检索结果-南通市图书馆

Journal of Thermal Science 2020年第5期29卷 1322-1332页

作者： LIU Changqing zhang liy HE Yan Yu Wei School of Mechanical and Energy Engineering Shaoyang UniversityShaoyang 422000China Key Laboratory of Hunan Province for Efficient Power System and Intelligent Manufacturing Shaoyang UniversityShaoyang 422000China College of Engineering Shanghai Polytechnic UniversityShanghai 201209China School of Mechanical and Electrical Engineering Qingdao University of Science and TechnologyQingdao 266061China

Nanofluids with full-spectrum absorption properties are highly desirable for direct solar thermal energy conversion *** this work,Ag and CsW03 nanofluids,which exhibit absorption both in the visible and near-infrared(NIR)region,are integrated to obtain two>component hybrid *** hybrid nanofluids show broad band absorption with a solar weighted absorption fraction of 99.6%,compared to 18%and 54%for the base liquid(ethylene glycol)and CsW03 nanofluids,*** highest photo-thermal conversion performance for the hybrid nanofluids is obtained with Ag/CsW03 weight ratio of 3/*** solar thermal conversion efficiency of the optimum hybrid nanofluids is 67%,10%and 15%higher than single Ag and CsW03 *** two-component hybrid nanofluid provides an alternative for making the best use of solar energy.

关键词： photo-thermal conversion nanofluids Ag cesium tungsten oxide near-infrared

Non-merohedrally Twinned Crystal Structure of the Co-crystal Ethyl 6-(2-5-(Ethoxycarbonyl)-pyridin-2-yl-1,2-dihydroxyethyl)pyridine-3-carb-oxylateethyl 6-(2-5-(Ethoxycarbonyl)pyridin-2-yl-2-hydroxyacetyl)pyridine-3-carboxylate(0.69/0.31)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2013年第8期32卷 1159-1162页

作者： zhang Wen-Hua ng Seik Weng Institute of Materials Research & Engineering Department of Chemistry University of Malaya Chemistry Department King Abdulaziz University

The two component molecules of the co-crystal 0.69（C18H2ON206）.0.31（C18H18N2O6） lie on a center-of-inversion that exists midway along the ethylene chain connecting the two aromatic rings. The two molecules are superimposed. The crystal is also a non-morohedral twin with a minor 37.7（2）% component. The refinement of this twinned and disordered crystal structure is detailed. Crystal data： C18H19.38N2O6, monoclinic, P21/c, a = 17.1687（8）, b = 5.4389（2）, c = 9.3261（4） A, b = 95.270（5）° and V= 867.18（6） A3 at -173 ℃.

关键词： co-crystal non-merohedral twin

Three-dimensional numerical analysis of plant-soil hydraulic interactions on pore water pressure of vegetated slope under different rainfall patterns

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3696-3706页

作者： Haowen Guo Charles Wang Wai ng Qi zhang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina

Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall ***,the hydrological response of vegetated slopes,especially three-dimensional(3D)slopes covered with shrubs,under different rainfall patterns remains unclear and requires further *** address this issue,this study adopts a novel 3D numerical model for simulating hydraulic interactions between the root system of the shrub and the surrounding *** series of numerical parametric studies are conducted to investigate the influences of slope inclination,rainfall pattern and rainfall *** rainfall patterns(advanced,bimodal,delayed,and uniform)and two rainfall durations(4-h intense and 168-h mild rainfall)are considered to study the hydrological response of the *** computed results show that 17%higher transpiration-induced suction is found for a steeper slope,which remains even after a short,intense rainfall with a 100-year return *** extreme rainfalls with advanced(PA),bimodal(PB)and uniform(PU)rainfall patterns need to be considered for the short rainfall duration(4 h),while the delayed(PD)and uniform(PU)rainfall patterns are highly recommended for long rainfall durations(168 h).The presence of plants can improve slope stability markedly under extreme rainfall with a short duration(4 h).For the long duration(168 h),the benefit of the plant in preserving pore-water pressure(PWP)and slope stability may not be sufficient.

关键词： Root-soil interactions Rainfall patterns Slope stability Three-dimensional(3D)

Positive combinations of projections in von Neumann algebras and purely infinite simple C*-algebras

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2011年第11期54卷 2383-2393页

作者： KAFTAL Victor ng PingWong zhang Shuang Department of Mathematics University of Cincinnati Cincinnati Ohio 45221-0025 USA Department of Mathematics University of Louisiana at Lafayatte Lafayette Louisiana 70504-1010 USA

We give an overview of the question： which positive elements in an operator algebra can be written as a linear combination of projections with positive coefficients. A special case of independent interest is the question of which positive elements can be written as a sum of finitely many projections. We focus on von Neumann Mgebras, on purely infinite simple C^＊-algebras, and on their associated multiplier algebras.

