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Optimistic Transaction Processing in Deterministic Database

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Journal of Computer Science & Technology 2020年第2期35卷 382-394页

作者： Zhi-yuan Dong Chu-Zhe Tang Jia-chen Wang Zhao-Guo Wang hai-Bo chen Bin-Yu Zang Institute of Parallel and Distributed Systems Shanghai Jiao Tong UniversityShanghai 200240China

Deterministic databases can improve the performance of distributed workload by eliminating the distributed commit protocol and reducing the contention ***,the current deterministic scheme does not consider the performance scalability within a single *** this paper,we describe a scalable deterministic concurrency control,Deterministic and Optimistic Concurrency Control(DOCC),which is able to scale the performance both within a single node and across multiple *** performance improvement comes from enforcing the determinism lazily and avoiding read-only transaction blocking the *** evaluation shows that DOCC achieves 8x performance improvement than the popular deterministic database system,Calvin.

关键词： deterministic database concurrency control scalability

Fatigue-creep interaction based on continuum damage mechanics for AISI H13 hot work tool steel at elevated temperatures

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Journal of Iron and Steel Research International 2018年第5期25卷 580-588页

作者： hai-sheng chen Yong-qin Wang Wei-qi Du Liang Wu yuan-xin LUO College of Mechanical Engineering Chongqing UniversityChongqing 400044 China State Key Laboratory of Mechanical Transmission Chongqing University Chongqing 400044 China Chongqing Research Institute of China Coal Technology and Engineering Group Corp Chongqing 400016 China

AISI H13 （4Cr5MoSiV1） is one of the commonly used materials for extrusion tool, and it suffers from fatigue-creep damage during the hot extrusion process. Stress-controlled fatigue and creep-fatigue interaction tests were carried out at 500℃ to investigate its damage evolution. The accumulated plastic strain was selected to define the damage variable due to its clear physical meaning. A new fatigue-creep interaction damage model was proposed on the basis of continuum damage mechanics. A new equivalent impulse density for fatigue-creep tests was proposed to incorporate the holding time effect by transforming creep impulse density into fatigue impulse density. The experimental results indicated that the damage model is able to describe the damage evolution under these working conditions.

关键词： AISI H13 hot work tool steel · Fatigue-creep · Damage evolution ·Continuum damage mechanics ·Nonlinear interaction · Damage exponent

Exact solutions to the angular Teukolsky equation with s≠0

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Communications in Theoretical Physics 2022年第11期74卷 1-15页

作者： Chang-yuan chen Xiao-Hua Wang yuan You Dong-Sheng Sun Fa-Lin Lu Shi-hai Dong School of Physics and Electronic Engineering Yancheng Teachers UniversityYancheng224007China Research Center for Quantum Physics Huzhou UniversityHuzhou313000China Laboratorio de Información Cuántica CIDETECInstituto Politécnico NacionalUPALMC.P 07700CDMXMexico

We first convert the angular Teukolsky equation under the special condition ofτ≠0,s≠0,m=0 into a confluent Heun differential equation(CHDE)by taking different function transformation and variable *** then according to the characteristics of both CHDE and its analytical solution expressed by a confluent Heun function(CHF),we find two linearly dependent solutions corresponding to the same eigenstate,from which we obtain a precise energy spectrum equation by constructing a Wronskian *** that,we are able to localize the positions of the eigenvalues on the real axis or on the complex plane whenτis a real number,a pure imaginary number,and a complex number,respectively and we notice that the relation between the quantum number l and the spin weight quantum number s satisfies the relation l=∣s∣+n,n=0,1,2….The exact eigenvalues and the corresponding normalized eigenfunctions given by the CHF are obtained with the aid of *** features of the angular probability distribution(APD)and the linearly dependent characteristics of two eigenfunctions corresponding to the same eigenstate are *** find that for a real numberτ,the eigenvalue is a real number and the eigenfunction is a real function,and the eigenfunction system is an orthogonal complete system,and the APD is asymmetric in the northern and southern *** a pure imaginary numberτ,the eigenvalue is still a real number and the eigenfunction is a complex function,but the APD is symmetric in the northern and southern ***τis a complex number,the eigenvalue is a complex number,the eigenfunction is still a complex function,and the APD in the northern and southern hemispheres is also ***,an approximate expression of complex eigenvalues is obtained when n is greater than∣s∣.

