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基于刻蚀处理的池沸腾传热性能实验研究

原子与分子物理学报 2025年第3期42卷 180-188页

作者：王菊萍匡纯纯刘妮上海理工大学制冷技术研究所上海200093

为探究刻蚀处理铜板表面对池沸腾传热性能的改善效果,搭建了可视化实验平台,制备不同刻蚀浓度和刻蚀时间处理的表面,采用去离子水为工质,进行饱和池沸腾实验.结果表明,氨水刻蚀浓度越大,表面的换热性能越强,氨水刻蚀时间越长,表面换热... 详细信息

为探究刻蚀处理铜板表面对池沸腾传热性能的改善效果,搭建了可视化实验平台,制备不同刻蚀浓度和刻蚀时间处理的表面,采用去离子水为工质,进行饱和池沸腾实验.结果表明,氨水刻蚀浓度越大,表面的换热性能越强,氨水刻蚀时间越长,表面换热性能越强.热流密度为43.2 W/cm^(2)时,0.05 mol/L氨水刻蚀4 h表面、0.05 mol/L氨水刻蚀5 h表面、0.05 mol/L氨水刻蚀8 h表面、0.03 mol/L氨水刻蚀4 h表面、0.05 mol/L氨水刻蚀4 h表面和0.10 mol/L氨水刻蚀4 h表面上的换热系数分别提高了46%、92%、105%、36%、45%、78%.此外,对其表面进行表征,结果说明了其优异的沸腾性能.刻蚀处理增强了表面粗糙度,有效面积,从而促进液体的补充,能够在较小的过热度下达到更高的临界热流密度.可视化研究结果表明,刻蚀表面具有更多的成核位点,更小的气泡离开直径和离开频率.这些结果显示出刻蚀表面强化池沸腾换热的潜力.

关键词：池沸腾刻蚀传热性能气泡动力学微纳结构表面

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ni-catalyzed cross-electrophile alkyl-alkyl coupling reactions

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Science China Chemistry 2025年

作者： Li-Xu You Lan Tian chun-Ling Guo Shun-Xi Li Yu-Cheng Liu Yu-Long Li Wei Shu College of Chemistry and Environmental Engineering Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan Sichuan University of Science and Engineering Guangming Advanced Research Institute Shenzhen Grubbs Institute Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and Technology

Introducing saturated carbon-carbon bonds into organic molecules significantly increases the three-dimensional configuration,thus altering the physical and chemical properties as well as the functions of molecules. Transition-metal-catalyzed carboncarbon cross-couplings represent one of the most straightforward, efficient and modular alternatives to build saturation in a single step. However, the efficient construction of alkyl-alkyl bonds remains a formidable challenge due to the precise manipulation of multiple alkyl metallic intermediates as well as associated competitive side reactions and selectivity control. Over the past years, ni-catalyzed cross-coupling under reductive conditions has gained more and more attention for alkyl-alkyl crosscoupling partially attributing to the low-valent state of metal centers under reducing conditions, which suppresses the competitive β-hydride elimination process, thus facilitating the formation of alkyl-alkyl bonds. In this review, the initiative and progress of ni-catalyzed cross-electrophile alkyl-alkyl cross-coupling, including the efforts in racemic and enantioselective formation of alkyl-alkyl bonds, have been summarized and discussed. Moreover, the challenges and further opportunities in this area have also been discussed.

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Influence of the Loading Protocol and Loading Rate on the Characteristics of Timber Nail Joints

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Journal of Renewable Materials 2022年第10期10卷 2655-2667页

作者： Shervin Shameli Derakhshan Lina Zhou chun ni Department of Civil Engineering University of VictoriaVictoriaV8P 5C2Canada Advanced Building Systems FPInnovationsVancouverV6T 1W5Canada

Nail joints are one of the key components that control the lateral performance of light wood frame shear *** previous experimental studies,researchers have used different loading rates,which failed specimens from less than a minute to more than an hour,to study the characteristics of nail ***,there have been different loading protocols used for testing of timber nail joints or shear *** some efforts have been made to address this subject,it is still unclear how the loading protocol and loading rate may influence the performance of nail *** this study,a total of 96 nail joints tests were carried out under monotonic and reversed-cyclic loads at three different loading rates,and under three different loading protocols(ISO,CUREE and SPD).The results of the test revealed that the loading rate did not have a noticeable effect on the mechanical properties of nail joints,while the loading protocol did influence those ***,protocols with larger cumulative damage demands lead to lower ultimate displacement and ductility of nail joints.

