铜中毒对雏鸭某些血液指标的影响

选用1日龄天府肉鸭210只,随机分为3组,分别喂以对照日粮(Cu12.16mg/kg)、铜中毒日粮(Cu850mg/kg)和铜中毒日粮(Cu1050mg/kg)。试验期7周。以血液病理学方法观察了铜中毒对雏鸭某些血液学指标的影响。结果显示铜中毒组、组雏鸭分别于2周龄和3周龄开始出现临床症状,死亡18只和5只。血液病理学变化表现为,红细胞大小不等、变形变性、坏死溶解;红细胞数量和血红蛋白含量显著降低(P<0.01),血清谷丙转氨酶、谷草转氨酶活性显著升高(P<0.05或P<0.01),血清铜蓝蛋白活性下降。结果表明,铜中毒对雏鸭的生长发育和上述血液指标影响明显。     

Effect of water restriction on milk yield and quality in Lacaune breed ewes

The effect of water restriction on body weight, body condition score, milk yield, and milk composition and rheological characteristics in intensively reared Lacaune ewes was evaluated. After 7 days of adaptation, the trial lasted 28 days. Thirty lactating ewes (48 ± 5 months of age; mean value ± standard deviation) at the beginning of third lactation month were divided into three groups (n = 10), corresponding to the following water restriction treatment: a group control received no drinking water restriction (W100), and two groups received water to the extent of 80% and 60% of W100 daily consumption (W80 and W60 group respectively). The effects of water restriction were assessed at the beginning of experiment (D0), at D14 and D28. The W60 group resulted in a significant decrease in body weight, body condition score, milk yield and feed consumption of hay due to the experimental treatment; whereas a marked increase in both W60 and W80 groups of milk lactose, urea, sodium, sodium chloride content and titratable acidity was observed. Rheological parameters of milk, rennet coagulation time and curd‐firming time were positively affected by water restriction treatments, with a decrease in both experimental groups of the time required for the formation of a stable and firm curd. Results highlight the importance of water consumption in dairy sheep. The scarce availability of water, significantly affecting ewes milk production, is worthy of particular attention in arid area where water stress‐resistant breeds should be considered. This study underlines that milk yield, being closely linked to the availability of water of the breeding habitat due to its high water content (about 81%), could be reached in area where water is not a limiting factor without reducing the genetic expression of the animals. Less severe water restrictions, such as 20% of daily voluntary water intake, produce no detrimental effect on milk yield.     

穗期玉米昼夜生理状态规律的遥感综合探测研究

针对QY、PRI、NDVI、水势分别从不同的方面反映玉米的生理状况,以甜糯二号玉米作为材料,通过田间试验测量玉米昼夜4个参数值,研究了QY、PRI、NDVI、水势4个参数的昼夜变化,并且分析它们之间的相关性。结果表明,QY、水势、PRI三者具有很强的相关性,并且能建立回归模型表示它们之间的联系。     

育苗轻型基质块配方研究

为充分利用南方果树废弃物资源,以香蕉菠萝废弃茎叶堆肥和椰糠作为基质材料,添加粘合剂、固化剂、改良剂,制作出基质块。采用正交法设定基质块配方,通过测试分析基质块的理化性状,确定最佳的基质块配方。结果表明,香蕉菠萝废弃茎叶堆肥和椰糠的配比是影响基质块理化性状的主要因素,各因素影响的主次顺序为:基质配比改良剂粘合剂固化剂;综合分析,A3B2C3D3组合配方具有最佳的理化性状,即基质配比(堆肥:椰糠)为4:6,粘合剂(聚乙烯醇)为4%,固化剂(硼砂)为2.5%,改良剂为140%。     

高校心理健康教育网络课程模式的构建与实例分析

计算机多媒体技术和网络技术日新月异的发展,教育信息化的推进,为努力实现高校心理健康教育课程教学内容、教学手段和教学方法的全面创新,本文以《心理健康教育》网络课程为例,尝试剖析其在模式构建、教学设计、交互安排、教学应用等方面的特征,以期为开辟高校心理健康教育课程的新模式提供思路。     

三维CAD技术在机械设计中的应用

现代计算机在技术和性能上越发成熟,再加之网络的普及和信息的智能化处理技术的提高,三维CAD技术本身也正逐步成熟,因此,正确地把握CAD技术的发展趋势对我国机械工程中的设计工作具有深远的意义.     

