检索结果-南通市图书馆

Thermal Transport Mechanism of Amorphous HfO_(2):A Molecular Dynamics Based Study

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第4期31卷 1052-1060页

作者： ZHANG Honggang WEI Han bao hua University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China

Amorphous hafnium dioxide(a-HfO_(2))has attracted increasing interest in the application of semiconductor devices due to its high dielectric ***,the thermal transport properties of a-HfO_(2) are not well understood,which hinders its potential application in *** this work,we systematically investigate the thermal transport property of a-HfO_(2) using the molecular dynamics *** non-equilibrium molecular dynamics simulations reveal that the thermal conductivity of a-HfO;is length-dependent below 100 *** decomposed heat current further proves that the thermal transport of propagons and diffusons is sensitive to the system *** thermal conductivity is found to increase with temperature using Green-Kubo mode *** also quantify the contribution of each carrier to the thermal conductivity at different *** find that propagons are more important than diffusons in thermal transport at low temperatures(<100 K).In comparison,diffusons dominate heat transport at high *** have negligible contribution to the total thermal conductivity.

关键词： amorphous HfO2 molecular dynamics thermal conductivity mean free path size effect temperature effect

Free energy calculation of single molecular interaction using Jarzynski's identity method:the case of HIV-1 protease inhibitor system

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2012年第3期28卷 891-903页

作者： De-Chang Li bao-hua Ji Biomechanics and Biomaterials Lab Department of Applied MechanicsBeijing Institute of TechnologyKey Laboratory.of Dynamics and Control of Flight VehicleMinistry of Education100081 BeijingChina

Jarzynski＇ identity （JI） method was suggested a promising tool for reconstructing free energy landscape of biomolecular interactions in numerical simulations and ex- periments. However, JI method has not yet been well tested in complex systems such as ligand-receptor molecular pairs. In this paper, we applied a huge number of steered molec- ular dynamics （SMD） simulations to dissociate the protease of human immunodeficiency type I virus （HIV-1 protease） and its inhibitors. We showed that because of intrinsic com- plexity of the ligand-receptor system, the energy barrier pre- dicted by JI method at high pulling rates is much higher than experimental results. However, with a slower pulling rate and fewer switch times of simulations, the predictions of JI method can approach to the experiments. These results sug- gested that the JI method is more appropriate for reconstruct- ing free energy landscape using the data taken from experi- ments, since the pulling rates used in experiments are often much slower than those in SMD simulations. Furthermore, we showed that a higher loading stiffness can produce higher precision of calculation of energy landscape because it yields a lower mean value and narrower bandwidth of work distri- bution in SMD simulations.

关键词： Molecular dynamics simulation. Single molecu-lar interaction ~ Molecular biomechanics ~ Steered moleculardynamics ~ Free energy calculation

Thermal transport mechanism of electrons and phonons in pristine and defective HfB_(2)

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第11期42卷 3651-3661页

作者： Ao Wang Shou-Hang Li hua bao Global Institute of Future Technology Shanghai Jiao Tong UniversityShanghai200240China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai200240China College of Mechanical Engineering Donghua UniversityShanghai201620China

Hafnium diboride(HfB_(2))is an important metallic ceramic that works in harsh environments,due to its high strength and thermal *** the thermal conductivity of HfB_(2) has been measured,the experimental results are ***,the thermal transport mechanism of HfB_(2) is not well *** this work,we study the thermal transport in both pristine and defective HfB_(2) from first-principles *** the pristine HfB_(2),the room-temperature thermal conductivities are 175.0 and 157.7 W·m^(-1)·K^(-1)on a-and c-axes,respectively,where the contributions from electron and phonon are *** Lorenz number is significantly smaller than the Sommerfeld value and shows a temperature dependence,which demonstrates that the Wiedemann-Franz law cannot be used to estimate electronic thermal *** phonon-isotope and the phonon-electron scattering are non-negligible compared to the phonon-phonon *** the defective HfB_(2),the grain size effects are negligible with length scales larger than 1μ*** pore can limit thermal conductivity when its occupancy is larger than 10%.The vacancy is found to induce scattered results in *** phonon thermal conductivity significantly reduces even with only 1%vacancy,while the electronic thermal conductivity is not sensitive to the *** study provides an in-depth understanding of the thermal transport in HfB_(2),and the revealed mechanisms provide important guidance on the design of HfB_(2)-based materials.