关键词： Loading protocol loading rate timber nail joint reversed-cyclic load monotonic load

Multi-verse optimizer based parameters decision with considering tool life in dry hobbing process

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Advances in Manufacturing 2021年第2期9卷 216-234页

作者： Heng-Xin ni chun-Ping Yan Shen-Fu ni Huan Shu Yu Zhang State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400030People’s Republic of China Hefei Meiya Photoelectric Technology Co.Ltd Hefei 230088People’s Republic of China

Dry hobbing has received extensive attention for its environmentally friendly processing *** to the absence of lubricants,hobbing process is highly dependent on process parameters combination since using unreasonable parameters tends to affect the machining ***,the consideration of tool life is frequently ignored in gear ***,to settle the above issues,a multiobjective parameters decision approach considering tool life is ***,detailed quantitative analysis between process parameters and hobbing performance,i.e.,machining time,production cost and tool life is ***,a multi-objective parameters decision-making model is constructed in search for optimum cutting parameters(cutting velocity v,axial feed rate f_(a))and hob parameters(hob diameter d_(0),threads z_(0)).Thirdly,a novel algorithm named multi-objective multi-verse optimizer(MOMVO)is utilized to solve the presented model.A case study is exhibited to show the feasibility and reliability of the proposed *** results reveal that(i)a balance can be achieved among machining time,production cost and tool life via appropriate process parameters determination;(ii)optimizing cutting parameters and hob parameters simultaneously contributes to optimal objectives;(iii)considering tool life provides usage precautions support and process parameters guidance for practical machining.

关键词： Process parameters Decision-making Tool life Dry hobbing Multi-objective multi-verse optimizer(MOMVO)

Variable selection in near infrared spectroscopy for quantitative models of homologous analogs of cephalosporins

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Journal of Innovative Optical Health Sciences 2014年第4期7卷 91-100页

作者： Yan-chun Feng Zhen ni Chang-Qin Hu National Institutes for Food and Drug Control(niFDC)Beijing 100050 P.R.China Tibet Institute for the Control of Food and Pharmaceutical Products Lhasa 850000 P.R.China

Two universal spectral ranges(4550-4100 cm^(-1) and 6190-5510 cm^(-1))for construction of quantitative models of homologous analogs of cephalosporins were proposed by evaluating theperformance of five spectral ranges and their combinations,using three data sets of cephalos-porins for injection,ie.,cefuroxime sodium,cetriaxone sodium and cefoperazone ***,the proposed ranges were validated by using eight calibration sets of otherhomologous analogs of cephalosporins for injection,namely cefmenoxime hydrochloride,ceftezole sodium,cefmetazole,cefoxitin sodium,cefotaxime sodium,cefradine,cephazolin sodium and ceftizoxime *** the constructed quantitative models for the eight kinds of cephalosporinsusing these universal ranges could fulill the requirements for quick *** that,competitive adaptive reweighted sampling(CARS)algorithm and infrared(IR)-near infrared(niR)two-dimensional(2D)correlation spectral analysis were used to determine the scientific basis of these two spectral ranges as the universal regions for the construction of quantitativemodels of *** CAR.S algorithm demonstrated that the ranges of 4550-4100 cm^(-1) and 6190-5510 cm^(-1) included some key wavenumbers which could be attributed to content changes of *** IR-niR 2D spectral analysis showed that certain wavenumbersin these two regions have strong correlations to the structures of those cephalosporins that wereeasy to degrade.

关键词： Near infrared spectroscopy cephalosporins quantitation spectral range selection

Interval arithmetic operations for uncertainty analysis with correlated interval variables

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Acta Mechanica Sinica 2016年第4期32卷 743-752页

作者： Chao Jiang chun-Ming Fu Bing-Yu ni Xu Han State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University

A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional parallelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation,and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addition, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.

