近50年来塔里木河干流水量、水质及耗水分析

近53年来阿拉尔站以上3条源流出山口天然径流量呈增加趋势,由178.0×108m3增至207.6×108m3,净增29.6×108m3;3条源流年代际区间耗水量由128.5×108m3增至171.1×108m3,净增42.6×108m3;入塔里木河水量由50.0×108m3减至38.0×108m3,净减少12.0×108m3.历史上塔里木河最大耗水区在中游,多年平均耗水量24.8×108m3.从20世纪60年代至今的近40年,上游中、下段河床处于淤积状况,总淤积厚度130 cm,平均年淤积3.6 cm.从2001年至今上游段已成为塔里木河干流最大的耗水区,上游段耗水量占阿拉尔站年径流量的50%增加到80%,导致下游水量减少,环境恶化.塔里木河上游段高矿化度农田洗盐压碱水是干流水质恶化的根本原因,污染源主要集中在肖夹克至英巴扎的上游河段,尤其是阿拉尔站附近东西长60 km,南北宽20 km.现有8条排(退)水渠,其中有6条排水渠严重超标,矿化度4 71013 100 mg/L,是盐碱土规定标准2 000 mg/L的2.46.6倍.位于渭干河的新沙总排干,矿化度5 820 mg/L,严重超标,是盐碱土规定标准的2.9倍.     

吉林省玉米田杂草发生与危害现状的研究

掌握不同生态条件下的玉米田杂草发生种类及优势种群情况,对于制定杂草综合治理方案,科学选用化学除草剂及其配套技术具有十分重要的指导意义。本文从生态学角度对吉林省玉米田杂草种群数量和群落组成进行了系统研究。结果表明,吉林省玉米田常见杂草有39种,分属16科。并根据不同生态区杂草的危害程度和优势度,确定了不同生态区主要杂草群落组成。     

两种蔷薇属植物果实品质质量的综合评价

针对果实品质质量难于客观评定的问题,提出基于加速遗传算法的投影寻踪模型用于解决果实品质质量高低的判定问题,该模型通过优化指标投影方向,将多维数据指标(样本评价指标)转换到低维子空间,并根据投影函数值的大小评价出各样本的优劣,最大限度避免了权重矩阵取值的人为干扰.在2种蔷薇属植物果实品质质量综合评价中的应用结果表明:采用投影寻踪法来确定权重,减小了人为因素的干扰,分析结果更加科学、准确.     

槲皮素对蛋鸡生产性能及脂类代谢的影响

试验旨在研究槲皮素对蛋鸡生产性能及脂类代谢的影响。选择240只29周龄的海赛蛋鸡,随机分为4组,每组6个重复,每个重复10只鸡。对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ组分别在基础日粮中添加0.02%、0.04%和0.06%槲皮素,试验期为8周。结果表明,与对照组相比,试验Ⅰ组槲皮素能显著提高蛋鸡产蛋率与血清胰岛素含量(P<0.05),显著降低肝脏粗脂肪含量(P<0.05);试验Ⅱ组槲皮素显著提高了蛋黄粗脂肪、蛋黄总磷脂、血清胰岛素和雌二醇的含量(P<0.05),显著降低料蛋比、肝脏粗脂肪含量(P<0.05),且低密度脂蛋白胆固醇有下降的趋势(P>0.05);试验Ⅲ组槲皮素能提高蛋鸡产蛋率、蛋黄粗脂肪与总磷脂的含量,但差异不显著(P>0.05)。因此,0.04%槲皮素为适宜添加量,能提高蛋鸡生产性能和蛋黄中磷脂含量,降低肝脏粗脂肪含量。     

阿什河流域非点源氮污染的δ15N源解析研究

农业活动往往沿着河流而发展,其产生的氮污染极大地影响了流域水质量。选择以种植业为主的阿什河作为典型流域,利用水质、土壤监测技术和¹⁵N稳定同位素示踪技术,对流域水体氮污染、种植业土壤氮特征以及氮污染来源进行解析。结果表明阿什河水质总氮浓度较高,氮污染较严重;位于上游的采样点水质较好,中游开始到下游水质逐渐恶化。种植业对于流域水体氮污染的影响根据水期以及种植周期的不同而有着不同的影响方式:平水期以种植业非点源氮污染为主要污染源的区域主要分布在中下游处,其δ¹⁵N值为0.46%～0.77%,表现为人工合成化肥和农田退水造成的土壤有机氮污染;丰水期以种植业非点源氮污染为主要污染源的区域较多,其δ¹⁵N值集中在0.19%～0.40%;上游地区以人工合成化肥为主要污染源,中下游以雨水及灌溉冲刷种植区土壤而形成的土壤有机氮来源为主。枯水期也有部分地区受到以人工合成化肥为主要污染源的氮污染,其δ¹⁵N值为0.11%～0.38%,主要是由于雨季人工合成化肥中的硝态氮下渗到土壤下层,当枯水期时地下径流补给河流,其中滞留的硝态氮对河水造成污染。     

