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China Foundry 2017年第2期14卷 85-92页

作者： Yu Zhang Xiao-feng Huang ying ma Ti-jun Chen Yuan Hao State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Lanzhou 730050 China

The application of segmental semi-solid thixoforming of magnesium alloys is confined due to the dimensional distinction existing in solid particles of the alloy billet from edge to center zones. In the present study, the effects of Sm addition on the microstructural evolution of Mg-6Zn-0.4Zr and Mg-6Zn-4Sm-0.4Zr alloys by semi-solid isothermal heat treatment were investigated, to obtain optimum semi-solid microstructures for the subsequently thixoforming. The results indicate that the grains of the Sm-bearing alloy are evidently refined and gradually evolve from dendritic to globular and elliptic particles. In addition, the distinctly dimensional effect of the Mg-6Zn-0.4Zr alloy is eliminated with 4% Sm addition; the particle sizes in all zones from center to the edge of the billet are almost identical. With the increment of isothermal heat treatment temperature, the dendritic microstructures completely disappear, and meanwhile, the irregular and globular particles gradually form. The size, morphology and the distribution of solid particles mainly depend on the formation and permeation of the liquid phase in the process of isothermal heat treatment. As the isothermal temperature increases from 570 °C to 610 °C, the average size and shape factor of solid particles of both the alloys with and without Sm addition gradually decrease while the liquid fraction gradually increases.

关键词： Mg-Zn-Zr magnesium alloy dimensional effect Sm semi-solid isothermal heat treatment non-dendritic microstructure

Industry news:the additive manufacturing of nerve conduits for the treatment of peripheral nerve injury

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Bio-Design and manufacturing 2022年第1期5卷 6-8页

作者： ying Han jun Yin The State Key Laboratory of Fluid Power and MechatronicSystems School of Mechanical EngineeringZhejiangUniversityHangzhou 310028China Key Laboratory of 3D Printing Process and Equipmentof Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310028China

Peripheral nerve injury and nerve conduit manufacturing The global nerve injury repair and regeneration market is expected to reach$9.7 billion by 2025,a compound annual growth rate of 9.1%between 2020 and 2025[1].One component alone,peripheral nerve injury(PNI),encompasses 5 million new cases worldwide every year[2].Although nerve autograft is considered the gold standard for PNI repair,this process sufers because of a short supply of autologous nerves as well as potential harm caused to the *** recent decades,as a promising alternative to autografts。

关键词： injury nerves additive

Phase synchronization and energy balance between neurons

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Frontiers of Information Technology & Electronic Engineering 2022年第9期23卷 1407-1420页

作者： ying XIE Zhao YAO jun ma Department of Physics Lanzhou University of TechnologyLanzhou730050China School of Science Chongqing University of Posts and TelecommunicationsChongqing430065China

A functional neuron has been developed from a simple neural circuit by incorporating a phototube and a thermistor in different branch *** physical field energy is controlled by the photocurrent across the phototube and the channel current across the *** firing mode of this neuron is controlled synchronously by external temperature and *** is energy diversity when two functional neurons are exposed to different illumination and temperature *** a result,synapse connections can be created and activated in an adaptive way when field energy is exchanged between *** propose two kinds of criteria to discuss the enhancement of synapse connections to *** energy diversity between neurons determines the increase of the coupling intensity and synaptic current for neurons,and the realization of synchronization is helpful in maintaining energy balance between *** first criterion is similar to the saturation gain scheme in that the coupling intensity is increased with a constant step within a certain period until it reaches energy balance or complete *** second criterion is that the coupling intensity increases exponentially before reaching energy *** two neurons become non-identical,phase synchronization can be controlled during the activation of synapse connections to *** two identical neurons,the second criterion for taming synaptic intensity is effective for reaching complete synchronization and energy balance,even in the presence of *** indicates that a synapse connection may prefer to enhance its coupling intensity *** results are helpful in discovering why synapses are awaken and synaptic current becomes time-varying when any neurons are excited by external *** potential biophysical mechanism is that energy balance is broken and then synapse connections are activated to maintain an adaptive energy balance between the *** results provi

关键词： Hamilton energy Coupling synchronization Synapse enhancement Neural circuit

Hybrid scheme for three-cell multi-user MIMO cellular networks

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The Journal of China Universities of Posts and Telecommunications 2014年第5期21卷 37-42页

作者： ma Yan-jun School of Communication Engineering Xi'an University of Science and Technology

Orthogonal schemes are usually adopted for cell-edge users in a cellular network, where the spectrum is poorly utilized. A new interference alignment （IA） based space-division hybrid （IA-SDH） scheme is proposed by joint design transmit precoding matrices and beamforming matrices for a three-cell constant cellular network, where users at cell-center work with a conventional scheme while users at cell-edge utilize an IA scheme. Therefore, the cell-edge users suffer no interference and cell-center users are only affected by negligible inter-cell interference. Analysis simulation shows that more users can be served simultaneously than that of a conventional scheme in certain user distributions.

