内蒙古半干旱区树木非结构性碳、氮、磷的分配格局

为探讨半干旱区树木各器官中养分浓度的分配格局、养分之间的化学计量关系,以及植物器官养分浓度与树种、土壤养分条件之间的关系,选取内蒙古东南缘的两种天然的典型树种（白桦和白杄）,对其叶片、树干、基部最粗根以及根尖中的总非结构性碳水化合物（TNC）、氮（N）和磷（P）浓度进行分析。结果表明：TNC浓度在叶片中最高,在根尖中最低,两者的浓度差异在53％以内;而N和P浓度在叶片和根尖中最高,树干和基部最粗根中最低,不同器官最大差异达98％。这种分配格局与各器官的生理功能（碳水化合物的生产、养分的吸收和储藏）密切相关。此外,白杄的TNC∶N和TNC∶P均大于白桦,这些格局不仅和树种本身的生理特性有关,而且反应了土壤的养分状况。     

LY12铝疲劳裂纹在冲击载荷下的演化研究

对LY12铝合金在低周疲劳条件下的裂纹情况和随后进行的动态拉伸条件下裂纹的发展给予了观察和统计分析，发现裂纹的累积数密度分布在损伤演化过程中保持指数形式，用NAG模型对实验结果进行分析，得出该材料裂纹演化发展方程的各种参数。     

保羅·郎之萬

一、生在劳动人民中间 1954年3月3日,在巴黎大學大禮堂中举行保罗·郎之万七十三壽辰慶祝大會。在大会上郎之万郑重地說明了他的思想。他说: “我之所以能够把我的全部力量用在科學工作和正義事业上,是由於我是在1870年战爭以後的環境中培养出來的。我的父母都是擁护共和制度的,甚至愿意犧牲他們的生命,同時我是生長在可爱的巴黎人民中间,對巴黎人我至今還是衷心熱爱的。我的父親虽然在十     

De Haas-van Alphen Effect of Free Electron Gas Revisited

The free electron gas in a uniform magnetic field at low temperature is restudied. The grand partition function previously obtained by Landau＇s quantitative calculation contains three parts, which are all approximate. An improved calculation is presented, in which two of the three parts are obtained in exact forms. A simple remedy for Landau and Lifshitz＇s qualitative calculation in the textbook is also given, which turns the qualitative result into the same one as obtained by the improved quantitative calculation. The chemical potential is solved approximately and the thermodynamic quantities are caiculated explicitly in both a weak field and a strong field. The thermodynamic quantities in a strong field obtained here contain both non-oscillating and oscillating corrections to the corresponding results derived from Landau＇s grand partition function. In particular, Landau＇s grand partition function is not sufficiently accurate to yield our nonzero results for the specific heat and the entropy. An error in the Laplace-transform method for the problem is corrected. The results previously obtained by this method are also improved.     

在京壮族语言文字使用情况及语言态度问卷调查分析——兼与广西地区壮族比较

文章在调查所得数据基础上,对北京地区壮族人语言文字使用情况及语言态度进行分析解释,兼与现有的对广西地区壮族的各项调查结果进行对比,对壮族语言文字的传承与发展提出相关建议。