关键词： operations uncertainty arithmetic correlative unified transformed considering convenient subtraction illustrated

Recent advances, perspectives, and challenges inferroelectric synapses

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Chinese Physics B 2020年第9期29卷 15-30页

作者： Bo-Bo Tian ni Zhong chun-Gang Duan Key Laboratory of Polar Materials and Devices(MOE) Department of ElectronicsEast China Normal UniversityShanghai 200241China Collaborative Innovation Center of Extreme Optics Shanxi UniversityShanxi 030006China

The multiple ferroelectric polarization tuned by external electric field could be used to simulate the biological synaptic weight. Ferroelectric synaptic devices have two advantages compared with other reported ones: One is that the intrinsic switching of ferroelectric domains without invoking of defect migration as in resistive oxides, contributes reliable performance in these ferroelectric synapses. Another tremendous advantage is the extremely low energy consumption because the ferroelectric polarization is manipulated by electric field which eliminates the Joule heating by current as in magnetic and phase change memories. Ferroelectric synapses have potential for the construction of low-energy and effective brain-like intelligent networks. Here we summarize recent pioneering work of ferroelectric synapses involving the structure of ferroelectric tunnel junctions (FTJs), ferroelectric diodes (FDs), and ferroelectric field effect transistors (FeFETs), respectively, and shed light on future work needed to accelerate their application for efficient neural network.

关键词： ferroelectric synapse ferroelectric tunnel junctions ferroelectric field effect transistors

Combined Cloud： A Mixture of Voluntary Cloud and Reserved Instance Marketplace

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Journal of Computer Science & Technology 2016年第6期31卷 1110-1123页

作者： Wei Shen Wan-chun Dou Fan Wu Shaojie Tang Qiang ni State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210046 China Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Information Systems University of Texas at Dallas Texas TX 75080 U.S.A. School of Computing and Communications Lancaster University Lancaster LA1 4WA U.K.

Voluntary cloud is a new paradigm of cloud computing. It provides an alternative selection along with some well-provisioned clouds. However, for the uncertain time span that participants share their computing resources in voluntary cloud, there are some challenging issues, i.e., fluctuation, under-capacity and low-benefit. In this paper, an architecture is first proposed based on Bittorrent protocol. In this architecture, resources could be reserved or requested from Reserved Instance Marketplace and could be accessed with a lower price in a short circle. Actually, these resources could replenish the inadequate resource pool and relieve the fluctuation and under-capacity issue in voluntary cloud. Then, the fault rate of each node is used to evaluate the uncertainty of its sharing time. By leveraging a linear prediction model, it is enabled by a distribution function which is used for evaluating the computing capacity of the system. Moreover, the cost optimization problem is investigated and a computational method is presented to solve the low-benefit issue in voluntary cloud. At last, the system performance is validated by two sets of simulations. And the experimental results show the effectiveness of our computational method for resource reservation optimization.

关键词： voluntary cloud system architecture resource reservation

Host-guest interaction tailored cucurbit[6]uril-based supramolecular organic frameworks(SOFs) for drug delivery

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Chinese Chemical Letters 2022年第3期33卷 1529-1532页

作者： chun Liu Yu Xia Zhu Tao Xin-Long ni Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province Guizhou UniversityGuiyang 550025China College of Chemistry and Chemical Engineering Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan ProvinceHunan Normal UniversityChangsha 410081China

An approach for the construction of crystalline porous supramolecular organic frameworks (SOFs) via outer-surface interactions of cucurbit[6]uril (Q[6]) with high yield is presented. This approach enables the noncovalent integration of guest molecules into ordered topologies and creates new host-guest-complex-based SOFs;i.e., the topology can be predesigned and constructed by using [ZnCl_(4)]^(2-) anions to induce the formation of solid Q[6]-SOFs, and the pore wall surface can be easily modified by the Q[6]-encapsulated guest molecules. In addition, one of prepared solid Q[6]-SOFs showed a high drug-loading capacity and smart potential release control for drug-delivery applications.

关键词： Cucurbituril SOFs Porous materials Host-guest interaction Drug delievery