time stage and the contact time stage. Actually, these two time stages correspond to two real physical processes. Based on this, we present a new numerical model that is intended to be more precise and useful in calculating the contact forces without mathematical springs. The propagation of the elastic wave during collision is of a characteristic length, which determines the volume of material involved in the contact force calculation. In conventional contact models, this range is always regarded as the length of one element, which may lead to an inaccurate calculation of contact forces. In fact, the real scale of this range is smaller than the length of a single element, and subdivided elements, which are refined according to the characteristic length and are presented in the new contact model. | LI ShiHai TANG DeHong WANG Jie | 2015 | Science China(Technological Sciences)2015，58，9： | 4 |
| 12 | Ecological pressures on grassland ecosystems and their conservation strategies in Northern China显示文摘In this study,we identified ecological pressures on grassland ecosystems and adaptive countermeasures in Northern China.Our research revealed that the main sources of these pressures included population growth,economic development,resources exploitation,and global climate change,with human-related activities being overriding factors.Overgrazing was an important reason for grassland imbalance,causing soil erosion and desertification,especially during the sensitive spring greening phase.In steppe zones,commercial coal mining was destructive to the ecological environment.Regarding long-term strategies,we recommend that policy-makers devote more consideration to a new conceptual approach for transforming grasslands through shifting the focus from die grassland's traditional production functions to meir ecological functions.Applying this concept,adaptive countermeasures should be developed to reduce human impacts based on the environmental capacities of grasslands.Moreover,we recommend the development of environment-friendly industries and reduction of pressures from human activities as effective measures for maintaining the balance between sustainable economic development and grassland conservation.Lastly,we suggest that restoration of degraded grasslands should conform to the principle of natural vegetation to further improve the ecological adaptability of plants and ecosystem stability.This study is expected to provide scientific support for policy-makers engaged in grassland protection. | Zhirong Zheng Chaoyang Feng Shengxing Ye Zhaoyan Diao Shihai Lü | 2015 | Chinese Journal of Population,Resources and Environment2015，13，1： | 4 |
| 13 | Impacts of energy feeds and supplemental protease on growth performance, nutrient digestibility, and gut health of pigs from 18 to 45 kg body weight显示文摘A total of 144 pigs with 18.4 ± 2.3 kg initial body weight(BW) at 6 wk of age were used in a 40-d trial to evaluate effects of protease(300,000 U/kg feed, BioResource International Inc., Durham, NC, USA) on growth performance, apparent ileal digestibility(AID) of nutrients, and gut health of pigs fed diets with sorghum. Pigs were randomly allotted to 4 treatments(12 pens per treatment, 3 pigs per pen) in a 2 x 2 factorial arrangement(corn or sorghum basal diets, and 0 or 0.05% protease as 2 factors) with sex and initial BW as blocks. Experimental period had phase 1(d 1 to 21) and phase 2(d 22 to 40). About 65%(phase 1) and 72%(phase 2) of cereal grains were used in corn or sorghum based diets. Both grains were ground to 400 μm. Body weight and feed intake were recorded weekly. On d 35, serum was collected to quantify tumor necrosis factor-a(TNF-a) and malondialdehyde(MDA). Titanium dioxide(0.3%) was added as an indigestible marker for an additional 4 d feeding. On d 40, 32 pigs(8 pigs per treatment)were euthanized to collect digesta from jejunum and ileum(for viscosity and AID), tissues(for morphology) and mucosa samples(for TNF-α and MDA) from duodenum, jejunum, and ileum. Replacing corn with sorghum in the diet increased(P < 0.05) overall average daily gain(from 756 to 787 g/day) and average daily feed intake(from 