5%烯唑醇微粉种衣剂的研制与应用

研制了以烯唑醇为主要成份防治玉米丝黑穗病的微粉种衣剂及其应用效果。经室内及盆栽试验筛选出防治玉米丝黑穗病的微粉种衣剂配方,并确定烯唑醇种衣剂加工工艺流程。通过盆栽试验、田间小区试验和区域试验,明确了烯唑醇种衣剂使用剂量、处理方法对玉米丝黑穗病的防治效果及对玉米生长发育的影响。试验结果表明,5%烯唑醇微粉种衣剂对玉米的发芽率、发芽势有提高的趋势。用烯唑醇微粉种衣剂包衣,在接种条件下防治玉米丝黑穗病效果在51.2%～60.3%,增产率38.6%～58.7%。异地试验示范防治玉米丝黑穗病效果在71.7%～96.2%,增产率6.8%～15.6%。生产上推荐剂量药种比1:200～1:300为宜。     

黄土高原小流域出口断面水力几何模型

流域出口断面水力几何关系能够为流域水文模型参数获取、洪水过程演变及灾害预警提供辅助工具。以黄土高原丘陵沟壑区桥子西沟和桥子东沟2水土流失对比流域为研究对象,首先采用幂函数、自然对数函数和二阶对数函数模型分别拟合桥子西沟流域1987—2006年出口断面水文观测数据,应用模型决定系数(R2)和模拟残差平方和(RSS)评价3种模型拟合结果,优选平均流速-流量、水面宽-流量与平均水深-流量的水力几何模型。然后将桥子西沟流域观测数据随机分为2部分:1987—2002年共594组数据用于率定优选模型,2003—2006年共362组数据用于验证。采用均方根误差(RMSE)、模型效率系数(E)以及图形拟合等手段评价各优选模型的有效性。桥子西沟流域模型率定及验证结果表明:平均流速-流量和平均水深-流量关系适用于自然对数函数表达(RMSE值为19.89%和30.70%,E值为0.59和0.84),而水面宽-流量关系则适用于二阶对数函数表达(RMSE=3.84%,E=0.87)。进一步应用桥子东沟流域1987—2006年出口断面共1 006组观测数据验证各优选水力几何模型在相似流域的适用性,结果表明:平均水深-流量关系拟合效果优于桥子西沟流域,而平均流速-流量和水面宽-流量关系拟合优度稍逊于桥子西沟流域。该研究为黄土高原地区小流域洪水监测与预报提供基础。      

28%灭菌唑悬浮种衣剂对玉米丝黑穗病防治效果试验

为选择新型防治玉米丝黑穗病的种衣剂,以玉米组合7551为试验材料,采用土壤接种玉米丝黑穗病病菌以测定28%灭菌唑悬浮种衣剂对其防治效果。结果表明:28%灭菌唑悬浮种衣剂对玉米丝黑穗病有较好的防治效果,且对玉米安全,可作为防治玉米丝黑穗病的种衣剂在生产上应用,建议28%灭菌唑悬浮种衣剂使用剂量为每100kg种子100~200mL·(100kg)-1。     

城市绿地不同植被群落对表层土壤入渗的影响

为探索郑州市城市不同植被群落对绿地表层土壤入渗的影响,以郑州市城区13种不同绿地表层土壤为对象,通过测定土壤物理性质及土壤饱和导水率,探讨了土壤物理性质对土壤入渗的影响。结果表明:1）不同绿地表层土壤的物理性质差别较大,乔灌草混合配置的绿地比单一种植的绿地理化性质更好,且土壤的物理理化性质易受到人为踩踏等因素的影响。2）不同绿地表层土壤水分入渗性能与持水能力差异显著,乔灌草混合配置的绿地比单一种植的绿地入渗性能和持水能力好,表现为较高的饱和导水率和田间持水量,其中银杏-麦冬配置的绿地饱和导水率最高,西府海棠-沿阶草配置的绿地饱和导水率最小;大叶黄杨单作绿地的田间持水能力最强,西府海棠-沿阶草配置的绿地田间持水能力最弱。3）土壤饱和导水率与总孔隙度呈极显著正相关关系,其中非毛管孔隙度与毛管孔隙度呈显著正相关关系。土壤饱和导水率与容重呈极显著负相关关系;田间持水量与土壤总孔隙度呈显著正相关。城市绿地建设采用乔灌草混合配置的形式,能有效提高绿地土壤的入渗能力和持水能力,降低城市内涝风险。     

水工弧形钢闸门振动及启闭机械维护分析

水工弧形钢闸门振动问题对水利枢纽营运安全具有重要意义。分析结构形式、工作性态与水力环境特点,得到环境边界条件、水流特性与结构自身形式对振动特性影响规律。数值计算与监测资料分析表明,开启角度、相对水深和结构形式均影响闸门振动位移、振动加速度、基频、自振频率等变化规律。     

甘蔗收获机切割器仿形机构研究现状与发展趋势

切割器是甘蔗收割机的重要工作部件之一。本文论述了国内外甘蔗切割器的研究状况和仿形技术的应用情况,对比了两种仿形机构模式的优缺点,针对蔗叶杂草等干扰传感器信号收集困难的问题,提出选用超声波传感器作为测距元件的方案,为甘蔗切割器仿形机构设计方案的选定提供了依据。     

Optical properties of the pineal window of Atlantic salmon (Salmo salar L.)

