日粮阴阳离子和纤维素酶对绵羊血液中生化指标的影响

选体重为38kg左右的永久瘤胃瘘管羊5只,采用5×5拉丁方设计,研究不同水平阴阳离子和纤维素酶对绵羊血液中生化指标的影响。对照组饲喂基础日粮,处理组1为纤维素酶组(日粮的0.2%),处理组2为DCAB(20mEq/100g DM),处理组3为纤维素酶(日粮的0.2%)+DCAB(20mEq/100g DM),处理组4为纤维素酶(日粮的0.2%)+DCAB(40mEq/100g DM)。试验结果表明:不同水平的阴阳离子和纤维素酶对T3、T4的浓度的影响差异不显著(P>0.05);对胰岛素浓度的影响差异显著,处理组高于对照组(P<0.05);血糖浓度对照组与处理组2差异显著(P<0.05),血液中其他生化指标均在正常生理范围内且组间差异不显著(P>0.05)。本试验结果表明日粮中添加0.2%纤维素酶和DCAB值为0~40mEq/100g DM的阴阳离子没有损害绵羊各组织器官。     

A method of production data analysis for multi-fractured horizontal well in shale gas reservoir

Production data analysis is an effective method of evaluating gas in place, parameters of reservoir and hydraulic fractures. Current model of production data analysis fails to make sense because of the existence of absorption, multi-fracturing, and stimulated reservoir volume (SRV). Considering the effect of desorption, fracture interacting and closed boundary, the authors calculate the productivity of multi-fractured horizontal well in shale gas by Laplace transform and pressure superposition principle. Then theoretical charts of Agarwal-Gardner production decline curves are presented by employing new definition of dimensionless material balance time and dimensionless production, which is based on asymptotic approximations. The result shows that Agarwal-Gardner curves can be divided into two parts where they are scattered in early transient period, and where their shape was influenced by parameters relevant to adsorption, position of each fracture and reservoir geometry, and then drawn to Arps harmonious decline in pseudo steady state period. Reservoir parameters, hydraulic fracture characteristics and gas in place are evaluated by using the type curve matching with actual production data.     

基于无线传感器网络的温湿度监测系统设计与实现

给出了以CC2430芯片为核心的环境监测无线传感器网络实现方案.设计中充分考虑到节点的剩余能量、链路质量和节点负载等因素,提出了一种能耗均衡树算法,使网络节点的负载逐渐趋于均衡,解决了因负载分配不均衡,使得网络节点出现过早失效、缩短网络寿命问题.实验表明,算法可均衡节点负载,延长网络的生存时间,实现网络的长效运行.     

玉米种子内部机械裂纹产生与扩展的微观机理

应用Cottrell位错塞积模型分析了玉米种子内部机械裂纹产生机理,采用Griffith能量平衡理论和分形几何理论推导了机械裂纹扩展速度与扩展路径维数计算公式,并对内部机械裂纹扩展速率进行分形分析.结果表明:当玉米种子局部所受应力达到一定时,其内部即产生机械裂纹;根据玉米种子内部机械裂纹扩展运动学公式,内部裂纹扩展宏观速度小于分形扩展速度;由玉米种子内部机械裂纹扩展路径的分形维数公式求出其维数为1.1395;淀粉颗粒尺寸相同时,裂纹沿淀粉颗粒扩展的速率最快.     

农田管理措施对滨海盐渍化土壤碳平衡的影响

为研究不同农田管理措施对滨海盐渍土壤碳平衡的影响,通过玉米-小麦轮作试验,研究农田土壤碳收支情况。试验共设6个处理:(1)常规对照(CK),(2)有机肥常量(OF),(3)氮肥增施(NF),(4)秸秆还田(S),(5)有机肥加秸秆(OF+S),(6)免耕(NT)。结果表明,秸秆还田和施用有机肥提高了土壤呼吸的强度,而NT处理的CO_2平均释放量最低,不同处理下土壤呼吸表现为OF+S处理S处理OM处理NF处理CKNT处理。各处理土壤有机碳量随着作物种植年份的增加而逐渐升高,其中OF与NT处理增加最多,而NF处理并没有显著提高土壤的有机碳量。在两季作物收获后,各处理的碳输入均高于碳输出,表现为碳净输入,呈现较强的碳汇特征。S处理和OF处理的碳净输入均显著高于CK,可有效减缓土壤CO_2排放,增加其有机碳的输入。     

