不同栽培密度对秋大棚黄瓜生育期及产量的影响

试验以黄瓜为材料,采用随机区组设计,研究了不同栽培密度对秋大棚黄瓜生育期及产量的影响。结果表明,当栽培密度为4000株/667m2时,产量和产值都达到最高。     

Long-term variation in brown trout, Salmo trutta L., stocking success in a large lake: interplay between availability of suitable prey and size at release

Abstract –  Factors affecting long-term variation in brown trout, Salmo trutta L., stocking success were examined in a large lake, Lake Oulujärvi, in central Finland. Brown trout were stocked in spring (late May to early June) in 1974–1991 and in summer (late June to early July) in 1992–2001. The biomass of the vendace, Coregonus albula (L.), population (prey) at release time had the largest positive effect on stocking success within both periods: biomass of adult vendace in spring and both 0+ and adult vendace in summer. Increasing the size of stocked fish had a positive effect if the vendace available at release were only adults. The increasing trend of predator-catch-per-unit-effort (CPUE) [combined CPUE of northern pike Esox lucius L., burbot Lota lota (L.), and pike-perch Stizostedion lucioperca (L.)] through the study period and its negative effect on trout stocking success suggested an increasing effect of predation within the entire time series.     

放牧系统的稳定性与载畜量的研究

本文研究了具有不同消费函数的放牧系统的稳定性,并确定出相应的系统的安全容纳量和最大容纳量。本文中有些结论改进并推广了Noy—Mcir于1976年得到的关于载畜量的有关结论。     

农村基层信访工作在社会危机管理中的效用研究

信访工作是党和政府联系群众的桥梁与纽带,是维护和实现群众民主权利的重要手段。随着农村经济的迅猛发展和农村改革的不断深化,给农村社会经济生活和人们的利益关系带来极大的变动,所引发的群众来信来访事件有所上升,有些过激行为和群体性事件对社会发展造成极其恶劣的影响。做好农村基层的信访工作,在社会危机管理中将发挥重大效用。     

网络时代高校思想政治教育的实效性探析

网络时代是一个信息资源丰富的新时期,它开阔了我们的眼界,拓展了我们的知识面,网络信息的发展促进了当今思想文化的新变化.而青年大学生作为利用网络的主群体,它必然会给大学生的思想道德、价值观念带来一定的影响,因此,网络时代的到来给高校思想政治教育带来了机遇和挑战.本文从网络时代的特点出发,探索性地分析了提高高校思想政治教育实效性的新途径.     

板栗低产林嫁接换冠成效的初步研究

对嫁接换冠技术在寿宁县清源乡龟洋茶场板栗果园上的应用效果进行了调查，结果表明：对投产的低产劣种板栗进行嫁接换冠，改劣换优，可保持板栗品种的优良特性，使低产劣种板栗树嫁接换冠后的第3年，95％的板栗均可挂果投产，总产量增长幅度达8．265倍；挂果株数提高了3．8倍，良种挂果株数提高了4．75倍，平均单价提高了3．7元/kg ，总产值提高了13．83倍，经济效益十分显著。     

陆良县农业生产防灾抗灾对策研究

陆良县是一个农业大县，近年来干旱、低温、霜冻、病虫害等农业灾害多发、濒发，对农业生产造成极大的危害和影响。总结该县采取的一些农业生产防灾抗灾做法及取得的成效，分析防灾抗灾中存在的问题，探讨进一步做好防灾减灾的对策措施。     

基于热力学定律的太阳能利用探究

本文对太阳能的起源、传播、与物质的相互作用以及储存和利用等各个方面所涉及的物理学定律,特别是对太阳能热利用所涉及的热力学定律进行了概括和归纳。根据热力学定律指出太阳能热利用的真正适用范围。     

Calculation of Maintenance Cost Based on the Proportional Life Setback Model

Maintenance cost is one of the most difficult parts to calculate in variant-cost, for it s decided by the reliability of components. As an important factor of reliability, life is largely affected by maintenance. The proportional life prolonged model based on maintenance is presented firsdy. Based on this model, the function of Mainenance--Life--Cost is deduced. Which provides a new method for power plant to calculate maintenance cost more accurately.     

Synthetic Evaluation of Talent Effectiveness Considering Talent Structure

Based on the widening of definition of talent effectiveness, using the indexes of talent structure and economic output types, many indexes of talent effectiveness are built up. A synthetic evaluation of regional talent utilization efficiency is presented based on principal components analyses. The result indicates that the talent utilization efficiency in east China is higher distinctly than in middle and west China and the talent utilization efficiency in middle is close to in west China without obvious hierarchy distribution