植物激素对刺五加离体繁殖的影响

选用刺五加枝条茎尖为实验材料,研究激素对刺五加愈伤组织继代培养、不定芽发生及生根的影响。结果表明:培养基中激素配比对刺五加愈伤组织的分化和诱导生根有很大影响。刺五加组织培养最佳初分化培养基为MS+6-BA1.0mgL+KT1.0mg/L+NAA0.15mg/L,继代分化培养基为MS+NAA3.0mg/L+6-BA2.0mg/L;生根培养基为1/2MS+IBA0.2mg/L。刺五加愈伤组织再分化能力主要受外植体类型及愈伤组织继代保存时间长短的影响较大。     

澜湄流域跨境航运的多层次网络治理机制

在"一带一路"倡议大背景下,澜湄合作机制将"互联互通"纳入五大优先合作方向,对澜沧江-湄公河流域的跨境航运治理提出了新要求。随着全球化、信息化和区域一体化的发展,流域内的单一科层治理、市场治理传统模式频现失灵,网络化提供了不同的视角与方法。兼具"圈层"和"网络"双重结构特征的多层次网络治理结构,从"政府-市场-社会"3个层面通过科层、市场、网络治理方式共同发力,借鉴莱茵河的成功治理经验,给予涉水企业、民众、NGO、智库、媒体、科研机构等非政府主体更多治理权限,并结合澜湄流域实际情况提出多层次网络治理机制体系建议,以求改善澜湄跨境航运合作困境。     

国外油公司浅层气钻井整体解决方案介绍

浅层气钻井作业属于高风险的高危作业,为了预防浅层气井喷,世界上很多国家的石油公司都制定了有关浅层气钻井的强制标准和作业指导。介绍了国外油公司对浅层气钻井的应对措施和整体解决方案要点,内容涉及浅层气钻井策略要点、风险评估、设计要求、施工措施等方面。     

兵团农业体制对农工专业合作组织发展影响研究

兵团特殊性和独特的农业双层经营体制决定了兵团农工专业合作组织的发展有别于地方农村的农民专业合作组织。那么,区别在哪里,兵团农业双层经营体制对农工专业合作组织发展影响又如何？本文在比较兵团农业双层经营体制与地方农村基本经营制度的基础上,结合兵团农工专业合作组织的发展现状,利用新制度经济学相关理论进行分析研究,得出以下主要结论：在兵团农业双层经营体制下,集体行动的困境是兵团农工合作经济组织发展缓慢以及大多数合作组织停留在专业技术协会层面而无法实现向农工专业合作社转变的组织行为学解释;成员资源禀赋不足及资源禀赋互补性不强对兵团农工专业合作组织的组建和发展影响明显;兵团农场“委托一代理”模式的交易费用的节约效用并不明显;兵团的农业种植结构对农工专业合作组织的发展并不是非常有利。最后提出相应对策建议。     

白杨派杨树组织培养技术研究

研究结果表明:杨树再生的最适外植体为叶片,愈伤组织诱导最佳培养基为MS+6-BA 0.1mg/L+NAA 0.1mg/L愈伤组织诱导率为34.8%;不定芽分化的最佳培养基为MS+6-BA 0.3mg/L+NAA 0.06mg/L,不定芽分化率为44.4%。     

大河煤矿区富煤二矿主采煤层对比方法探讨

文章利用生物化石、岩性、岩相标志,煤层夹矸、顶、底板岩性特征以及煤岩层的组合规律、层间距、测井曲线等组合性标志对富煤二矿含煤地层中煤层进行对比,达到判别煤层层位的效果,对矿区生产及周边矿区的勘探、生产工作具有一定的指导意义。     

Extinction accounting and accountability: Empirical evidence from the west European tissue industry

Recently, human activities are more and more invasive with respect to biodiversity. Several studies highlighted the key role played by accountants in contributing to the development of tools able to support company in assessing, reporting, and disseminating, as well as accomplishing, the preservation of natural species and ecosystems (King and Atkins, 2016). Corporate reporting of environmental information might increase the credibility of forest certifications, given that some scholars argued that certified forests are not often run, in a sustainable way. Moreover, certifications sometimes cover harmful forest practices (Elad, 2014) and do not ensure a good quality of environmental reporting and performance. The research question therefore intends to explore how extinction accounting and accountability (EAA) is able to reflect ex post the company's business strategy and, at the same time, influence ex ante its formulation by easing the prevention of deforestation risk and addressing the issue of credibility through specific actions. In more detail, the “Emancipatory Framework for Extinction Accounting and Accountability” (EFEAA) (Atkins and Maroun, 2018) was tested using content and interpretative analyses based on the reports inherent to top four companies working in West Europe in the tissue industry, where the preservation of forest heritage is a “compulsory route” for assuring the business sustainability, in terms of both raw material renewal and brand reputation. The findings highlighted the first attempt to carry out a qualitative research over the management of forest issues. In our study, companies tend to report advantages arising from the use of forest, but this kind of disclosure is too generic without providing evidence over the ecosystem services forests produce. Moreover, firm size affects the quantity and the quality of disclosure. At last, managerial implications and future research avenues are outlined and discussed.     

深厚层无碾压土石围堰防渗施工技术的研究与应用

作者讲述本人在四川嘉陵江上石盘电航综合枢纽工程施工中,对水下深厚层无碾压土石围堰防渗体系施工技术的研究与成功应用,为类似土石围堰工程防渗施工提供借鉴和成功经验。     

Optimal reinsurance under general law-invariant risk measures

In recent years, general risk measures play an important role in risk management in both finance and insurance industry. As a consequence, there is an increasing number of research on optimal reinsurance decision problems using risk measures beyond the classical expected utility framework. In this paper, we first show that the stop-loss reinsurance is an optimal contract under law-invariant convex risk measures via a new simple geometric argument. A similar approach is then used to tackle the same optimal reinsurance problem under Value at Risk and Conditional Tail Expectation; it is interesting to note that, instead of stop-loss reinsurances, insurance layers serve as the optimal solution. These two results highlight that law-invariant convex risk measure is better and more robust, in the sense that the corresponding optimal reinsurance still provides the protection coverage against extreme loss irrespective to the potential increment of its probability of occurrence, to expected larger claim than Value at Risk and Conditional Tail Expectation which are more commonly used. Several illustrative examples will be provided.     

基于两次平衡计算的南昌市耕作层土壤剥离再利用空间配置研究

研究目的:探讨耕作层土壤剥离再利用空间配置思路与方法,并以南昌市为例进行实证研究,为相关工作提供借鉴。研究方法:提出基于线性规划及OD成本矩阵方法的两次平衡计算的耕作层土壤剥离再利用土方空间配置思路。首先,确定剥离、覆土优先度并结合供求关系划定供需圈,在供需圈内部进行第一次调配平衡;其次,对于内部不能平衡的供需圈,进行第二次跨圈调配平衡,达到缩短运输距离,控制成本目的。研究结果:(1)南昌市耕作层剥离量能够满足覆土数量与质量的需求;(2)空间配置结果共划定18个供需圈,供需圈内土方调配加权平均运输距离为6 682 m,小于期望值10 km,满足项目实施要求;(3)共有15个供需圈存在土方量不平衡问题,跨圈调配的距离平均为72 071 m,满足短距离运输的要求。研究结论:以耕作层土壤剥离、覆土优先度及供求关系为基础划定供需圈,基于线性规划及OD成本矩阵的两次平衡计算的空间配置思路与方法,可以优化运输距离,减少运输成本,提高项目实施效益。本文提出的空间配置思路可以为耕作层剥离再利用工程的顺利实施提供理论与方法借鉴。