长白山阔叶红松林林隙特征及对树种更新的影响

长白山阔叶红松林实际林隙面积小于250m2的林隙数量占被调查林隙的70以上，扩展林隙面积大部分分布在100m2-500m2之间（70%左右），林隙最大面积大部分分布在300m2-900m2之间，林隙模型所模拟的面积应在500m2-900m2之间。40%的阔叶红松林林隙是风干扰形成的。每个林隙的平均林隙形成木的数量是2.65株。最大林隙形成木集中分布在50cm-60cm和60cm-70cm两个径级内，占总数量的50%以上，红松、紫椴、蒙古栎和春榆在最大林隙形成木中占95%以上，其中紫椴（40%）所占比例最大，红松（34.5%）次之。林隙内的树种更新密度比林冠下提高了30%左右。根据树种对林隙的反应可分为4类：鱼鳞云杉、水曲柳、青楷、白扭、红松、臭冷杉、胡桃楸和色木对林隙反应中等；紫椴、裂叶榆和春榆对林隙有强烈反应；白桦、山杨、蒙古栎和落叶松需要强烈林隙干扰才能引起树种更新。     

连续时间的网络截流选址模型与算法——以防御性醉酒驾驶的拦截问题为例

首先提出了连续时间的网络截流选址问题,并以保护整个道路交通网络为目标,建立了防御性醉酒驾驶拦截问题的模型。根据问题的特征,分别设计了基于时间的迭代改进算法和离散选址问题的拉格朗日启发式算法,并通过随机实例对算法进行了测试。结果表明:连续时间的同步拦截问题可以通过分离连续的时间变量和离散的选址变量的方法,多次求解覆盖问题而有效解决,并且迭代改进算法对时间的搜索性更强,从而能够用较少的迭代次数解决原问题。     

Effects of oncoming target velocities on rapid force production and accuracy of force production intensity and timing

The present study aimed to clarify the effects of oncoming target velocities on the ability of rapid force production and accuracy and variability of simultaneous control of both force production intensity and timing. Twenty male participants (age: 21.0 ± 1.4 years) performed rapid gripping with a handgrip dynamometer to coincide with the arrival of an oncoming target by using a horizontal electronic trackway. The oncoming target velocities were 4, 8, and 12 m · s^?1, which were randomly produced. The grip force required was 30% of the maximal voluntary contraction. Although the peak force (Pf) and rate of force development (RFD) increased with increasing target velocity, the value of the RFD to Pf ratio was constant across the 3 target velocities. The accuracy of both force production intensity and timing decreased at higher target velocities. Moreover, the intrapersonal variability in temporal parameters was lower in the fast target velocity condition, but constant variability in 3 target velocities was observed in force intensity parameters. These results suggest that oncoming target velocity does not intrinsically affect the ability for rapid force production. However, the oncoming target velocity affects accuracy and variability of force production intensity and timing during rapid force production.     

基于尺度耦合特性分析的侦听网络流量扩张模型

在能量受限的侦听网络中,需要大量的信息交换,由于瓶颈节点的能量消耗无法满足侦听网络的流量需求,需要进行流量扩张模型构建。传统方法采用对偶子梯度法实现对侦听网络的流量扩张,方法只能考虑一种流量和节点的组合,适应性能不好。提出一种基于小波变换尺度耦合特性分析的侦听网络流量扩张模型,对侦听网络流量时间序列进行采集与分析,通过小波尺度耦合分析,对路由接收的调度任务指令数量做出有效预测,从而为调度模型的建立提供准确的数据基础。分析流量序列的瞬时频率线性变化规律,得到带宽频间谐振模型,通过小波尺度耦合特性约束,提高了流量的流通量,实现流量扩张。仿真结果表明,算法能有效提高侦听网络的数据流吞吐量,网络流量通道得到有效扩张,提高了侦听网络的安全性和通信效率,展示了较好的应用性能。     

焦化废水处理中酚降解细菌的分离及降解特性的初步研究

通过对合肥四方化肥厂曝气池和沉淀池中活性污泥的处理,进行菌种分离、筛选、鉴定,以及测定phen-10菌株的酚降解能力,旨在找到一些对酚处理效果好的优势菌株,并记录优势菌株的最佳生长条件,为今后的进一步研究提供依据。     

Interpersonal variability in timing strategy and temporal accuracy in rapid interception task with variable time-to-contact

In rapid interceptive actions such as hitting a baseball, cricket ball or tennis ball, ball speed varies between trials, and players have to compensate the time lag by controlling the moment of movement onset and movement duration. Previous studies have found that these two variables can flexibly co-vary and are robustly influenced by target speed (i.e. velocity-coupling effect: faster movement for faster target). However, some studies reported an interpersonal variability in the timing control strategy and the relationship between the strategy and temporal accuracy in rapid interception is unclear. We used a baseball-simulated rapid interceptive task to assess this issue. Under relatively easy time constraints, there was a large interpersonal variability, and participants were distinctively divided into two groups: those who mainly modulated their movement duration and those who mainly controlled their movement onset. When the time constraint became severe, the second strategy shifted to the first strategy in most of the second group participants. In the both cases, being able to mainly control movement onset resulted in higher temporal accuracy. These results suggest that minimising the velocity-coupling effect is an important factor to achieve high temporal accuracy in rapid interception.     

谈网球练习中的凌空截击

本论文对辽宁师范大学2002级网球专选59人上网时的心理应对和截击技术的技术环节等方面的问题进行分析,结合大量文献资料,全面、综合的分析了练习中掌握凌空截击的技术环节,并为其他练习者提供了练习依据。     

两种天体高度定位的直接解法

论述了天体高度定位的两种直接解法——直接解析法和迭代解法，并通过算例，说明这两种解法避免了高度差法的方法误差，而且完全适用于太阳特大高度定位，其定位计算精度均在０．１ｎｍｉｌｅ之内。     

稻田生态系统的优化调节

为了掌握稻田生态系统的特征，改进系统结构，增强系统功能，增加水稻产量，1985年以来，以辽粳5号、沈农91为试材，采用规范化设计，研究了氮、磷、钾施用量，播种量和移栽秘密度对水稻生长发育的影响。试验结果名表明，处理条件不同，稻田生态系统结构和功能不同。群体中的个体数和叶面积指数存在适宜范围。群体中的光强度、湿度和温度都受叶面积指数制约。后期冠层结构理想、群体生长率高的群体容易成为群体。高效稻田生态系统的建立和调节措施是选用高产品种、旱育稀播、合理稀植、平衡措施、节水灌溉、综合防治病虫草害和生育调节。     

非点源污染防治现状及研究进展

非点源污染主要集中在农村和矿区,城市也有分布,受自然和人为两大因素影响。防治问题主要表现在资金不足、技术落后、重视不够、责任不明确、污染原因多样等方面。研究提出将非点源污染按污染源、污染范围不同划分为不同类型的污染,进行分类防治与管理,并对国内外非点源污染研究进展进行了阐述。以鄱阳湖为例,阐述利用GIS技术建立非点源污染信息数据库,对种植业、养殖业非点源污染提出不同的防治措施。针对鄱阳湖水体富营养化开发出一套低成本的循环利用新方式,为营养元素引起的非点源污染防治提供了科学依据。