我国三北地区春季第一场透雨指标的确定

利用我国北方地区1951～1995年降水和气温资料，以考虑降水量和温度的春旱指标为基础，统计确定了东北、华北和西北地区东部等地春季第一场透雨的指标和分区，并分析和讨论了各分区出现第一场透雨的特征和概率。这对监测和预报春季干旱的发生和缓解具有较好的指示作用。     

黄河三角洲土壤盐分空间变异性与合理采样数研究

以黄河三角洲地区一块约520hm^2的田块为研究区，采用经典统计学和地统计学方法进行不同层次土壤盐分（0～20cm，20～60cm，60～100cm，100～140cm）的空间变异及其合理采样数量研究。结果表明：研究区土壤盐分普遍较高且表聚作用明显；各层土壤盐分均属于中等变异强度;受结构性因素和随机性因素的共同作用，各土层盐分均具有中等的空间相关性。对Kriging插值结果分析表明，土壤盐分的空间分布受微地形和气候条件的影响较大．且研究区各土层盐分分布存在着空间上的相似性。应用Cochran公式和分层采样方法对合理采样数量进行了分析，发现采用分层采样方法可以有效降低采样数量，且采用最适分配法可以获得最为理想的采样数量，该方法较比重分配法采样数降低幅度最大达35％左右。该研究为黄河三角洲地区盐渍土地的科学管理、改良以及利用提供一定的理论依据和技术参考。     

土壤中痕量指示性多氯联苯三种质谱检测技术的分析比较

为分析土壤复杂基质中7种痕量多氯联苯(PCBs)指示剂,分别采用常规气相–四级杆质谱(GC Q-MS)、气相–飞行时间质谱(GC TOF-MS)和全二维气相–飞行时间质谱(GC×GC TOF-MS)对土壤样品进行检测。结果显示:GC Q-MS检测方法未能检测出复杂体系中的痕量目标物;GC TOF-MS定性出其中2种PCBs,并检测出另外4种目标物的主要特征离子;GC×GC TOF-MS则能够一次性清晰分离出样品中7种PCBs指示剂,并同时检测到样品中其他20种PCBs、杀虫剂和多环芳烃类物质,且均获得较高匹配度。因此,相比于常规GC Q-MS,GC TOF-MS具有更高的定性检测能力,GC×GC TOF-MS分离能力最强,且具有较高的灵敏度和分辨率。     

1978-2011年呼图壁河径流的变化趋势

[目的]分析新疆维吾尔自治区呼图壁河径流变化特征与长期变化趋势,为制定科学合理的呼图壁地区水资源供需平衡发展战略提供理论支撑。[方法]采用变差系数法、距平累积法、Mann-Kendall非参数秩次相关检验法及Morlet连续复小波变换对呼图壁河石门水文站1978—2011年实测日流量资料进行分析。[结果]呼图壁河径流的年内变化主要受降水与气温的影响,其主要径流产生于5—9月,汛期为6—8月,径流量占全年径流量的69.4%,枯水期为12月至次年3月。呼图壁河的Cv平均值为0.149。近34a来径流量整体呈现出不显著的增加趋势,径流量的年际变化小,年际间持续枯水与持续丰水的时间几乎相同。此外,呼图壁河年径流存在4个较为显著的周期波动,其中18和29a分别为径流量年际变化的第Ⅰ、第Ⅱ主周期。[结论]呼图壁河近34a来径流量呈增加趋势,径流量的年际变化呈现出较为显著的周期性,径流量的年内分配很不均匀。     

应用RNA沉默技术获取抗黄瓜花叶病毒(CMV)和烟草花叶病毒(TMV)转基因烟草

RNA沉默是迄今最为有效的抗病毒策略,利用该策略不但能获得免疫转基因植株,且所得植株不易与其他病毒基因重组或异源包壳、生物安全性较高。将本实验室已构建的携带有烟草花叶病毒(TMV)部分移动蛋白基因(ΔMP)和黄瓜花叶病毒(CMV)部分复制酶基因(ΔRep)反向重复结构的植物表达载体pBIN438-MP-Rep(i/r),用农杆菌浸润法转化普通烟草品种K326,共得196株转化植株,经卡那霉素筛选和PCR检测发现128株为阳性转基因株;PCR-Southern和RT-PCR分析表明外源基因已整合到烟草基因组并在转录水平上得到表达;ELISA结果显示20.3%的转基因植株对CMV和TMV复合侵染表现免疫性。本结果为利用RNA沉默技术进行植物抗多种病毒育种提供重要数据,为防治其他多种病毒复合侵染提供借鉴。     

