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New technique of precision necking for long tubes with variable wall thickness

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Frontiers of Mechanical Engineering 2020年第4期15卷 622-630页

作者： Yongqiang GUO Chunguo XU Jingtao HAN zhengyu wang Beijing Research Institute of Mechanical and Electrical Technology Beijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

This study analyzed the deformation law of rear axles with variable wall thickness under bidirectional horizontal extrusion and found that necking was accompanied by upsetting deformation through theoretical calculation, numerical simulation, and experimental research. The sequence and occurrence of necking and upsetting deformations were obtained. A theory of deformation was proposed by controlling the distribution of temperature field. Effective processes to control the wall thickness of rear axle at different positions were also proposed. The ultimate limit deformation with a necking coefficient of 0.68 could be achieved using the temperature gradient coefficient. A new technology of two-step heating and two-step extrusion for a 13 t rear axle was developed, qualified test samples were obtained, and suggestions for further industrial application were put forward.

关键词： extrusion rear axle necking coefficient temperature gradient

Dispatch and bidding strategy of active distribution network in energy and ancillary services market

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Journal of Modern Power Systems and Clean Energy 2015年第4期3卷 565-572页

作者： Yao JIN zhengyu wang Chuanwen JIANG Yu ZHANG School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Guizhou Power Grid Corporation Power Grid Planning&Research Center Guiyang 550002China

The active distribution network(ADN)is able to manage distributed generators(DGs),active loads and storage facilities *** is also capable of purchasing electricity from main grid and providing ancillary services through a flexible dispatching mode.A competitive market environment is beneficial for the exploration of ADN’s activeness in optimizing dispatch and bidding *** a bilateral electricity market,the decision variables such as bid volume and price can influence the market clearing price(MCP).The MCP can also have impacts on the dispatch strategy of ADN at the same *** paper proposes a bilevel coordinate dispatch model with fully consideration of the information interaction between main grid and *** results on a typical ADN validate the feasibility of the proposed method.A balanced proportion between energy market and ancillary services market can be achieved.

关键词： Active distribution network(ADN) Energy market Ancillary services market Optimal dispatch Bidding Strategy

Low-strain binary hexacyanoferrate nanocuboids with concentration-gradient structure towards fast and durable energy storage

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Journal of Energy Chemistry 2022年第11期31卷 72-84,I0004页

作者： Yutong Lin Bing Han Donglan Zhang Xueya Liu Zili wang zhengyu wang Liang Si Sen Zhang Chao Deng Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationCollege of Chemistry and Chemical EngineeringHarbin Normal UniversityHarbin 150001HeilongjiangChina College of Materials Science and Chemical Engineering Harbin Engineering UniversityHarbin 150001HeilongjiangChina

The exploration of low-strain and high-performance electrode is a crucial issue for aqueous potassiumion battery(AKIB).Herein,a novel potassium mediated iron/manganese binary hexacyanoferrate nanocuboid,i.e.,K_(x)Fe_(y)Mn_(1-y)[Fe(CN)_(6)]·nH_(2)O(KFeMnHCF)nanocuboid,with the concentration-gradient(CG)structure is designed as a high-performance cathode for *** the CG-KFeMnHCF nanocuboids,the manganese content gradually decreases from the interior to the surface and the iron content changes reverse,resulting in the concentration-gradient *** experimental and finite element simulation(FEA)results demonstrate the lower internal stress and better mechanical characteristics of CG structured nanocuboid than the homogenous structured one upon ion intercalation/deintercalation ***,the electrochemical testing and theoretical calculation(DFT)results disclose the substitution of Fe to Mn in the KMnHCF crystal results in the enhanced electronic conductivity,potassium migration and electrochemical *** both advantages from the well-designed architecture and optimized crystal structure,the CG-KFeMnHCF achieves the superior rate capability and ultrahigh stability in aqueous potassium ion *** particular,the CG-KFe_(0.31)Mn_(0.69)HCF achieves the best comprehensive properties among all the *** full AKIBs based on CG-KFe_(0.31)Mn_(0.69)HCF cathode achieves the high energy density(83 Wh kg^(-1)),superior power density,high capacity retention(83%)over high-rate long-term cycles,good adaptation to a wide temperature range(-20 to 40℃)and high reliability even under outside ***,this work not only provides a new clue to design the highperformance cathode,but also promotes the applications of AKIBs for diverse electronics and wide working environments.

