相变诱导塑性钢生产现状与发展趋势   总被引：2，自引：0，他引：2  

刘永前  陈宇 《武汉工程职业技术学院学报》2010,22(3):23-26

通过相变诱导塑性(transformation induced plasticity,TRIP)效应使钢板中残余奥氏体在塑性变形作用下发生马氏体相变,TRIP钢以其高强度、优异的成形性能成为近年来汽车用钢研究的热点。概述了相变诱导塑性(TRIP)钢的理论研究现状,讨论了其化学成分、微观组织形态、残余奥氏体含量等因素对材料性能的影响。介绍了国内外TRIP钢工业应用情况,并对TRIP钢的发展趋势做了展望。  相似文献   

Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system     

Zan P  Yang BH  Shao Y  Yan GZ  Liu H 《Journal of Zhejiang University. Science. B》2010,11(12):931-936

This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10–10⁷ Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system.  相似文献   

当前高校多媒体教学存在问题及解决思路探讨——以西安建筑科技大学为例     

程洁  陈宇玺  张渝生  伍喜媛 《中国科教创新导刊》2010,(20):173-174

多媒体教学日益成为当前高校的重要教学手段,在使用多媒体进行教学的过程中存在种种问题。本文研究多媒体教学在高校中存在的主要问题并提出了一些参考意见及解决思路。这些解决思路可供学校教学管理者、教师、多媒体设备维护者参考。  相似文献   

Silicon＇s organic pool and biological cycle in moso bamboo community of Wuyishan Biosphere Reserve   总被引：3，自引：0，他引：3  

Li ZJ  Lin P  He JY  Yang ZW  Lin YM 《Journal of Zhejiang University. Science. B》2006,7(11):849-857

Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the widely distributed and woody Phyllostachys heterocycla var. pubescens (moso bamboo) contributes to storing silicon by biomineralization and, thus, prevents eutrophication of nearby waterbodies through silicon’s erosion of soil particles. A study on the organic pool and biological cycle of silicon (Si) of the moso bamboo community was conducted in Wuyishan Biosphere Reserve, China. The results showed that: (1) the standing crop of the moso bamboo community was 13355.4 g/m², of which 53.61%, 45.82% and 0.56% are represented by the aboveground and belowground parts of moso bamboos, and the understory plants, respectively; (2) the annual net primary production of the community was 2887.1 g/(m²·a), among which the aboveground part, belowground part, litterfalls, and other fractions, accounted for 55.86%, 35.30%, 4.50% and 4.34%, respectively; (3) silicon concentration in stem, branch, leaf, base of stem, root, whip of bamboos, and other plants was 0.15%, 0.79%, 3.10%, 4.40%, 7.32%, 1.52% and 1.01%, respectively; (4) the total Si accumulated in the standing crop of moso bamboo community was 448.91 g/m², with 99.83% of Si of the total community stored in moso bamboo populations; (5) within moso bamboo community, the annual uptake, retention, and return of Si were 95.75, 68.43, 27.32 g/(m²·a), respectively; (6) the turnover time of Si, which is the time an average atom of Si remains in the soil before it is recycled into the trees or shrubs, was 16.4 years; (7) the enrichment ratio of Si in the moso bamboo community, which is the ratio of the mean concentration of nutrients in the net primary production to the mean concentration of nutrients in the biomass of a community, was 0.64; and lastly, (8) moso bamboo plants stored about 1.26×10¹⁰ kg of silicon in the organic pool made up by the moso bamboo forests in the subtropical area of China. Project (No. 30370275) supported by the National Natural Science Foundation of China  相似文献   

Inactivation of infectious bursal disease virus by binary ethylenimine and formalin   总被引：1，自引：0，他引：1  

Habib M  Hussain I  Fang WH  Rajput ZI  Yang ZZ  Irshad H 《Journal of Zhejiang University. Science. B》2006,7(4):320-323

