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The tropical-subtropical evergreen forest transition in East Asia:An exploration

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Plant Diversity 2020年第4期42卷 255-280页

作者： Peter Ashton hua zhu Arnold Arboretum Harvard UniversityRoyal Botanic GardensKewUK Center for Integrative Biology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYunnanPR China

The transition from tropical to subtropical(warm temperate)evergreen forests is more clearly apparent in East Asia,fromNepal to the western Pacific coast,than elsewhere in the *** review the nature of this transition and hypothesize the physical,ultimately climatic,factors thatmay maintain it,with a special focus on how the increasing instability and warming of climates will affect these forests.A primary climatic mediator of the transition is proposed,thereby offering a testable hypothesis for the climateeforest transition *** is known of this transition is summarized in context of the primary climatic mediators of elevational zonation of forest formations in equatorial Asia to the tree line,in the Himalaya at the India-Indo-Burma northern tropical margin,and as both elevational and latitudinal zonation in southern *** secondary edaphic and other physical changes are described for the Himalaya,and hypothesized for southern *** forest ecotones are seen to be primarily defined by tree floristic change,on which account changes in structure and physiognomy are *** montane tropical-subtropical transition in the Himalaya is narrowand observed to correlate with an as yet ill-defined frost line.A distinct tropical-subtropical transition forest is recognized in the southwest *** is a total change in canopy species at the Himalayan ecotone,but subcanopy tropical species persist along an elevational decline of c.400 *** latitudinal transition in South China is analogous,but here the tropical subcanopy component extends north over ten degrees latitude,albeit in *** tropical-subtropical transition is uniquely clear in East Asia because here alone a tropical wet summer-dry winter monsoon extends to 35north latitude,encompassing the subtropical evergreen forest,whereas subtropical evergreen forests elsewhere exist under drier temperate summer climate regimes.

关键词： Tropical Subtropical Forest transition Ecotone East Asia

Inclusion variations and calcium treatment optimization in pipeline steel production

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International Journal of Minerals,Metallurgy and Materials 2011年第5期18卷 527-534页

作者： Jian-hua Liu hua-jie Wu Yan-ping bao Min Wang Research Institute of Metallurgy Engineering University of Science and Technology Beijing Beijing 100083 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

SiCa line and SiCaBaFe alloy were injected into liquid pipeline steel at the end of LF refining as calcium treatment,and samples were taken from the ladles,mould,and *** of Ca content and inclusions shows that Ca content in steel decreases obviously in the following process after calcium treatment;the compositions,morphology,and sizes of inclusions also vary much in the production;primary inclusions in the ladles prior to calcium treatment are mainly Al2O3 inclusions,but they turn to fine irregular CaS-CaO-Al2O3 compound inclusions after the treatment,then become fine globular CaO-Al2O3 inclusions in the mould,and finally change to a few larger irregular CaS-CaO-Al2O3 complex inclusions in the *** study reveals that inclusion variations are related with the preferential reactions among Ca,Al2O3,and S and the precipitation of S in CaO-Al2O3 inclusions with high sulfur *** evaluation standards for calcium treatment in high-grade pipeline steel were put forward according to the inclusion variations and requirements of pipeline steel on inclusion controlling,and the calcium process was studied and optimized.

关键词： pipeline steel refining inclusions calcium treatment thermodynamics precipitation

Au(Ⅰ)-Catalyzed Annulation of Benzofurazan N-oxides with Ynamides: From Predicting the Chemo-Selectivity to the Synthesis of 7-Nitroindole Derivatives

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Chinese Journal of Chemistry 2020年第1期38卷 57-62页

作者： Changlei zhu Luyao Kou Xiaoguang bao College of Chemistry Chemical Engineering and Materials ScienceSoochow University199 Ren-Ai RoadSuzhou Industrial ParkSuzhouJiangsu215123China