The spectral composition and intensity of light penetrating different parts of fresh preparations of the upper part of the skull of Atlantic salmon (Salmo salar) (fork length 25–30 cm) was investigated. All measurements were made in an aqueous medium, by moving the tip of an optical fibre in a three dimensional lattice below preparations that were illuminated by a parallel light source from above. The intensity of the transmitted light showed a well-defined maximum just below the pineal groove. Light that penetrated the skull from a source vertically above was refracted to produce a focusing point in the approximate position of the pineal body. Light projected from angles of 45° relative to the vertical position was only slightly (25%) attenuated, thus indicating a wide acceptance angle. There was an almost uniform transmission of light (of 3%) between 500 and 700 nm. The transmittance of UV light (350 nm) was about 10% of that of green light. These differences are small when compared with the intensity range reported for the pineal light receptors. The transmission properties are discussed in relation to the known diurnal changes in the spectral composition of natural light.     

濒危物种─—新疆大头鱼的生态和资源调查与保护对策的研究

１９９２年起对濒危物种──新疆大头鱼的生态进行了调查。调查的水域有：叶尔羌河、阿克苏河及其上游托什干河和库马里克河、塔里木河、博斯腾湖及上游开都河和天鹅湖、大西海子水库、渭干河水系及克孜尔水库和车尔臣河及新发现的喀依拉克湖等水域，行程１００００多ｋｍ。初步查清了新疆大头鱼的分布范围、生态要求及其数量演变。新疆大头鱼分布的海拔高程为８００～１２００ｍ之间，最高不超越１５００ｍ。栖息于水温较高的静水或缓流的湖泊中，仅为了产卵进行短距离的溯河徊游。现存有新疆大头鱼的水域仅为阿克苏河下游的艾西曼湖群、车尔臣河的喀依拉克湖和渭干河水系的克孜尔水库，并在库区下的河道中发现幼体。目前新疆大头鱼物种已极度濒危。新疆大头鱼系裂腹鱼亚科中生长快、个体大、性成熟年龄晚、繁殖力低的大型食肉性鱼类。运用Ｖｏｎ．Ｂｅｒｔａｌａｎｆｆｙ的理论生长方程求得的生长参数：－Ｋ＝０．０６３；ｔｏ＝０．２７５；Ｌ＝１１８．２ｃｍ；Ｗ＝２５８８４ｇ；ｔｉｐ＝１７．１龄；ｔｍａｘ＝４７．２龄。与历史上捕获的最大个体基本一致。并对新疆大头鱼的食性、繁殖、及其生态环境进行了初步研究。新疆大头鱼濒危的原因：１、新疆大头鱼生物学特性的本身决定它对环境要求苛刻     

Effect of dietary vegetable oils on health and liver histology of gilthead seabream (Sparus aurata) growers

There is an increasing trend towards the replacement of fish oil (FO) by vegetable oils in feeds for farmed fish, particularly marine carnivores. Previous researches on partial or complete replacement of FO by alternate vegetable oils for young gilthead seabream (Sparus aurata) were successful. The aim of the present study was to investigate the effects of different dietary vegetable oils on seabream growers' health and liver structure. Two dietary vegetable oil blends (Mix 1 and Mix 2), namely sunflower oil, cottonseed oil and either linseed oil (LO) or soybean oil (BO), were tested as 60% FO substitutes versus the 100% FO control (CTR) diet. Three isonitrogenous (∼47% CP) and isolipidic (18.2% L) diets were fed, twice a day, 6 days a week to apparent satiation, to triplicate groups of seabream growers (mean IW, 130.85 g) in PVC tanks. The growth trial lasted for 20 weeks at an average ambient water temperature of 27.0±1.8°C. At the end of the experiment, fish attained market size (300–400 g) and their health status was evaluated by blood analyses, head kidney prints and liver histology. Haemoglobin and haematocrit contents, erythrocyte (RBC) and leucocyte (WBC) count remained significantly unaffected by any dietary treatments. Despite the apparent relatively higher thrombocyte counts for fish fed vegetable oil diets, especially Mix 2 as compared with those of CTR fish, variations were found to be insignificant (P>0.05). However, a slight deformation in erythrocyte shape was noticed in the blood films of fish fed the vegetable oil diets. Inclusion of either dietary vegetable oil blend had also elevated the number of both developing myelocytes and phagocytes in fish head kidney prints examined compared with those of CTR fish particularly for Mix 2 group. Liver from seabream fed vegetable oils showed slightly swelled hepatocytes due to accumulation of oil droplets in the cytoplasm. In the liver sections investigated ultra‐structurally, nuclei and cytoplasmic organelles were shifted towards the cell periphery. Hepatocytes of fish fed Mix 2 diet showed relative shrinkage and picnotic nuclei, compared with those of CTR fish, suggesting an effect on lipid transport and/or metabolism in fish. The comparative hepatic features between experimental fish groups were described. Accordingly, Mix 1 diet (with LO) was considered better than Mix 2 (with BO) in terms of influence on seabream growers' health status.     

YZC28-200液压机主液压缸泄漏故障分析及其改进

分析了YZC28—200液压机主液压缸发生泄漏的原因,其是由主液压缸O形密封圈压缩率过小所致。采用在柱塞端部新增沟槽的方法解决了这一泄漏问题,改进后液压机工作正常。