Expression and histogenesis of matrix metalloproteinase-9 and transforming growth factor-beta 1 in acute cerebral ischemia model of rats

AIM:To observe the expression and tissue localization of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta 1 (TGF-β1) in the rat acute cerebral ischemia model. METHODS:Male Wistar rats were used to establish acute cerebral ischemia model by a suturing method. The rats were divided into normal control group, sham group and ischemia 6 h, 12 h, 1 d, 2 d, 6 d and 14 d groups. The rat cerebral cortex and hippocampus of the brain were collected at different time points.The mRNA and protein levels of MMP-9 and TGF-β1 in the brain tissues were detected by real-time PCR and in situhistochemistry staining, respectively. The levels of MMP-9 and TGF-β1 in the plasma were also measured by ELISA. RESULTS:The results of real-time PCR showed that the mRNA levels of MMP-9 began to increase 6 h after acute ischemia and reached to a peak 2 d after acute ischemia. Similarly, the mRNA level of TGF-β1began to rise 12 h after acute ischemia and reached to the highest level 6 d after acute ischemia. Compared with the sham rats, the mRNA levels of MMP-9 and TGF-β1 in the rat brains that collected at ischemic time of 12 h, 1 d, 2 d, 6 d and 14 d were significantly increased. Moreover, results of in situhistochemical staining showed that the expression of MMP-9 was detected at cerebral cortex and hippocampus 1 d after acute cerebral ischemia.Further studies showed that MMP-9 dyeing of the rat cerebral cortex was most obvious 2 d after the acute cerebral ischemia. Similarly, the rat cortex and hippocampus began to express TGF-β1 2 d after acute ischemia and TGF-β1 staining at rat cerebral cortex was most obvious 6 d after the acute cerebral ischemia. In addition, ELISA showed that the increase in MMP-9 and TGF-β1 was detected in the plasma 12 h after ischemia. Compared with the sham rats, the level of these 2 factors significantly upregulated since 1 d after ischemia. CONCLUSION: The brain tissue itself contributes to the upregulation of MMP-9 and TGF-β1 post acute cerebral ischemia, which shed light on the related research in the field.     

Correlation Between Physicochemical Properties and Eating Qualities of Rice

Correlation among physicochemical properties, which include amylose content, alkali spreading values, gel consistency, water absorption, expansion rate, solid content of rice-water, protein content and fat content, and eating qualities of six kinds of rice samples planted in Heilongjiang Province were studied. Correlation analysis showed that amylose content, water absorption and expansion rate were negatively correlated with eating qualities, yet gel consistency, alkali spreading values, solid content of rice-water and fat content were positively correlated with eating qualities. Among them, eating quality had an obvious correlation with amylose content and gel consistency, but no significant correlation with protein content. The regression equation, which described the relationship of the eating quality scores and physicochemical indexes, was Y=94.439–12.711X1–23.721X2–0.701X3＋0.570X4＋186.938X5（X1, X2, X3, X4 and X5 represented amylose content, water absorption, expansion rate gel, consistency and fat content）. The single factor analysis of variance showed that six kinds of rice existed significant differences in quality category.     

利益群体视角下参与式技术开发的动机研究

采用参与式观察法对参与式实用技术创新研究过程参与者(农民研究人员和专业研究人员)需求、动机和行为进行了观察，并从心理学和行为学角度进行分析，初步提出确保农民和研究工作者主动参与的动力机制和约束机制，以期为参与式项目研究和管理提供方法论层面的指导。     

温度对烟草叶片细胞壁物质含量及组成变化的影响

为探究温度影响烟草叶片细胞壁建成的机理和烟叶品质的机制,连续2年设置不同温度(15℃、20℃、25℃、30℃)处理的盆栽试验,研究不同温度对烟草叶片细胞壁物质含量和组成及合成酶基因表达量的影响.结果表明,含碳化合物在烟草叶片生长过程中及温度处理过程中发生了重新分配,随着烟草生长时间的延长,叶片中结构性碳水化合物(纤维素...     

阿特拉津降解菌W24的分离鉴定和土壤修复效果研究

从玉米田土壤中分离出1株阿特拉津降解菌W24,通过生理生化反应和16S rRNA序列分析,鉴定该菌株为类节杆菌(Paenarthrobacter sp.)。菌株W24能利用阿特拉津作为氮源生长,当底物浓度为100 mg/L时,在适宜温度(20℃～35℃)、pH值为6～9,该菌株对阿特拉津的降解率均在40%以上、在最适温度(30℃)、pH值为7条件下培养72 h后,降解率达94.2%;当底物浓度为500 mg/L时,阿特拉津降解率仍达到40.4%。污染土壤的生物修复结果表明,菌株W24在培养35 d时对污染土壤中阿特拉津(50 mg/kg)的降解率为83.5%,菌株W24表现出很好的应用潜力。