镉胁迫对矮生四季豆种子萌发和幼苗生长发育的影响   总被引：3，自引：0，他引：3  

金海燕  奚涛  时唯伟  戢太云  邢海波  支月娥  姜华  周培 《中国农学通报》2009,25(1):119-124

以水培法研究了不同浓度的Cd2＋溶液对四季豆种子萌发和幼苗生长发育的影响。结果表明：当Cd2＋浓度较低时,Cd2＋对种子萌发及幼苗生长发育毒害作用较小,一定浓度范围内（0.05～0.5mg/L）还有促生作用,高浓度Cd2＋(5～100mg/L)能严重抑制四季豆幼苗根及下胚轴的生长;Cd2＋胁迫对四季豆幼苗体内过氧化物酶 (POD),超氧化物歧化酶（SOD）,过氧化氢酶（CAT）活性存在低浓度激活和高浓度抑制的效应,且同一浓度的Cd2＋对四季豆幼苗POD、CAT活性的抑制作用表现为根系大于下胚轴,Cd2＋浓度＞0.5mg/L时,根系SOD活性大于下胚轴中的活性;Cd2＋胁迫下,四季豆下胚轴和根的丙二醛（MDA）含量增加,且根部含量大于下胚轴的量。  相似文献   

Experimental Analysis for Steel Box Concrete Composite Beam of Arch Bridge   总被引：2，自引：0，他引：2  

FAN Liang  ZHOU Zhi xiang 《保鲜与加工》2009,(6):15-21

A new steel concrete composite structure was proposed which composed of steel box beam, PC beam and PBH Shear connection. Bend test was carried out for the performance study of deformation and stress. It was found that Material advantages of steel and concrete were fully used and crack of concrete and local instability of steel box were avoided. And the deformation between steel box and concrete can be smoothed with PBH shear connection. As the calculated values showed good agreements with the test results, the proposed formulas can be reliably applied to the practice analysis. With the different parameters analysis, mechanic performance of the composite was obtained.  相似文献   

Energy delivery model for implanted devices     

TANG Zhi de  XIE Di  FENG Li xiao  WU Ming peng 《保鲜与加工》2009,(7):823-828

FEMlab3.3(Finite Element Model Lab) is used to develop an energy delivery model for implanted devices. We designed three different shape electrodes made of Ag to enhance current transmitting efficiency. Several voltages were used for pursuing perfect goal. With the body safety current, we can get the results with a current transmitting efficiency of 20% and the energy delivery efficiency of 4%~9%. It is clear that the high energy delivery efficiency can be obtained and the results provide references for further study of energy delivery through body conduction.  相似文献   

Factors influencing activation of wet fly ash     

WU Chuan-ming  HOU Peng-kun  WANG Ke-jin  WANG Zhi  LUO Hui 《保鲜与加工》2009,(6):643-647

To use fly ash, it is necessary to understand its activity variation under different wet conditions. Four low-calcium wet fly ash preparations are simulated in the laboratory. Fly ash activity is indicated by measuring specific compressive stre  相似文献   

Effective working areas of the electro hydraulic power impulse     

LIAO Zhen fang  PAN Zhi min  WANG Zhao hui  CAI Zhen hong 《保鲜与加工》2009,(10):1122-1125

In order to ascertain the numbers of the electrodes (treatment for the sewage) and forecast the grain size property of the cracked mineral, based on the hypothesis of the equivalent effective volumes of one discharge of electro hydraulic power impulse technology, the formulas are worked out for computing the effective working areas of the two common working modes. The theoretic analysis and the results of the experiments of the treatment of bacillus coil liquid and crushing of quartz ceramic show that the results conform to the formulas relatively, and the precision of the calculated data has relations with the polluted degree of the sewage, the intensity, elasticity and dimension of the solid material, and the formulas for computing the effective working areas are feasible.  相似文献   

Analysis of the distorted scaling factor in wind tunnel modeling of power transmission line system     

WANG Zhi song  SUN Bo  LI Zheng liang  XIAO Zheng zhi 《保鲜与加工》2009,(11):1328-1333

Because of the limitation of the model making and the existing wind tunnel’s size, it is difficult to keep the line and tower in the same scaling factor in developing the aeroelastic model of the power transmission lines system, and a distorted scaling factor is needed in span length of the lines. With the instance of a 1 000 kV two circuit power transmission lines, the finite element analysis under the along wind load in time history is conducted with keeping the tower in the same and the line scaling factor being 1, 0.5 and 0.25 respectively. The results show that the response of the power transmission lines systems keep in the same, and then the wind induced vibration of the distorted model in the wind tunnel test can actually reflect the response of the power transmission lines system under the wind load.  相似文献   

Fast algorithm for apparent resistivity calculation based on back propagation neural networks   总被引：1，自引：1，他引：0  

XIE Pin fang  XIE Lin tao  FU Zhi hong  ZHANG Huai qing 《保鲜与加工》2009,(9):1111-1116

To avoid the complex numerical calculation for the electromagnetic field and determine underground abnormality, a neural network based method is proposed. In consideration of turn off transmitter current, the effect of a linear ramp turn off current on transmitter is corrected. The characteristics of transient expression and the traditional calculation algorithm for apparent resistivity are analyzed, and a predigest structure of network is obtained based on the kernel expression. The three layer back propagation(BP) neural network is trained by using sample data in homogeneous half space, and its number in hidden layer was determined. The method proposed is compared with two traditional calculation methods with simulation experiments. The result demonstrates that BP neural network has a high speed of processing data and is useful in explanation of the transient electromagnetic method.  相似文献   

面粉品质及组分对小麦淀粉和谷朊粉分离效果的影响     

郑学玲  李利民  孙志 《农产品加工．学刊》2009,(3)

对小麦淀粉和谷朊粉的生产方法,即面团水洗法和离心分离法进行了概述;论述淀粉与谷朊粉分离对面粉品质的要求,以及面粉主要组分(蛋白质、淀粉、非淀粉多糖、脂类)对小麦淀粉和谷朊粉分离效果的影响。  相似文献   

食品科学与工程专业导论课程的构建与实践   总被引：1，自引：0，他引：1  

姜松  崔恒林  朱帜  刘杏荣  曲云进  董英  马海乐  赵杰文 《农产品加工．学刊》2009,(8):84-87

通过开设专业导论课,探索大学新生中普遍存在的学习动力不足和学习适应困难问题的解决途径。分析了专业导论课的现状和开设课程的目的、意义,构建了食品专业导论课的课程体系,并对教师选择、教学方式、教学重点、重点内容剖析方法、课程定位、教材建设等教学实践中的关键问题作了分析总结,提出了18个字"是什么、学什么、为什么、怎么样、怎样学、干什么"(关键是9个字"学什么,为什么,怎样学")教学的基本思路。  相似文献   

小议当前城市工厂庭院绿化     

葛红英  余长新  施义香  王欢欢 《林业科技情报》2009,41(4):46-48

城市工厂庭院绿化是城市园林绿化的重要组成部分。当前虽受金融危机的影响,各工矿企业家必须从全局出发,结合工厂绿化特殊性的特点着手抓好园林绿化的总体规划,重视厂区绿化建设,特别是因地制宜地做好防护林带的建设,科学选好绿化树种。  相似文献