玉米秸秆铺放装置开仓机构的一设计

目前,玉米秸秆的整株收获还是一个世界性技术难题,现有的几种秸秆收获装备存在结构复杂、体积大、耗能高和可靠性差等问题.针对这一种状况,设计了一种适宜于玉米联合收获机安装的秸秆铺放装置开仓机构,介绍了其工作原理和参数计算选择.该机构由间歇运动机构、行程放大机构以及仓门打开机构组成,能够将割台下收集的秸秆铺放至地面.其参数选择兼顾农机和农艺的要求,整个机构具有结构简单、体积小、可靠性高等特点,符合目前玉米秸秆整株收获及玉米联合收获机的装配需要,是一种秸秆整株收获的可行设备.     

基于修正A值法的西安市大气环境容量估算

估算西安市大气环境容量,为西安市大气总量控制提供科学依据.应用国标<制定地方大气污染物排放标准的技术方法>(GB/T 13201-91)中规定的以箱模型为基本模型推导出的宏观总量控制A值法.西安市SO2、NO2和PM10大气环境容量分别为11.38、12.04及4.83,单位为104t/a.估算结果表明,SO2和NO2...     

纳他霉素复合涂膜处理对红地球葡萄的防腐保鲜效果

研究在冷藏条件下纳他霉素复合涂膜处理对葡萄的防腐保鲜效果。以"红地球"葡萄为试材,将质量分数1%壳聚糖分别与质量分数0.2%、0.4%、0.6%纳他霉素复合涂膜处理果实(分别记为T1、T2、T3),以用蒸馏水处理和仅用质量分数1%壳聚糖涂膜处理的果实作为对照(分别记做CK1、CK2),比较处理果和对照果的腐烂率、落粒率、质量损失率及呼吸强度和果实相关生理品质的影响。结果表明,CK1的呼吸强度、质量损失率、腐烂率和落粒率均高于CK2,但处理组T1、T2、T3果实的上述指标均低于CK1、CK2,且与对照相比果粒硬度维持在较高的水平。同时处理组T1、T2、T3的果实维生素C、可滴定酸质量分数较CK1、CK2果实下降缓慢,但对可溶性固形物质量分数没有显著影响。纳他霉素复合涂膜处理对红地球葡萄具有良好的保鲜效果,能显著延长果实贮藏时间。综合考虑,质量分数0.4%的纳他霉素壳聚糖复合涂膜处理对葡萄果实的保鲜效果最佳。     

小鼠Foxc2质粒载体的构建及功能鉴定

构建pcDNA3.1-Foxc2真核表达载体,并以脂质体转染3T3-L1前体脂肪细胞,探究Foxc2对脂代谢的影响。取孕后15d小鼠腹部脂肪组织提取总RNA,用PCR扩增Foxc2全长序列并连接至pMD18-T载体,测序正确后克隆至pcDNA3.1(+)真核表达载体,成功构建pcDNA3.1-Foxc2重组质粒载体。重组质粒转染3T3-L1前体脂肪细胞系,以未转染和空载体转染作为对照,通过RT-PCR和Western blotting法检测Foxc2核酸及蛋白表达,同时检测3T3-L1前体脂肪细胞中脂代谢相关基因FAS、ATGL、HSL及PPARγ的表达。结果显示,重组质粒转染组细胞中Foxc2的核酸和蛋白水平均显著高于对照组。同时发现超表达Foxc2显著降低FAS表达,显著升高HSL及PPARγ的表达,但是对ATGL的表达无显著影响,表明Foxc2具有抑制脂肪沉积的功能。     

Large Span Concrete Box Beam Construction Technology

Combined with the engineering practice, the method of large span post tensioned prestressed box beam construction technology was introduced, which can provide the reference for the similar project.     

