北京春玉米生产经营现状分析——基于9区县的调查

通过对北京地区春玉米生产经营的成本收益等情况进行调研,发现农户生产中面临着规模化水平低、机械化水平低、效益低和种植意愿总体不强等问题。建议通过促进土地规模经营、提高机械化和社会化服务水平等,保护春玉米种植者生产积极性,提高北京地区的春玉米生产能力。     

基于峰谷电价和年费用法进行输水方案的比选

选择合理的输水方案是降低输水工程费用的重要途径,合适的比较方法则是优选方案的前提。该文提出了基于峰谷电价的年费用法作为输水方案的比较方法。在满足输水水量、水压和可靠性的要求下提出不同的输水方案,考虑资金的时间价值、管网的动力费用、峰谷电价、折旧大修费用等因素,计算不同输水方案的最小年费用值,比较其大小,以此作为输水方案的优选依据。     

转基因棉和常规棉叶片对抗Cry1Ac近等基因系棉铃虫生长发育的影响

利用室内饲喂法,以抗Cry1Ac近等基因系棉铃虫为材料,比较转基因棉花33B和SGK321及其对照亲本DP5415和石远321对抗、感棉铃虫生长发育的影响。结果表明,抗性棉铃虫在取食常规棉叶后表现出一定的适合度代价。取食DP5415和石远321两种常规棉花后,抗性品系棉铃虫的幼虫存活率显著低于敏感品系,取食33B和SGK321两种转基因棉花的抗性棉铃虫,不仅其幼虫存活率显著高于敏感品系,而且致死中时间也比敏感品系延长。取食9天后,抗性品系在常规棉花石远321和DP5415上发育到3龄和4龄幼虫的比例显著低于敏感品系,取食33B和SGK321转基因棉花的抗性品系发育到3龄幼虫的比例均显著高于敏感品系。抗性品系在常规棉上的蛹重均显著低于敏感品系,部分取食转基因棉花的抗性品系棉铃虫可以化蛹,而敏感品系不能在转基因棉花上化蛹。     

A method of estimating timeliness costs in forage harvesting illustrated using harvesting systems in Sweden

A method for estimating timeliness costs, depending on dry-matter yield and nutritive value of forage is presented, and used to estimate timeliness costs, to examine different harvesting systems and to present conclusions on machinery selection when harvesting silage for dairy cows in Sweden. Timeliness costs (in € ha⁻¹ d⁻¹) of forage for silage were significantly higher for the first cut compared with the second or third cuts in the season. It is, therefore, important to avoid delaying the first cut. The timeliness costs also varied greatly between years. Harvesting costs decreased with increasing forage area up to a certain threshold area beyond which decreasing machinery costs were outweighed by increasing timeliness costs due to a longer duration of harvest. At increasing transport distances, the difference in cost between different harvesting systems and different sizes of machinery increased. Harvesting of forage by contractors decreased harvesting costs, particularly for small forage areas, since increased annual use of the machinery lowered the machinery costs and enabled larger machines with higher capacity to be used. To avoid high timeliness costs it is important to avoid delays in harvesting.     

平衡根系无纺布容器苗造林试验

对应用平衡根系无纺布容器苗、塑料袋容器苗、蘸泥浆苗和裸根苗(对照)造林的8个树种的成活率、栽植初期生长量进行了分析,并比较了采用不同类型苗木造林时侧柏苗的造林成本。结果表明:应用无纺布容器苗、塑料袋容器苗、蘸泥浆苗造林的8个树种的平均成活率较裸根苗造林提高151.9%~522.8%,栽植当年平均新梢生长量提高325.0%~1475.0%;应用平衡根系无纺布容器苗(侧柏)与塑料袋容器苗(侧柏)的造林成本相当,比裸根苗降低30.5%~32.1%,蘸泥浆苗与裸根苗的造林成本基本相当。应用平衡根系无纺布容器苗造林,不仅造林成活率高,在造林初期苗木的新梢生长量大,生长状况良好,其造林成本也较低。     

强化七大管理,助力森工集团提质降本增效

对于集团企业而言,加强管理是企业永恒的主题。综合管理的欠缺,不仅会激化企业的内部矛盾,还会使企业的发展方向产生偏离。有效的管理,可以充分调动职工的积极性,提高企业的竞争能力,引导企业向更好更强的方向发展。     

Economics of wastelands afforestation in India,a review

India has vast tracts of wastelands. Afforestation of these wastelands is one of the many alternative uses of such lands. Given the scarcity of capital in India, it becomes imperative to determine the economics and financial feasibility of wastelands afforestation projects. The studies reviewed in this paper deal with cost and financial feasibility analysis of wastelands afforestation projects in India. The main rationale behind this review is to examine the prospects of increasing investments in the afforestation projects. This also has a global significance, since afforestation augments carbon sequestration, which has become an exigency in view of externalities associated with global warming. The study uses review of existing literature and regression analysis as analytical tools. The review reveals that reclamation of wastelands through afforestation is not an expensive venture in India. Afforestation projects are financially viable even when no environmental benefits are taken into consideration. The results of the study suggest that polluting companies/countries should explore the possibility of investing in afforestation in India to gain carbon credits economically, once the parties to the Kyoto Protocol to the United Nations Framework Convention on Climate Change decide to approve it. The studies reviewed reveal that researchers have used different sets of criteria for financial feasibility analysis of the afforestation projects. Almost all the studies have ignored non-market benefits of afforestation projects. Such methodological differences need to be addressed in view of the increasing importance of plantations as carbon sinks. Some socioeconomic issues like investment in tree crops vis-à-vis agricultural crops, preference for mixed plantation and wastelands development as a means of resource development have also emerged from this review.     

不同线路方案运材车速度及耗油量的比较

林道工程师早就知道如何估算运材道路的建筑费用,但在道路建成之前,却无法很好地预估道路建成之后的车辆运营费。本文阐述了如何在线路方案比较中,考虑运营费的两个主要部份——运行时间及燃油消耗。文中数据是作者在留学新西兰期间的实测数据,但所阐述的基本方法则是任何国家都可采用的。     

伦敦海事仲裁中的费用担保制度

费用担保制度在伦敦海事仲裁中是一项用于维护可能胜诉的被请求人利益的十分重要的制度.1996年英国仲裁法顺应国际商事仲裁的发展趋势,对费用担保制度作出了重要的改革:取消了英国法院命令费用担保的权力,并将此项权力赋予仲裁庭.这无疑有利于促进伦敦海事仲裁中费用担保制度的高效运作,也更符合仲裁的本质和目的.     

高等教育人才培养成本核算的意义及体系的探讨

对高等教育人才培养成本的内涵进行了深刻的阐述，并得出了两个方面的初步结论：（1）高等教育人才培养成本是受教育者接受高等教育服务而耗费的资源价值；（2）在理论上人们对高等教育人才培养成本的含义和计量已基本达成共识，但实际的计量工作却不尽人意。为此开展高等教育人才培养成本核算意义重要，结合当前高校会计制度核算体系中的基本方法，对开展高等教育人才培养成本核算应遵循的原则、核算的主体、核算的对象、核算的期间、核算的项目、核算的程序及方法进行阐述，探讨出了高等教育人才培养成本核算的体系和具体方法。