城市输配水管网水质变化模型及其数值方法

论述了水质在管网中变化的稳态和动态数学模型，分别给出了求解稳态模型的方法和用拉格朗日法求解动态模型的典型数值方法。     

四川桤木无性系采穗圃修枝与施肥试验初报

为提高四川桤木无性系采穗圃穗务产量,对其无性系进行了修枝与施肥试验,试验表明：在无性系定杆150cm高时,将其抽发的侧枝进行短截修剪,修剪强度以轻、中短截效果最佳,可显著提高无性系穗条产量,在无性系定杆120cm高时,施用氮肥可显著提高无性系穗条产量?     

陇中地区降水量对小麦产量的影响

为探讨生育期降水对小麦(Triticum aestivum)产量的作用机制和规律, 以甘肃省定西市1971-2005年小麦产量和各生育期降水量为研究对象, 运用APSIM模型模拟, 并用二次多项式逐步回归法分析了生育期降水量对小麦产量的影响。结果表明, 小麦产量除与年降水总量有关外, 还与生育期降水量的变化有关。不同生育期降水量对小麦产量影响表现为苗期拔节期挑旗期抽穗期灌浆期开花期, 其中, 苗期和拔节期的降水量与小麦产量呈开口向下抛物线型变化。且苗期和拔节期降水量效应分别是挑旗期降水量效应的6.6和3.7倍, 而抽穗期、挑旗期、开花期和灌浆期降水量对小麦产量影响在研究区降水范围内出现二次叠加递增变化。甘肃陇中地区小麦产量的主要限制因子是苗期和拔节期降水量。     

Polymorphism of Kappa-casein gene and its associations with milk performance traits in red steppe

为研究草原红牛κ-酪蛋白基因的多态性及与泌乳性状相关性,采用PCR-RFLP方法检测κ-酪蛋白基因外显子5的遗传多态性.结果检测到TT、TC和CC三种基因型,统计分析表明,此多态位点与草原红牛乳蛋白和乳糖呈显著相关,乳蛋白:CC基因型极显著高于CT基因型和TT基因型(P＜0.01),而CT基因型也极显著高于TT基因型(P＜0.01).乳糖:TT基因型和TC基因型极显著高于CC基因型(P＜0.01),而TT和TC基因型之间差异不显著(P＞0.01).其他泌乳性状的基因型间差异不显著(P＞0.01).结果表明,κ-CN基因对草原红牛乳蛋白和乳糖具有较大的遗传效应,可初步推断κ-CN是控制这一性状的众多基因之一,是影响草原红牛乳蛋白和乳糖的一个主效基因或与主效基因相连锁,可作为选育草原红牛高乳蛋白及低乳糖奶牛的分子标记,用于标记辅助选择意义重大.     

移动插入式灌水器的结构研究与抗

通过对现有滴头、滴箭等产品结构的研究、改进与优化,设计开发出一种抗堵塞功能较强的插入式地下灌水器产品,整体上具有快速装拆、移动灵活、滴流量偏差小、水力性能稳定等特点。为检验其抗堵塞功能的优劣,分别进行了自由出流和插地出流条件的滴水试验。结果表明：移动插入式灌水器出流均匀,具有较强的抗堵塞性能,自由出流时的平均滴水量与多次间歇式插地出流时的平均滴水量相当,其波动范围在5％以内,较适合于在移动式地下滴灌系统中应用。     

NaCl胁迫对不同苜蓿种质苗期生长特性的影响

试验以来自俄罗斯的48份苜蓿种质为研究材料,采用室内盆栽法,在0.3%,0.4%,0.5%,0.6%NaCL胁迫下,通过测定不同种质的存活率、株高、地上、地下生物量等形态指标,分析了不同NaCl浓度胁迫对苜蓿种质苗期生长特性的影响,并运用聚类分析法对引进种质的耐盐性进行综合评价。结果表明:随着盐浓度的增加,供试苜蓿种质的存活率、株高、地上生物量、地下生物量呈下降趋势,不同材料间表现出显著性差异,试验共筛选出ZXY05P-776、ZXY05P-1026、ZXY05P-1091、ZXY05P-1104、ZXY05P-1040、ZXY05P-785、ZXY05P-809、ZXY05P-857、ZXY05P-820、ZXY05P-1115、ZXY05P-1140、ZXY05P-1232、ZXY05P-1215、ZXY07P-3537等15份耐盐性较强的种质。     

PFI-Private Finance in Public Works

PFI is one of the novel approaches for the private finance in public works. The initiative aims on encouraging the private sector to undertake infrastructure projects and the provision of services on a project basis, rather than by the traditional means of procurement. PFI has been widely applied in a large number of fields in public works of government. PFI has become one of the government's main instruments for delivering higher quality and more effective public services. Two of the principal tenets of PFI is: the first is to secure value for money for the public sectors and the second to transfer the ongoing risk in the continued delivery of a service away from the public sector to the private sector.     