Summaryof main observation and conclusion It could be proposed that gold(I)-catalyzed reactions of ynamides with benzofurazan N-oxidesmightproceed through eitherO-attack or N-attack to affordα-oxo orα-imino Au(I)-*** studies were performed to predict that benzofurazan N-oxides are ready to undergo the chemoselective N-attack tothe Au(I)-activatedynamides to generate theα-imino Au(I)-carbenoid *** studies were carried out to confirm the computational results and the 7-nitroindole derivatives were synthesized in a concise and efficient *** unfavored O-attack for benzofurazan N-oxides,which is in contrast to nitrones and pyridine/quinoline N-oxides,in the Au(I)-catalyzed reactions with ynamides is rationalized.

关键词： oxides catalyzed indole

Mechanistic Applications of Nonlinear Effects in First-Row Transition-Metal Catalytic Systems

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Chinese Journal of Chemistry 2023年第22期41卷 3097-3114页

作者： Xiaotao zhu Yajun Li Hongli bao Key Laboratory of Coal to Ethylene Glycol and Its Related Technology Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China Universityof Chinese Academy of Sciences Beijing 100049China

Knowledge of asymmetric catalytic reaction mechanism is very important for rational design and synthesis of new chiral catalysts or catalytic systems with high catalytic activity and *** studies of nonlinear effect have attracted wide attentions as a simple and practical mechanistic tool to probe complex asymmetric catalytic reactions.

关键词： Asymmetric catalysis Nonlinear effect Metal catalysis Reaction mechanisms Reactive intermediates Aggregation

Ruin Probabilities in the Risk Process with Random Income

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Acta Mathematicae Applicatae Sinica 2008年第2期24卷 195-202页

作者： Zhen-hua bao Zhong-xing Ye School of Mathematics Liaoning Normal University Dalian 116029 China Department of mathematics Shanghai Jiaotong University Shanghai 200240 China

We extend the classical risk model to the case in which the premium income process, modelled as a Poisson process, is no longer a linear function. We derive an analog of the Beekman convolution formula for the ultimate ruin probability when the inter-claim times are exponentially distributed. A defective renewal equation satisfied by the ultimate ruin probability is then given. For the general inter-claim times with zero-truncated geometrically distributed claim sizes, the explicit expression for the ultimate ruin probability is derived.

关键词： Beekman convolution formula Defective renewal equation Ruin probability Zero-truncated geo-metric distribution

A Local Quadratic Embedding Learning Algorithm and Applications for Soft Sensing

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Engineering 2022年第11期18卷 186-196页

作者： Yaoyao bao Yuanming zhu Feng Qian Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

Inspired by the tremendous achievements of meta-learning in various fields,this paper proposes the local quadratic embedding learning(LQEL)algorithm for regression problems based on metric learning and neural networks(NNs).First,Mahalanobis metric learning is improved by optimizing the global consistency of the metrics between instances in the input and output ***,we further prove that the improved metric learning problem is equivalent to a convex programming problem by relaxing the *** on the hypothesis of local quadratic interpolation,the algorithm introduces two lightweight NNs;one is used to learn the coefficient matrix in the local quadratic model,and the other is implemented for weight assignment for the prediction results obtained from different local ***,the two sub-mod els are embedded in a unified regression framework,and the parameters are learned by means of a stochastic gradient descent(SGD)*** proposed algorithm can make full use of the information implied in target labels to find more reliable reference ***,it prevents the model degradation caused by sensor drift and unmeasurable variables by modeling variable differences with the LQEL *** results on multiple benchmark datasets and two practical industrial applications show that the proposed method outperforms several popular regression methods.

