低温下金属热膨胀系数的同位素效应

以Cu为例，在考虑德拜温度随温度，原子质量变化后，利用统计物理理论对低温下的金属热膨胀系数及其同位素效应进行了定量的探讨，结果表明；同位素各组分含量对金属热膨胀系数的影响随温度，组分含量而变化，该变化可以定理求出；温度较低时变化较快，较高时较慢。     

Nanometer properties of oceanic polymetallic nodules and cobalt-rich crusts

An ammonia leaching process was utilized to extract Co, Ni and Cu from oceanic polymetallic nodules, whereas an acid leaching process was utilized to extract Co, Ni, Cu, Zn and Mn from cobalt-rich crusts. Both processes produced nanometer materials—ammonia leaching residue and acid leaching residue. A systematic study was conducted on the phase, composition and physicochemistry properties of these residues. The result shows that both residues contain a large amount of nanometer minerals. Ammonia l eaching residue mainly consists of rhodochrosite, with the average grain diameter of 17.9 nm; whereas the acid leaching residue mainly consists of well-developed bassanite, with the average grain deameter of 9.5 nm. The bassanite also has a microporous structure, the volume of the pore space is 1.23 × 10⁻² mL/g. Both the ammonia and acid leaching residues have a large specific surface area, and they display a strong adsorption capacity to saturate sodium chloride vapour, N₂ and SO₂. Both residues have high contents of rare earth elements, and most of these elements exist in the state of ionic adsorption. The content of σ FeO is high. The P₂O₅ enrichment is observable in acid leaching residues. The unique composition and nanometer solid properties of the leaching residues displayed their potential value and promised a bright future for their application in the field of environmental protection and materials.     

Change of water use efficiency and its relation with root system growth in wheat evolution

Raising crop water use efficiency (WUE) is the physiological basis to implement crop high efficiently using water. The present soil column and field experiments are designed to investigate the change of wheat WUE (Triticum aestivum L.) at whole plant level and root system growth in evolution and the relationship between WUE and its root system growth using 10 wheat evolution genotypes with different ploidy chromosomes sets. Results show that in wheat evolution from 2n→6n, WUE at whole plant level increases with the increase of ploidy chromosomes, and root system growth (root weight, root length) and root/shoot ratio of wheat decrease with the increase of ploidy chromosomes under dry and irrigated conditions. WUE is negatively correlated with root weight and root/shoot ratio of wheat in evolution, significantly. Root system growth has an adverse redundancy for WUE in wheat evolution, and the root redundancy reduces with the increase of ploidy chromosomes, which result in the increase of wheat WUE at whole plant level.     

Research situation and progress of non-equilibrium plasma chemistry

Generally, the non-equilibrium plasma is produced at low pressure by a glow discharge (1.33 Pa—1.33 kPa) including the radio frequency (13.56 MHz), microwave (2450 MHz), AC or DC high voltage discharges. As a method to directly apply energy to a reaction system, some successful applications have been obtained in the fields such as chemical synthesis and decomposition at plasma, sputtering and filming, deposition at the gas state, polymerization, modification on the material surface, etching, ashing at low temperature and so on. For example, in 1999, Zhang et al.^[1] got a high conversion rate of 98.2% for CH₄ synthesis by a glow discharge at the condition of 850℃ with the catalyst of Ni/a-Al₂O₃. In 1990, Matsumoto et al.^[2] reduced the concentration of CO₂ from 10% to 8% by DC corona torch discharge with Ar catalyst at 0.08 kPa. In 1988, Boenig et al.^[3] synthesized rare N₂H₄ and H₂O₂ with a glow discharge, in which N₂H₄ is a kind of pureness fuel and propellant of rocket. Tanaka et al.^[4] investigated the synthesis of ammonia from nitrogen-hydrogen plasmas in radiofrequency and microwave discharges with catalysts of iron and molybdenum wires of 100 pieces at 620 K and 650 Pa. After 2-h synthesis, the amounts of synthesized NH₃ and N₂H₄ were only 1.5 mmol/g and 2.5 mol/g, respectively. Because it is only at low pressure that electrons can obtain enough energy to carry out chemical reaction, the vacuum system is necessary, which results in the complicated technology and low production efficiency.......     

Effect of alkyl substitutions on self-assembly

The self-assemblies of 4-hexadecyloxybenzoic acid and 3,4,5-trihexadecyloxybenzoic acid have been studied by using scanning tunneling microscopy (STM). The well-ordered assemblies with different arrangement have been investigated. The structural change is attributed to the different number of substituted alkyl chains on periphery.     

关于S-W BPRE灭绝概率积分表示的构作举例

利用分式线性概率母函数的特性 ,借助对偶过程及其函数变换 ,在作了一些适当的特殊假设的情况下 ,探讨了随机环境分枝过程 BPRE的灭绝概率的具体表示形式 ;并通过两个举例 ,构作了两类独立同分布随机环境分枝过程灭绝概率的积分表示。从而在特殊情况下 ,可通过简单的积分计算求得随机环境分枝过程的灭绝概率。     

长江江苏河段嘶马弯道崩岸与护岸研究

在总结前人研究的基础上，对长江江苏河段把弯道来水来沙，河床边界组成，弯道横向环流情况下的水沙运动和河床演变进行了分析，探讨了嘶马弯道崩岸坍江的原因，特点和工程防护措施，对弯道的稳定性运用钱宁公式进行了计算分析研究。结合嘶马河段护岸工程实践，对丁坝，沉排，平顺抛石等护岸形式进行总结比较，探求最佳护岸类型，进一步对长江扬中河段特别是嘶马弯道作出系统的整治规则。     

梅山水电站右坝肩渗流特征分析

依据水文地球化学原理，库水作为一种溶液，在向坝基渗透过程中，既传递水的物理特性如压力、水量等，又与坝基岩石、帷幕、混凝土间产生物理化学作用，形成新的水质特征。为此，对梅山水电站右坝肩坝基排水孔水位、水量、水质进行定期观测，并对现场水pH值测试资料进行了系统分析。分析结果表明：工程措施效果明显；拱廊道内大流量排水孔水主要来自库水；拱廊道少数排水孔水中K^ Na^ 含量较丰富，此是坝基水化学潜蚀的结果。     

多不饱和脂肪酸保健八宝粥的研究

多不饱和脂肪酸是人体必需的脂肪酸，对人体有保健功能，本实验利用富含多不饱和脂肪酸的黑加仑油添加到八宝粥中，同时去除异味，防止氧化，制成一种具有保健功能的八宝粥。     

采动建筑物破坏程度预测及破坏机理的研究

地面建筑物受地下开采的影响,会产生不同程度的破坏,为了正确指导采动建筑物的保护或新建建筑物的设计,本文提出了采动区上的建筑物破坏程度的预测方法,研究了建筑物的研究机理.