1,374 to 1,473 g/day), reduced(P < 0.05) overall gain:feed ratio(from0.553 to 0.537), and did not affect AID. Pigs fed diets with sorghum had lower(P < 0.05) MDA content in serum(from 14.61 to 6.48 μmol/L) and jejunum(from 1.42 to 0.91 μmol/g protein), and reduced(P < 0.05) villus height(from 492 to 396 μm) and crypt depth(from 310 to 257 μm) in jejunum. Dietary protease improved(P < 0.05) AID of crude protein(from 81.8% to 86.0%), decreased MDA level(from 1.20 to 0.98 μmol/g protein) in duodenum, and increased(P < 0.05) the ratio of villus height to crypt depth(from 1.08 to 1.21) in duodenum. Overall, use of sorghum fully replacing corn in diets could benefit pigs with enhanced growth and feed intake potentially by reducing oxidative stress, whereas feed efficiency was compromised. Supplementation of protease improved protein digestion and maintained gut health,irrespective of sorghum or corn based diets. | Hongyu Chen Shihai Zhang Inkyung Park Sung Woo Kim | 2017 | Animal Nutrition2017，，4： | 4 |
| 14 | Nutritional strategies to alleviate oxidative stress in sows显示文摘The performance of high-yielding sows is directly related to the productivity of pig farming. Fetaldevelopment mainly occurs during the last month of pregnancy, and the aggressive metabolic burden ofsows during this stage eventually leads to systemic oxidative stress. When affected by oxidative stress,sows exhibit adverse symptoms such as reduced feed intake, hindered fetal development, and evenabortion. In addition, milk synthesis during the lactation period causes a severe metabolic burden. Thebiological response to oxidative stress during this period is associated with a decrease in milk production,which further affects the growth of piglets. Understanding the nutritional strategies to alleviateoxidative stress in sows is crucial to maintain their reproduction and lactation performance. Recently,advances have been made in the field of nutrition to relieve oxidative stress in sows during late pregnancyand lactation. This review highlights the nutritional strategies to relieve oxidative stress in sowsreported within the last 20 years. | Qihui Li Siwang Yang Fang Chen Wutai Guan Shihai Zhang | 2022 | Animal Nutrition2022，，2： | 4 |
| 15 | Martensitic Transformation and Magnetic-Field-Induced Strain in Magnetic Shape Memory Alloy NiMnGa Melt-Spun Ribbon显示文摘A magnetic shape memory alloy with nonstoichiometric Ni5oMn27Ga23 was prepared by using melt-spinning technology. The martensitic transformation and the magnetic-field-induced strain (MFIS) of the polycrystalline melt-spun ribbon were investigated. The experimental results showed that the melt-spun ribbons underwent thermal-elastic martensitic transformation and reverse transformation in cooling and heating process and exhibited typical thermoelastic shape memory effect. However the start temperature for martensitic transformation decreased from 286 K for as-cast alloy to 254 K for as-quenched ribbon and Curie temperature remains approximately constant. A particular internal stress induced by melt-spinning resulted in the formation of a texture structure in the ribbons, which made the ribbons obtain larger martensitic transformation strain and MFIS. The internal stress was released substantially after annealing, which resulted in a decrease of MFIS of the ribbons. | Shihai GUO, Yanghuan ZHANG, Jianliang LI, Baiyun QUAN, Yan QI and Xinlin WANG Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China | 2005 | Journal of Materials Science & Technology2005，21，2： | 3 |
| 16 | Effects of L-lysine·H2SO4 product on the intestinal morphology and liver pathology using broiler model显示文摘Background: Lysine is used widely in livestock production due to the shortage of feed protein resources.Llysine·H2SO4 contains L-lysine sulphate as well as fermentation co-products which contain other amino acids and phosphorus.However,there are few articles about L-lysine·H2SO4 product regarding intestinal morphology and liver pathology of broiler chickens.In this article,we focus on the absorption and metabolism of L-lysine·H2SO4 revealed in the variation of intestinal morphology and liver pathology to