重金属铜对鳉鱼的急性毒性试验

以鳉鱼为受试生物,采用静水法生物测试,以致死率为指标研究了重金属铜对鳉鱼的急性毒性。结果表明,(1)在同一暴露时间,随着硫酸铜溶液浓度的增大,鳉鱼的死亡率逐渐上升;(2)24h、48h、72h和96h的半致死浓度(LC50)分别为0.211mg/L、0.173mg/L、0.105mg/L、0.069mg/L,该LC50表明,铜对鳉鱼是剧毒物质。铜对鳉鱼的安全质量浓度(0.007mg/L)略低于渔业水域水质标准,此状况应引起有关部门注意。     

Cr3+凝胶动态循环成胶界限室内评价

选取中分分子量聚合物,HD-4、HD-5、HD-6型交联剂配制的Cr3+凝胶在经过五层互成45度25目筛网循环装置的条件下分别对Cr3+凝胶体系进行动态成胶浓度界限进行评价.实验表明:聚合物成胶最低浓度在800～850mg/L,对应交联剂成胶最低浓度为70mg/L～90mg/L,低浓度的Cr3+凝胶体系成胶时间一般在24h～120h之间,成胶后体系粘度会显著上升,表明Cr3+凝胶体系成胶.     

目前黄酒行业中小企业主要存在的生产质量问题是什么

黄洒根据含糖量可分为干黄酒(总糖含量低于或等于15．0g/L)、半干黄酒(又称加饭酒)(总糖含量在15．0g／L～40．0g／L)、半甜黄酒(总糖含量在40．1g／L～100 g／L)、甜黄酒(总糖含量高于100 g/L)。其中半干黄酒是黄酒中较高档的酒种。“半下”表示酒中的糖份还未全部发酵成酒精,还保留了一些     

基于石墨烯/离子液体/壳聚糖修饰电极的制备及对2-羟基-4-甲氧基二苯甲酮的测定

文章利用滴涂法制备了氧化石墨烯/离子液体/壳聚糖化学修饰电极,并用于2-羟基-4-甲氧基二苯甲酮的检测。实验利用扫描电镜和透射镜分别表征了氧化石墨烯的表面形貌和内部结构。此外,实验考察了2-羟基-4-甲氧基二苯甲酮的电化学行为,结果表明,2-羟基-4-甲氧基二苯甲酮在282 nmol/L~1 992 nmol/L浓度范围内,其浓度和峰电流呈良好的线性关系,且线性回归方程为:Ipa(μA)=-0.008 C(nmol/L)+0.2101(n=6,R2=0.9 978),检测限为1.5×10-7M(S/N=3),可用于污水中2-羟基-4-甲氧基二苯甲酮的测定。     

农田水中吡虫啉的残留HPLC测定

文章采用高效液相色谱法测定农田水中吡虫啉的残留,试样用二氯甲烷震荡提取,以甲醇-水(28:72体积比)为流动相,高效液相色谱带紫外检测器检测,此方法吡虫啉浓度在0.05～100.00mg/L之间有很好的线性关系,最低检测限为0.005 mg/L,回收率在88%～101%之间,方法重复性良好.     

硝基苯生产废水处理工程设计及运行

江苏南京某硝基苯生产企业生产废水处理工程设计规模100吨/天,采用fenton-铁碳微电解-水解酸化-UASB-缺氧-接触氧化工艺进行二级处理,进水CODcr、硝基苯、苯胺浓度分别为12000～13000 mg/L、1200 mg/L、60 mg/L;出水CODcr、硝基苯、苯胺浓度分别为420 mg/L、4 mg/L、4 mg/L,去除率分别为96.8%、96.7%、93.3%,达到《污水综合排放标准》(GB8978-1996)三级标准。     