In this experiment conducted to study the inactivation dynamics of infectious bursal disease virus （IBDV） by binary ethylenimine （BEI） in comparison with formalin, IBDV was isolated from the bursa of infected chickens and its confirmation was done by agar gel precipitation test. Viral suspensions were subjected to inactivation with BEI and formalin for pre-set time in- tervals. BEI was employed at concentrations of 0.001 and 0.002 mol/L while formalin was used at 0.1% and 0.2%. Sampling was done at 6, 12, 24, 36 and 48 h of incubation and samples were tested for their inactivation status in 9-day-old embryonated eggs and 3-week-old broiler chickens. IBDV was completely inactivated by 0.001 and 0.002 mol/L BEI after 36 h of incubation at 37℃, whereas formalin at 0. 1% and 0.2% concentrations inactivated IBDV in 24 h.  相似文献   

Chronic morphine drinking establishes morphine tolerance, but not addiction in Wistar rats   总被引：1，自引：0，他引：1  

Binsack R  Zheng ML  Zhang ZS  Yang L  Zhu YP 《Journal of Zhejiang University. Science. B》2006,7(11):892-898

Objective： Some animal models apply morphine in the drinking water to generate addiction, but related reports are not free of conflicting results. Accordingly, this study aimed to figure out if chronic consumption of morphine in the drinking water can induce morphine addiction in Wistar rats. Methods： For 3 weeks, the animals received a daily morphine dose of 35 mg/kg by offering a calculated volume of sugar water （5% sucrose） with morphine （0. l mg/ml） to each rat; animals receiving just sugar water served as controls. Immediately after the treatment phase, the tail immersion test was used to check for morphine tolerance, and all animals were then kept on tap water for one week （withdrawal phase）. Afterwards, all rats were allowed to choose their drinking source by offering two bottles, containing sugar water without and with morphine, simultaneously for two days （preference phase）. Results： While the chronic consumption of morphine led to a reduction in body weight and to morphine tolerance, the morphine-treated Wistar rats did not show any preference for the opiate-containing sugar water. Conclusion： Body weight loss and tolerance do not reveal a condition of drug craving, and current animal models should be re-evaluated regarding their potential to establish morphine addicted animals.  相似文献   

Study of cellulolytic soil fungi and two nova species and new medium     

Khalid M  Yang WJ  Kishwar N  Rajput ZI  Arijo AG 《Journal of Zhejiang University. Science. B》2006,7(6):459-466

This study is aimed at identifying and determining the percentage of occurrence frequency of cellulose decomposing soil fungi. The soil samples were inoculated into culture plates prepared in Sabouraud medium under sterilized conditions and incubated at 30 ℃ for 4 to 7 d. The identified fungal species were incubated in self-designed cellulose medium for testing their cellulolytic ability. Forty-two species, including2 nova species, representing sixteen genera showed growth and sporulation in the cellulose medium. Most of the isolated species were from genus Aspergillus and Penicillium. Aspergillus niger and Mucor hiemalis showed highest occurrence frequency （45% and 36% respectively）, as these species were collected from about 80% of soil samples. Being agar free and cheaper, the new fungal medium designed showed results equivalent to Sabouraud medium.  相似文献   

面向任务的无人侦察机试飞方案设计     

杨晓萍  陈宇 《中国科技信息》2019,(10)

采用基于系统工程的正逆双向交叉设计方法,进行面向任务的无人侦察机试飞方案设计,从战略体系层面理解无人侦察机作战意图和飞机使命任务,以"任务"为牵引,自顶向下逐层分解,形成清晰的树形试验结构和评估要素集,对无人侦察机的未来试飞具有指导意义。  相似文献   

简谈砂性土高填方路基施工中的排水防护     

陈宇  李德明 《云南科技管理》2018,(3)

由于砂性土粘聚力小的特点,在采用砂性土路基的高填方区常出现滑坡现象,而造成滑坡的主要因素为水的影响。结合刚果(金)罗安格-洛瓦公路项目的工程实践,浅析砂性土高填方区的排水防护措施。  相似文献   

英国国家职业资格证书制度的质量保证体系     

胡晓勇  陈宇 《职业技术教育》1997,(12)

英国国家职业资格委员会在教育与就业部宏观政策指导下,在推行国家职业资格证书制度的过程中,建立了一整套严密的组织管理体系,其中每个工作机构、每个考评人员都有明确的质量保证职责,并以层层负责和环环相扣的质量控制链的形式具体运作,从而保证了国家职业资格证书的高质量。  相似文献