determine the tolerance of chicks for L-lysine·H2SO4.Methods: To evaluate the tolerance of broilers for L-lysine·H2SO4,240 one day old broilers were allocated randomly to one of five dietary treatments which included corn-soybean diets containing 0,1%,4%,7% or 10% L-lysine·H2SO4(L-lysine content = 55%).Results: Supplementation of 1% L-lysine·H2SO4 in the diet had no negative effects.However,4%,7% or 10% Llysine·H2SO4 supplementation produced negative responses on broiler performance,carcass characteristics,blood biochemistry,and particularly on intestinal morphology and liver pathology compared with broilers fed the control diet.Conclusion: Our results show that supplementation with 1% L-lysine·H2SO4 had no negative effects on performance,carcass characteristics,blood biochemistry,intestinal morphology and liver pathology in broilers,but supplementation with 4%,7% or 10% L-lysine·H2SO4 produced a negative response,particularly with respect to intestinal morphology and liver pathology. | Hongmin Jia Ting He Haitao Yu Xiangfang Zeng Shihai Zhang Wenfeng Ma Jie Zhang Shiyan Qiao Xi Ma | 2019 | Journal of Animal Science and Biotechnology2019，10，3： | 3 |
| 17 | Structure and Corrosion Resistance of Microarc Oxidation Coatings on AZ91D Magnesium Alloy显示文摘Magnesium alloys are widely used as shells of 3C (computer, mobile phone and consumer electronics) equipments for its impressive mechanical and physical properties, such as low density, good resistance to electromagnetic radiation, suitable for high pressure diecasting and easily recycling, etc. But poor corrosion resistance confines its extensively application. In this paper, protective coatings was successfully prepared on AZ91D magnesium alloys by micro-arc oxidation (MAO) and painting process. Microstructures and phases of MAO coatings were invesgated with scanning electron microscope (SEM) and X-Ray diffractometer. Mechanical properties of MAO coating, such as adhesive force and corrosion resistance, were also tested. Results showed that MAO coatings were a good base for painting process. MAO coatings with paint have good adhesive properties to base metal and excellent corrosion resistance. Micro-arc oxidation with painting process is a good kind of surface treatment to improve the corrosion resistance of mobile phone shell made of AZ91D magnesium alloys. | Cui Shihai Han Jianmin Li Weijing Li Ronghua Zhu Xiaowen Wang Jinhua | 2004 | Journal of Rare Earths2004，22，z2： | 3 |
| 18 | mRNA profiles of cytokine receptors in unstimulated peripheral blood mononuclear cells from patients with chronic idiopathic urticaria显示文摘This present study was aimed to investigate the roles of the receptors of Th1/Th2 cytokines and chemokines in the pathogenesis of chronic idiopathic urticaria (CIU).Thirty patients with CIU,30 patients with dermographism and 30 healthy controls were randomly enrolled.Reverse transcription-PCR (RT-PCR) was used to analyze the mRNA of cytokine receptors in peripheral blood mononuclear cells (PBMCs).The mRNA levels of tumor necrosis factor receptor (TNFR),interferon-γ receptor (IFN-γR),and interleukin-10 receptor (IL-10R) were statistically increased in the CIU group (P < 0.05),while IL-2R,IL-4R,IL-6R,and IL-13R showed no significant differences between the CIU and other groups.The mRNA levels of CCR3 and CCR6 were statistically increased in the CIU group (P < 0.05).The toll-like receptor 2 (TLR2) mRNA level was significantly lower in the CIU group than the healthy control group (P < 0.05).These findings indicate that the regulation of mRNA of TNFR,IFN-γR,IL-10R,CCR3,CCR6 and TLR2 may be involved in the pathogenesis of CIU. | Jianming Gao Aizhen Yang Min Chen Ansheng Li Xu Yao Yumei Li Shihai Xie Xueyuan Yang Liansheng Zhong Zhiqiang Chen | 2011 | The Journal of Biomedical Research2011，25，2： | 3 |