关键词： Local quadratic embedding Metric learning Regression machine Soft sensor

Recent progress in organic mechanoluminescent materials

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Chinese Chemical Letters 2018年第2期29卷 245-251页

作者： bao-hua Di Yu-Lan Chen Tianjin Key Laboratory of Molecular Optoelectronic Science. Department of Chemistry Tianjin University Tianjin 300354 China Tianjin Key Lab of Composite and Functional Materials School of Materials Science and Engineering Tianjin University Tianjin 300072 China

Mechanoluminescence（ML） refers to the light emission from various organic and inorganic materials upon mechanical stimulus. As a new class of smart materials, mechanoluminescent materials are widely applicable for fluorescence switches, mechanosensors, security papers, optoelectronic devices and data storage etc. In the past few years, systematic investigations have been carried out, resulting in the production of a variety of mechanoluminescent materials. In this review, recent progress in pure organic mechanoluminescent materials is summarized, including mechanofluorescent and triboluminescent effects from conjugated small molecules.

关键词： Conjugated molecules Mechano-responsive Mechanofluorochromic materials Triboluminescence Mechanoluminescence

Intrinsic background radiation of LaBr3(Ce)detector via coincidence measurements and simulations

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Nuclear Science and Techniques 2020年第10期31卷 33-42页

作者： Hao Cheng bao-hua Sun Li-hua zhu Tian-Xiao Li Guang-Shuai Li Cong-Bo Li Xiao-Guang Wu Yun Zheng School of Physics Beihang UniversityBeijing 100191China Beijing Advanced Innovation Center for Big Data-Based Precision Medicine School of Medicine and EngineeringBeihang UniversityBeijing 100191China China Institute of Atomic Energy Beijing 102413China

The LaBr3(Ce)detector has attracted much attention in recent years because of its superior characteristics compared with other scintillating materials in terms of resolution and ***,it has a relatively high intrinsic background radiation because of the naturally occurring radioisotopes in lanthanum,actinium,and their daughter *** limits its applications in low-counting rate *** this study,we identified the radioactive isotopes in theφ3"x 3"Saint-Gobain B380 detector by a coincidence measurement using a Clover detector in a low-background shielding ***,we carried out a Geant4 simulation of the experimental spectra to evaluate the activities of the main internal radiation *** total activity of the background radiation of B380 is determined to be 1.523(34)Bq/cm^*** main sources include 138La at 1.428(34)Bq/cm^3,207Tl at 0.0135(13)Bq/cm^3,211Bi at 0.0136(15)Bq/cm^3,215Po at 0.0135(3)Bq/cm^3,219Rn at 0.0125(12)Bq/cm^3,223Fr at 0.0019(11)Bq/cm^3,223Ra at 0.0127(10)Bq/cm^3,227Th at 0.0158(22)Bq/cm^3,and 227Ac at 0.0135(13)Bq/cm^*** these,the activities of 207Tl,211Po,215Po,223Fr,and 227Ac are deduced for the first time from the secular equilibrium established in the decay chain of 227Ac.

关键词： LaBr3 Coincidence measurement technique Intrinsic radiation GEANT4 simulation

Analysis and discussion on launching mechanism and tactical electromagnetic railgun technology

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Defence Technology（防务技术） 2018年第5期14卷 484-495页

作者： bao-ming Li Qing-hua Lin National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyP.O.Box210094NanjingPR China China Academy of Ordnance P.O.Box100089BeijingPR China

This paper begins with a discussion on the significance of multi-physical fields in the research of railgun launching mechanism, followed by an introduction of research work about dynamic measurements and numerical simulations. The application of some measurement methods including the atomic emission spectrum, fiber-optic strain, optical level, pulsed X-ray, and high-speed video in observing the launching process was introduced. The models about the electromechanical dynamic processes and multi-physical fields in a railgun were developed. The mechanisms of the grooving, arc transition, and gouging were analyzed. These work provided a deeper understanding of launching mechanism of electromagnetic railgun. Some issues about the tactical railgun, such as the fiber composite overwrapped barrel, recoil,loading modes and eddy current loss were also discussed. Taking a medium-caliber launcher as an example, the basic process of design and analysis was introduced.

关键词： Railgun Launching mechanism Dynamic measurement Numerical simulation