金昌市郊农田土壤重金属的污染特征

以金昌市郊农田表层土壤(0～20 cm)为研究对象,研究了土壤中重金属Zn、Ni、Pb、Cu、Cd的含量情况及可能来源,并对土壤中重金属污染进行了潜在生态风险评估.结果表明,金昌市郊农田土壤重金属的累积现象比较明显,尤其是Cu、Ni,二者的几何平均值均超过了国家土壤环境质量二级标准(GB15618-1995).相关性分析表明Cu与Ni,Pb与Cd之间分别呈显著正相关;Pb与Ni、Cu之间则呈显著负相关.因子分析显示,研究区土壤中的Cu和Ni主要来源于工矿业活动;农业生产活动则对Zn、Cd、Pb的贡献最大.潜在生态风险评估的结果为Pb、Zn这两种元素的潜在生态风险均处于低危害水平,Cd、Cu、Ni则均存在不同程度的潜在生态风险,具体的潜在生态风险排序为Cd＞Cu＞Ni＞Pb＞Zn.     

Study on the Changes of Reproductive Hormone and Regulation of Follicle Development During the Reproductive Cycle of Yili Goose in Xinjiang

This experiment was aimed to study the changes of reproductive hormone and regulation of follicle development during the reproductive cycle of Yili goose in Xinjiang. 2 years old Yili goose were chosen which were in good health and similar weight. 32 samples were randomly selected to take blood samples for hormone detection during the laying, broodiness and ceased periods, and 15 samples were randomly selected to gather ovarian tissue for the observation of the development of ovary and follicular. The results showed that during the laying period, the GnRH of the Yili goose was extremely significantly higher than the broodiness and ceased periods of 16.78% and 58.29% (P<0.01);PRL was significantly lower than the broodiness period of 13.00% (P<0.05), and was extremely significantly higher than the ceased period of 28.94% (P<0.01); FSH was higher than the broodiness period of 6.98% (P>0.05),and was extremely significantly higher than the ceased period of 21.12% (P<0.01); LH was extremely significantly lower than the broodiness period of 8.38% (P<0.01),and was extremely significantly higher than the ceased period of 16.84% (P<0.01); E₂ were extremely significantly higher than that the broodiness and ceased periods of 29.80% and 112.40% (P<0.01); P₄ levels were extremely significantly higher than the broodiness and ceased periods of 28.89% and 30.34% (P<0.01). The ovary volume and weight of Yili goose were extremely significantly higher than that of broodiness and ceased periods (P<0.01). In the laying period, the mature follicles of Yili goose were significantly larger than that of the broodiness and resting periods, the number of secondary follicles was more and the number of primary follicles was lesser. Ovarian growth and mature follicle atresia, granule layer shrinkage, inward depression, cytoplasmic cavity, follicular atrophy at all levels in the broodiness period. The follicle cytoplasmic cavity of the ovary was larger in the ceased period than broodiness period, and inward concave further deeper, a large number of primordial follicles evenly arranged. Thus, during the laying period, the responses of GnRH, E₂ and LH of Yili goose were active and played a leading role on the development of ovarian and follicular. PRL and LH maintained a high level of secretion, cooperated to maintain the broodiness behavior during the broodiness period.     

Physiological but not morphological adjustments along latitudinal gradients in a human commensal species,the Eurasian tree sparrow

Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural environments. Their morphological and physiological phenotypes can therefore dissociate from habitat characteristics. Understanding how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping mechanisms. Here, we studied morphological traits in breeding Eurasian tree sparrows (ETSs; Passer montanus) among low-latitude (Yunnan and Hunan) and middle-latitude (Hebei) localities in China. We then compared body mass; lengths of bill, tarsometatarsus, wing, total body, and tail feather; and baseline and capture stress-induced levels of plasma corticosterone (CORT) and the metabolites including glucose (Glu), total triglyceride (TG), free fatty acid (FFA), total protein, and uric acid (UA). None of the measured morphological parameters varied with latitude except in the Hunan population, which demonstrated longer bills than those in other populations. Stress-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude, but total integrated CORT levels did not vary with latitude. Capture stress-induced significantly increased Glu levels and decreased TG levels, independent of site. However, the Hunan population had significantly higher baseline CORT, baseline and stress-induced FFA levels, but lower UA levels, which differed from other populations. Our results suggest that rather than morphological adjustments, physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in ETSs. It is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.     

