饲料氟含量测定中的数据处理及注意事项

论述了饲料氟含量测定中用标准回归方程法代替格氏图解连续标准加入法的数据处理问题 ,总结并提出了测定过程中的注意事项     

Deconfined quantum critical points

The theory of second-order phase transitions is one of the foundations of modern statistical mechanics and condensed-matter theory. A central concept is the observable order parameter, whose nonzero average value characterizes one or more phases. At large distances and long times, fluctuations of the order parameter(s) are described by a continuum field theory, and these dominate the physics near such phase transitions. We show that near second-order quantum phase transitions, subtle quantum interference effects can invalidate this paradigm, and we present a theory of quantum critical points in a variety of experimentally relevant two-dimensional antiferromagnets. The critical points separate phases characterized by conventional "confining" order parameters. Nevertheless, the critical theory contains an emergent gauge field and "deconfined" degrees of freedom associated with fractionalization of the order parameters. We propose that this paradigm for quantum criticality may be the key to resolving a number of experimental puzzles in correlated electron systems and offer a new perspective on the properties of complex materials.     

关于VFP教学中的几点思考

本文阐述了非计算机专业课程的教学现状，指出如何改进教学思路，提高课堂效果。通过实践表明了VFP教学课改、教学方法、教学实践有利于培养学生的科学素养和综合素质，有利于提升学生的实践技能。     

Focal points in mass spectrometry

Mass spectrometry has advanced with the renaissance of time-of-flight mass analysis, the use of ion traps as analyzers and reactors, the application of tandem mass spectrometers to problems in ionic reaction mechanisms and chemical analysis, and the development of new desorption ionization techniques. These developments have allowed determination of the molecular weight distributions for polymers through the 10,000-dalton range, as well as the molecular weight and partial sequence of biopolymers of similar size. Surfaces can be characterized by use of the mass, energy, and angle distributions of particles ejected by sputtering or by laser-induced desorption. Mass spectrometry has yielded new information on the kinetics of catalytic surface reactions and on the reactivity of metal clusters.     

大豆种植技术要点

大豆是最受欢迎的豆类作物之一,不仅有营养,而且非常有价值:它不仅可以作为一种食 物,而且可以作为一种促进畜牧业发展的食物。为了保证大豆的产量和质量,种植技术是必不可 少的。本文介绍了大豆种植技术的关键问题,仅供大家借鉴和参考。     

编目中的模糊现象及其解决对策

 

简要介绍了模糊现象，分析和讨论了其产生的原因以及对编目工作、读者检索效果的

影响，提出了降低、消除模糊现象的几种措施。

     

Universal signatures of fractionalized quantum critical points

Ground states of certain materials can support exotic excitations with a charge equal to a fraction of the fundamental electron charge. The condensation of these fractionalized particles has been predicted to drive unusual quantum phase transitions. Through numerical and theoretical analysis of a physical model of interacting lattice bosons, we establish the existence of such an exotic critical point, called XY*. We measure a highly nonclassical critical exponent η = 1.493 and construct a universal scaling function of winding number distributions that directly demonstrates the distinct topological sectors of an emergent Z(2) gauge field. The universal quantities used to establish this exotic transition can be used to detect other fractionalized quantum critical points in future model and material systems.     

计算机数据属性及SQL数据的查询

计算机科学中计算机数据是计算机科学应用的关键。计算机数据的属性因计算机软件开发的要求的不同而异。文章就计算机数据的属性论述了一些有关数据属性的分类,数据属性的标准,以及独立开发计算机数据属性的可能带来的正反两方面的影响。并对一些国际通用的计算机数据的属性,例如,计算机汉字的编码GB码,图像文件的编码以及图像文件的各类编码。数据库SQL数据的编码,以度对SQL数据结构化查询语言的数据进行了论述。     

大荚荷兰豆春季栽培技术要点

大荚荷兰豆是以采收嫩荚为商品的豌豆品种,荷兰豆可用来炒食、拌菜、做汤等,质地清脆、口味美好,内含蛋白质、胡萝卜素、核酸等营养元素,是国际市场上畅销的高档水果型蔬菜。1播前准备1.1土壤选择选用土层深厚肥沃、土质疏松、通气良好、排水便利的地块,并要求前茬未种过豆科作     

籼稻杂交育种的亮点

通过回顾杂交籼稻育种过程,对2000年以来审定通过的一批优质不育系进行比较,分析新育成杂交稻组合的特点,指出杂交籼稻优质组合育种生产的方向。     

无公害大蒜高产栽培技术要点

梅江区城北地处梅州城区，是梅州城区蔬菜生产的主要基地，大蒜是我区栽培的主要蔬菜之一，城北镇远离工矿区，周边无“三废”排放企业。农田大气环境良好，灌溉水质、土壤环境质量符合无公害蔬菜生产条件，土壤耕层深厚、土质肥沃，有机质含量在1．0％以上，适宜大蒜生长。     

Carbon dioxide compensation points in related plant species

Both high and low C0(2) compensation concentrations were found in the plant genera-Panicum, Cyperus, and Euphorbia. Within each genus, however, high and low compensations were found in different subgenera. Thus, they may not be genetically closely related. No significant differences in CO(2) compensation were found among 100 genetic lines of Triticum aestivum L. or among 20 lines of Hordeum vulgare L.