铁锰营养平衡与水稻生长发育

通过实地考查、土培试验，对水稻“黄化病”与铁锰平衡的关系、铁锰平衡失调对水稻生长发育的影响及其调控措施进行了探讨．结果表明；水稻“黄化病”是由于土壤中过量的锰及有效铁锰比低，使水稻积累过多的标而降低活性铁含量水平，使水稻受到生理缺铁胁迫和铁锰营养平衡失调，而诱发的生理病害；铁锰平衡失调使水稻生长发育严重受阻、产量极显著降低；施用硅酸盐、石灰或叶面喷施铁后，均有利于改善水稻铁锰营养平衡，促进水稻生长发育．     

山东省引黄项目区农业灌溉水平衡分析研究

山东省利用世界银行贷款加强灌溉农业(二期)引黄项目区,插花分布在10个县,水资源时空变化大,灌溉水源除当地水外还引用黄河水补充灌溉,引黄水和当地水丰枯遭遇不同,因此进行项目区水资源供需平衡分析对项目立项和建成后可持续发展具有重要作用。采用典型年净平衡和水平衡模拟模型2种方法,对引黄项目区农业灌溉水资源水平衡进行了分析计算,使农业灌溉水资源评价结果更加科学和符合实际。     

Evolution of dinitrogen and nitrous oxide from the soil to the atmosphere through rice plants

Summary It is commonly assumed that a large fraction of fertilizer N applied to a rice (Oryza sativa L.) field is lost from the soil-water-plant system as a result of denitrification. Direct evidence to support this view, however, is limited. The few direct field, denitrification gas measurements that have been made indicate less N loss than that determined by ¹⁵N balance after the growing season. One explanation for this discrepancy is that the N₂ produced during denitrification in a flooded soil remains trapped in the soil system and does not evolve to the atmosphere until the soil dries or is otherwise disturbed. It seems likely, however, that N₂ produced in the soil uses the rice plants as a conduit to the atmosphere, as does methane. Methane evolution from a rice field has been demonstrated to occur almost exclusively through the rice plants themselves. A field study in Cuttack, India, and a greenhouse study in Fort Collins, Colorado, were conducted to determine the influence of rice plants on the transport of N₂ and N₂O from the soil to the atmosphere. In these studies, plots were fertilized with 75 or 99 atom % ¹⁵N-urea and ¹⁵N techniques were used to monitor the daily evolution of N₂ and N₂O. At weekly intervals the amount of N₂+N₂O trapped in the flooded soil and the total-N and fertilized-N content of the soil and plants were measured in the greenhouse plots. Direct measurement of N₂+N₂O emission from field and greenhouse plots indicated that the young rice plant facilitates the efflux of N₂ and N₂O from the soil to the atmosphere. Little N gas was trapped in the rice-planted soils while large quantities were trapped in the unplanted soils. N losses due to denitrification accounted for only up to 10% of the loss of added N in planted soils in the field or greenhouse. The major losses of fertilizer N from both the field and greenhouse soils appear to have been the result of NH₃ volatilization.     

碳平衡法测量汽油车燃油消耗量的研究

针对当前车辆燃油消耗量测量操作不便的问题,根据碳平衡法油耗量原理,建立了采用流量计的碳平衡法油车油耗测量模型及测量系统,并在实车上进行了试验验证,结果表明：该方法具有较高的精度及稳定性,为车辆耗油量的不解体测量提供了理论依据及应用可能性。     

长江中下游地区温室内温湿度预测模型的研究

该文利用传热学理论,以温室热平衡模型为基础,分析了温室内温度和湿度的动态模型,并以此建立了室内温湿度预测模型.最后,作者通过SR5.2型连栋塑料温室的实验研究,求出该模型参数,为实现智能温室前馈控制奠定基础.