科创中国

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.

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.

运用瑞典圆弧滑动法对围堰布置及结构形式进行了验算,阐释了施工方法和施工过程.通过实践表明工程实施中采用木桩拦栅围挡、就近水中取土筑施工围堰,能有效地解决了土源问题,节约工程造价,缩短工程工期.木桩拦栅筑堤土围堰技术方案在浅滩、湖泊、内河等水面宽阔、水深在2~4m的地域推广运用,能取得明显的社会和经济效益.

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.

以南水北调中线SG09标石方开挖爆破施工为例,采用理论计算、数值分析和本工程实际施工相结合的方法,详细分析了爆破对周围环境的影响范围及安全控制措施,为类似工程的施工提供了参考.

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.

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.

结合南水北调天津干线工程建设管理具体工作实践,对南水北调中线天津干线施工控制体系构建、主要做法和成功经验进行了分析梳理总结,结果表明南水北调天津干线工程施工中的土方工程、混凝土工程,施工受季节影响以及施工工期受资源配置、施工方案的选择影响较大,在建设实施过程中通过合理安排施工,配置资源合理,优化施工方案,充分发挥整体钢模台车的整体优势,对加强工程实体质量控制等方面的实践是成功的,对进一步提高南水北调天津干线工程以及其它大型水利工程建设水平具有一定的借鉴意义.

生态景观建设是南水北调东线江苏段工程重要组成部分.在建筑与环境景观设计的前期规划及组织实施过程中,均考虑建立合理有效的环境分区体系,同时也将工程的供水功能、生态功能以及环境效应有机结合.通过建筑与环境专项设计过程的实践,提出整体、综合设计的模式的设计思路,从而实现水与自然、水与社会和谐的目标.

项目管理预算是项目管理投资控制的重要环节,结合南水北调天津干线工程建设管理工作实践,从编制方法和编制原则方面论述了概算和项目管理预算不同的编制过程,从南水北调投资价差编制和投资控制考评及奖惩等不同的角度反映了项目管理预算的重要性.事实证明,有效的利用项目管理预算与项目工程价款结算对比,能够对投资有效控制,减少投资风险.有利于提高管理水平,加强成本控制,提高经济效益.