Analysis of Sewage-water Heat Exchanger withthe Function of Auto-de-fouling

A sewage-water shell-tube heat exchanger with the function of de-fouling was proposed and designed for sewage-source heat pump. Its new simulation program which relies on a distribution parameter computational method was set up. Then the model was solved with the method of Matrix Control. Based on the model, the distribution of bilateral fluid temperature were studied, under the conditions of different flow rates and heat exchange area before and after the de-fouling. Results showed that there will be heat anti-transfer phenomenon if the heat exchanger area is bigger than need and the region of this phenomenon was point out. Setting the function of auto-de-fouling in shell-tube heat exchanger and reducing the equipment's volume accordingly can make the sewage-water heat exchanger run in the best conditions.     

Mechanism and implementation of directional quantum-behaved particle swarm optimization in OC-SVM

This paper uses the training of OC-SVM to analyze the mechanism of the Quantum-behaved particle swarm and develops a method of training OC-SVM based on the directional- QDPSO .The new position of the directional particle is calculated based on the current global best point(gBest), which identified the optimized direction conforms to Zoutendijk fastest decline method principle.In the initialization, the position of one particle is initialized according to SMO, which makes its position nearer to the global optimum solution. The boundary points of subjected plane are concerned as the initialized position of other particles, so as to make the searching area wider.The experiment result shows that the convergence and the generalization of D-QDPSO is good, the misrecognition of D-QDPSO is 0.12% lower than that of SMO, and the operating speed is 2 times faster than that of LPSO.     

The EME rules of composed coal and rock samples with hard roof failure and their application

The electric magnetic emission (EME) rules of deformation and failure of composed coal and rock samples are studied by lab experiments and fractal theory. The results show that at the initial stage of loading, EME signals increase, then decline slightly and stay at a stable level. Substantial increase appears when the composed coal and rock samples are close to the main fracture, and EME signals decline slowly when they are in the stage of residual deformation. The EME signals have a positive exponent relation to roof ratio in the composed coal and rock samples. The EME pulse count has the fractal characteristic, and the fractal dimensions increase with the process of loading. When the composed coal and rock samples are close to main fracture, the fractal dimensions decline suddenly, and it has a positive linear relation to the ratio of roof in the composed coal and rock samples. With the achieved rules, the burst danger has been forecasted successfully in face 7251.     

Comparative study of low voltage ride-through techniques for doubly-fed induction generator wind turbines under asymmetrical grid faults

Asymmetrical grid faults occur more frequently and have more adverse effects on the doubly fed induction generator (DFIG) than symmetrical grid faults in the transmission system. The transient response of DFIG under asymmetrical grid faults is analyzed firstly. Meanwhile, operation behaviors of several low voltage ride-through (LVRT) techniques under severe asymmetrical grid faults are given by simulation with the Matlab/Simulink software. Then the characteristics of these LVRT techniques are further researched and analyzed based on the simulation results. Finally, the economies of these LVRT techniques are discussed. The conclusion lays a certain foundation for engineering development of these LVRT techniques.     

Job-Shop scheduling based on improved immune cloning algorithm

Parallel immune clone algorithm is proposed based on population coevolution theory and parallel computing affinity of individual at multiple compute nodes. Introducing the immune memory mechanism, the evolution processes of antibody population and memory units are conducted simultaneously, meanwhile, it improves mutual cooperation among antibodies, and ensures solution set approaching optimal solution from the inside of feasible region or infeasible region border. Clone proliferation, high frequency variation and operation of crossover operators increase the chance that better individuals gain affinity maturation by the operation of clone expansion, improve diversity of antibody population distribution, achieve the balance of optimization between depth and range, and ensure the convergence of the algorithm and the diversity of the search range. A computational study for a standard data set is carried out to test the validity of the algorithm, and the effect of algorithm parameters on the results is analyzed. The simulation results show that the global search capability, local search capability, algorithm stability and computing speed of the algorithm are all superior to conventional optimization algorithms such as normal immune clone optimization algorithm, genetic algorithm, etc.