多传感器与道路网数据用于汽车导航的研究

对车载导航系统中GPS接收机，车论计数器和电子罗盘传感器数据与导航电子地图所提供的道路网络数据进行了综合处理，建立了道路网络数据的网络拓扑关系，在此基础上提出了基于道路网络拓扑关系，利用GPS接收机，车轮计数器和电子罗盘传感器对汽车进行实时定位的算法。最后，对导航中汽车的定位误差进行了分析。实验证明，GPS接收机，车轮计数器和电子罗盘传感器与道路网络数据综合，在导航过程中能够补偿GPS信号技失，实时、高精度、高可靠性地确定汽车的位置。     

洛阳市水资源可持续开发利用对策研究

洛阳市是一个水资源总量偏少的地区。按可供水资源量、现状尚可维持．预计2005年和2010年全区将缺水0．75亿m^3／a和2．43亿m^3／a。为了保证洛阳市经济快速、持续的发展，水资源的可持续开发利用已成为关键性因素之一。对于本市来讲，依法治水、科学用水、节约用水、污水资源化是实现市域水资源开发利用和保护良性循环的重要举措，核心是抓好农业节水和城镇用水。本文对域内水资源可持续开发利用，进行了可行性研究。     

同朔地区水资源危机及对策

针对同朔地区自然条件、水资源状况和供需之间的矛盾，分析了该地区河川径流量和地下水可开采量，客观地论证了该地区水资源的短缺程度。估算了全区目前总需求和2010年需求水量。根据区内现有水利设施的可供水量，提出了解决水资源短缺供需矛盾的对策，以期能解决或缓解同朔地区水的供需矛盾。     

浮游植物粒级研究方法的比较

基于 2 0 0 1年 8月胶州湾浮游植物综合调查资料 ,对显微测量粒径分析法、叶绿素 a粒级分离法、电子粒度分析仪法这 3种浮游植物粒级结构研究方法进行了初步比较 ,以期为较准确研究浮游植物的粒级结构提供科学依据。发现 ,当调查区内优势种为小细胞种类的链状群体时 ,使用叶绿素 a粒级分离、电子粒度分析仪法区分粒径的结果会低估小细胞的种类。用显微测量粒径分析法 ,测量出各种类的粒径参数 ,可以较准确地推算出浮游植物群落粒级结构。这对浮游植物群落的粒级结构分析是 1个必要的补充     

液体闪烁计数测定海水中氚的条件优化研究

本研究采用常压蒸馏法测量,利用Quantulas 1220超低本底液闪谱仪测量海水样品中氚活度的方法,对影响测量结果的测量时间、无氚水、闪烁液以及二者混合比例等进行研究.在优化了这几个参数后,使得方法检测限为1.07Bq/dm~3.为了检测方法的适用性,本研究课题组参与IAEA海水氚样品测量,测量结果为2.91±0.35 Bq/dm~3,与IAEA参考值(2.80±0.06 Bq/dm~3)相对偏差仅为3.9%,证明了该方法测量海水的可行性.此外,与文献值比较,本方法适用于核电厂运行后,邻近海域海水中氚的测量.     

Relationship of heterogeneous nucleation and condensational growth on aerosol nanoparticles

Heterogeneous nucleation and condensation of dibutylphthalate, octadecane, octadecanol, and octadecanoic acid vapors at various pressures on insoluble AgCl and Ag nanoparticles in a turbulent mixing condensation nuclei counter (TMCNC) have been studied theoretically. A method to interpret the particle size distributions measured with a DMA and estimate the parameters for nucleation on single particles is proposed. Based on this semi-empirical method, the Gibbs free energy is calculated and a rate of heterogeneous nucleation on single particles is estimated directly from the experimental “condensation spectra” of inactive and active CN using the DMA data. In some cases, the dependence of the Gibbs nucleation energy on the vapor supersaturation had two maximums and one minimum, instead of one maximum as described by Gibbs' classical thermodynamics of phase transitions. This phenomenon, called “double barrier nucleation” (DBN) is caused by the surface heterogeneity of nano-CN; this is first experimental verification of DBN that had been previously predicted theoretically. Two types of heterogeneity may be present: topographic or energetic. Focusing on energetic heterogeneity, a theoretical model of DBN for spherical geometry is developed. The surface heterogeneity for insoluble nano-sized CN is shown to be critical to explaining the unusual transformation of a monomodal size distribution of inactive CN into a bimodal distribution of activated CN when coagulation is excluded. Future studies will be directed toward more data for further refining the theory and developing a model that simultaneously accounts for both types of surface heterogeneity of nano-CN.     

今生颗石藻的有机碳泵和碳酸盐反向泵

海洋今生颗石藻同时具有有机碳生产和钙化作用两个过程，对海洋碳的生物地球化学循环具有重要作用。今生颗石藻通过有机碳泵（生物泵）和碳酸盐反向泵调节大气p(CO₂)，最终影响全球的气候变化。介绍了今生颗石藻对全球气候变化的影响，重点讨论其碳酸盐反向泵过程，从今生颗石藻碳酸盐反向泵的生理学基础、钙化作用与光合作用的耦合机制、全球气候变化下今生颗石藻的有机碳泵和碳酸盐反向泵耦合机制改变等几个方面进行了描述。对中国近海今生颗石藻的研究进行了展望。     

三峡库区水环境面临的问题和对策

经过近10年的综合治理,三峡库区水环境恶化的趋势虽然有所减缓,但污染依然严重,水体含沙量仍居长江沿线之最。究其原因,主要由于目前库区环境监控能力较弱、水环境治理缺乏法制约束、环境管理机制缺乏活力、环保设施缺乏市场运行手段、库区及上游影响区产业结构不合理、民众生态道德观念淡薄所致。要从根本上解决库区水环境问题,必须导入循环经济和生态经济理念,重建库区及上游影响区生态型产业结构,建立和完善治污处理系统及其市场运行机制,构建相对独立的环境执法运行体制,扩大公众环保知情权,鼓励公众参与环境监督,建立绿色GDP统计体系和地方政府官员环保政绩评价体系,全面推进城市生态化发展步伐,构建现代化的综合性监控预警系统。     

Balloon-Borne Optical Counter for in Situ Aerosol Measurements

A new balloon-borne optical particle counter has been developed to make in situ measurements of stratospheric aerosols. The intensity of light scattered at 60° from the forward direction by individual particles is measured. Aerosol number concentrations in seven size channels can be inferred. The counter has been calibrated using polystyrene and polyvinyl toluene latex spheres. There is good agreement between measured and calculated individual pulse intensities for aerosol with radii from 0.16 to 2.6 µm. The size resolution is limited by broadening of the pulse count/pulse height spectrum, arising mainly from the photoelectron statistics of photomultipliers. Stratospheric aerosol measurements have been made using this instrument at Kiruna (68°N, 21°E), Sweden, in February 1995, and at Aire sur l'Adour (44°N, 0°W), France, in 1992, 1993, and 1994. The uncertainties in the measurements are discussed. The retrieved aerosol concentrations and size distributions are presented, and shown to be broadly consistent with measurements made by the University of Wyoming optical particle counter.