关键词： C^*-algebras linear combinations positive combinations projections

LOW-RANK MATRIX COMPLETION WITH POISSON OBSERVATIONS VIA NUCLEAR NORM AND TOTAL VARIATION CONSTRAINTS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第6期42卷 1427-1451页

作者： Duo Qiu Michael K.ng Xiongjun zhang School of Mathematics and Physics Wuhan Institute of TechnologyWuhan 430205China Department of Mathematics Hong Kong Baptist UniversityKowloon TongHong Kong SARChina School of Mathematics and Statistics and Hubei Key Laboratory of Mathematical Sciences Central China Normal UniversityWuhan 430079China

In this paper,we study the low-rank matrix completion problem with Poisson observations,where only partial entries are available and the observations are in the presence of Poisson *** propose a novel model composed of the Kullback-Leibler(KL)divergence by using the maximum likelihood estimation of Poisson noise,and total variation(TV)and nuclear norm *** the nuclear norm and TV constraints are utilized to explore the approximate low-rankness and piecewise smoothness of the underlying matrix,*** advantage of these two constraints in the proposed model is that the low-rankness and piecewise smoothness of the underlying matrix can be exploited simultaneously,and they can be regularized for many real-world image *** upper error bound of the estimator of the proposed model is established with high probability,which is not larger than that of only TV or nuclear norm *** the best of our knowledge,this is the first work to utilize both low-rank and TV constraints with theoretical error bounds for matrix completion under Poisson *** numerical examples on both synthetic data and real-world images are reported to corroborate the superiority of the proposed approach.

关键词： Low-rank matrix completion Nuclear norm Total variation Poisson observations

Eco-geotechnics for human sustainability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第12期65卷 2809-2845页

作者： ng Charles Wang Wai zhang Qi ZHOU Chao NI JunJun Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong Kong 999077China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China School of Transportation Southeast UniversityNanjing 211189China

As a result of climate change and increasing engineering activities, soil-related disasters such as slope failures and sandstorms have become more frequent worldwide. These disasters have caused not only loss of life, but also have led to serious economic losses as well as ecological and environmental damage. To sustain mankind, a new discipline, eco-geotechnics, has rapidly become established and developed in recent years. It integrates scientific knowledge from soil mechanics, rock mechanics,ecology, biology, and atmospheric science to develop cross-disciplinary theories and carry out experiments to tackle grand world challenges such as the effects of climate change. Through the development of eco-geotechnics, various eco-friendly technologies have been developed to mitigate sandstorms and to improve the performance of earthen structures such as embankments, slopes and landfill covers. This state-of-the-art review introduces and discusses the important advances in the field of eco-geotechnics,covering theoretical developments, laboratory testing, centrifuge modelling, field monitoring and engineering ***, the research gaps and future needs of eco-geotechnics are highlighted and discussed.

关键词： sustainability eco-geotechnics atmosphere-plant-soil interactions ecology unsaturated soil mechanics

Neutrophil diversity and plasticity:Implications for organ transplantation

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2023年第9期20卷 993-1001页

作者： Junwen Qu Jingsi Jin Ming zhang Lai Guan ng Shanghai Immune Therapy Institute Renji HospitalShanghai Jiao Tong University School of MedicineShanghai 200127China Department of Urology Renji HospitalShanghai Jiao Tong University School of MedicineShanghai 200127China

Neutrophils,as the first defenders against external microbes and stimuli,are highly active and finely regulated innate immune *** evidence has challenged the conventional dogma that neutrophils are a homogeneous population with a short lifespan that promotes tissue *** findings on neutrophil diversity and plasticity in homeostatic and disease states have centered on neutrophils in the *** contrast,a comprehensive understanding of tissue-specialized neutrophils in health and disease is still *** article will first discuss how multiomics advances have contributed to our understanding of neutrophil heterogeneity and diversification in resting and pathological *** discussion will be followed by a focus on the heterogeneity and role of neutrophils in solid organ transplantation and how neutrophils may contribute to transplant-related *** goal of this article is to provide an overview of the research on the involvement of neutrophils in transplantation,with the aim that this may draw attention to an underappreciated area of neutrophil research.