关键词： Concentration-gradient structure Binary hexacyanoferrate nanocuboid AKIBs Low-strain FEA modeling

Effects of ambient humidity and thermal aging on properties of Nomex insulation in mining dry‐type transformer

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High Voltage 2021年第1期6卷 71-81页

作者： Lu Li Jiancheng Song Zhipeng Lei Ailiang Kang zhengyu wang Rujia Men Yun Ma Shanxi Key Laboratory of Mining Electrical Equipment and Intelligent Control College of Electrical and Power EngineeringTaiyuan University of TechnologyTaiyuan ShanxiChina Zhengzhou Power Supply Company State Grid Henan Electric Power CompanyZhengzhou HenanChina Jinzhong Power Supply Company State Grid Shanxi Electric Power CompanyJinzhong ShanxiChina

Temperature and humidity are the main factors that cause the decomposition of Nomex paper widely used as turn‐to‐turn insulation material of mining dry‐type transformers. In this study, for understanding the effect of ambient humidity and thermal aging on the properties of Nomex paper, specimens with the initial moisture content of 7% were aged in the oven for 168, 504, 672 h at 180°C, respectively. After thermal aging, corona discharge experiments of unaged and aged specimens with different aging degrees were carried out at different relative humidity (RH) levels from 10 to 70%. The characteristic parameters of corona discharge, such as the average discharge amplitude and the number of discharges, were measured. Then, the surface conductivity and the surface potential decay rate were measured. The morphology and attenuated total internal reflectance Fourier transform infrared spectroscopy were also analysed for explaining the difference of properties be-tween unaged and aged specimens. The experiment results indicate that the average discharge amplitude decreases with the increase of RH or the deepening of the aging degree of specimens, but the number of discharges shows the reversal tendency. The changes in the physical structure and chemical composition, which is induced by the hydrolysis reaction of Nomex paper, accelerate the surface potential decay and increase the surface conductivity.

关键词： aging thermal humidity

A mechanically tuned Kerr comb in a dispersion-engineered silica microbubble resonator

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Science China(Physics,Mechanics & Astronomy) 2020年第5期63卷 92-97页

作者： FangJie Shu PeiJi Zhang YanJun Qian zhengyu wang Shuai Wan Chang Ling Zou GuangCan Guo ChunHua Dong Department of Physics Shangqiu Normal Universiy Shangqius 476000.China FCAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

This paper discusses the developement and investigation of a silica microbubble resonator(MBR) that is optimized to cancel mode dispersion with material dispersion, at a wavelength of approximately 1550 nm and maintain a quality factor of an optical mode as large as 5.4 × 10~7. Benefitting from the near-zero dispersion and high quality factor, a primary optical comb is generated in the MBR using cascaded four-wave mixing processes, which span over 300 nm with several tens of teeth. Furthermore, the frequency comb could be gradually tuned by mechanically stretching the MBR. This tunable Kerr comb has multiple potential applications in precision measurements and sensing applications, such as molecular spectroscopy and ranging.

关键词： microresonator nonlinear optics frequency comb

Mechanical compression management of the right middle cerebral artery inferior trunk using a stent during coil embolization of middle cerebral artery aneurysms:A case report and literature review

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Journal of Interventional Medicine 2023年第3期6卷 126-129页

作者： zhengyu wang Zhiqing Peng Liang Chen Wanbin Li Yongli wang Department of Interventional Radiology The Sixth People's Hospital South CampusShanghai Jiao Tong UniversityShanghaiChina

