变流量冷冻水系统温差控制法的适用性

研究了末端设置通断控制阀的一次泵变流量系统在温差控制下的水力特性,并结合风机盘管与房间的非线性换热耦合特性,进一步探讨了温差控制的适用条件以及变温差控制温差值的设定方法。结果表明：末端设置通断控制阀的系统,当管网整体负荷分布均匀且各开启用户的负荷变化规律相近时,温差控制同样是较为适用的,此时系统的水力失调对室内温湿度的影响较小;采用变温差控制时,仅以不同的总负荷率分段设置温差值,并不能获得良好的室内温湿度控制效果,建议以优先保证风盘除湿能力和室内干球温度为原则设定温差值,相比于目前的方法,在同等的室内相对湿度波动下,室内温度的稳定性可以得到保证。     

寒冷地区建筑负荷对围护结构热工参数的敏感性分析

为研究建筑围护结构属性对同一热工分区不同城市节能建筑负荷影响的敏感性,以同属于寒冷地区的兰州和郑州为研究目标所在城市,在节能65%的前提下将4种外墙、3种外窗和4种窗墙比进行组合得到了48个可能的办公建筑围护结构计算房间。分别计算了这些房间的冷负荷、热负荷和全年总负荷并分析了各热工参数对负荷的影响。通过与基准房间负荷对比,获得了具有不同热工性能的计算房间的节能率及最优的办公建筑围护结构。     

农大高诱1号对黔西北玉米不同种质资源单倍体诱导研究

以农大高诱1号作父本,进一步从黔西北玉米不同种质资源中筛选单倍体诱导率较高的合适母本,实现配子选择,有利于优良基因型的入选频率,用于选育综合性状好的纯系,组配出更加高产和优质的玉米新品种。研究表明,农大高诱1号对黔西北玉米不同种质均有一定的诱导率。自交系的单倍体平均诱导率为1.86%,其中P群的02 H 58诱导率最高(5.54%),兰卡斯特群的木6次之(2.43%);在不同杂交种质中,兰卡斯特×P群杂优模式下的毕单18诱导率最高(5.85%),苏湾×苏湾杂优模式下的T 32×R 273次之(4.94%)。不同基因型单倍体诱导率有一定的差异。     

K近邻的自适应谱聚类快速算法

利用时域递归展开算法对墙体内热湿耦合传递方程进行求解。以木板为例,应用该算法进行了热湿耦合传递的分析计算,在时间域和空间域上分别运用递归展开法和控制容积法进行离散,从而得到递归形式的线性方程组,运用MATLAB软件对这一过程进行求解。计算结果与有限差分算法、解析解计算结果以及实验数据吻合良好,表明该算法能够用于求解多孔介质热湿耦合传递模型。时间步长的改变对计算结果影响较小,可通过增加时间步长方法来减少工作量。     

巴西橡胶树单个花粉细胞显微分离

巴西橡胶树是一种重要的热带产胶作物。因巴西橡胶树基因高度杂合,容易受到遗传或环境影响,为了不受群体效应的干扰,以巴西橡胶树‘热研7-33-97’的幼嫩雄花为试验材料,利用显微分离技术获取单个花粉细胞,使用5%纤维素酶+4%果胶酶混合酶和8%纤维素酶+6%果胶酶+3%蜗牛酶混合酶在不同条件(温度,时间)下,探索花粉细胞壁的最佳酶解体系。结果表明：8%纤维素酶、6%果胶酶和3%蜗牛酶混合酶在42℃条件下水浴15 h酶解效果最佳;同时利用随机引物(S2147和S1402)对酶解后的单个细胞进行酶解去壁效果的RAPD-PCR扩增鉴定,结果揭示该酶解体系能对花粉细胞进行去壁,使核酸物质得以释放并扩增。本试验以单个花粉细胞为研究对象,进行花粉细胞的显微分离,酶解去壁及RAPD-PCR扩增鉴定,为后续进一步开展‘热研7-33-97’单细胞全基因组测序、构建遗传图谱及橡胶树分子辅助育种等提供了科学依据。     

