CO-W-P刷镀层的晶化动力学与热模具寿命

研究了 ＣＯ－Ｗ－Ｐ电刷镀层加热时结构的转变。实验测定了镀层的等温和变温晶化综合动力学曲线及各种动力学参数。提出了瞬时晶化温度的概念。详细分析了晶化过程中硬度的变化，发现晶化伴随有一个硬化效果很强烈的沉淀过程。ＣＯ－Ｗ－Ｐ刷镀层能显著增进热模具的使用寿命，主要原因在于模具成形时，同时发生晶化和沉淀析出过程，产生二次硬化效应，提高了模具表层的红硬性以及热磨损抗力。     

平衡式电力测功机的测试精度分析

本文根据计量学的一般原理明确地给出了电力测功机的精度定义.从电力测功机的力矩平衡出发,分析了影响其测试精度的各种因素,提出了提高扭矩测试精度的措施和标准力矩的设计原则,介绍了静态标定和动态标定方法及其实际应用的结果。     

The terrestrial NPP simulations in China since Last Glacial Maximum

Based on Atmosphere-Vegetation Interaction Model （AVIM）, the magnitude and spatial distribution of terrestrial net primary productivity （NPP） in China is simulated during three different geological eras, Last Glacial Maximum （LGM）, Mid-Holocene （MH） and the present. The simulation shows that the glacial-interglacial variation of East Asian summer monsoon in China is the key factor affectfng the NPP change. During the three eras, mean NPPs are 208 g/m^2·a, 409 g/m^2·a, and 355 g/m^2·a. The total NPPs are 2.05 Pg/a, 3.89 Pg/a and 3.33 Pg/a, respectively. The terrestrial NPP in China during warm-humid climate is larger than that during cold-arid eras, and the correlation analysis between NPP and climate factors suggests that temperature is the primary factor affecting the terrestrial NPP during 21 kaBP （LGM）, and for 6 kaBP （MH） and the present the primary factor is precipitation.     

Structural stability of infinite-layer CaCuCO<Subscript>2</Subscript> under high pressure

Since the discovery of high temperature supercon-ductivity by Bednorz et al. in 1986[1], many series of cu- prate superconductors have been synthesized. Critical temperature has been improved continuously. But no verdict has been given upon what mechanism causes su- perconductivity. CaCuO2 conductive layers are the parent structure of the high Tc cuprate superconductors, such as Cu-12 (n-1)n[2], Tl-12(n-1)n[3] and Hg-12(n-1)n[4,5] super- conductor families. In 1988, infinite-layer (Ca0.86S…     

听力过程分析及听力能力的培养

论述了学习者在听力过程中要了解听的心理过程及听的特点,并提出听力的实践训练和听力能力的培养.     

再制造系统中零部件供应优化模型

针对制造商经常面临零部件供应决策问题,分析了传统制造与再制造过程中零部件的来源及构成,并以一种常见的再制造系统为原型,讨论再制造系统中零部件供应优化问题.分析不同零部件供应条件下的成本结构,建立了一个混合整数规划模型,通过最大化传统制造与再制造中零部件总成本之间的差额(即再制造总成本节约),获得再制造系统中零部件供应问题的优化解,并以算例论证了模型的有效性.实际算例表明,通过再制造系统获取零部件,往往比纯粹外购新件更加节约成本.     

Value of Access to Jobs and Amenities: Evidence from New Residential Properties in Beijing

<正>Introduction When households are faced with the choice of where to live in a city, one of the foremost concerns is the loca-tion’s accessibility to jobs and various other amenities, such as schools, hospitals, and parks[1]. A home in a city is a gateway to urban opportunities, and obviously     

Optimal procedure for fitting the magnetic susceptibility vs J couplings

To provide efficiency in calculating the energy-levels of paramagnetic spin clusters with high nuclear -ity, a fitting program of irreducible tensor operator is developed for the calculation of / couplings. An optimal data-access process is given, which greatly enhances the computational aspects of such modeling. Upon the program's application, the coupling constants of the moderate-sized clusters are fitted automatically by the least-squares calculations in PCs.     

关于新型冠状病毒命名的思考与建议

2019年12月,一种由新型冠状病毒(2019-nCoV)引起的病毒性肺炎开始在武汉暴发流行。2020年2月11日,世界卫生组织(WHO)将新型冠状病毒肺炎命名为COVID-19(冠状病毒病2019),国际病毒分类学委员会(ICTV)的冠状病毒研究小组(CSG)建议把新型冠状病毒命名为SARS-CoV-2(严重急性呼吸综合征冠状病毒2),既没有与疾病名称一致,也没有完全真实地显示该病毒本身的特征,因而立即引发关注和争议。基于COVID-19的病原学、流行病学和临床特征的基本信息,建议将新型冠状病毒命名为“人类冠状病毒2019”(human coronavirus 2019,简称HCoV-19)。文章回顾并评价了CSG的命名方法,指出他们使用基于基因序列信息进行病毒命名的方法并不合适,建议采用传统的联系疾病的病毒命名方法对具有明显疾病特点的病毒如2019-nCoV进行命名。     

长白山区垂花百合园艺栽培技术

垂花百合(Lilium cernuum)野生资源分布稀疏、数量较少,是园林杂交育种的重要野生种源,具有较高的经济价值.对垂花百合的形态学特征、地理分布、生态学习性及长白山区垂花百合的物候特征进行描述,并重点对其繁育技术、田间管理、病虫害防治等进行研究.结果发现:人工栽培的垂花百合在花、叶、鳞茎的生长上都明显优于野生自然生长的垂花百合;引种栽培后病害较多,易倒伏;第1年遮阴栽培是关键,需遮阴50%;有性繁殖时,种子需暖温处理,发芽率可达70%以上.无性繁殖生长较快.