关键词： Neutrophil Heterogeneity Transplantation

Design and control of deformable quadrotor with varying length arms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第5期66卷 1225-1234页

作者： SUN YiChong XIE MingNa LI YeHui ng WingYin zhang Heng LI Zheng Multi-Scale Medical Robotics Centre The Chinese University of Hong KongHong Kong 999077China Department of Surgery The Chinese University of Hong KongHong Kong 999077China Department of Electrical and Electronic Engineering The University of Hong KongHong Kong 999077China College of Optoelectronic Engineering Chongqing UniversityChongqing 400044China

Deformable quadrotors can manipulate their specific structure for specialized tasks or excellent flight performance under diverse *** added deformation mechanism,the quadrotor exhibits higher flexibility;however,this is accompanied by difficulties in modeling analysis and controller design,which are crucial ***,a novel deformable quadrotor that can alter its arm's length is designed by combining the crank-slider mechanism and *** dynamics,including the attitude and position systems,are analyzed and the former is further described as switched linear parameter varying(SLPV)systems from a control-oriented *** addition,a combined SLPV/proportion-integration-differentiation(PID)attitude controller is developed to handle different deformable quadrotor modes,which guarantees the stability of the closed-loop attitude system during the deformation process and achieves attitude ***,together with the cascade PID position controller,the entire flight controller is constructed whose feasibility is verified via fixed-point hovering and trajectory tracking experiments.

关键词： deformable quadrotor mechanics and control LPV systems switched control strategy specialized aerial system

Analysis of a landfill cover without geomembrane using varied particle sizes of recycled concrete

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1263-1273页

作者： Charles Wang Wai ng Cheuk Lam ng Junjun Ni Haowen Guo Qi zhang Qiang Xue Rui Chen Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyHong KongChina School of Transportation Southeast UniversityNanjingChina State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Department of Civil and Environmental Engineering Shenzhen Graduate SchoolHarbin Institute of TechnologyShenzhenChina

Previous studies have demonstrated the effectiveness of a novel three-layer landfill cover system constructed with recycled concrete aggregates(RCAs)without geomembrane in both laboratory and ***,no systematic investigation has been carried out to optimize the combination of the particle sizes for fine-grained RCAs(FRC)and coarse-grained RCAs(CRC)that can be used for the three-layer landfill cover *** aim of this paper is to assist engineers in designing the three-layer landfill cover system under a rainfall of 100-year return period in humid climate conditions using an easily controlled soil parameter D10 of *** numerical study reveals that when D10 of FRC increases from 0.05 mm to 0.16 mm,its saturated permeability increases by 10 *** a result,a larger amount of rainwater infiltrates into the cover system,causing a higher lateral diversion in both the top FRC and middle CRC *** further changes in the lateral diversion are observed when the D10 value of FRC is larger than 0.16 *** the particle sizes of FRC and CRC layers are shown to have a minor influence on the percolation under the extreme rainfall *** implies that the selection of particle sizes for the FRC and CRC layers can be based on the availability of *** it is well known that the bottom layer of the cover system should be constructed with very fine-grained soils if possible,this study provides an upper limit to the particle size that can be used in the bottom layer(D10 not larger than 0.02 mm).With this limit,the three-layer system can still minimize the water percolation to meet the design criterion(30 mm/yr)even under a 100-year return period of rainfall in humid climates.

关键词： Capillary barrier Landfill cover Particle size Recycled concrete

Markov branching processes with killing and resurrection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2016年第3期59卷 573-588页

作者： CHEN An Yue LU Ying ng Kai Wang zhang Han Jun Department of Financial Mathematics and Financial Engineering South University of Science and Technology of China Department of Mathematical Sciences University of Liverpool Department of Statistics and Actuarial Science University of Hong Kong School of Mathematics and Computational Science Xiangtan University

In this paper, we consider Markov branching processes with killing and resurrection. We first show that the Markov branching process with killing and stable resurrection is just the Feller minimum process which is honest and thus unique. We then further show that this honest Feller minimum process is not only positive recurrent but also strongly ergodic. The generating function of the important stationary distribution is explicitly expressed. For the interest of comparison and completeness, the results of the Markov branching processes with killing and instantaneous resurrection are also briefly stated. A new result regarding strong ergodicity of this difficult case is presented. The birth and death process with killing and resurrection together with another example is also analyzed.

关键词： Markov branching processes killing stable and instantaneous resurrections uniqueness existence limiting and stationary distributions ergodicity strong ergodicity