| 19 | Growth–climate response and drought reconstruction from tree-ring of Mongolian pine in Hulunbuir,Northeast China显示文摘Aims Drought affected by atmosphere–ocean cycle is a dominant factor influencing tree radial growth of sandy Mongolian pine(Pinus sylvestris var.mongolica)and regional vegetation dynamics in Hulunbuir,China.However,historical droughts and its correlations with tree radial growth and atmosphere–ocean cycle in this area have been little tested.Methods We developed tree-ring chronologies of Mongolian pine from Hulunbuir,Inner Mongolia,China and analyzed the correlations between tree-ring width index,the normalized difference vegetation index and Palmer drought severity index(PDSI),then developed a linear model to reconstruct the drought variability from 1829 to 2009.Long-term trends and its linkages with atmosphere–ocean cycle were performed by the power spectral,wavelet and teleconnection analysis.Important Findings The local moisture variations affected largely the regional vegetation dynamics and tree-ring growth of Mongolia pine in the forest–grassland transition.Using tree-ring width chronology of Mongolian pine,the reconstruction explains 49.2%of PDSI variance during their common data period(1951–2005).The reconstruction gives a broad-scale regional representation of PDSI in the Hulunbuir area,with drought occurrences in the 1850s,1900s,1920s,mid-1930s and at the turn of the 21st century.Comparisons with other treering drought reconstructions and historical records reveal some common drought periods and drying trends in recent decades at the northern margin zones of the East Asian summer monsoon(EASM).The drying trends in these zones occurred earlier than weakening of the EASM.A REDFIT spectral analysis shows significant peaks at 7.2,3.9,2.7–2.8,2.4 and 2.2 years with a 0.05 significance level,and 36.9,18.1 and 5.0 years with 0.1 significance level.Wavelet analysis also shows similar cycles.Drought variations in the study area significantly correlated with sea surface temperatures in the western tropical Pacific Ocean and middle and northern Indian Ocean,and the Pacific Decadal Oscillation and North Atlantic Oscillation.This suggests a possible linkage with the El Niño-Southern Oscillation,the EASM and the Westerlies. | Zhongjie Shi Lihong Xu Linshui Dong Jixi Gao Xiaohui Yang Shihai Lü Chaoyang Feng Aiyun Song Hao Guo Xiao Zhang | 2016 | Journal of Plant Ecology2016，9，1： | 3 |
| 20 | Blue LED-pumped intense short-wave infrared luminescence based on Cr^(3+)-Yb^(3+)-co-doped phosphors显示文摘The growing demand for spectroscopy applications in the areas of agriculture,retail and healthcare has led to extensive research on infrared light sources.The ability of phosphors to absorb blue light from commercial LED and convert the excitation energy into long-wavelength infrared luminescence is crucial for the design of cost-effective and high-performance phosphor-converted infrared LEDs.However,the lack of ideal blue-pumped short-wave infrared(SWIR)phosphors with an emission peak longer than 900 nm greatly limits the development of SWIR LEDs using light converter technology.Here we have developed a series of SWIR-emitting materials with high luminescence efficiency and excellent thermal stability by co-doping Cr^(3+)-Yb^(3+) ion pairs into Lu_(0.2)Sc_(0.8)BO_(3) host materials.Benefitting from strong light absorption of Cr^(3+) in the blue waveband and very efficient Cr^(3+)→Yb^(3+) energy transfer,the as-synthesized Lu_(0.2)Sc_(0.8)BO_(3):Cr^(3+),Yb^(3+) phosphor emits intense SWIR light in the 900-1200 nm from Yb^(3+) under excitation with blue light at~460 nm.The optimized phosphor presents an internal quantum yield of 73.6%and the SWIR luminescence intensity at 100℃can still keep 88.4%of the starting value at 25℃.SWIR LED prototype device based on Lu0.2Sc0.8BO3∶Cr^(3+)Yb^(3+) phosphor exhibits exceptional luminescence performance,delivering SWIR radiant power of 18.4 mW with 9.3%of blue-to-SWIR power conversion efficiency and 5.0%of electricity-to-SWIR light energy conversion efficiency at 120 mA driving current.Moreover,under the illumination of high-power SWIR LED,covert information identification and night vision lighting have been realized,demonstrating a very bright prospect for practical applications. | Yan Zhang Shihai Miao Yanjie Liang Chao Liang Dongxun Chen Xihui Shan Kangning Sun Xiao-Jun Wang | 2022 | Light(Science & Applications)2022，11，6： | 3 |
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