两级DTRO工艺处理建制镇垃圾渗滤液工程实例

对云南省某建制镇生活垃圾填埋场中渗滤液处理工程所采用的两级DTRO工艺从工艺流程设计、处理效果、运行成本等方面进行介绍,该工程处理规模为15m~3/d,运行结果表明,出水CODcr质量浓度不超过34mg/L,BOD5质量浓度不超过17mg/L,NH3-N质量浓度不超过8mg/L,TN质量浓度不超过10mg/L,SS质量浓度降至0mg/L,出水水质稳定且满足《生活垃圾填埋场污染控制标准》(GB16889-2008)对渗滤液排放标准的要求。     

COBR工艺在石化污水深度处理中的应用

采用催化臭氧氧化和内循环曝气生物滤池组合工艺(COBR)对常规生化处理出水进行深度处理。试验表明:在进水COD平均100mg/L、臭氧投加量10mg/L、催化氧化停留时间2 h和曝气生物滤池停留时间3 h条件下,出水COD≤50mg/L,去除率达60%以上。     

硝基苯生产废水处理工程设计及运行

江苏南京某硝基苯生产企业生产废水处理工程设计规模100吨/天,采用fenton-铁碳微电解-水解酸化-UASB-缺氧-接触氧化工艺进行二级处理,进水CODcr、硝基苯、苯胺浓度分别为12000～13000 mg/L、1200 mg/L、60 mg/L;出水CODcr、硝基苯、苯胺浓度分别为420 mg/L、4 mg/L、4 mg/L,去除率分别为96.8%、96.7%、93.3%,达到《污水综合排放标准》(GB8978-1996)三级标准。     

含铬废水的光催化降解研究

介绍了SiO2-TiO2系玻璃光催化降解含铬废水的实验。在Cr6+浓度为80mg/L、体积为100ml的废水中,投加0.7g组成SiO2与TiO2的分子比为8:2的SiO2-TiO2系玻璃,光照反应体系3h,Cr6+去除率达99.9%。     

丰田氢能源燃料电池及氢燃料罐中国专利态势分析

文章综述了氢能源燃料电池汽车的工作原理,针对丰田在中国的相关专利文献,通过宏观的态势分析使国内的相关行业和企业了解丰田在燃料电池汽车方面的总体情况。     

A volume and material handling cost based heuristic for designing cellular manufacturing cells

One of the major problems in a group technology or cellular manufacturing environment is the formation of part groups and machine cells. Because of the combinatorial nature of the cell formation problem, it is difficult to solve the problem optimally. Most of the procedures related to cell design in cellular manufacturing operate on the part-machine incidence matrix in an attempt to identify block diagonality. If complete block diagonality does not exist, the decision about cell configuration is left to the subjective judgement of the designer. These procedures are also generally based on part routing only, and do not consider part volume and material handling costs.In this paper we develop an integer programming model, as well as a heuristic to effectively assign machines to cells. In these procedures we consider component volumes, costs related to movement of components between and within cells, and penalty for not using all machines in a cell visited by a component. Since the integer programming formulation becomes large even for small problems, an efficient heuristic is developed to solve larger problems. The heuristic solutions to 180 randomly generated small problems were compared against the optimal solutions obtained by the integer programming model. The heuristic has been found to identify optimal solutions in all 180 cases.This heuristic is also compared to several well known algorithms on 900 larger test problems. These problems were generated to cover a wide range of environmental situations such as varying levels of block diagonality in the part-machine incidence matrix, and diversity in the component volumes and material handling costs. In 99% of the problems our heuristic generated solutions which are better or as good as the best solution obtained by other algorithms. Further, in situations where complete block diagonality in the part-machine incidence matrix did not exist, our heuristic produced even better results. Since the maximum number of iterations required in our heuristic is the number of machines in the problem, the heuristic is computationally efficient.     

