The economics of climate change in agriculture

This paper presents a conceptual frameworkof the impact of climate change onagriculture. It assumes that climatechange will result in a fertilizationeffect and a shift of agro-ecologicalconditions away from the Equator towardsthe Poles. The agro-ecological shift islikely to reduce yield because of reducedacreage and the fertilization effect willincrease yield. The aggregate effectdepends on whichever of the two dominates. The overall effect of climate change may beless significant than its distributionaleffects and the results are consistentwith previous empirical studies. Theimpact of climate change depends on itspace. Faster changes in climate willresult in higher cost. The assessment ofthe cost has to consider that climatechange is a dynamic phenomenon that mayrequire continuous adjustment. Environmental regulation that emphasizesconservation may increase cost ofadjustment and environmental policiesshould emphasize adaptation andflexibility.     

某石化企业粉体料仓爆燃事故原因分析

本文以某企业HDPE料仓的一次爆燃事故为案例,通过分析事故的成因,提供了调查料仓事故的思路及整改方案的确定方法.     

温度对氨法脱硫率影响的实验研究

对使用氨（NH3）脱除烟气中气态污染物的技术进行了分析和总结，认为氨洗涤法洗涤净化烟气是一种很有前景的方法，并就温度对SO2脱除率的影响进行了实验研究。实验研究结果显示，当温度超过54℃时，NH3对SO2仍有很高的脱除率。并根据实验结果建议，在实际氨法脱硫工程中，脱硫过程温度宜控制在60℃以下或在80℃以上。     

Vegetation patterns and nature reserve construction in an extremely-arid desert in Anxi,NW China's Gansu Province

Anxi County is located in the northwestern part of the Hexi Corridor in gansu Province and has the sole national level nature reserve of extremely-arid desert in China.Phytosociological methods (Braun-Blanquet,1964) are used to classify plant community types in this area.Eleven are disting uished,including six of deserts,four of oases and one transitional type between deserts and oases.Direct gradient analysis (DCA) is employed to correlate the distribution of plant communities to physiogeographic conditions.This study makes clear that water is the most important ecological factor for the distribution of plant species and communities in this area.The effects of water have been demonstrated in different ways.A vegetation gradient from lower altitude to higher altitude in the southern part of the reserve is driven by a precipitation gradient.The effects of the depth of ground water table contribute to the differentiation of vegetation from desert to oasis in the flat area.In a finer scale,the washed gullies have obviously higher species richness and also higher vegetation cover than the surround gobi surfaces,possibly caused by the effects of floods.The vegetation patterns demonstrate that the area of Anxi County is a complete landscape unit.The range of the current nature reserve is not large enough for the purpose of conserving the unique biodiversity in this area.     

区域(城市)水体中主要有机毒物的筛选

本研究发展了区域(或城市)水体中主要有毒化学品的筛选方法。 在城市下游采集大体积水样,用CH_2Cl_2洗脱,再用有机溶剂萃取,用硅胶柱把有机物分成许多馏分,馏分最终变为水溶液。每个馏分中有机物浓度比原水大1000倍。用这种馏分水溶液进行溞的急性毒性试验和Ames试验。只对毒性大的馏分进行色谱/质谱/数据系统的鉴定和定量分析,然后根据各个化合物的急性毒性、降解难易和“三致”物质的资料及原水样中有机物的浓度资料,就可筛选出一个区域(城市)水体中的主要有毒化学品。     

危险废物安全填埋场运行机制与收费标准

危险废物安全填埋场应探讨企业化经营模式。在单一处理模式、一体化经营模式和依托于大型企业模式中选择适宜的模式。填埋场建设资金筹集渠道中,由废物产生单位集资建设是可行办法。探讨了填埋场收费标准的计算方法,并给出计算公式。     

离子对烷基化法在2,4-D和2,4,5-T残留分析中的应用

有机阴离子可以和长碳链的季胺盐阳离子结合生成可溶于高介电常数有机溶剂的离子对.在此溶剂中,它可以和某些卤代烃发生复分解反应,生成季铵盐阳离子的卤化物及有机阴离子的相应烷基化物,故称离子对烷基化反应.此反应条件温和,转化率高,被广泛地应用于酸性及其它含活泼氢的有机化合物的烷基衍生物合成中.在这类有机物的分析中也得到应用.但尚未见应用于农药及其降解物残留分析中的报道. 2,4-D,2,4,5-T是典型的酸性有机农药,广泛用作农田除草剂.在二者的残留分析中,通常用CH_2N_2、BF_3CH_3OH、(CH_3)_2SO_4将它们烷基化,然后用气相色谱加以分析.近几年也有人用多卤素取代醇的BCl_3络合物或五氟苄基溴化物同Na_2CO_3作为     

一个耐受镉毒害的拟南芥突变体的筛选

从甲基磺酸乙酯(EMS)诱变获得的拟南芥M2代群体(Columbia型)中筛选获得一个耐受镉Cd2 毒害能力显著增强的拟南芥突变体(命名为cdr1-1).遗传分析表明,该突变性状为隐性单基因突变,与野生型相比,cdr1-1突变体在不同发育时期均能耐受Cd2 毒害,且其对Cd2 的积累能力也显著高于野生型.此外,还发现cdr1-1突变体体内的还原型谷胱甘肽(GSH)水平显著高于野生型,用GSH合成抑制剂丁硫氨酸亚矾胺处理cdr1-1突变体,导致其耐受Cd2 毒害能力显著下降,几乎接近野生型水平,表明cdr1-1突变体对Cd2 的耐受性至少部分依赖于GSH介导的途径.     

汉江下游突发“水华”的调查研究

对１９９２年春汉江下游水体暴发“水华”进行了调查研究，对“水华”的特征，产生的原因以及对策，建议等进行了分析、探讨。结果表明，其直接原因是以小环藻为主的硅藻的急剧增殖造成的。