Endovascular coil embolization is a minimally invasive,rapid,and effective method for the treatment of intracranial ***,complications associated with coil embolization,such as intraoperative aneurysm rupture or arterial occlusion,should be promptly managed during the procedure to avoid catastrophic *** study presents a case of mechanical compression management of the right middle cerebral artery(MCA)inferior trunk during coil embolization for bilateral MCA *** inferior trunk of the right MCA was abruptly occluded due to mechanical compression during coil embolization of the right MCA bifurcation aneurysm.A Solitaire AB stent(4×20 mm,Covidien/Medtronic,Dublin,Ireland)was implanted in the inferior trunk of the right MCA after tirofiban was injected via a microcatheter,and the right inferior trunk was *** patient also underwent coil embolization of the left MCA bifurcation aneurysm,without any *** is crucial to recognize compressive occlusion of adjacent aneurysm branches to avoid severe complications during intracranial aneurysm *** placement is a rescue treatment option for recanalization of an occluded artery.

关键词： Endovascular coil embolization Intracranial aneurysm Mechanical compression Stent

WheatGene: A genomics database for common wheat and its related species

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The Crop Journal 2021年第6期9卷 1486-1491页

作者： Diego F.Garcia zhengyu wang Jiantao Guan Lingjie Yin Shuaifeng Geng Aili Li Long Mao Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081China

Common wheat(Triticum aestivum) is a hexaploid plant(AABBDD) derived from genetically related tetraploid wheat T. turgidum(AABB) and a diploid goatgrass Aegilops tauschii(DD). Recent advances in sequencing technology and genome assembly strategies allow the acquisition of multiple wheat genomes, calling for a centralized database to store, manage and query the genomics information in a manner to reflect their evolutionary relationship and to perform effective comparative genome analysis. Here,we built WheatGene, a database that contains five wheat genomes of 318,102 genes and 945,900 transcripts and their expression information in 998 RNA-seq samples that can be searched and compared in an interactive manner. WheatGene was developed with Drupal, a popular content management system and the toolkit Tripal managed the biological information. The database was accessible through a web browser with species, search, gene expression, tools, and literature entries. Tools available were BLAST,synteny viewer, map viewer, JBrowse, data downloads, gene expression heatmap and bar chart, and homologs viewer. Moreover, the map viewer connected genomics data with genetic maps and QTL that can be searched for markers for molecular breeding. WheatGene was developed with open-source modules and libraries. WheatGene is available at http://***.

关键词： Wheat Genome Comparative genomics Database Genome browser

SOME COMBINATORIAL PROBLEMS ON ORDERED TREES

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Chinese Annals of Mathematics 1983年第4期4卷 501-504页

作者：王振宇 Wuhan Digital Engineering Institute

Some formulas are established to calculate the number of leaves on all structurallydifferent ordered trees with n nodes,and the total leaf path length and the total node pathlength for those ***,respective average numbers are obtained(the average pathlength may be considered as the average height of random ordered trees with n nodes),Actually,this paper presents a general method dealing with some classes of combinaorialproblems on ordered trees.

关键词： node tree SOME COMBINATORIAL PROBLEMS ON ORDERED TREES

“美本”与“纳帕”:民族杂居背景下纳西族祭天习俗的变迁

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思想战线 2020年第5期46卷 58-64页

作者：王正宇西南民族大学西南民族研究院四川成都610041

在纳西族与藏族深入交往、交流、交融背景下,盐井的祭天习俗晚近发生了变迁。根据对参与观察、深入访谈以及相关历史文献资料的分析可以发现,盐井祭天习俗的变迁,不能单纯地理解为现代性或现代化带来的结果,更不能以此建构针对民族文化... 详细信息

在纳西族与藏族深入交往、交流、交融背景下,盐井的祭天习俗晚近发生了变迁。根据对参与观察、深入访谈以及相关历史文献资料的分析可以发现,盐井祭天习俗的变迁,不能单纯地理解为现代性或现代化带来的结果,更不能以此建构针对民族文化变迁形成的传统与现代之间的潜在张力。在民族杂居背景下,家庭结构的变迁是纳西族祭天习俗晚近变迁的核心原因。这一过程体现了历史形成的当地各民族在文化与社会上的深度交流的延续,而不是现代性对传统的威胁。

关键词：西藏盐井纳帕民族杂居纳西族