关键词： Thermal conductivity Electrical transport properties Boltzmann transport equation Vacancy scattering First-principles calculation

Quantile Regression of Ultra-high Dimensional Partially Linear Varying-coefficient Model with Missing Observations

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2023年第9期39卷 1701-1726页

作者： bao hua Wang Han Ying Liang School of Mathematical Sciences Tongji UniversityShanghai200092P.R.China

In this paper,we focus on the partially linear varying-coefficient quantile regression with missing observations under ultra-high dimension,where the missing observations include either responses or covariates or the responses and part of the covariates are missing at random,and the ultra-high dimension implies that the dimension of parameter is much larger than sample *** on the B-spline method for the varying coefficient functions,we study the consistency of the oracle estimator which is obtained only using active covariates whose coefficients are *** the same time,we discuss the asymptotic normality of the oracle estimator for the linear *** that the active covariates are unknown in practice,non-convex penalized estimator is investigated for simultaneous variable selection and estimation,whose oracle property is also *** sample behavior of the proposed methods is investigated via simulations and real data analysis.

关键词： Missing observation oracle property partially linear varying-coefficient model quantile regression ultra-high dimension

Load-balanced broadcast routing in wireless Ad-hoc networks

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 1-4,42页

作者： HU Tian ZHAO bao-hua Department of Computer Science and Technology University of Science and Technology of China Hefei 230027 China

In wireless Ad-hoc networks, where mobile hosts are powered by batteries, the entire network may be partitioned because of the drainage of a small set of batteries. Therefore, the crucial issue is to improve the energy efficiency, with an objective of balancing energy consumption. A greedy algorithm called weighted minimum spanning tree （WMST） has been proposed, in which time complexity is O（n^2）. This algorithm takes into account the initial energy of each node and energy consumption of each communication. Simulation has demonstrated that the performance of the proposed algorithm improves the load balance and prolongs the lifetime.

关键词： wireless Ad-hoc networks broadcast routing load balance lifetime

Ruin Probabilities in the Risk Process with Random Income

在线全文

学校读者我要写书评

暂无评论

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

Recent progress in organic mechanoluminescent materials

在线全文

学校读者我要写书评

暂无评论

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

Hydrolyzing Condition and Immunocompetence of Sheep Bone Protein Enzymatic Lysates

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2009年第11期8卷 1332-1338页

作者： YANG hua LIU Yu-hua MA Li-zhen KONG bao-hua College of Food Science and Engineering Shanxi Agricultural University Taigu 030801 t~R.China College of Food Science Northeast Agricultural University Harbin 150030 P.R. China Food Science Department Tianjin Agricultural College Tianjin 300384 P..R. China

Utilizing collagen of sheep bone as material to get immunocompetent peptide, enzymatic hydrolysis conditions were optimized using quadratic regression general rotation design. The effect of temperature （T）, time （t）, enzyme/substrate （E/S） ratio, and substrate concentration （S） on the amount of tricarboxylix acid cycle （TCA） soluble peptides were investigated. The content of soluble peptide in the acquisition was measured by Folin-hydrozybebzebe method, and the correlation between soluble peptide content and immunocompetence was analyzed by SAS software. The best enzymatic hydrolysis condition was gotten from Design Expert 7.1.2 software. The optimal condition under which immunocompetent peptides could be prepared was 1 576 U g^-1 （E/S）, 64.05℃ （T）, 0.271 kg L^-1 （S）, and 7.22 h （t）. The correlation coefficient between TCA soluble peptides and the immuneocompetence was 0.045 〈r0.05 = 0.355, which indicated that they had no significant correlation. The result showed that the soluble peptide contained immunocompetent peptides which content was independent of immunocompetence in the hydrolasates.

关键词： sheep bone papain soluble peptide immunocompetence

The arms race between Magnaporthe oryzae and rice: Diversity and interaction of Avr and R genes

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2017年第12期16卷 2746-2760页

作者： WANG bao-hua Daniel J.Ebbole WANG Zong-hua College of Plant Protection/Fujian University Key Laboratory for Plant-Microbe Interaction Fujian Agriculture and Forestry University Department of Plant Pathology and Microbiology Texas A&M UniversityCollege Station Ocean Institute Minjiang University

Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevolution of the host and pathogen, and provide the appropriate methods for preventing or controlling rice blast disease, researchers have focused on the evolution of virulence factors and resistance genes. Thus far, more than 30 rice blast resistance（R） genes and 12 avirulence（Avr） genes have been cloned. This review summarizes the cloned rice blast R genes, cloned Avr genes of M. oryzae and the interaction between them. This discussion also considers some of the major unanswered questions concerning this pathosystem and the opportunities for future investigations.

关键词： rice Maganporthe oryzae resistance gene avirulence gene co-evolution genetic diversity