关键词： angular Teukolsky equation linearly dependent Wronskian determinant

An entirely new approach based on remote sensing data to calculate the nitrogen nutrition index of winter wheat

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Journal of Integrative Agriculture 2021年第9期20卷 2535-2551页

作者： ZHAO Yu WANG Jian-wen chen Li-ping FU yuan-yuan ZHU Hong-chun FENG hai-kuan XU Xin-gang LI Zhen-hai Key Laboratory of Quantitative Remote Sensing in Ministry of Agriculture and Rural Affairs/Beijing Research Center for Information Technology in Agriculture Beijing 100097P.R.China National Engineering Research Center for Information Technology in Agriculture Beijing 100097P.R.China College of Geomatics Shandong University of Science and TechnologyQingdao 266590P.R.China

The nitrogen nutrition index(NNI)is a reliable indicator for diagnosing crop nitrogen(N)***,there is currently no specific vegetation index for the NNI inversion across multiple growth *** overcome the limitations of the traditional direct NNI inversion method(NNI_(T1))of the vegetation index and traditional indirect NNI inversion method(NNI_(T2))by inverting intermediate variables including the aboveground dry biomass(AGB)and plant N concentration(PNC),this study proposed a new NNI remote sensing index(NNI_(RS)).A remote-sensing-based critical N dilution curve(Nc_(_RS))was set up directly from two vegetation indices and then used to calculate NNI_(RS).Field data including AGB,PNC,and canopy hyperspectral data were collected over four growing seasons(2012–2013(Exp.1),2013–2014(Exp.2),2014–2015(Exp.3),2015–2016(Exp.4))in Beijing,*** experimental datasets were cross-validated to each of the NNI models(NNI_(T1),NNI_(T2)and NNI_(RS)).The results showed that:(1)the NNI_(RS)models were represented by the standardized leaf area index determining index(sLAIDI)and the red-edge chlorophyll index(CI_(red edge))in the form of NNI_(RS)=CI_(red edge)/(a×sLAIDI~b),where"a"equals 2.06,2.10,2.08 and 2.02 and"b"equals 0.66,0.73,0.67 and 0.62 when the modeling set data came from Exp.1/2/4,Exp.1/2/3,Exp.1/3/4,and Exp.2/3/4,respectively;(2)the NNI_(RS)models achieved better performance than the other two NNI revised methods,and the ranges of R2 and RMSE were 0.50–0.82 and 0.12–0.14,respectively;(3)when the remaining data were used for verification,the NNI_(RS)models also showed good stability,with RMSE values of 0.09,0.18,0.13 and 0.10,***,it is concluded that the NNI_(RS)method is promising for the remote assessment of crop N status.

关键词： nitrogen nutrition index(NNI) critical nitrogen dilution curve standardized leaf area index determining index(s LAIDI) the red-edge chlorophyll index(CI_(red edge))

Quantum deleting and cloning in a pseudo-unitary system

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Frontiers of physics 2021年第5期16卷 61-67页

作者： Yu-cheng chen Ming Gong Peng Xue hai-Dong yuan cheng-Jie Zhang School of Physical Science and Technology Ningbo UniversityNingbo315211China Key Laboratory of Quantum Information University of Science and Technology of ChinaCASHefei230026China Beijing Computational Science Research Center Beijing100084China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina School of Physical Science and Technology Soochow UniversitySuzhou215006China

In conventional quantum mechanics,quantum no-deleting and no-cloning theorems indicate that two different and nonorthogonal states cannot be perfectly and deterministically deleted and cloned,***,we investigate the quantum deleting and cloning in a pseudo-unitary *** first present a pseudo-Hermitian Hamiltonian with real eigenvalues in a two-qubit *** using the pseudo-unitary operators generated from this pseudo-Hermitian Hamiltonian,we show that it is possible to delete and clone a class of two different and nonorthogonal states,and it can be generalized to arbitrary two different and nonorthogonal pure qubit ***,state discrimination,which is strongly related to quantum no-cloning theorem,is also *** but not least,we simulate the pseudo-unitary operators in conventional quantum mechanics with post-selection,and obtain the success probability of ***-unitary operators are implemented with a limited efficiency due to the ***,the success probabilities of deleting and cloning in the simulation by conventional quantum mechanics are less than unity,which maintain the quantum no-deleting and no-cloning theorems.

