统计量分布函数概率的计算方法与软件设计

统计量的各类分布函数如正态分布、ι分布、ｘ￣２分布和Ｆ分布等在农业试验统计分析中有着重要的作用。本文探讨了各类分布函数概率值的计算方法，并以ι分布为例用Ｃ语言设计了相应的计算概率值的计算机软件，从而为农业试验数据的计算机处理分析提供了一种实用的计算方法。     

森林资源规划设计调查模式

宁夏创新合作模式,在国家林业局西北林业调查规划设计院的技术指导下,开展了"二类调查"工作.通过采用"3S"新技术调查方法,解决了调查工作中的主要技术难题,全面摸清了宁夏森林资源的实际情况,建立了森林资源数据库和信息管理系统,提升了宁夏森林资源调查、信息管理和动态监测水平.     

大学生职业设计与职业选择的调查与思考

本文从大学生职业设计与职业选择的调查和实证研究入手,探讨了大学生职业理想和择业观念的形成及特点,分析了大学生就业准备与职业选择的状况及存在的问题,并从高校共青团的角度提出服务大学生择业和就业的对策和思考。     

New approaches to robotics

In order to build autonomous robots that can carry out useful work in unstructured environments new approaches have been developed to building intelligent systems. The relationship to traditional academic robotics and traditional artificial intelligence is examined. In the new approaches a tight coupling of sensing to action produces architectures for intelligence that are networks of simple computational elements which are quite broad, but not very deep. Recent work within this approach has demonstrated the use of representations, expectations, plans, goals, and learning, but without resorting to the traditional uses of central, abstractly manipulable or symbolic representations. Perception within these systems is often an active process, and the dynamics of the interactions with the world are extremely important. The question of how to evaluate and compare the new to traditional work still provokes vigorous discussion.     

Orchard management with small unmanned aerial vehicles: a survey of sensing and analysis approaches

Precision Agriculture - Advances in sensor miniaturization are increasing the global popularity of unmanned aerial vehicle (UAV)-based remote sensing applications in many domains of agriculture....     

Immunotherapeutic approaches to Alzheimer's disease

Although neurodegenerative diseases such as Alzheimer's disease are not classically considered mediated by inflammation or the immune system, in some instances the immune system may play an important role in the degenerative process. Furthermore, it has become clear that the immune system itself may have beneficial effects in nervous system diseases considered neurodegenerative. Immunotherapeutic approaches designed to induce a humoral immune response have recently been developed for the treatment of Alzheimer's disease. These studies have led to human trials that resulted in both beneficial and adverse effects. In animal models, it has also been shown that immunotherapy designed to induce a cellular immune response may be of benefit in central nervous system injury, although T cells may have either a beneficial or detrimental effect depending on the type of T cell response induced. These areas provide a new avenue for exploring immune system-based therapy of neurodegenerative diseases and will be discussed here with a primary focus on Alzheimer's disease. We will also discuss how these approaches affect microglia activation, which plays a key role in therapy of such diseases.     

Practical approaches to green solvents

Solvents are widely used in commercial manufacturing and service industries. Despite abundant precaution, they inevitably contaminate our air, land, and water because they are difficult to contain and recycle. Researchers have therefore focused on reducing solvent use through the development of solvent-free processes and more efficient recycling protocols. However, these approaches have their limitations, necessitating a pollution prevention approach and the search for environmentally benign solvent alternatives. This report highlights opportunities for the practical implementation of such green solvents.     

Computational approaches to developmental patterning

Computational approaches are breaking new ground in understanding how embryos form. Here, we discuss recent studies that couple precise measurements in the embryo with appropriately matched modeling and computational methods to investigate classic embryonic patterning strategies. We include signaling gradients, activator-inhibitor systems, and coupled oscillators, as well as emerging paradigms such as tissue deformation. Parallel progress in theory and experiment will play an increasingly central role in deciphering developmental patterning.     

Therapeutic approaches to bone diseases

The strength and integrity of our bones depends on maintaining a delicate balance between bone resorption by osteoclasts and bone formation by osteoblasts. As we age or as a result of disease, this delicate balancing act becomes tipped in favor of osteoclasts so that bone resorption exceeds bone formation, rendering bones brittle and prone to fracture. A better understanding of the biology of osteoclasts and osteoblasts is providing opportunities for developing therapeutics to treat diseases of bone. Drugs that inhibit the formation or activity of osteoclasts are valuable for treating osteoporosis, Paget's disease, and inflammation of bone associated with rheumatoid arthritis or periodontal disease. Far less attention has been paid to promoting bone formation with, for example, growth factors or hormones, an approach that would be a valuable adjunct therapy for patients receiving inhibitors of bone resorption.     

