根癌农杆菌介导工业化产甘油假丝酵母的遗传转化

通过构建质粒pCAM3300-zeocin,将其电击转化到根癌农杆菌LBA4404中.将含有目的质粒pCAM3300-zeocin的根癌农杆菌和工业化产甘油假丝酵母(Candida glycerinogenes)WL2002-5共培养,利用zeocin抗性基因为筛选标记,实现了pCAM3300-zeocin对产甘油假丝酵母的转化.并根据产甘油假丝酵母的生长特性,对转化条件进行了优化,在共培养时间为24h,产甘油假丝酵母和根癌农杆菌的细胞比例为1∶(500～1000)时最高转化率达到2个转化子/104个酵母细胞.初步建立了根癌农杆菌介导转化产甘油假丝酵母的转化方法.     

Pyrrolizidine alkaloids between plants and insects: A new chapter of an old story

Summary Among alkaloids the pyrrolizidine alkaloids (PAs) play a unique role in the interactions between plants and adapted insects. InSenecio spp. (Asteraceae) PAs are synthesized in the roots as alkaloidN-oxides which are specifically translocated into shootsvia the phloem-path and channeled to the preferred sites of storage (e.g. inflorescences) where they are stored in the cell vacuoles. In differentSenecio spp. senecionineN-oxide is produced as the common product of biosynthesis, which subsequentlyvia a number of simple but specific reactions is transformed into typical speciesspecific PA-patterns. Insects from diverse taxa sequester PAs for their own defense. Lepidopterans (e.g. arctiids such asTyria jacobaeae andCreatonotos transiens) may hydrolyze plant acquired ester-PAs and convert the resulting necine base into insect-specific PAs by esterification with an acid of their own metabolism. Adapted arctiids and the grasshopperZonocerus take up PAs in the state of the tertiary amine.N-Oxides are reduced in the guts prior to uptake. In the bodies the tertiary PAs are rapidlyN-oxidized by a specific mixed-function oxigenase and are maintained in theN-oxide state. The importance of the reversible interconversion of the nontoxicN-oxide (pro-toxine) into the toxic tertiary alkaloid is discussed as the specific feature of PAs in plant-insect interactions.     

机械加工业清洁生产的一则技改实例

一家机械加工厂采用先进的工艺和设备代替落后的工艺和设备，并且撤消了一些工序和对生产车间进行了重新布局，不仅提高了工作效率，而且减少了环境污染，促进了清洁生产，对此，从废水，废气，噪声和废渣四个方面进行了详细评述。     

Influence of micro-organisms on the dissolution of metallic platinum emitted by automobile catalytic converters

Platinum emitted by automotive catalyst converters mainly exists in the metallic form, which is not bioavailable. Several investigations showed that finely dispersed metallic platinum is dissolved in organic matrices to a significantly high degree [1,2]. In an exclusion experiment, observations were made as to whether the transformation of Pt(0) and other platinum compounds is mainly of a chemical nature or is influenced by micro-organisms. A previous experiment [2], concerning the interaction of several platinum compounds with a clay-like humic soil was repeated under sterile conditions to rule out the influence of micro-organisms. During the time of interaction (3–60 d), no significant differences were observed between the sterile and non-sterile modes. Thus, the dissolution of metallic platinum into soluble species, observed previously within this time period [2], seems to be mainly of a chemical nature. On leave from Liaoning University, Department of Chemistry, 110036 Shenyang, PR China     

平煤集团坑口电厂除尘设施的技术改造

平煤集团坑口电厂原有文丘里水膜除尘器不能使排放烟尘达标排放 ,在保留原有两台文丘里水膜除尘器基础上 ,并在其前串联两台单室二电场静电除尘器 ,经改造后 ,电除尘 文丘里水膜除尘串联组合技术总除尘效率达 99 9% ,排放浓度为 10 3mg/Nm3,实现了达标排放     

国内"城中村"改造研究浅探

研究和探索科学有效的"城中村"改造方式,已成为构建和谐社会的当务之急.本文试图从现有城中村改造的文献中来认识、思考、探索城中村改造.     

规范变换降维与误差修正结合的环境系统的一元线性回归预测

针对高维、非线性环境系统的传统预测模型存在结构复杂、收敛速度慢、求解精度低的局限,提出对环境系统预测量及其影响因子进行幂函数与对数函数相结合的规范变换.此规范变换能使变换后的各影响因子皆等效于一个线性化的规范因子,从而将多因子、非线性的预测建模简化为简单的一个"等效"规范因子的一元线性回归建模;并对预测样本的模型输出进行误差修正,以提高样本的预测精度.在规范变换的基础上,由有m个规范因子的每个建模样本生成一个规范因子的m个"等效"训练样本,n个建模样本共生成N=m×n个训练样本.应用最小二乘法,建立基于规范变换的一元线性回归预测模型.将基于规范变换的一元线性回归预测模型与相似样本误差修正法相结合,分别用于某市5个点位的SO_2浓度预测和南昌市城市降水酸度pH值预测及某河段COD_(Mn)预测,并与多种传统预测模型和方法及基于规范变换与误差修正的3种智能预测模型的预测结果进行了比较.结果表明:该预测模型用于3个实例预测的相对误差绝对值的平均值分别为1.14%、0.49%和1.45%;最大相对误差绝对值分别为2.22%、0.87%和1.85%,与基于规范变换与误差修正的3种智能预测模型的相应误差几乎没有差异,甚至还要小;均远小于多种传统预测模型和方法的相应误差,其预测精度甚至提高了一个数量级以上.基于规范变换与误差修正的一元线性回归预测模型简单、预测精度高、稳定性好,不存在"维数灾难",因而可广泛用于任意系统的预测建模.     

土壤中元素磷的地球化学

土壤磷素包括无机磷和有机磷。由于生物有效性的不同 ,无机磷和有机磷又可分为各种形态的无机磷和有机磷组分。土壤磷素的生物地球化学行为受多种因素的影响。为此本文概述了土壤中元素磷的地球化学行为及其影响因素。     

产品开发中绿色技术的评价、选择和创新

对产品开发中的绿色技术进行了研究分析 ,从技术的审核、技术的选择、技术的过渡以及技术的创新等方面提出了相应的问题和解决方法 ,并对有关内容建立了分析模型     

水环境中重金属的存在形态和迁移转化规律综述

本文综述水环境中重金属的存在形态和污染特征以及迁移转化规律的研究概况。水体中重病态民的存在形态了子交换态，碳酸盐结合态、铁氧结合态、有机质和硫化物结合态和残渣态，重金属形态和生物效应有关，对重金属在水体中迁移和转化规律及其过程的动力学水质模型的建立进行了论述。