Herbicide activity of monosulfuron and its mode of action

Monosulfuron was developed for weed control in the field of wheat( Triticum, aestivum L.) and millet( Panicum miliaceum L.)with the application rate ranging from 15 to 60 g ai/hm^2 . Herbicidal.activity of monosulfuron was evaluated systematically by bioassay using maize( Zea mays L. ) taproot as indicator and weed fresh weight of Acalypha australis L. and Echinochloa phyllopogon. Maize CAU 3138 was the most tolerant cultivars to monosulfuron with IC50 (concentration of .50% inhibition) of 8.5μg/kg, Yedan 13 was one of the most sensitive cultivars to monosulfuron with IC50 of 6.4 μg/kg. Monosulfuron inhibited the growth of Acalypha australis L. strongly comparing with that of Echinochloa phyllopogon. Monosulfuron was a good acetolactate synthase(ALS) inhibitor in vitro, the 150 (50% of inhibition) of monosulfuron, chlorsulfuron, tdbenuron-methyl and nicosulfuron for CAU 3138 were 32, 2, 19 and 26 nmol/L respectively, for Yedan 13 the /50 were 1.5, 3, 17 and 6.5 nmol/L respectively. In vivo ALS inhibition occurred only in higher concentration of 4 sulfonylurea herbicide tested. Comparison study of this test indicated that the mode of action of monosulfuron was the same as that of other sulfonylurea herbicides such as chlorsulfuron, tribenuron-methyl and nicosulfuron, they were all inhibitors targeted at the ALS.     

两种菠菜累积硝酸盐特性差异的研究

水培试验结果表明,日本超能菠菜生长后期的生长量较大,硝酸盐累积量较低,氮素吸收量较少,可以肯定其优良性;在生长后期供给等量硝、铵态氮的条件下,日本超能菠菜吸收硝态氮较少,还原硝酸盐的相对能力又较高,因而累积硝酸盐较宁夏圆叶菠菜低;在仅供给铵态氮源的条件下,日本超能菠菜还原硝酸盐能力较小,可能与其易于吸收和利用铵态氮源有关。     

泥石流滩地的开发利用对流域环境的影响—以云南蒋家沟为例

泥石流滩地是泥石流地区地势平坦、水热条件较好的土地资源,对它的开发利用有助于改善泥石流地区的环境状况,本文在野外调查并结合航片的基础上,分析了滩地利用现状、利用可行性并比较滩地利用与上人类活动对环境的影响。     

3种菌剂对小麦秸秆好氧堆肥降解效果比较

为探讨不同菌剂接种对小麦秸秆好氧堆肥一次发酵阶段的处理效果,选用3种商业菌剂QD、DH和VT,并以厨余垃圾作为调节剂,进行了好氧堆肥发酵实验.通过研究堆肥过程中物料的温度、含水率、浸提液理化性质、挥发份固体(VS)含量和C/N比的变化情况,比较了3种菌剂对小麦秸秆好氧堆肥降解效果的影响.结果表明,QD、DH和VT处理下...     

大连北三市土地利用景观格局及其生态环境效应

以大连市北部的县级市瓦房店市、普兰店市和庄河市为研究区,引用2005年土地利用矢量数据,选用生态意义较明确的景观特征指数,对大连北三市土地利用景观格局及其生态环境效应进行比较分析。揭示土地利用景观格局对生态环境的影响。     

中小城市中学师生环保意识调查——以湖南省永州市为例

公众的环保意识对国家环境保护政策的制定与实施具有重要影响。最大限度地促进公众参与环保与和谐社会的创建,能有力地推进整个社会环保工作的开展。中学师生作为公众的关键性窗口群体,其环保意识的强弱直接关系到该地区或国家的民众环保意识、公众参与环保水平及未来环境可持续发展状况。本文通过对湖南省永州市城区中学师生环保意识随机抽样调查,分析了师生的环保意识水平。总体来看,大多数师生具备必要的环境知识,但其中相当一部分环境意识比较薄弱,而环保行为更是普遍不足,因此加强在校学生的环境教育和培养在职教师自身环保素质尤显重要。并提出相应的建议。     