5个玉米自交系数量遗传分析

选用5个玉米优良自交系按双列杂交设计,对其株高、穗位高、茎粗等7个主要性状进行遗传分析.结果表明各个性状广义遗传力达到29%以上,其中穗长的遗传力最大,达到 59%;在杂种优势率方面,Suwan3×Suwan1、Suwan3×下层云优78、NS1×下层云优78、台南 17×Suwan1、台南 17×下层云优78组合较好.其中Suwan3×下层云优78、台南 17×下层云优782个组合鲜重的中亲优势率均为正值,最高迭 13.05%.其超亲优势率分别为 4.86%和 3.12%;在配合力方面,穗长一般配合力并不显著,而特殊配合力却达到极显著水平,表现出较强的非加性效应.可见,5个自交系的遗传力均达到中等及以上强度,下层云优 78、Suwan1 表现出较高的遗传力.在育种中具有一定的利用价值.     

稳定性氢氧同位素在植物用水策略中的研究进展

作为一种新的分析方法和示踪手段,稳定同位素技术近20多年来在植物生态研究中得以快速发展。文章系统介绍了稳定性氢氧同位素在植物用水策略研究中的最新进展,着重对该技术在确定不同生境下植物用水策略、区分不同功能群植物水分来源、植物水分再分配及指示环境气候信息等研究中的应用及前景作了阐述。     

京津地区夏季着装行为对办公建筑空调能耗的影响

着装行为通过影响室内空气参数的设定而影响建筑空调能耗。利用能耗模拟软件DeST,计算出该地区典型着装行为下实测运行参数与期望参数对应的建筑空调能耗比推荐标准下能耗分别降低了10.86%和13.16%。而基于典型着装行为的实验热学性能参数下,平均只降低4%,说明由着装热阻关联的主观温度需要按地区着装行为进行修正。提出了控制建筑空调能耗的着装行为调节模型,着装行为节能率ε_c为负值时节能,为正值时不节能。京津地区办公建筑节能率为0的临界服装热阻为0.563 clo,空调系统设计和运行节能的前提是,着装热阻低于临界值。着装行为调节模型为地区着装形式和着装面料提供了量化标准,为精确控制建筑能耗提供了一种方法。     

果胶酶和纤维素酶对尤力克柠檬出汁率的影响

以尤力克柠檬为材料,利用果胶酶和纤维素酶酶解柠檬浆,研究2种酶对尤力克柠檬出汁率的影响,确定柠檬最佳酶解工艺为:果胶酶用量0.2%,纤维素酶0.5%,酶解时间4h,酶解温度45℃,出汁率73.45%。     

衡阳盆地紫色土丘陵坡地自然恢复灌丛阶段植物群落主要种群生态位特征

通过对衡阳盆地紫色土丘陵坡地自然恢复灌丛阶段植物群落生态位特征进行研究,结果表明：（1）大部分种群水平生态位宽度不宽,只有3个种群宽度大于0.5以上;（2）垂直生态位也较窄,各种群垂直生态位多集中于0.1-0.3之间,占84.5%,表明对垂直空间利用不充分;（3）虽然各种群之间的生态位重叠值均非常小,但有78.00%的种对间存在水平生态位重叠,表明各种对间对资源的共享趋势较为明显,各种群对资源分享的程度很高;（4）所有的种对均存在垂直生态位重叠,表明各种对资源的分享程度极为剧烈;（5）各种对水平生态位相似性比例较低,而高度生态位相似性比例则较高,说明各种群对以光为主导因子的高度资源要求相似。     

一种新型淀粉基塑料玩具的制备及特性研究

以玉米淀粉为主要原料,辅以增塑、交联和增强反应,采用模压成型工艺,制备新型绿色环保淀粉玩具。采用物性测试仪,分析研究了制品的质构特性,并探讨了淀粉玩具的环境适应性能以及生物降解性能。结果表明,当淀粉∶PVA∶增塑剂∶交联剂∶辅强剂的质量比为100∶40∶60∶4∶26时,制备的淀粉玩具的最佳性能为:硬度14113.43g,内聚性0.972,弹性0.931,回复性0.682。将淀粉基塑料玩具在室温空气中放置10d后,其最大失水率为16.08%,弹性下降了9.1%;封装前最佳老化时间为24h;最适相对湿度为73.6%;土埋80d后,失质量率达到62.1%。     