Effects of magnesium on apoptosis and expression of Foxp3 in peripheral CD4+CD25+ regulatory T cells from asthma patients

AIM:To observe the apoptosis and the expression of forkhead box protein 3(Foxp3) induced by magnesium in CD4⁺CD25⁺ regulatory T cells isolated from healthy and asthmatic human peripheral blood. METHODS:Peripheral blood from healthy volunteers and asthma patients was collected. CD4⁺CD25⁺ T cells were separated by Percoll centrifugation and magnetic separation. The cells were cultured for 72 h and treated with magnesium(10 mmol/L) or control solution. The apoptotic rate and the expression of Foxp3 in the cells were analyzed by flow cytometry. RESULTS:The purity of CD4⁺CD25⁺T cells was 77.4%~92.3% in health group, and was 75.2％~93.8％in asthma group. The proportion of CD4⁺CD25⁺ T cells in CD4⁺T cells was 4.12%~7.98% in healthy adults, and 4.51%~8.68% in asthma patients. No significant difference between the 2 groups was observed. Magnesium at concentration of 10 mmol/L up-regulated the apoptotic rate of CD4⁺CD25⁺ T cells(P<0.05) and did not affect the Foxp3 expression in the cells in both health and asthma groups. CONCLUSION:Magnesium plays therapeutic effects on asthma by inducing the apoptosis of peripheral CD4⁺CD25⁺ regulatory T cells.     

Prognostic significance of FOXA1 and BRCA1 expression in triple negative breast cancer

AIM: To investigate the expression of forkhead box protein A1(FOXA1) BRCA1 protein,P53 and vascular endothelial growth factor (VEGF) in triple negative breast cancer (TNBC) and non-TNBC, and the relevance with the clinicopathological parameters for evaluating the prognosis. METHODS: The tumor samples were collected from 113 cases of breast cancer patients in the First Affiliated Hospital of Jinan University,and divided into TNBC group, luminal subtype group and HER-2 overexpression subtype group by the immunohistochemical results of estrogen receptor, progesterone receptor and HER-2. EnVision two-step method was used to detect the expression of FOXA1, BRCA1, P53 and VEGF in the tumor samples. RESULTS: Total FOXA1 positive expression rate was 63.7% (72/113), with 45.2% (19/42) in TNBC, 88.0% (44/50) in luminal subtype and 42.9% (9/21) in HER-2 overexpression subtype.The statistically sigfnificant difference among the 3 groups was observed (P<0.01). Total BRCA-1 positive expression rate was 47.8% (54/113), with 66.7% (28/42) in TNBC, 44.0% (22/50) in luminal subtype and 19.0% (4/21) in HER-2 overexpression subtype.The statisticallysignificant difference among the 3 groups was also observed (P<0.01). In the cases of clinical stages Ⅰ~Ⅱand histological grades 1~2, FOXA1 positive rate was higher than the FOXA1 negative rate (P<0.01). Negative correlations between FOXA1 positive rate and expression of P53/VEGF, and between FOXA1 positive rate and the recurrence rate were found (P<0.05). In the cases of clinical stages Ⅱ~Ⅲ and histological grades 2~3, the BRCA1 positive rate was higher than the BRCA1 negative rate (P<0.05). Positive correlations between BRCA-1 positive rate and the expression of P53/VEGF, and between BRCA1 positive rate and the recurrence rate were also observed (P<0.05). CONCLUSION: Expression of FOXA1 and BRCA1 in breast cancer is different. BRCA1 may be an adverse prognostic indicator for triple negative breast cancer.     

梁格法分析变宽斜预应力混凝土箱梁桥

变宽斜箱梁桥在公路、城市互通立交中应用广泛,其构造和力学特点与直线桥梁有很大区别,在运用程序建模分析中选择合适的方法对分析结果的精确度有着较大的影响。本文通过对某斜桥进行梁格法建模分析,介绍了梁格模型在变宽斜箱梁桥中的应用。     

浅谈桥梁博士计算变截面连续箱梁时通用截面拟合的应用

通过利用桥梁博士对变截面连续箱梁的结构计算,阐述了单箱双室截面、斜腹板的变截面连续箱梁（箱梁截面变化复杂,顶板、底板、腹板厚度,梁高均为变化值,且梁底呈二次抛物曲线变化）的建模过程。阐明若采用普通方法输入截面,需计算各个节点截面特性,然后逐个输入;采用通用截面拟合工具输入函数,可一次完成。     

白灵菇化学保鲜技术研究

采用化学保鲜液浸泡白灵菇子实体,可以明显延长其保鲜贮藏时间。该试验结果表明:用浓度0.2%焦亚硫酸钠浸泡白灵菇5min后,晾干表面水分,用塑料托盘保鲜膜包装,在温度5～10℃下贮藏,保鲜效果最佳。该方法可使白灵菇保鲜期延长至10d。