小鼠脑皮质神经干细胞体外培养及miRNAs影响其分化能力

目的 系统建立小鼠脑皮质神经干细胞(NSCs)体外培养的技术平台,并探索一组micmRNA对NSCs分化能力的影响.方法 胎鼠(E14)脑皮质分离NSCs进行体外培养;免疫荧光法检测NSCs向神经元和星型胶质细胞的自然分化;Real-time定量PCR筛选一组分化前后表达水平有显著性差异的microRNA;应用新一代脂质体高效转染NSCs,将该组microRNA或其抑制物导人NSCs;Western blot检测导入的RNA序列对NSCs分化能力的影响.结果 基于小鼠NSCs体外培养模型,筛选出一组NSCs分化前后表达水平存在显著性差异的mieroRNA(miR-124,137,128).Western blot结果显示miR-124的反义链能够明显下调β-tubulin Ⅲ的表达(P<0.01),过表达miR-137和miR-128后β-tubulinⅢ的表达量有所升高.结论 脂质体转染技术能够将miRNAs高效导入NSCs中;microRNA-124,137,128能够影响NSCs的分化.     

Sequencing rules and due date setting procedures in flow line cells with family setups

The purpose of this study is to investigate due date setting procedures and dispatching decisions in a flow line cell with family setups. In this environment, setups are not required when switching from a job in a given family to a job in the same family. However, switching from a job in one family to a job in another family requires a setup. Family setups in this shop are sequence independent. The dispatching decisions in this shop are threefold: (1) when should the decision to switch from one part family to another be made; (2) once the decision to switch families is made, how should the next part family be chosen (next family decision); and (3) how should the jobs within a family be prioritized (next job decision)? If the decision to switch classes can only be made after the current family is exhausted, the rule is called a class exhaustion rule. Otherwise the rule is a truncated rule. The results indicate that the due date setting procedure has a major impact on how dispatching should be performed in the shop. The family exhaustion procedure using the APT next family rule and the SPT next job rule is the best performer for mean flow time. When setup times are long, the SEQ due date rule using the family exhaustion procedure with the FCFS next family and the EDD next job rules performed well for due date criteria. When setup times are short, the EDD/T, Sawicki truncation rule and the family exhaustion rules performed well for due date criteria.     

On efficiency of estimation and testing with data quantized to fixed number of cells

Metrika - In continuous parametrized models with i.i.d. observations we consider finite quantizations. We study asymptotic properties of the estimators minimizing disparity between the observed and...     

加强改进党建思想政治工作促进学院改革创新发展——我院加强党建思想政治工作促进改革创新发展实践探析

近年来,我院党委坚持以邓小平理论和"三个代表"重要思想为指导,坚持"围绕中心工作抓党建和思想政治工作,抓好党建和思想政治工作促发展"的指导思想和工作方针,紧密结合学院的实际,把握大局,突出重点,讲求实效,切实加强、改进党建和思想政治工作,取得明显成效,促进了学院的改革、创新和发展.     

Financial participation and recruitment and retention: causes and consequences

Using a sample of over 5000 establishments in Germany, we analyze the antecedents and effects of profit sharing (PS) and employee share ownership (ESO) with respect to the ability of firms to meet their recruitment and retention objectives and to achieve employment growth. We draw on both economic and behavioral perspectives to argue that firms that adopt PS and ESO plans do so in order to attract and retain employees. Using logistic regression and a propensity score matching technique, we find that firms that face higher recruitment problems, and those that have greater employment growth objectives, are more likely to use ESO and PS. Unlike ESO, PS enhances firm-level employment growth. However, neither ESO nor PS help firms to fully resolve recruitment and retention problems.     

廊坊与京津的产业对接及融合

认为京津冀都市圈区域规划的编制和实施,将极大地促进该都市圈内生产要素的大范围流动和资源的优化配置。廊坊置身于京津冀都市圈,与京津山水相连,具有对接京津产业的良好基础。廊坊市应深度融合京津资源,积极搭建开放平台,规划廊坊市与京津产业对接的思路,确定与京津产业对接的领域,以此促进廊坊市的经济和社会的快速发展。     

我国中小微企业的特点与优劣势分析

本文对我国中小微企业的特点进行了分析,探讨了中小微企业的优势与劣势。通过分析研究,一方面使社会对中小微企业的生存发展有更深的认识和了解;另一方面帮助中小微企业明确自身定位,扬长避短,推动中小微企业的可持续发展,为社会经济的发展做出贡献。