基于出行方式和活动交互作用的小汽车使用预测模型

为改进我国传统小汽车出行需求预测方法,基于活动理论建立了小汽车使用预测非集计模型.从小汽车使用者活动模式的统计分析入手,对小汽车使用模式进行划分,在多项Logit(MNL)模型的基础上建立协同进化Logit小汽车使用预测模型.模型中采用协同进化方法计算确定了个体出行活动选择顺序,体现了小汽车使用者出行方式选择和活动的交互作用.模型适应性分析表明,该模型可用于城市小汽车出行需求预测和交通需求管理政策的‘评价.以沈阳市为例对模型进行了实例分析,结果表明模型预测正确率达88.9%,65%以上的小汽车使用者先确定小汽车使用模式再进行活动模式的选择,验证了出行活动选择顺序的个体差异性,提高了小汽车出行需求预测方法的精度.     

Technique for advanced electrochemical oxidation treatment of nanofiltration concentrate of landfill leachate

Landfill leachate treated with combined process of ＂pretreatment ＋biological treatment ＋advanced treatment （NF）＂ to produce nanofiltration concentrate, which bio-chemical ratio （B/C） is less than 0.1 and CODer concentration is 2 000-2 500 mg/L, high salt content. Which cannot be discharged under existing environ- mental standards. According to analysis based on electrochemical advanced oxidation mechanism, a two-step electrochemical tech- nique was recommended. In the first step, a pulse electrochemical technique was adopted. With Fe as consumption electrode and current density of 10 mA/cm2, the pollutants were removed by means of Fenton reaction, electroflotation and electrocoagulation. In the second step, a double function electrode was used to per- form electrocatalytic oxidation by means of titanium metallic oxi- dates. In the condition that current density being 12.5 mA/cm2, the pollutants were further removed by oxidation and electrolytic deposition. Result shows that the removing rate of CODer, NH3-N and CI were 70%-85%, 90% and 25%, respectively; average value of B/C ratio increased from 0.09 to 0.38 and conductivity reduced by 10%.     

Advances in the hyperlens

As a superlens to overcome the well-known diffraction limit, the hyperlens has received much attention due to its super resolving power and magnifying capabilities. In this article, we review the recent developments, including theoretical and experimental studies on the hyperlens. We also discuss its limitations and potential.     

完全单半群的nil-扩张上的群同余

论述了完全单半群的nil-扩张上的群同余与同余子半群之间的一一对应关系,即每个同余子半群可诱导出一个群同余,而每个群同余的核是一个同余子半群．     

自动固相萃取法(SPE)提取血(尿)中的吗啡及其色谱检测

目的:建立了一种在同一条件下同时净化提取血(尿)中吗啡(Morphine)的自动固相萃取法(Solid-Phase Extraction,SPE);方法:利用Waters公司的Isolutetmspe柱(离子交换柱:Confirm HCX)进行分离提取,采用气相色谱-质谱法(GC/MS)和高效液相色谱法(HPLC)进行检测;结果:利用GC/MS和HPLC法检测,其样品中Morphine的回收率均可达95%以上;结论:该法具有简便快捷、提取回收率高、杂质含量少、背景噪音低等优点。     

Implementation of an efficient segregated algorithm-IDEAL on 3D collocated grid system

The segregated algorithm-IDEAL (inner doubly-iterative efficient algorithm for linked-equations) is an efficient and stable algorithm. In this algorithm, there exist inner doubly-iterative processes for pressure equation, which almost completely overcome two approximations in SIMPLE algorithm. Thus the coupling between velocity and pressure is fully guaranteed, greatly enhancing the convergence rate and stability of iteration process. In this paper, implementation of the IDEAL algorithm on a 3D collocated grid system is conducted. The interface velocity is calculated by the modified momentum interpolation method (MMIM), by which the converged result is independent of the under-relaxation factor. Finally, five three-dimensional incompressible fluid flow and heat transfer problems are provided to compare the convergence rate and robustness between the IDEAL and three other most widely-used algorithms (SIMPLER, SIMPLEC and PISO). By the comparison it can be concluded that the IDEAL algorithm is more robust and efficient than the three other algorithms. Supported by the Key Project of National Natural Science Foundation of China (Grant No. 50636050), Fundamental Projects of Research and Development in China (973) (Grant Nos. 2006CB601203 and 2007CB206902)     

酸性铬蓝K-高碘酸钾催化动力学光度法测定痕量铬

在酸性介质中,微量铬(Ⅵ)能显著催化高碘酸钾氧化酸性铬蓝K褪色.研究了该指示反应的动力学行为,建立了测定痕量铬的新催化动力学分析方法,方法的线性测定范围为1.0～10.0μg/25ml,检出限为(4.14×10-8)g/ml.本法可用于电镀废水中Cr(Ⅵ)的测定,结果满意.     

南京紫金山地区蜻蜓目昆虫区系及多样性

于2005至2007年对江苏南京紫金山地区的蜻蜒资源进行了调查,经过对采集标本的鉴定,初步确定南京紫金山地区蜻蜒目昆虫有30种,隶属8科24属,其中8种是江苏省新纪录.该地区蜻蜒目区系组成的特点是:广布种所占的比例较大,东洋种次之,古北种最少.     

A distributed dynamic clustering algorithm for wireless sensor networks

This paper proposes a distributed dynamic k-medoid clustering algorithm for wireless sensor networks (WSNs), DDKCAWSN. Different from node-clustering algorithms and protocols for WSNs, the algorithm focuses on clustering data in the network. By sending the sink clustered data instead of practical ones, the algorithm can greatly reduce the size and the time of data communication, and further save the energy of the nodes in the network and prolong the system lifetime. Moreover, the algorithm improves the accuracy of the clustered data dynamically by updating the clusters periodically such as each day. Simulation results demonstrate the effectiveness of our approach for different metrics. Biography: WANG Leichun (1974–), male, Ph.D. candidate, research direction: wireless communication.     

克拉玛依沥青的SBS改性试验研究

为了解决西部地区沥青路面的横向开裂等主要病害,对西北地区常用的克拉玛依基质AH 110#沥青及AH 90#沥青使用SBS4303,1401,1301改性剂进行了室内改性试验.结果显示,影响SBS改性沥青性能,特别是低温性能的主要因素为基质沥青的性质、组分的比例,其次为改性剂的型号和剂量;优良的基质沥青并不能通过SBS改性达到适合于本地区改性沥青的技术要求.