铁改性生物炭的制备及其在重金属污染土壤修复技术中的应用进展

生物炭已被广泛应用于修复重金属污染土壤,但粒径大、力学性能差、吸附点位较少等缺点限制了其应用。由铁基化合物和生物炭制备的铁改性生物炭,可优化生物炭的性能,弥补生物炭修复能力的不足,表现出良好的重金属钝化效果。综述了铁改性生物炭的制备方法,以及该材料对重金属污染土壤修复的研究进展：介绍了铁改性生物炭的制备方法和常用表征手段;总结了制备及修复过程中的主要影响因素 (原材料、温度、投加量、修复时间等) ;从静电作用、离子交换、络合、氧化还原、共沉淀作用等方面阐明了铁改性生物炭对重金属的固定化机制;分析了施用铁改性生物炭对土壤微生态的影响;最后指出了铁改性生物炭材料在应用中可能存在的问题。以期为铁改性生物炭在重金属污染土壤修复中的应用提供理论依据。     

玉米乙酰乳酸合成酶活性的测定及其性质初探

为了解抑制剂对乙酰乳酸合成酶 (ALS)的作用机制 ,建立生理生化水平上 ALS酶抑制剂的筛选方法。详细研究了玉米离体和活体乙酰乳酸合成酶 (AL S)活性的测定方法。对酶反应条件的研究表明 ,底物丙酮酸钠的浓度和辅助因子氯化硫胺素焦磷酸盐 (TPP)、黄素腺嘌呤二核苷酸 (FAD)以及氯化镁 (Mg Cl2 )的浓度在一定范围内对酶的反应有影响 ,温度和酸度也是影响该酶反应的重要因素 ;对酶反应产物显色反应的研究发现 ,α-萘酚和肌酸单钠盐共同协调影响显色反应的进行。玉米 AL S酶的比活力与反应时间呈线性关系 ,符合 Michaelis- Meten方程。烟嘧磺隆是玉米 ALS酶的非竞争性抑制剂 ,农大 1 0 8玉米 ALS的 Km为 (7.51± 1 .0 0 ) mmol· L- 1 。     

Maintenance-related major accidents: Classification of causes and case study

The potential for major accidents is inherent in most industries that handle or store hazardous substances, for e.g. the hydrocarbon and chemical process industries. Several major accidents have been experienced over the past three decades. Flixborough Disaster (1974), Seveso Disaster (1976), Alexander Kielland Disaster (1980), Bhopal Gas Tragedy (1984), Sandoz Chemical Spill (1986), Piper Alpha Disaster (1988), Philips 66 Disaster (1989), Esso Longford Gas Explosion (1998), Texas City Refinery Explosion (2005), and most recently the Macondo Blowout (2010) are a few examples of accidents with devastating consequences.Causes are being exposed over time, but in recent years maintenance influence tends to be given less attention. However, given that some major accidents are maintenance-related, we intend to concentrate on classifying them to give a better insight into the underlying and contributing causes.High degree of technological and organizational complexity are attributes of these industries, and in order to control the risk, it is common to deploy multiple and independent safety barriers whose integrity cannot be maintained without adequate level of maintenance. However, maintenance may have a negative effect on barrier performance if the execution is incorrect, insufficient, delayed, or excessive. Maintenance can also be the triggering event.The objectives of this article are: (1) To investigate how maintenance impacts the occurrence of major accidents, and (2) To develop classification schemes for causes of maintenance-related major accidents.The paper builds primarily on model-based and empirical approaches, the latter being applied to reports on accident investigation and analysis. Based on this, the Work and Accident Process (WAP) classification scheme was proposed in the paper.     

电动轮矿用车变流器典型装配结构螺栓紧固扭矩衰减研究

本文针对矿用车变流器典型装配结构进行螺栓紧固扭矩衰减特性研究,得出关键结构螺栓紧固扭矩衰减率。基于VDI 2230采用衰减后的扭矩值对功率模块紧固螺栓进行可靠性校核,最后通过工装振动试验验证其适用性。研究成果对电动轮矿用车变流器的紧固螺栓可靠性评估提供了重要的方法。