慢性冷暴露对小鼠肝脏抗氧化功能的影响

本试验旨在探讨慢性冷暴露对小鼠肝脏抗氧化功能的影响。体内慢性冷暴露模型建立：试验将12只3周龄C57BL/6雄性小鼠饲养1周后随机分为2组（对照组和冷暴露组）,每组6只。冷暴露组小鼠每日随机放置在4℃环境中3 h,连续4周。冷暴露结束后将所有小鼠同时安乐死,并收集其血液和肝脏。体外冷暴露模型建立：将小鼠肝细胞系AML12细胞随机分为4组（对照组、冷暴露1 h组、冷暴露3 h组、冷暴露6 h组）,先在37℃培养箱中培养24 h,然后将冷暴露组细胞置于32℃培养箱中分别亚低温冷刺激0、12、24、36 h,冷刺激结束后将细胞刮取下来进行后续试验。用酶联免疫吸附测定（ELISA）法对小鼠血清中谷胱甘肽（GSH）和丙二醛（MDA）含量进行检测,用Western Blot检测小鼠肝细胞和肝脏组织中抗氧化蛋白硫氧还蛋白-1(Trx-1)和硫氧还蛋白互作蛋白（TXNIP）的表达情况。结果显示：与对照组相比,冷刺激36 h后AML12细胞数量显著下降（P<0.05）。与对照组相比,Trx-1的蛋白表达量在组织和细胞中都显著降低（P<0.05）,TXNIP的蛋白表达量显著增加（P<0....     

Effect of L-carnitine on apoptosis and oxidant damage of cardiomyocytes induced by hypoxia/reoxygenation in vitro

AIM: To examine the effects of L-carnitine on apoptosis and oxidant injury in cultured neonatal rat cardiomyocytes induced by hypoxia/reoxygenation and its possible mechanism. METHODS: The cultured cardiomyocytes were divided into three groups， control， A/R group （anoxia for 120 min, reoxygenation for 240 min） and L-carnitine treatment group, in which cells were exposed to 20 mg/L, 50 mg/L, 100 mg/L, 200 mg/L L-carnitine respectively at 2 h before anoxia. The superoxide dismutase (SOD), succinate dehydrogenase (SDH) activities and malondialdehyde (MDA) content were examined, and the apoptosis was determined by flow of cytometry (FCM). In addition, the ultrastructure was observed by transmission electron microscopy. RESULTS: In A/R group, SOD and SDH activities were lower, the apoptosis rate and MDA content were higher than those in control group (P<0.05). In L-carnitine treatment group, SOD and SDH activities were higher, the apoptosis rate and MDA content were lower than those in A/R group, a L-carnitine concentration-dependent effect was found. Moreover, impairment of myocardial ultrastructure was more severe in A/R group than L-carnitine treatment group. CONCLUSION: L-carnitine can protect cardiomyocytes against hypoxia/reoxygenation-induced injury in a dose-dependent manner.     

In vitro inhibitory effect of CD8+ cells from patients with aplastic anemia on normal CFU-Mk growth is blocked by cimetidine

AIM: To investigate the effect of CD8+ cells from aplastic anemia (AA) patients and its histamine type II (H2) receptors on the growth of normal CFU-Mk. METHODS: The effects of CD8+ cells and/or cimetidine, on normal human CFU-Mk growth were studied by using CFU-Mk assay. RESULTS: The CD8+ cells from the perpheral blood of AA patients significantly suppressed the growth of normal allogeneic CFU-Mk. This inhibitory effect was blocked by cimetidine at concentration of 1.0×10-5 mol/L. 1.0×10-5 mol/L cimitidine alone didn't inhibit the growth of normal CFU-Mk. CONCLUSION: H2 receptor antagonist cimitidine abolishes the suppressive effect of AA patients CD8+ cells on the growth of normal CFU-Mk.