关键词： iterference alignment degree of freedom interference channel

Effects of Y content on microstructures and mechanical properties of as-cast Mg-Zn-Nd alloys

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China Foundry 2015年第5期12卷 339-348页

作者： Ti-jun Chen Da-hua Zhang Wei Wang ying ma Yuan Hao State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology

The effects of Y addition amount on the microstructures and mechanical properties of as-cast MgZn-Nd alloy have been investigated by using an optical microscope, a scanning electron microscope, backscattered electronic imaging technique, an X-ray diffractometer, a differential thermal analyzer and a universal testing machine. There are three kinds of ternary phases in the Mg-Zn-Y system alloys, such as I phase(Mg3Zn6Y), W phase(Mg3Zn3Y2) and Z or X phase(Mg12Zn Y). The experimental results in the present study indicate that the Mg-Zn-RE(RE includes Y and Nd) ternary phases change from the I + W phases in turn to unique W, W + Z and unique Z as the Y content increases from 0% to 3%. Simultaneously, their distribution gradually changes from small particle-like form to continuous network form. The grain size first decreases as the Y content increases from 0% to 1% Y, then increases when the Y content exceeds 1% and finally decreases again when the content exceeds 3% due to the variation of growth restriction factor caused by the increased Y element and the change of the ternary phases. The hardness continuously increases because of the increased ternary phase amount. The ultimate tensile strength and elongation first increase within the range of 0-1% Y, also due to the increased ternary phase amount and grain refinement, and then decreases because of the grain coarsening, porosity formation and continuous network distribution of the ternary phases. The grain bonding strength of the W phase-containing alloys is quite strong and the W phase is an ideal strengthening phase if a given amount of it distributes in discontinuous and small-sized form. The alloy with 1% Y only has one ternary phase of W, but has the best combination of mechanical properties. The fracture regimes of these alloys always present a transgranular mode.

关键词： Mg-Zn-Y alloy microstructure mechanical properties ternary phase fracture regime

Research on FRP bolt-end failure mechanism

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Mining Science and Technology 2009年第4期19卷 522-525页

作者： LI ying-ming ma Nian-jie YANG Ke SHI Jian-jun School of Energy and Safety Anhui University of Science and Technology Huainan Anhui 232001 China MOE Key Laboratory for Coalmine Safety and High Efficiency Mining Anhui University of Science and Technology Huainan Anhui 232001 China School of Resources and Safety China University of Mining and Technology Beijing 100083 China School of Safety Engineering North China University of Science and Technology Beijing 101601 China

Given the fact that FRP bolts for roadway support are often under a certain amount of eccentric load,we studied the problems of failure of FRP bolt-ends using mechanical analysis,numerical simulation and a laboratory experiment to reveal the FRP bolt-end failure *** results show that bolt-end stress increases rapidly,making the maximum stress under an eccentric load to be 5 to 7 times greater than that under a normal load,resulting first in the formation of some fractures at the bolt-end,which then spreads to the entire cross-section of the bolt.

关键词： FRP bolt bolt-end eccentric load failure mechanism

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环介导等温扩增技术检测酸奶中嗜酸乳杆菌

食品安全质量检测学报 2016年第11期7卷 4581-4585页

作者：张蕴哲张先舟李英军马晓燕张伟河北农业大学食品科技学院保定071001

目的建立环介导等温扩增法(loop-mediated isothermal amplification,LAMP)检测酸奶中嗜酸乳杆菌。方法以嗜酸乳杆菌16S r RNA保守区的基因序列为靶序列设计引物,优化建立LAMP反应体系和程序,并研究引物的特异性,同时确定嗜酸乳杆菌的... 详细信息

目的建立环介导等温扩增法(loop-mediated isothermal amplification,LAMP)检测酸奶中嗜酸乳杆菌。方法以嗜酸乳杆菌16S r RNA保守区的基因序列为靶序列设计引物,优化建立LAMP反应体系和程序,并研究引物的特异性,同时确定嗜酸乳杆菌的灵敏度和检出限。结果本方法可通过凝胶电泳和离心后焦磷酸镁白色沉淀检测反应结果,检测时间为5.5 h,灵敏度为62 CFU/m L,人工污染酸奶样品的检出限为120 CFU/m L,12株非嗜酸乳杆菌细菌非特异检测结果均为100%。结论该方法灵敏性好、特异性强、操作简单、耗时短,可适合于酸奶中的嗜酸乳杆菌的快速测定。

关键词：环介导等温扩增法嗜酸乳杆菌酸乳

Etiology spectrum and clinical characteristics of renal artery stenosis in a Chinese cohort

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Journal of Geriatric Cardiology 2021年第2期18卷 104-113,I0001页

