旋转煤粉分离器阻力特性研究

从理论和实验两方面分析了旋转分离器的阻力特性，并探讨和分析了阻力与转速、流量和给粉浓度的关系。     

土料非线性滞回本构模型的半解析半离散构造方法

通常的土体动力真非线性分析方法难以同时合理地拟合整个应变范围内实际的动剪切模量Gs及阻尼比eq随应变γ的非线性变化规律，为了克服这一缺陷，本文对于含固定参数的解析类骨架方程及相应的滞回曲线构造准则加以修正，即在原本构模型中取定或引进两个随应变幅值而变化的参数，并根据实测得的经验曲线，Gs-γ及－γ直接推求这些参数的变化规律，具体分析表明：如此所建立的动态本构模型既简便可行，又符合实际。     

SAR imagery coding based on blocking high frequency energy matching

A new fractal image compression algorithm based on high frequency energy (HFE) partitioning andmatched domain block searching is presented to code synthetic aperture radar (SAR) imagery. In the hybridcoding algorithm, the original SAR image is decomposed to low frequency components and high frequencycomponents by wavelet transform (WT). Then the coder uses HFE of block to partition and searchthe matched domain block for each range block to code the low frequency components. For the high frequencycompone...     

妫河下游土壤含水量与植物群落的关系研究

通过对妫河流域河岸带植物群落物种多样性的调查研究,探讨了河岸带植物多样性及地上生物量与土壤含水量之间的关系.结果表明:(1)利用抛物线方程进行拟合,河岸带植物多样性与土壤含水量之间具有极显著的相关性(R2=0.970,P=0.009＜0.01),回归方程为Y=1.051+8.799x-21.001x2+12.500x3,反映了植物的生长对土壤水分的需求具有最适阈值,高于或低于其生长所需的适量水分,都会使植物群落多样性降低;(2)7月和9月群落地上生物量和土壤含水量之间呈正相关,而在5月两者之间呈负相关,但相关性均不显著.     

面向"差生"的教学方案

如何对"差生"进行有效的教育,是职业学校教学工作的重大课题.要树立关心爱护学生的办学思想,不嫌弃差生,要根据其实际知识水平和能力进行教学,开展丰富多彩的活动,以开发其非智力因素.     

浅谈工程施工中的安全管理

安全管理是企业生产的保障,由于施工项目的流动性大、高空作业多、作业条件差,建设管理水平参差不齐,影响施工安全的因素多,科学管理对做好安全工作来讲是极其必要的.     

Banach空间二阶常微分方程两点边值问题解的存在唯一性定理

通过变换证明了二阶常微分方程解的存在唯一及迭代收敛性，并给出了收敛速度的估计式．     

社会科学数据库建设初探

本文从中外社科数据库的发展情况,阐述如何建立中文社科数据库;确定数据库的标准;数据库的设计;加强专业人员的培养;建立完整的管理机构     

Gas seepage on the sea floor of Okinawa Trough Miyako Section

A marine geophysical survey was carried out,on the R/V Science 1 of the Institute of Oceanography, Chinese Academy of Sciences (IOCAS), in 2000, at the Miyako Section of Okinawa Trough. Here we present seismic and acoustic evidence of a gas seep on the sea floor on the western part of the Okinawa Trough, near the lower slope of the East China Sea Slope and discuss the possibility of related formation of gas hydrate. A gas column reflection was observed in echo-sounder data above a section where the sea floor reflector was missing, on both the echo-sounder and the seismic data for line H14. The seismic data also show an acoustic curtain reflection and a turbidity reflection at this section.These anomalies are the evidence of the existence of a gas seep, which occupies .an area 2.2 km in diameter. Based on the acoustic curtain on line H14, we believe that the amount of gas contained in the sediments below the gas seep is larger than 1% by volume of sediment. Tectonically, the gas seep developed in a small basin controlled by basement uplift in the north, south and east. The thickness of the sediment layer can be greater than 3.5 km. A mud diapir structure was found in layer D beneath the gas seep. Over-pressure may occur due to the large sediment thickness and also the tectonic basement uplift in the north, south, and east. The mud diapir could be the preferential pathway for methane-rich fluids. The acoustic curtain may indicate that free gas related to the gas seep can be formed on the sea floor. We also note that the layer above the acoustic curtain on profile H14 may contain gas hydrate.     

Effect of total aluminum concentration on the formation and transformation of nanosized Al13 and Al30 in hydrolytic polymeric aluminum aqueous solutions

Influence of total aluminum concentration （CAIT） on the generation and transformation of nanosized AI13 and AI30 in hydrolytic polyaluminum aqueous solutions was investigated using high field 27AI NMR and time-developed AI-Ferron complex colorimetry. When prepared at the optimal basicity （B） of Al13 generation and 80℃, the All3 species in polyaluminum solution tends to further polymerize and convert to AI30 and higher polymers when CAI; 〉0.2 mol· L^-1, but Al13 does not convert to AI30 quantificationally, as the formation of Alu from Al13 and AI30 is accelerated in the same way. The conversion rate of All3 is accelerated by the increase in CAIT. When CAlT 〉0.75 mol·.L^-1, Al13 content decreases rapidly, and AI30 content increases continuously and becomes the dominant nanometer polynuclear aluminum species. AIm is one of prerequisites of Al13 conversion to AI30. When CAI; increases and B reduces, the polymerization rate between Al13 and Aim increases, and at the same time, the dissociation reaction rate of All3 and AI30 by H^＋ also increases. The latter becomes the dominant reaction in polyaluminum solution with low B value, so AI30 decreases with the increasing CAlT. The hydrolytic polyaluminum solution with Al13 content beyond 80% can only be prepared under the condition of CAlT〈0.5 mol· L^-1 and optimal B value.