一类高阶多点边值问题在共振条件下的可解性

考虑非线性高阶多点边值问题x（n）（t）=f（t,x（t）,x＇（t）,…,x（n-1）（t））＋e（t）,t∈（0,1）,x（i）（0）=0,i=0,1,…,n-2,x（n-2）（1）=∑m-2j=1βjx（n-2）（ηj{）解的存在性,这里f：[0,1]×n→是连续函数,e（t）∈L1[0,1],βj（j=1,2,…,m-2）为符号不全相同的实数,0〈η1〈η2〈…〈ηm-2〈1.利用Mawhin连续性定理对于上述共振条件下的非线性n阶多点边值问题建立了解的存在性结果.     

甲醇用作柴油替代燃料的研究进展

在比较甲醇、柴油及汽油物化特性的基础上,分析了甲醇作为柴油替代燃料的优劣势,综述了柴油机燃甲醇的方法;同时,结合西华大学制定《M10车用甲醇汽油》四川省地方标准和甲醇在柴油机中应用的研究工作,指出甲醇用作柴油替代燃料的应用趋势,为甲醇用作柴油替代燃料的研究提供参考.     

生态清洁小流域建设经验在北京市东南郊水网工程中的应用

北京市在其东南郊水网工程建设中引入生态清洁小流域理念,把生态清洁小流域的建设管理经验应用到工程建设中,初步取得了有水则清,一水多用、循环使用,提高地下水位的效果。介绍了北京市东南郊水网工程建设的背景、目标、内容和把生态清洁小流域建管理念引入工程建设的具体做法。     

基于宽窄行种植模式下稻秸非均匀性覆盖对土壤特性及小麦产量的影响

为探究宽窄行种植模式下稻秸非均匀性覆盖还田对土壤理化特性和小麦产量的影响,在大田条件下,本研究通过前期不同行间距配置试验筛选出30 cm+15 cm的优势宽窄行组合,并在此基础上设置5个不同梯度的宽窄行稻秸分布比例处理(T1:0、T2:25％、T3:50％、T4:75％、T5:100％),分析窄行(苗带)土壤理化性质和...     

Relationship between endothelial dysfunction and renin-angiotensin-aldosterone system under the condition of fatigue stress and effect of herbs to dredge collaterals

AIM: To investigate the mechanisms and relationship among endothelial dysfunction, renin-angiotensin-aldosterone system (RAAS) and family of interleukins under the condition of excessive fatigue, by using the rats with fatigue stress. METHODS: Healthy male Wistar rats were randomly divided into control group, homocysteine (HCY) group, fatigue stress group, renshen group, shuangshen group and tongxinluo group. Radioimmunoassay was carried out to detect plasma renin activity (PRA), angiotensin II (AngⅡ), aldosterone (ALD), endothelin (ET), thromboxane-2 (TXA2), prostaglandin I2 (PGI2) in plasma and interleukin-1β, 2, 6, 10 (IL -1β, IL -2, IL -6) in sera. ELISA was used to detect NE and IL -10. The content of nitric oxide (NO) in sera was also detected. The bioinformatical analysis was used to determine the relationship between RAAS and endothelial dysfunction. RESULTS: Compared with control group, the levels of ET-1 and TXA2 in fatigue stress group were significantly increased (P<0.01, P<0.05), but the content of PGI2 and NO was significantly decreased (P<0.01, P<0.01). Compared with control group, the renin activity in plasma of animals in fatigue stress group was significantly decreased (P<0.01), the AngⅡ, IL -1β, IL -6 level was significantly increased compared with the control group (P<0.01, P<0.01), and was significantly increased compared with the HCY group (P<0.05, P<0.01, P<0.01). The NE level showed the tendency of decrease in different degree. After the intervention of three kinds of herbs to dredge collaterals, the ET-1, AngⅡ, IL -1β, IL-6 level in plasma was decreased in different degree (P<0.05, P<0.01, P<0.01), and at the same time, the contents of NO and NE level were significantly increased (P<0.05). The ALD level in tongxinluo groups was apparently higher than that in control group and the fatigue stress group (P<0.05). The bioinformatics analysis showed that Ang II and ET, IL-1; PGI2 and ALD; NO and ALD composed of three subsystems and interrelated according to the principle of optimality of complex system, and gradual change regulation was also observed in fatigue stress group. However, in control group, HCY group and tongxinluo group, the same interrelation among subsystems was not existed. CONCLUSION: In a state of long-term excessive fatigue, vascular endothelial dysfunction may be induced, and is related with renin-angiotensin-aldosterone system imbalance and serious turbulence of the autonomic dysfunction. Herbs to dredge collaterals could improve it significantly. The results suggest that bearing excessive fatigue and pressure in long-term may be the potential risk factors to induce vascular endothelial dysfunction and further result in cardio-cerebro vascular diseases, Tongluo therapy may be one of the useful ways to prevent such diseases.     

Apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol

AIM: To investigate the molecular mechanism of the apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol. METHODS: Human primary gastric cancer cells were planted into nude mice to establish the cancer model. Resveratrol at different doses were injected near the carcinoma on the nude mice. After treatment, transmission electron microscope and TUNEL staining method were used to detect the apoptosis of implanted tumor cells. Immunohistochemical staining and RT-PCR were used to detect the expression of apoptosis-related genes bcl-2 and bax in implanted tumor. RESULTS: Resveratrol significantly inhibited carcinoma growth when it was injected near the carcinoma. The apoptotic cells in implanted tumor induced by resveratrol were detected by transmission electron microscope and TUNEL staining, immunohistochemical staining and RT-PCR showed resveratrol inhibited bcl-2 expression and increased bax expression in human primary gastric cancer cells. CONCLUSION: Resveratrol inhibits implanted tumor of human primary gastric cancer cells in nude mice through inducing apoptosis. This apoptosis may be mediated by down-regulation of bcl-2 expression and up-regulation of bax expression.     

Ni/Al2O3-MxOy催化剂催化松香氢化反应研究

研究了自制非贵金属纳米催化剂Ni/Al2O3-MxOy催化松香的氢化反应。结果表明,松香氢化的最适工艺条件为:反应温度210℃、反应压力4.5 MPa、反应时间2 h、催化剂用量2.5%、搅拌转速500 r/min,在此条件下枞酸转化率可达98%以上,催化剂可重复使用4次。     

中国网民的基本特征对电子商务发展的影响

电子商务的发展给整个世界带来了翻天覆地的变化,中国网民基本特征是反映中国网民与网络关系的一些基本特征,包括结构特征、行为特征和心理特征等。就中国互联网络信息中心历次发布的调查统计数据进行了详细的分析,阐述了网民结构与电子商务发展的关系。     

高寒地区蓝鳃太阳鱼养殖技术研究

本探讨了蓝鳃太阳鱼（Lepomis macrochirus)在高寒地区的生长成活状况。实验结果表明，在东北地区蓝鳃太阳鱼夏季养殖成活率可以达到85%（单养）和65%（混养），6-8月生长速度较好，混养比单养生长速度快，冰下可以安全越冬。