桑园主要害虫的空间分布型研究

为了了解害虫种群的重要属性,笔者运用5种聚集度指标和2种回归分析方法,对桑园3种主要害虫桑白粉虱（Bemisia myricae Kuwana）、桑螟（Diaphania pyloalis Walker）、朱砂叶螨（Tetranychus cinnabarinus Boisduval）的空间分布型和抽样技术进行研究。结果表明,白粉虱随机分布型和均匀分布型中间偏于随机分布型,朱砂叶螨为聚集分布和随机分布型中间偏于随机分布型,桑螟为随机分布型和均匀分布型中间型,结果为这3种害虫的种群系统研究奠定了良好的基础。     

纤维素酶解辅助水提黄芪多糖的工艺条件

以蒙古黄芪为试验材料,研究纤维素酶解辅助水提黄芪多糖的工艺条件。考察水提温度、水提时间、水提次数、料液比4个单因素对黄芪多糖提取率的影响,在单因素试验的基础上,选择4因素3水平进行正交试验优化工艺参数。结果表明,蒙古黄芪在纤维素酶解预处理后,水提温度对黄芪多糖提取率影响显著,其次是料液比和水提次数,水提时间影响较小。在料液比1:12,水提温度100℃,水提时间1.5 h,水提3次,黄芪多糖提取率达4.76%,与传统水提法(3.09%)相比,黄芪多糖提取率提高了54.05%。     

Control strategy and parameters optimization outsourcing production inventory system under uncertainty

This paper proposes a control strategy for the optimal control of the outsourcing production inventory system based on production point and production batch. The statistical probability distribution is used to describe the uncertainty of the production capacity of cooperative enterprises and the transportation time. The optimization model of the control parameters is developed with random production capacity for cooperative enterprises and random transportation time in order to minimize the holding cost,setup cost as well as the cost of production capacity waste. A simulation-based control parameters optimization algorithm is designed to solve the proposed model. The control strategy of production inventory system and the control parameters optimization algorithm proposed are validated by an example. We analyze the influence of the variation of the production point and production batch to the performance of the outsourcing production inventory system.     

Fast Algorithm of Loads Equalization for Distribution Networks Based on Partition-hierarchical Model

Along with enlargement of scope of distribution, algorithms of reconfiguration for distribution networks become difficult to satisfy real-time require of engineering applications. This paper provides a new algorithm a fast algorithm based on partition-hierarchical model. It is found that partition of loads is relation of the smallest load of vertex that is bigger than average and the biggest load of vertex that is smaller than average. The method reduces the numbers of switches combination by searching smallest load of vertex that is bigger than average and the biggest load of vertex that is smaller than average and realize a fast algorithm of the loads global optimal equalization for distribution networks by transferring the loads. Results of test show that the method presented is applicable and efficient.     

Temperature Fuzzy PID Control for Variable Air Volume System

Fuzzy PID controller was applied in variable air volume system. The task was to control the temperature of supply air and the temperature of air conditioned room (the return air temperature) close to their respective targets. The fuzzy PID control system of supply air temperature and return air temperature was designed respectively. The supply air temperature was controlled through adjusting the valve opening of chilled water. And the indoor temperature was controlled through adjusting the rotational speed of variable frequency ventilator. The supply air temperature and the indoor temperature (return air temperature) were controlled online by fuzzy PID controller. Thus, it was shown that the design of fuzzy PID controller was reasonable and the effect of fuzzy PID control was well.     