关键词： quantum deleting quantum cloning pseudo-unitary

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移动Agent在恶意主机中安全问题

微机发展 2004年第3期14卷 110-112页

作者：万定生卞海红陈元斌河海大学计算机及信息工程学院江苏南京210098

在电子商务应用中,移动Agent被用于代表客户搜索某个特定的产品,在这个过程中移动Agent很容易受到恶意主机的攻击。文中在分析了现有对付恶意主机方法上所存在缺陷的基础上,提出了一种基于改进RSA算法的非交互性CEF签名机制,能够在无交... 详细信息

在电子商务应用中,移动Agent被用于代表客户搜索某个特定的产品,在这个过程中移动Agent很容易受到恶意主机的攻击。文中在分析了现有对付恶意主机方法上所存在缺陷的基础上,提出了一种基于改进RSA算法的非交互性CEF签名机制,能够在无交互的条件下进行快速加密和安全的签名,使得客户的签名不会被滥用,解决了移动Agent在恶意环境中所遇到的问题,保证了移动Agent的秘密性和完整性。

关键词：计算机网络网络安全恶意主机移动Agent 电子商务数字签名

A new triterpenoid from Alisma orientalis

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Chinese Chemical Letters 2008年第4期19卷 438-440页

作者： Xue Yan Hu yuan Qiang Guo Wen yuan Gao hai Xia chen Tie Jun Zhang School of Pharmaceutical Science and Technology Tianjin UniversityTianjin 300072China Department of Pharmaceutical Sciences Nankai UniversityTianjin 300071China Tianjin Institute of Pharmaceutical Research Tianjin 300193China

A new triterpenoid,named 11,25-aahydro-alisol E was isolated from the rhizomes of Alisma orientalis together with nine known *** structures were elucidated by spectroscopic *** compounds showed weak anti-tumor activit... 详细信息

关键词： Alisma orientalis Triterpcnoid 11,25-Anhydroalisol F

Eutectic high entropy alloy syntactic foam

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Journal of Materials Science & Technology 2023年第18期149卷 177-189页

作者： Jin Meng Yu Qiao Tian-Wei Liu yuan-yuan Tan Fu-Hua Cao Yan chen hai-Ying Wang Lan-Hong Dai State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences(CAS)Beijing 100190China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Engineering Science University of Chinese Academy of SciencesBeijing 101408China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China

High-strength metallic foams have a wide range of applications in engineering as lightweight structural and energy-absorbing ***,it is challenging to obtain metallic foam with both good energy absorption performance and high ***,we developed a novel metal matrix syntactic foam fabri-cated with AlCoCrFeNi_(2.1) eutectic high entropy alloy and alumina cenospheres that exhibits a remarkable combination of high strength and energy absorption performance under both quasi-static and dynamic *** porous structure of syntactic foam fully exploits the properties of the AlCoCrFeNi_(2.1) alloy matrix with a unique FCC/B2 dual-phase eutectic microstructure and thus yields exceptional *** discovered that this dual-phase microstructure not only provides high strength but also allows the pores to collapse in a progressive and diffusive way,which enables the formation of a high and smooth energy absorption *** is found that the heterogeneity between the two phases in the matrix can provide back stress strengthening,and it also induces multiple micro shear bands and microcracks as additional energy dissipation modes as the deformation *** unique mechanism ensures the strength of microstructures and makes them fracture promptly,which causes the balance of strengthening and softening on the macro *** work opens the avenue for developing advanced high-strength lightweight structural and energy-absorbing materials.

关键词： Eutectic high entropy alloy Foams Metal matrix composites(MMCs) Energy absorption

Amide as an efficient ligand in the palladium-catalyzed Suzuki coupling reaction in water/ethanol under aerobic conditions

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Chinese Chemical Letters 2011年第6期22卷 738-740页

作者： hai Yang Liu Kun Wang hai Yan Fu Mao Lin yuan Hua chen Rui Xiang Li Key Lab of Green Chemistry and Technology Ministry of Education the Institute of Homogeneous Catalysis College of Chemistry Sichuan University Chengdu 610064 China

Amide,which is derived from proline and is inexpensive and air-stable,has been synthesized and characterized by ~1H NMR,^（13）C NMR,and *** was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling *** the Pd/amide catalytic system,aryl bromides can be coupled with phenylboronic acid in ethanol/water（1：2;v/v） in excellent yields even with a low Pd loading of 0.01 mol%.Moreover,the scope of the reaction is broad,and a wide variety of functional groups are tolerant.

关键词： Suzuki cross-coupling Palladium catalyst Aryl bromides Amide Water