中林-46杨他感作用初探

为了提高中彬－４６杨混农速生丰产林的生产能力,用中林－４６杨根系浸提液处理主要农作物和常见田间杂草种子进行发芽试验,结果表明：中林－４６杨的他感作用是存在的,其根浸的液对大豆种子的萌发没有影响,但对其幼苗的生长有极显著的促进作用;低浓度的浸提液对花生生长的影响不明显,高浓度时则有极显著的促进作用;     

An in vivo analysis of the therapeutic and synergistic properties of Chinese medicinal formula Yin-Chen-Hao-Tang based on its active constituents

6,7-Dimethylesculetin (D), geniposide (G) and rhein (R) are the three major active ingredients of Yin-Chen-Hao-Tang (YCHT), a famous Chinese herbal formula, which has been shown to be clinically effective for treating hepatic injury (HI) syndrome. The present study was conducted to investigate the therapeutic and synergistic effects of COC (combination of D, G and R) on HI rats by combining pharmacokinetic with biochemical analysis strategy. Plasma was analyzed by using reversed-phase high performance liquid chromatography (RP-HPLC). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) models were built to evaluate the therapeutic and synergistic effects of COC at the biochemical level. Here, we report that the COC combination could increase the plasma level, slow elimination rate, exert a more robust therapeutic effect than any one or two of the three individual compounds by hitting multiple targets in a rat model of HI. Overall, this beneficially accounts for the popular view that traditional Chinese medicine (TCM) formula usually takes multi-component to exert their therapeutic effects. We suggest that dissecting the mode of action of clinically effective formula to be capable of producing a sufficient effect at low doses.     

补饲不同配方酶制剂对犊牛断奶后生产性能的影响

选择健康无病、6- 7月龄间断奶的公牛犊 30头 ,随机分成 3组 ,即对照组 CK、试验组 TE1和 TE2 ,每组 1 0头。对照 CK组饲喂基础日粮 ;试验 TE1和 TE2 组分别补饲0 .1 %由纤维素酶、果胶酶、蛋白酶与淀粉酶组成的酶制剂 E1和由木聚糖酶、果胶酶、蛋白酶与淀粉酶组成的酶制剂 E2 ;试验 60 d,测定加酶对生产性能的影响。结果表明 ,与 CK组相比 ,TE1组日增重提高 7.51 % (P<0 .0 5) ,混合精料、粗料与增重比各下降 7.0 0 % (P<0 .0 5)、1 .2 3% (P<0 .0 5) ;TE2 组增重提高 4.2 0 % (P<0 .0 5) ,混合精料、粗料与增重比各下降 3.86% (P<0 .0 5)和 0 .31 % (P>0 .0 5) ;试验组犊牛断奶后对粗饲料的适应性有所增强 ;两组酶配方中 ,以纤维素酶为主的 E1效果优于 E2     

新型肘形进水流道水力特性预测

提出一种新型肘形进水流道,具有型线简单,容易设计和施工方便等优点。采用定常雷诺平均N S方程和标准kε紊流模型,数值模拟了该新型肘形进水流道的三维紊流。在详细分析内部流态的基础上,从流道出口断面轴向流速分布均匀度、出口水流偏流角和流道阻力系数3个方面对其水力特性进行了全面的预测,并与按常规设计的肘形进水流道的水力特性进行了比较。计算结果表明,新型肘形进水流道具有优良的水力特性,出口水流的轴向流速分布均匀度高,偏流角小,可为水泵提供良好的进水条件。     

基于MIKE BASIN的汕尾市水资源优化配置

在对汕尾市水文水资源情况调查分析基础上,基于MIKE BASIN数字平台构建了汕尾市水资源优化配置模拟模型。采用四级流域套县为计算单元,以河流、水库和山塘为供水水源,对基准年与规划水平年(2020年)在不同保证率下、不同需水推荐方案和供水推荐方案情况下,分别进行水资源供需平衡分析,从而使得城镇生活用水、农村生活用水、工业用水和农业灌溉用水及生态用水获得优化配置,以满足汕尾市规划水平年各类需水要求。     

马齿型玉米种子侧立定向定距输出装置的设计与试验

为了实现玉米种子的定向定距输出,该文设计了一种玉米种子侧立定向定距输出装置,并对其定向定距原理进行了分析。该装置包括侧立排序机构和定向定距机构2部分。侧立排序机构能够对成堆玉米种子进行分散、排序输送、分选和姿态变换使之变为一列呈侧立姿态排序的玉米种子,定向定距机构能够对侧立姿态的玉米种子进行定向和定距,使其尖端统一朝前、相邻种子之间间距一致,然后排序输出。以侧立喂入轨道的倾角α、振幅Z_1、定向定距转盘的角速度w和侧立输出轨道的振幅Z_2为因素,以玉米种子的定向定距成功率和定距间距为指标,对定向定距机构进行仿真试验,得到最佳工作参数:α为3°、Z_1为0.3 mm、w为30°/s、Z_2为0.3 mm。搭建玉米种子侧立定向定距输出装置进行性能试验,结果表明在最佳工作参数下该装置工作稳定,玉米种子定向定距成功率为90.7%,定距间距平均为45 mm。该研究为后续机械化玉米定向播种提供了参考。     

双质量飞轮内部传动结构强度及疲劳寿命分析

随着初级飞轮与次级飞轮相对转角的变化,分段变刚度双质量飞轮具有不同的刚度特性和非线性变化转矩,双质量飞轮内部传动结构作为传递动力和运动部分,结构可靠性和使用寿命必须保证.将建立的三维CAD模型导入HyperMesh软件中进行有限元分析前处理,建立了有限元分析模型,经过仿真求解计算,分析了结构变形、应力分布特点,对比分析...