作者： Xu MENG Yi ZHOU Xiong-Jing JIANG jun CAI Hui-Min ZHANG Hai-ying WU Wen-jun ma ying LOU Ya-Xin LIU Xian-Liang ZHOU Department of Cardiology Fuwai HospitalNational Center for Cardiovascular DiseaseChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Emergency and Critical Care Center Fuwai HospitalNational Center for Cardiovascular DiseaseChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

OBJECTIVE To analyze the causes of renal artery stenosis(RAS)and compare the clinical characteristics in accordance with the primary disease among patients aged from 30 to *** Patients were grouped by etiologies of *** were retrospectively examined and compared regarding demographic data,clinical manifestations,laboratory findings,and imaging *** A total of 152 patients(74 females,78 males;mean age:40.70±6.01 years)were enrolled,including 84 patients(55.3%)with atherosclerosis(AS),46 patients(30.3%)with Takayasu arteritis(TA),18 patients(11.8%)with fibromuscular dysplasia(FMD),and four patients(2.6%)with other *** in AS group had greater body mass index,higher prevalence of comorbidities and higher rate of smoking and drinking *** patients showed more constitutional symptoms and vascular findings,and higher erythrocyte sedimentation *** in both AS group and TA group mainly located on ostia and proximal segments,but RAS in FMD group mainly involved middle to distal segment of renal *** AS group had significantly lesser stenosis than the other *** renal function evaluated by the estimated glomerular filtration rate did not significantly differ among the groups,the incidence of kidney shrinkage was significantly higher in the TA and FMD groups(39.1%and 50%,respectively)than in the AS group(8.3%).The FMD group had milder cardiac damage than other *** AS was the most common cause of RAS in patients aged from 30 to 50,followed by TA and *** etiology of RAS should be carefully distinguished based on clinical manifestations,laboratory findings,and imaging to ensure that proper treatment is provided.

关键词： clinical stenosis finding

Defining the biosynthesis of ketocarotenoids in Chromochloris zofingiensis

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Plant Diversity 2020年第1期42卷 61-66页

作者： ying Ye jun-Chao Huang Department of Economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of SciencesKunming650201People's Republic of China University of Chinese Academy of Sciences Beijing100049People's Republic of China

Carotenoids are important pigments in photosynthetic organisms where they play essential roles in photoreception and *** zofingiensis is a unicellular green alga that is able to accumulate high amounts of ketocarotenoids including astaxanthin,canthaxanthin and ketolutein when growing heterotrophically or mixotrophically with glucose as a carbon *** we elucidate the ketocarotenoid biosynthesis pathway in *** by analyzing five algal *** mutants were shown to have a single nucleotide insertion or substitution in β-carotene ketolase(BKT) gene 1,which resulted in a lack of ketocarotenoid production in Cz-bktl-1,and decreased ketocarote noid co ntent in the other four *** mutants accumulated much higher amounts of non-ketocarotenoids(β-carotene,zeaxanthin and lutein).Interestingly,the Cz-bktl-5 mutant synthesized 2-fold the ketolutein and only 1/30 of the canthaxanthin and astaxanthin as its parent strain,suggesting that the mutated BKT1 exhibits much higher activity in catalyzing lutein to ketolutein but lower activity in ketolating β-carotene and *** and WT BKT2 gene sequences did not *** together,we conclude that BKT1 is the key gene involved in ketocarotenoid biosynthesis in *** study provides insight into the biosynthesis of ketocarotenoids in green ***,Cz-bktl mutants may serve as a natural source for the production of zeaxanthin,lutein,and β-carotene.

关键词： Chromochloris zofingiensis Astaxanthin Ketocarotenoid β-carotene ketolase

Effects of Measuring Positions on the Measured Aerodynamic Performance of a Centrifugal Compressor

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Journal of Thermal Science 2010年第2期19卷 110-114页

作者： Hongwei ma jun ZHANG School of Jet Propulsion Beihang University Beijing 100191 China National Key Laboratory of Science and Technology on Aero-Engines Beijing 100191 China

This paper performs a numerical simulation of three-dimensional flow field in a centrifugal compressor with long inlet and outlet pipes using CFX *** arranging virtual probes at different positions in both inlet and outlet planes,the aerodynamic performance of the centrifugal compressor is measured and compared with each *** effects of measuring positions on measurement results are *** results show that it will generate notable measuring errors of the pressure ratio and efficiency if the inlet total pressure is measured using a single-point *** inlet total pressure data can be accurate when they are measured using a 3-point *** outlet total pressure and total temperature data can not be accurate if they are respectively measured at one circumferential position even using a multi-point *** tangential measuring positions at the outlet is effective to improve the test *** the outlet total pressure and total temperature are respectively measured at 3 tangential positions,the data can be almost accurate.

关键词： centrifugal compressor aerodynamics performance measuring error measurement position probe.