Response of Root Branching and Shoot Water Potentials of French Beans (Phaseolus vulgaris L.) to Soil Moisture and Fertilizer Potassium

Extensive branching patterns of roots and the maintenance of adequate water within shoots enables plants to overcome water stress. However, information on the relationship between fertilizer potassium, root branching patterns and shoot water potentials of food legumes grown under different soil moisture regimes is scarce. Thus, an experiment was conducted in a phytotron to ascertain the effect of fertilizer potassium on root branching patterns and shoot water potentials of a popular tropical food legumes (Frenchbeans Phaseolus vulgaris L). The plants were grown in a sand medium with 0.1, 0.8 or 3.0 mM of potassium under a suboptimal and optima) soil moisture regime.
Root lengths and dry weights were enhanced by potassium, especially under a suboptimal soil moisture regime. The branching patterns changed due to potassium, where the numbers of second and third order roots increased under both soil moisture regimes, although the impact was greater in plants grown with low soil moisture. Plant water contents measured in terms of shoot water potential, relative water contents, rurgid weight: dry weight ratio and water uptake capacity were also increased by potassium. A positive relationship was observed between root branching patterns and water potentials with increasing potassium levels especially in plants grown under suboptimal soil moisture conditions. Shoot growth and nodulation was also promoted by potassium. The ability of plants to develop a more extensive branching pattern of roots by inducing a greater number of second and third order roots and changing the root branching habit from a herringbone to a dichotomous type to maintain a greater shoot water potential especially under low soil moisture regimes is presented.     

Calculation Method of Hydraulic Characteristics for Direct-Return Chilled Water System

In order to optimize design and operation, it is necessary to calculate accurately hydraulic characteristics large central air-conditioning systems. Simplified Model can not be applied to hydraulic calculation of large pipe network topological structure for its large calculation error. Taking into account the regulating characteristics of terminal branch temperature regulating valve, a direct-return chilled water system is studied, an accurate mathematical model of pipe network hydraulic characteristics has been established and a computer logic algorithm with virtual flow has been given. A direct-return pipe network with ten AHU branches is used as simulation calculation object, the pipe network supply-return water pressure difference is calculated, and also the temperature regulating valve opening and actual flow of each branch are calculated in the condition of different supply-return water pressure difference. The calculated results accord with the natural characteristics of high pressure difference unbalanced for direct-return pipe network. The calculation method can ensure calculation convergence.     

相思拟木蠹蛾调查及虫孔空间分布

为了研究柳州市主要园林绿化树种紫薇、荷花玉兰受相思拟木蠹蛾的危害情况及发生规律,为该虫防治提供一定的理论依据和参考。逐株调查紫薇、荷花玉兰行道树枝干上的虫孔数,计算其被害株率、有虫孔株率、平均每枝（株）虫孔数、不同高度的虫孔数及虫孔比例;采用分布型指数法及回归模型法探讨相思拟木蠹蛾的虫孔空间分布格局;并计算最适抽样及序贯抽样。结果表明,紫薇被害株率、有虫孔株率均100%,平均虫孔数5.8个/枝,枝条不同高度均有虫孔分布,以离地高度250~300 cm处虫孔最多,占总虫孔数的23.0%;荷花玉兰被害株率、有虫孔株率均为23.5%,平均虫孔数为3.1个/株,以离地高度200~250 cm处虫孔最多,占总虫孔数的20.4%。紫薇枝条上虫孔呈聚集型分布,分布的基本成分为个体群。当允许误差D=0.2,平均虫孔数5.8个/枝时,调查的枝条理论抽样数为14条;本次调查枝条数n=33枝,累计虫孔数为191个,远远超过防治指标上下限（113,86）。综上所述,紫薇、荷花玉兰受相思拟木蠹蛾的危害很严重,已极大地影响其观赏,造成枝枯现象,应及时进行防治。     

Speed Ratio Matching Strategies of Metal V-belt Type CVT System

The ratio control strategy and the relevant pulley clamping control strategy of the Metal Pushing V-belt Type CVT C Continuously Variable Transmission are key technology of CVT system matching. The engine output torque model and oil consumption model are given in numerical table by cubic spline interpolation to fit engine test result. Based on the engine speed feature, the speed ratio changing strategy of CVT in the numerical table are given to realize the optimal fuel economy and optimal performance mode within the ratio range of the CVT system.