数量性状全基因组关联分析中上位效应遗传位点检测方法研究进展

数量性状的表型变异受到大量效应微小的遗传位点和诸多环境因素的共同作用,但在数量性状的遗传研究领域,关于不同遗传位点之间加性效应与上位效应相对重要性的认识却存在着分歧。近年来,伴随着全基因组关联分析在人类及家养动物数量性状研究中的发展,在全基因组关联分析的框架内进行上位效应遗传位点的检测越发受到重视。文章以遗传力失踪问题为出发点,首先综述了标记-QTL连锁分析和GWAS框架下传统上位效应遗传位点的检测方法,然后对基于表型方差同质性检验和广义线性混合模型方法的上位效应统计推断以及混杂因素的处理方法进行了总结与梳理,旨在为数量性状全基因规模上位效应的相关研究提供理论参考。     

基于GIS的土地详查信息系统的设计和实现

基于土地管理部门的需求,以现有的土地详查数据为依据,以建立区域地理信息为目标,用面向对象的编程方法和思想分析基于GIS的土地详查信息系统的设计及各个功能模块的实现方法,进行了GIS系统集成技术在土地管理领域的应用研究。     

New approaches to nuclear proliferation policy

Nuclear proliferation is not one but a complex of problems. One relates to the collapse of the Soviet Union and its effect on the spread of nuclear weapons and knowledge. Second, Iraq's violation of its Non-Proliferation Treaty obligation has exposed certain weaknesses in the traditional regime of multilateral nonproliferation institutions and treaties. Third, Pakistan's achievement of a nuclear weapons capability in the late 1980s brings the postproliferation question to the forefront in South Asia. There is no single solution to this complex set of problems, but the beginning of wisdom is to build upon the successes of the past, add new policy procedures, and, above all, increase the priority given to the issue. Otherwise, we may be faced with the ironic outcome that the widely welcomed end of the Cold War may increase the prospect of nuclear use.     

Innovative approaches to plasminogen activator therapy

Plasminogen activator therapy for acute myocardial infarction has become standard medical practice. Bleeding complications, however, limit the utility of the currently available agents. This article reviews how the tools of molecular biology and protein engineering are being used to develop safer and more effective plasminogen activators.     

Immunological approaches to the nervous system

Immunology has had a major impact on neurobiology, expanding dramatically the number of subjects amenable to investigation. Studies with antibodies to neuropeptides, transmitters, and transmitter enzymes have disclosed a great heterogeneity among neurons and have provided clues for interpreting anatomical connections. Monoclonal antibodies are being used to identify functionally related subpopulations of neurons and cell lineages in development and to study mechanisms by which axons grow along stereotypic pathways to reach their targets. Other antibodies have identified molecules that appear to participate in cell aggregation, cell migration, cell position, and axon growth. Antibodies have revealed that many proteins are concentrated in anatomically distinct regions of the neuron. Moreover, these studies have suggested that individual proteins have different antigenic epitopes shielded or modified in different parts of the same neuron. Antibodies to membrane proteins crucial for neuronal function, such as ion pumps, ion-selective channels, and receptors, have been used to map their distributions and to study their structures at high resolution.     

New approaches to surface structure determinations

Progress in understanding the many scientifically interesting and technologically important processes that occur at surfaces has been slowed by the absence of basic structural information. A variety of new techniques are being developed to attack this central problem in surface science. With the new surface probes it is now possible to quantitatively determine the arrangement of atoms in the first monolayers of a solid. This provides the basis for exciting advances in surface science.     

配合力分析在甘蔗育种上的应用

本文总结了以往１０ａ所开展的９次不完全双列杂交的试验结果，侧重分析了甘蔗有性世代农艺性状的遗传效应、常用或新引进亲本农艺性状和抗性的一般配合力效应以及较好组合的特殊配合力效应．分析结果认为，甘蔗育种上应用不完全双列杂交技术和配合力分析方法，有助于甘蔗育种者合理评价亲本的遗传特点和育种潜力，提高组合选配的预见性和后代选择的效率．文章还简要讨论了甘蔗更多性状的配合力分析、配合力与环境互作以及亲本创新的问题。     

试论创造性教育开展之途径

新世纪经济的发展离不开创造性人才的培养，这已成为不争的事实，而创造性人才的培养要靠创造性教育。本通过对当前教育弊端的认识，论证了创造性人才的培养要靠学生自身、教师、学校及社会各方面的努力。其途径是构建创造性学校、培训创造性教师、从而培养创造性人才。     

Quantum statistical corrections to dynamic nuclear magnetic resonance

A quantum statistical treatment of the chemical exchange between molecular eigenstates or conformations revealed previously unsuspected dynamic terms in the spin Hamiltonian operator that describes fast exchange. These terms resulted from the effect of nuclear spin on rotational and vibrational relaxation. With the traditional theory, an interpretation of new carbon-13 nuclear magnetic resonance measurements of the chemical shift of methylcyclohexane in solution showed fast-exchange equilibrium constants that were inconsistent with the slow-exchange free-energy difference and were spread over a range of 30 percent for the various carbon-13 positions. Modeling of the new terms indicated that they have the correct magnitude and temperature dependence to reconcile these inconsistencies.