碳酸盐草甸土玉米配合施用磷锌效应研究

通过两年试验研究，揭示了东北北部碳酸盐草甸土磷、锌化学特征与玉米生长发育关系及磷、锌肥施用技术。在碳酸盐草甸土上，施磷可以明显提高土壤速效磷的含量，但同时抑制了土壤锌的有效性，使有效锌减少了22.7％—45.5％；施锌可以明显提高土壤速效锌的含量，但同时抑制了土壤磷的有效性，使有效磷减少了11.3％—17.9％。施磷可以明显提高玉米植株磷的含量，但同时抑制了玉米植株对土壤锌的吸收，植株锌含量减少了74.1％—92.4％；施锌可以明显提高玉米植株锌的含量和产量，产量可以提高19.68％，但同时抑制了玉米植株对土壤磷的吸收，使植株磷含量减少了26.0％—33.1％。适宜的磷、锌配施可以提高玉米产量，增产的幅度为9.32％—31.53％，磷、锌在土壤和玉米植株体内都有拮抗作用。表9，参7。     

东北平原典型农业县不同利用方式对耕地土壤养分状况的影响研究

研究不同利用方式对耕地土壤养分状况的影响,可以为有效地指导农业生产、促进土地资源的保护和持续利用提供科学依据。在获取大量土壤养分数据的基础上,系统地分析了不同耕地利用方式对吉林省德惠市土壤养分状况的影响。结果表明,在11种土壤养分中,有效锰、有效磷、有效锌、有效铁和有效铜在不同利用方式下变异系数较大。不同耕地利用方式对土壤全氮、有效磷、速效钾、缓效钾具有显著影响,而对土壤有机质的影响不显著。因农户对菜地的投入及管理水平明显高于粮田,造成菜地土壤的大量元素含量高于粮田。除有效钼在旱田和水田中的含量无显著差异外,水田中的有效铜、锌、铁、锰、硼均明显高于旱田,主要原因为水稻田施微肥较多。表4,参16。     

水稻对土壤硫吸收规律分析

通过在黑土、草甸黑土、草甸土3种不同土壤上连续种植水稻的盆栽试验，研究水稻植株吸硫量与土壤无机硫含量的关系，以及土壤无机硫下降量的变化规律，探讨水稻对土壤硫的吸收规律。研究初步得出：水稻吸硫量与土壤初始无机硫含量呈正相关；土壤中无机硫下降量与土壤初始无机硫含量呈正相关。图2，表4，参4。     

沼肥施用方式对灰枣中矿质元素含量的影响

在不同沼肥施用方式条件下分析灰枣果实中主要矿质养分元素的含量,结果表明：不同沼肥施用方式处理的灰枣果实中氮、磷、钾的含量都表现为氮〉钾〉磷,果实中磷的含量在不同施肥方式中变化比较平缓,沼液喷施有利于灰枣果实对氮、钾元素的吸收和积累,而沼夜滴施则有利于磷素的吸收和积累;沼液喷施有利于提高灰枣果实中矿质元素铁、锌、铜、锰、钙、镁的含量,改善果实品质。不同沼肥施用方式中以沼液喷施效果最佳。     

三江平原小叶章湿地土壤中硝态氮和铵态氮含量的季节变化特征

选择三江平原典型小叶章湿地不同水分带上的两种土壤类型（草甸沼泽土和腐殖质沼泽土）为研究对象,对比研究了二者硝态氮和铵态氮含量的季节变化特征。结果表明,二者不同土层硝态氮含量的季节变化特征差异较大,缺乏相似性,而铵态氮含量的季节变化特征尽管差异较大,但存在一定相似性;二者不同土层硝态氮和铵态氮含量季节变化特征的差异主要与不同生长期植物吸收作用、融雪补给、大气氮沉降、冻层深度、土壤结构和水分条件的差异有关;不同土层硝态氮淋失、对铵态氮的吸附以及不同时期有机氮矿化和硝化一反硝化作用等进行的程度对其也有重要影响;尽管硝态氮和铵态氮含量的季节变化特征在两种土壤不同土层间差别较大,但均可用四次多项式进行模拟,模拟效果比较理想．基本反映了二者硝态氮和铵态氮含量的季节变化特征。图2,表2,参14。     

我国各地区现代化与工业化、城市化、知识化及经济协调发展的初步研究

工业化、城市化、知识化和现代化是一个地区经济、社会发展的必然过程 .本文以各省区为对象 ,以统计数据为基础 ,用多种统计分析方法 ,从不同的角度探讨了我国各地区现代化与工业化、城市化、知识化及经济发展之间的关系 .东、中、西三大地带各项指标都是由东到西逐渐降低 ,但南北方之间却不协调 :北方社会指标较高 ,南方经济指标相对超前 ;城市化、知识化、现代化随着经济的发展而呈生长曲线提高 ,但它们与工业化之间的关系并不显著 ,以乡镇工业为主导的工业化和再工业化所蕴涵的社会发展动力并没有得到充分发挥.     

未来我国人口、经济、资源、环境与可持续发展的情景分析

通过未来 5 0年我国人口、经济、资源、环境与可持续发展的情景分析 ,认为人口基数大 ,仍是我国可持续发展的首要问题 ,2 1世纪我们还必须坚持计划生育 ,严格控制人口增长的基本国策.     

