科创中国

官厅水库是首都北京的备用水源地,在分析官厅流域水功能区2009年水环境状况基础上,根据污染物入河量,建立官厅流域水功能区限制纳污红线,按照2015年、2020年控制目标,把限制纳污红线指标细化分解到各个排污口,为限制纳污红线的实施提供更加切实可行的技术支撑.

鉴于南水北调中线工程线路选择的位置对工程安全、水质保护、投资等方面影响较大,虽然南水北调中线工程总干渠线路的选择经过了几十年的论证,在总体线路方案已经确定的情况下,仍需开展局部线路论证工作并对其进行调整与优化.现以十里河段为例对局部线路的调整与优化进行了分析与研究.在开展十里河段线路优化工作阶段,经过现场查勘并考虑地形、地质条件及村镇分布等情况,初步选择了深挖方的北线方案及高填方的南线方案,并对北线、南线两个方案开展了有关工程安全、投资、技术等方丽的分析与研究工作,最终提出了技术可行、经济合理的输水线路布置方案.

Straight-line compliant mechanisms are important building blocks to design a linear-motion stage,which is very useful in precision applications.However,only a few configurations of straight-line compliant mechanisms are applicable.To construct more kinds of them,an approach to design large-displacement straight-line flexural mechanisms with rotational flexural joints is proposed,which is based on a viewpoint that the straight-line motion is regarded as a compromise of rigid and compliant parasitic motion of a rotational flexural joint.An analytical design method based on the Taylor series expansion is proposed to quickly obtain an approximate solution.To illustrate and verify the proposed method,two kinds of flexural joints,cross-axis hinge and leaf-type isosceles-trapezoidal flexural(LITF)pivot are used to reconstruct straight-line flexural mechanisms.Their performances are obtained by analytic and FEA method respectively.The comparisons of the results show the accuracy of the approach.Both examples show that the proposed approach can convert a large-deflection flexural joint into approximate straight-line mechanism with a high linearity that is higher than 5 000within 5 mm displacement.This can lead to a new way to design,analyze or optimize straight-line flexure mechanisms.

目的利用AAV介导的体细胞基因敲除技术,在人大肠癌细胞系HCTll6中对靶基因Sirt1进行敲除,达到基因沉默的目的.方法构建Sirtl打靶载体,通过病毒包装、感染、药物筛选、PCR鉴定、Westernblotting鉴定等步骤获得Sirt1基因敲除的细胞株.结果经过筛选和鉴定后获得两个Sirtl-/-阳性克隆,成功构建HCTll6Sirtl.一细胞系.结论通过体细胞敲除技术,我们成功地获得Sirtl敲除肠癌细胞株.

近些年来,我国中小城市快速发展,城乡建设水平不断提高,水资源供需矛盾日益突出,由于水资源配置工程体系不完备,水环境污染仍然严重.从环境治理、水利建设和生态保持等综合角度,寻求切实可行的中小城市水环境建设与管理方法,具有重要的理论及现实意义.

Objective To detect the cell viability and the expressions of stem cell surface markers after chemotherapeutic drug treatment.Methods We observed the cytotoxic effects of three chemotherapeutic agents[epirubicin(Epi),fluorouracil(5-FU)and cyclophosphamide(Cyc)]in three cell lines,and the cell viabilities after removed these chemotherapeutic agents.Expressions of stem cell surface markers CD44,CD24,CD90,CD14 and aldehyde dehydrogenase1(ALDH1)in breast cancer cells were analyzed by real-time PCR.The post hoc analysis(Tukey's tests)in conjunction with one-way ANOVA was used for statistical analysis.Results The initial cytotoxic efficacy was most notable.After the treatment of the same therapeutic agents,cell viability was decreased by 64.8%35.14%,32.25%in BT-483 cells,66.4%,22.94%and 45.88%in MDA-MB-231 cells,97.1%,99.5%and 76.4%in MCF cells.The difference was significant compared with that before treatment(P=0.000).However,the inhibitory effects were diminished after chemotherapeutic agent withdrawal.Cell viabilities were increased to 167.9%,212.04%and 188.66%in MDA-MB-231 cells at48 h after withdrawal.At 72 h after withdrawal,cell viability was increased with a significant difference in three cell lines(all P values=0.000).Expressions of CD44 and ALDH1 were most prevalent for MDA-MB-231,BT-483 and MCF-7 cells.ALDH1 mRNA level was significant higher in BT-483(HER-2 overexpression cell line)than MDA-MB-231(triple negative cell line)(P=0.012).CD14 mRNA level in MCF-7 cells were significantly lower than that in MDA-MB-231 and BT-483(P=0.003,0.001).BT-483 showed significantly higher level of CD44 than MDA-MB-231 and MCF-7 cell line(P=0.013,0.020),and no significant difference was detected between MDA-MB-231 and MCF-7 breast cancer cells(P=0.955).CD90 mRNA expressions were detected in MDA-MB-231 cells and MCF-7 cells,but not in BT-483 cells.Conclusion Some malignant cells could survive in vitro and begin to proliferate again between cycles of chemotherapy.

为提高石家庄市民心河水质预测的精度和实用性,对石家庄市民心河水样进行了检测,利用模糊综合评价法对水质污染现状进行了评价,得出民心河大部分水样监测点水质都在V类,部分指标超出了景观用水水质标准,河水受到污染.因此需要采取措施改善水环境质量.

根据金沟河涡管排沙工程的布置形式及排沙要求,提出了排沙涡管开口宽度、涡管直径、涡管与渠道轴线夹角、涡管开口长度、涡管纵向坡度等技术指标的确定方法,计算并分析了排沙涡管截沙率及排沙效果.结果表明:通过对排沙涡管进行改进,金沟河排沙平均耗水量占引进水量的4.51%,符合原设计的技术指标.

通过对工业用接线端子台顶端本体零件的工艺分析,按照塑料模具设计的相关原则,从分型面选择、浇注系统设计、抽芯机构设计、冷却系统设计、到模具零件的设计和加工工艺流程,实现了该复杂零件的一模两腔模具设计结构.

为进一步了解衡水市地表水质的时空变化规律,现从地表水化学特征、河流湖库现状水质、水质变化趋势等方面分析和评价了衡水市地表水资源质量状况,并对加强当地水资源保护工作,提出了措施与建议.衡水湖是国家级湿地自然保护区,对衡水市的持续发展有极其重要的作用,对此,本文重点对衡水湖的水质状况、综合污染情况等进行了分析研究.