枸杞果实发育模式及营养物含量变化研究

通过对枸杞果实发育过程中果实生长模式、碳水化合物、有机酸、Vc、可溶性蛋白质、多糖、类胡萝卜素含量的测定，系统分析它们在果实整个生长发育过程中的动态变化。结果表明枸杞果实发育呈双“S”曲线；可溶性总糖、还原糖含量生长前期变化不明显，近成熟时迅速积累至最高；淀粉含量前期积累，后期降低。成熟时果实中不含淀粉；总酸含量呈现先升高后降低的变化趋势；Vc含量变化总体上呈先升高后降低的变化趋势；果实在发育前期可溶性蛋白质含量较低。随后升高。至花后27d达最高峰，以后逐渐减少；多糖、类胡萝卜素含量在发育前期较低，于花后27d迅速增加，到成熟时达最大值。     

氮素对辣椒产量和硝酸盐积累的影响

在施等量有机肥的前提下,随着施氮量的增加,辣椒营养生长旺盛,株高株幅增加;辣椒产量在一定范围的施氮量内逐步增加,超过一定施氮量反而下降;随着施氮量的增加,辣椒果实和叶片的硝酸盐含量均随之上升,其中以叶片中积累量最高,其次是果皮,果肉中硝酸盐的含量最低;各处理对辣椒亚硝酸盐的积累没有影响。     

温度对斯氏伞锥象生长发育速度的影响

在17、20、24、28和32℃条件下，研究温度对防治柽柳的植食性昆虫斯氏伞锥象发育历期的影响。用线性方程拟合了斯氏伞锥象发育速率与温度间的关系式。用直线回归法计算出卵、幼虫、预蛹、蛹、产卵前期成虫及全世代的发育起点温度，依次为13．48、12．48、10．32、13．28、8．71和11．44℃，有效积温依次为：46．52、121．52、31．70、62．17、186．19和445．78日度。并推算出斯氏伞锥象理论年发生代数为3．24代。     

青海河湟地区水资源综合开发与区域经济发展研究

本文分析了河湟地区水资源特征、开发利用现状及存在的问题,在此基础上,论述了河湟地区水资源开发利用与区域经济发展模式。研究表明:加快开发黄河水能资源,建立以水能资源开采业为主导的产业群发展;浅山地区因地制宜推广雨水集流利用工程,走出“水窑+科技+节水产业+生态”的发展模式;“引大济湟”工程有助于提高水资源可利用量,推进湟水流域全面发展。     

杂交狼尾草生育特性研究

研究了杭州生态条件下移栽杂交狼尾草的生育特性,试验表明,杂交狼尾草平均每叶展开需积温前３叶为７５．９℃、９叶至２０叶为６２．３℃;４叶１心开始分蘖;单株干物质积累高峰期出现地拔节后,茎叶粗蛋白含量随生育期而下降;重施拔节肥是高产优质的关键,根茎安全越冬应保持地温在１０℃以上。     

Enhancement in Nutrient Accumulation and Growth of Oil Palm Seedlings Caused by PGPR Under Field Nursery Conditions

Abstract

Plant growth promoting rhizobacteria (PGPR) (e.g., Azospirillum and Bacillus spp.) have been reported to enhance growth and fix N₂ with several nonleguminous crops. These rhizobacteria have the potential to be applied to oil palm seedlings and, consequently, reduce the cost of nitrogenous fertilizer. The rhizobacteria are also known as a bioenhancer for the ability to increase root growth and enhanced water and nutrient absorption by the host plants. An experiment was carried out in the field nursery station, Federal Land Development Authorities (FELDA), Bukit Mendi, Pahang, Malaysia, to observe the effects of PGPR inoculation on enhanced nutrient accumulation and plant growth (tops and roots) of oil palm seedlings under field nursery conditions. The inoculation process showed positive response in enhancing higher accumulation of nitrogen (N), phosphorus (P), and potassium (K) in the plant tissues, enhanced root dry weight and top growth (dry matter and leaf chlorophyll content) of the host plants under field nursery conditions.     

家用生物质气化炉市场现状与技术发展

生物质能是很好的替代能源,因而生物质气化技术的开发利用及相关设备的研制得到许多国家和企业的重视.近几年,我国生物质气化技术开发利用与推广力度较大,特别是家用生物质气化炉涌向农村市场.但现用户对家用生物质气化炉产品褒贬不一,技术推广的难点是燃气热值低、焦油含量高以及使用操作繁杂.因此,发展家用生物质气化炉要正确宣传引导、加强技术培训,特别是要开发产气稳定、燃料利用率高、结构简单、操作方便、价格低廉且使用安全可靠的产品.     

Duration of load effects of solid wood: A review of methods and models

Abstract

Test methods for studying the effect of long-term loading on the load-carrying capacity of structural wood are discussed. The impact of sampling procedures on test results is investigated and is exemplified. It is concluded from this investigation that the sampling method has a significant impact on the test results. A number of mathematical models for estimation of the effect of load duration are also presented and brief outlines of the theoretical background for five categories of models are given. No attempt is made to compare the models in order to nominate the best model. Effort is, however, made to illustrate the futility of calibrating models against one type of test when the model is redundant to the test type.     

家用生物质气化炉市场现状与技术发展

生物质能是很好的替代能源，因而生物质气化技术的开发利用及相关设备的研制得到许多国家和企业的重视。近几年，我国生物质气化技术开发利用与推广力度较大，特别是家用生物质气化炉涌向农村市场。但现用户对家用生物质气化炉产品褒贬不一，技术推广的难点是燃气热值低、焦油含量高以及使用操作繁杂。因此，发展家用生物质气化炉要正确宣传引导、加强技术培训，特别是要开发产气稳定、燃料利用率高、结构简单、操作方便、价格低廉且使用安全可靠的产品。     

Bioaccumulation of cadmium and its biochemical effect on selected tissues of the catfish (<Emphasis Type="Italic">Clarias gariepinus</Emphasis>)

The present study examines the pattern of accumulation of cadmium (Cd) and its biochemical effects on selected tissues of a variety of African catfish (Clarias gariepinus), after exposure to various doses of Cd. The results obtained indicate that at the end of 21 days of exposure, the total tissue organ cadmium concentration followed the pattern kidney > gill > liver > muscle for each of the exposure concentrations. The levels of Cd in these organs were higher than those in ambient water. Moreover, while the rate of uptake of Cd increased with time in the kidney, liver and muscle, it decreased in the gill. Superoxide dismutase (SOD) was significantly elevated only in the kidney of catfish treated with 0.2 and 0.4 ppm of Cd for 7 days compared with the control. Conversely, gill SOD was significantly decreased in the same concentrations of Cd-treated catfish relative to the control. Statistically similar levels of SOD were observed in the liver, brain and muscle with all the treatments after the same duration of treatment. In the fish exposed for 21 days, SOD activity was significantly decreased in the kidney with a corresponding increase in lipid peroxidation (LPO), but it manifested only with the 0.2- and 0.4-ppm Cd treatment relative to the control. In the liver, however, Cd exposure significantly increased SOD in the 0.2- and 0.4-ppm treatments of the same duration. In conclusion, the present study indicates that the accumulation of Cd and its effect on SOD and LPO in C. gariepinus is dependent on concentration, tissue and time