Roles,Politics, and Ethics in Action Research Design

For novice action researchers, issues of roles, politics and ethics are critical, particularly in design. The field of organization development (OD) provides many useful considerations of roles, politics and ethics. This article proposes a systemic design-based framework of the action research process that includes context, inquiry mechanisms, inquiry cycle and outcomes. Such perspective brings to the forefront the issues of context, roles, politics dynamics and ethics that are embedded in the action research process and influence its emergent process, quality and outcomes. A set of propositions for further explorations is advanced and briefly discussed.     

两因素HJM模型下债券、期货、期权的定价

在HJM模型下考虑远期利率由2个独立布朗运动驱动的零息票债券的期限结构,给出零息票债券和债券期货的定价公式,以及债券期货期权的定价公式。     

TSINGHUA UNIVERSITY, Beijing, China Faculty Position in Any Field

The School of Economics and Management (SEM) invites applications for positions at all levels(Lecturer (equivalent to Assistant Professor), Associate Professor and Full Professor) in any field ofaccounting, economics, finance, information systems, and operations management. The school offers     

Making learning critical: Identity, emotion, and power in processes of management development

In recent years, a substantial volume of broadly critical knowledge of management and organization has been established, but comparatively little attention has been given to the question of how the insights of such knowledge might be communicated or applied pedagogically. The temptation or danger, arguably, is for critical knowledge to be substituted for the content of “traditional management education,” with minimal regard for its contribution to processes of personal, social, and organizational development. The chief purpose of this paper is to put some flesh on the claim that critical theory can make an important contribution to the principles and practice of management education. After summarizing some key differences between “traditional management education” and action learning (concerning learning and personal experience), these differences are illustrated by reference to a case study, which in turn, provides a basis for highlighting the relevance of critical thinking for addressing problems and issues thrown up through action learning for managers.     

国企并购中政企银三方利益取向及博弈

国有企业并购的过程中政府、国有企业和国有银行各有不同的利益取向，三者在各自利益的驱动下进行着博弈。在对各自利益取向剖析的基础上，通过建立各博弈方之间的博弈模型，可以寻找出或证实制约并购博弈均衡结果的相关因素主要是国有资产委托一代理机制的健全程度、并购的相关击律制度的健全程度、对国有资产的监管力度、社会保障体制、政府的职能角色等等。     

大安牛心套堡湿地芦苇（Phragmites communis）生物量的动态研究

于2006年6～10月在大安牛心套堡湿地芦苇气候环境的调查基础上,分析了大安牛心套堡湿地芦苇的生长季节动态和地上生物量的变化规律.结果表明:芦苇群落的平均株高呈单峰曲线,9月株高最高为200.4cm,6月株高最低为110.3cm;芦苇群落的平均叶片数和茎节数呈一定的规律;芦苇地上生物量整体上出现上涨趋势(干重),鲜重的生物量峰值出现在7月,达2 636g/m2;茎生物量在生长季中不断增加,鲜重在7月最高,达1 780g/m2;叶片生物量在8月出现最大值,为309g/m2,然后下降,鲜重和干重出现同样的波动;叶鞘生物量随季节推移,不断增加,鲜重在6月时最大,达308g/m2,然后逐渐减小,8月后又增加,到9月出现次高,然后下降.图6,参15.     

Air Pollution,Government Pollution Regulation,and Industrial Production in China

Over the last four decades, a severe deterioration in air quality has accompanied China's rapid industrialization. As a result, the Chinese government has implemented stricter policies and regulation to control air pollution. In this paper, the authors create a measure of government policies on air pollution by tracking all pollution-related government announcements in Chinese newspapers. The authors then use this variable, along with measures of actual pollution, to investigate how air pollution,industrial production, and government policies on air pollution are interrelated. The authors conduct this investigation nationwide, as well as in five large cities in China. A vector autoregression model suggests that, nationwide, government policies seem to decrease air pollution without significantly affecting industrial production. However, the effect appears to be short-lived, dissipating after a few months. In addition, the authors find that the dynamic relationship among these variables differs by city. For instance, following an adverse air quality shock in Beijing, government efforts to control pollution seem to have an ameliorating city-wide effect, decreasing local air pollution in subsequent months. In Shanghai and Guangzhou, while the local government reacts to adverse air pollution shocks,the ameliorating effects are not statistically significant. In Chengdu and Shenyang, the authors detect no significant local government reaction to adverse air pollution shocks. Moreover, in these cities, local government policies do not impart a statistically measurable effect on air pollution.     

小卫星姿控系统设计、分析与仿真测试一体化平台开发

基于并行工程的开发理念,依据星上姿控系统的技术特点和开发流程,搭建了一个集任务分析、控制算法设计与优化、软硬件开发、分系统及整星仿真、测试和验收于一体的"小卫星姿控系统设计、分析与仿真测试一体化平台",实现"边设计边测试"的高级开发理念,可为小卫星姿控系统研制开发全过程提供一整套技术解决方案,对于减少整星集成测试出错及零部件返工、提高系统开发过程中的柔性、缩短系统开发周期具有重要意义。仿真试验结果表明,集成平台可大幅提高卫星姿控系统开发效率,对后续系列型号卫星姿控系统的研制开发也具有重要应用价值。