Temperature modeling of a land-based aquaculture system for the production of Gracilaria pacifica: Possible system modifications to conserve heat and extend the growing season

Temperature control is a major cost for numerous aquaculture systems. Solar thermal engineering techniques can be used to identify inexpensive methods for conserving and capturing heat. Gracilaria pacifica, also known as the culinary ingredient ogo, is currently grown in land-based tanks at a site in Goleta, CA where influent sea water temperatures infrequently reach the 21–28 °C range that provides for optimal growth. The major objective of this study was to explore various designs of a G. pacifica tank culture system that maintain optimal water temperature year round to maximize growth. A model was constructed and calibrated by comparing results to a one-third scale pilot system operated in Davis, CA. For model calibration the most sensitive parameter such as cover optical properties were adjusted first and less sensitive parameters were adjusted later. The pilot system consisted of six tanks, three insulated with foam and a clear polyethylene cover (experimental), and three uninsulated and uncovered (controls). The model had weather data inputs including air temperature, humidity, wind speed, and solar radiation. The model was then compared to a full-scale system operated in Santa Barbara during the winter. The experimental pilot system was 4.93 °C warmer than the control pilot system under optimal weather conditions. The full-scale experimental system was 2.80 °C warmer than the control system under non-ideal conditions. The model demonstrated predictive accuracy under most weather conditions. Furthermore the model is robust enough to accept estimated values for many inputs and still produce accurate results, this suggests a simpler model may be feasible. A polyethylene cover and insulation are not sufficient in general for raising the water temperature to the optimum range during the winter; they may be during other times of the year when more solar energy is available, thereby extending the growing season.     

基于Web内嵌Office控件的文档管理平台研究

阐述了基于web内嵌office控件的文档管理平台的基本框架结构,详细介绍了利用web-office控件实现模板的创建和文档的创建的设计原理,以及整个文档管理平台模块的详细功能实现。     

食用菌文化在现代景观设计中的应用探索

回归现实生活、构建人文审美体系是现代景观设计的发展趋势。在现代景观设计过程中,对食用菌文化元素进行合理改造、运用,使景观富有文化内涵,呈现独特的艺术气息。通过分析食用菌文化在现代景观设计中的应用背景与价值,提出提取造型、创造生态场景和营造审美意境等设计建议。     

行星轮系水稻钵苗移栽机构正反求设计方法研究

为了解决现有行星轮系水稻钵苗移栽机构较难同时具备理想的移栽轨迹和姿态的问题,提出了正向设计与局部轨迹微调的反求设计相结合的设计方法。以非圆齿轮行星轮系水稻钵苗移栽机构的设计为例,阐述该方法的实现过程。建立行星轮系水稻钵苗移栽机构设计要求,并分析其工作原理,在前期正向设计的基础上,局部调整其移栽静轨迹,通过反求设计进一步优化设计移栽机构。进行局部反求设计的运动学分析和运动学建模,基于Matlab平台开发计算机辅助设计软件,通过人机交互的方式得到移栽机构的机构参数,使其不仅满足移栽臂移栽的姿态要求,同时获得更理想的移栽工作轨迹。根据最终得到的机构参数设计移栽机构结构,完成三维建模、虚拟仿真试验,加工、装配移栽机构物理样机,完成了高速摄像运动学试验。将移栽机构理论计算、虚拟仿真、样机试验得到的移栽静轨迹比较,同时逐一将轨迹相关参数、取秧角、推秧角、角度差等设计目标参数与相应数值化目标进行对比,结果显示,均满足要求,验证了设计方法的正确性。与以往单一的正向设计、反求设计方法相比,该方法设计的移栽机构不仅具有更优的移栽工作轨迹,也可满足较好的移栽姿态要求。