利用驻极体提供均匀外场和屏蔽外场的设计

利用驻极体具有的可任意切割、拼装、黏接的特性，从静电学的基本规律及由泊松方程构成的静电边值问题出发，对驻极体既可对外提供电场又可设计为屏蔽电场的2个相异思维的研究结果展开了讨论，从而，从理论上指出驻极体既可以制成提供均匀外场的材料又可以制成一种透气性静电屏蔽材料．这为驻极体的工程实际应用提供了基础．     

多孔陶粒结晶床除磷试验研究

实验以多孔陶粒为载体，在一定条件下，利用非均相及二次成核作用在陶粒表面沉积一层羟基磷酸钙晶体，从而培养出初级晶种．实验将粒径为1．25mm多孔陶粒与石英砂相对比，结果表明采用多孔陶粒作载体形成结晶体效果较好．用该晶种的连续流固定床除磷，获得令人满意的效果．当原水含磷质量浓度在2～5mg/L范围内时，空床线速不大于2．5m/h，水力停留时间不小千12min时, 脱磷固定床除磷率较高且稳定，磷去除率可达90％以上．     

基于势能平衡的图像骨架抽取算法

基于骨架的基本特征和势能的概念，提出了一种基于势能平衡方式的二值图像骨架抽取算法．将抽取对象的边缘点作为零势能的等势点，计算出处于势能平衡点上的基本骨架点，并据此通过向势能小处延伸的方式构建出骨架，还解决了由于各点周围参考零势能点数量不同而带来的各点势能值间难以比较的问题。通过计算机模拟显示，本算法对于边界噪声影响不太敏感，且在端点处的畸变比最大圆盘方式小。     

内电解法处理工业废水的研究进展

综合近十几年国内外有关内电解法废水处理技术研究文献 ,综述了内电解在理论、实践应用方面的研究现状 .对内电解的反应机理、铁屑改性、助剂和催化剂的选用、内电解处理设备的研制等方面进行了研究 ,并对内电解法在目前研究中存在的问题及今后的研究方向做了进一步探讨     

Technical Breakthroughs in the Construction of TGP

1Introduction　TheThreeGorgesProject(TGP)isavitalbackboneprojectinthedevelopingandharnessingoftheYangtzeRiver.Asamulti purposehydro developmentprojectthatcanproducecomprehensivebenefitsmainlyinfloodcontrol,powergenerationandnavigationimprovement,TGPwillexertasignificantimpactonthenationalsocio economicdevelopmentofChinaafteritscompletion .Withthenormalpoollevel (NPL)at1 75m ,thereservoirhasatotalstoragecapacityof39 3billionm3 .Theprojectiscom posedofadam ,twopowerplantsandnavigationfacil…     

蚂蚁算法在公交查询最短路径求法中的应用

公交乘客出行路径选择是公交乘客信息系统的关键技术 ,提出以换乘次数最少为首要目标、出行距离最短为第二目标的算法 ,本算法是基于广度优先搜索并结合蚂蚁算法提出公交路线最短路径选择的新算法     

Identification of antiviral- relevant genes in the cultured fish cells induced by UV-inactivated virus

~~Identification of antiviral- relevant genes in the cultured fish cells induced by UV-inactivated virus~~     

^210Pbex depth distribution in soil and calibration models for assessment of soil erosion rates from ^210Pbex measurements

Throughout the past decade, the potential for using nuclear weapon-produced 137Cs ( half-life 30.2 a) fallout to quantify soil erosion rates on both cultivated and uncul- tivated lands for medium-term timescales (≈ 40 a) has been successfully demonstrated in a wide range of envi- ronments in different regions of the world[1—6]. Because in difficulties of distinguishing Chernobyl-derived compo- nent from total 137Cs input in many parts of Europe, and in measuring low activity samples of…     

Inorganic chemical composition and source signature of PM2.5 in Beijing during ACE-Asia period

Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 Ilg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 μg/m^3, respectively.These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.     

Mechanical Studies on Treatment of Malignant Tumour by Ultralow Frequency Pulsed-Gradient Magnetic Fields

Ultralow frequency (ULF) pulsed-gradient magnetic field (with the maximum intensity of 0.6-2.0 T, gradient of 10-100 T·m-1, pulse width of 20-200 ms and frequency of 0. 16-1. 34 Hz) treatment of mice can inhibit murine malignant tumour growth and can induce apoptosis of cancer cell. The apoptotic cancer cell contracted, became rounder and divorced from adjacent cells; the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane; the endoplasmic reticulums expanded and fused with the cellular membrane; many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma. By Lorentz force the magnetic field keeps the moving ions within bounds of Larmor radius. Thus, penetrating capability of the positive and negative ions through the cell membrane was affected, even the role on the cell membrane formed.