ON THE EVALUATION OF OPERATIONAL CLOUD SEEDING PROJECTS1

ABSTRACT Operational cloud seeding projects, those designed to produce a desired change in the weather and that are nonexperimental in nature, continue to be pursued widely in the United States. A recurring question by scientists, project sponsors, and cloud seeders has been, “was the weather altered and if so, by how much?” Evaluation of such projects is now recognized as having scientific benefits, and a four-year study has addressed various techniques and statistical methods to perform evaluations and to learn more about how to modify the weather. Most such evaluations hinge on some type of space-time comparisons, but valid comparisons can be obtained only avoiding biases in the project design and operation. Through simulated changes in weather conditions, it was determined that the principal component regression techniques were used to evaluate selected rain and hail modification projects, revealing modification in certain projects and none in others. Various relevant issues have been examined such as use of other weather variables (covariates) to increase detection power, the validity of using historical data as controls for discrete operational periods, possible randomization options during cloud seeding operations, and analyses of individual rain events versus that based on monthly or seasonal units.     

STORM CHARACTERISTICS OF CONVECTIVE-SCALE PRECIPITATION1

A classification scheme for convective precipitation, having applications in both analysis and modeling of meteorological and hydrological events, is presented. The method is based upon observations of rainfall at the ground, radar scans of storm events, and visible and infrared satellite imagery of larger storm systems. Empirical and theoretical frequency distributions are derived for total storm rainfall, rainfall duration and time between storms for each of the convective categories. This stratification is directly applicable to the experimental design and evaluation of weather modification projects and may be useful for the development and interpretation of meteorological and hydrological models. When atmospheric conditions limit storm development to cells, rainfall was seldom observed. Small clusters also produce small amounts of rainfall but have a longer lifetime than cells and are likely candidates for cloud seeding attempts to encourage their growth to large clusters. Large and nested clusters usually produce large amounts of natural precipitation. A few large storms account for most of a season's rainfall.     

光和生物改性溶解性有机质介导17α-乙炔基雌二醇厌氧降解

自然水体溶解性有机质(DOM)在光照和微生物存在的条件下理化性质会发生改变,从而影响其对类固醇类雌激素降解的介导作用.本研究通过对从洱海沉积物中提取的两种典型DOM物质—胡敏酸(HA)和富里酸(FA)分别经过72 h的微生物改性和48 h的光改性,分别比较厌氧条件下光改性前后DOM介导微生物降解17α-乙炔基雌二醇(EE2)的能力变化,以及微生物改性前后DOM介导光降解EE2的能力变化.同时,通过紫外可见吸收光谱、三维荧光光谱和电子供给能力对改性前后的DOM进行分析.结果表明:经过微生物改性后,HA和FA的荧光强度和腐殖化程度都有所提高,但紫外吸光强度和芳香性降低,并且与污染物的结合能力提高,使得光照条件下其介导的EE2更容易发生降解反应.微生物改性后HA介导下的EE2光降解效果要明显好于FA的介导效果.经过光改性后,HA和FA紫外吸光强度和芳香性升高,荧光强度和电子供给能力降低.光改性后HA介导下的EE2微生物降解效果要明显好于FA的介导效果.可见自然水体中微生物改性DOM介导的EE2降解效果相比光改性DOM的介导更加明显.     

改性煤矸石对上覆水磷及底泥磷代谢关键基因的影响

将热活化煤矸石和镧改性煤矸石应用于封闭水体除磷固磷试验,采用16SrRNA高通量测序技术分析底泥微生态群落结构、聚磷细菌和磷代谢功能基因的变化.结果表明：镧改性煤矸石对上覆水TP的去除能力最高,稳定期上覆水TP浓度为0.023~0.028mg/L,较对照组低83.5%以上,热活化煤矸石对上覆水TP的去除能力较差,稳定期上覆水TP浓度为0.15mg/L左右,略低于对照组.热活化煤矸石和镧改性煤矸石均提高了底泥中微生物多样性,变形菌门（Proteobacteria）和绿弯菌门（Chloroflexi）为底泥优势菌种.不同处理组底泥中聚磷细菌为Tetrasphaera和Candidatus_Accumulibacter,镧改性煤矸石显著降低了底泥中聚磷细菌的相对丰度.热活化煤矸石和镧改性煤矸石对多聚磷酸盐激酶（PPK）影响不大,但对外切聚磷酸酶（PPX）的抑制较大,热活化煤矸石抑制最大.     

混合单体对等离子体法改性PTFE膜微生物亲和性能的影响

膜材料氧传质性能和微生物亲和性对MABR（膜曝气生物膜反应器）的稳定运行及处理效果有重要影响,为探究混合单体对等离子体法改性PTFE（聚四氟乙烯）膜微生物亲和性能的影响,采用两步等离子体法分别在PTFE膜表面接枝聚合DOPA（左旋多巴）/GMA（甲基丙烯酸缩水甘油酯）、Lys（赖氨酸）/GMA、BA（苯胺）/GMA和DEA（乙二胺）/GMA四种混合单体,测定改性前、后PTFE膜的微生物亲和性,并进一步确定最佳混合单体改性PTFE膜的氧传质性能.结果表明:与未改性PTFE膜和仅接枝聚合GMA单体改性复合膜相比,DOPA/GMA、Lys/GMA、BA/GMA和DEA/GMA混合单体改性复合膜表面的微生物亲和性均有提高;Lys/GMA混合单体改性复合膜表面的微生物亲和性最佳,显著高于未改性PTFE膜,膜表面的生物量用ρ（DNA）和ρ（TOC）表示,分别为9.67 ng/μL和103.44 mg/L,比未改性PTFE膜高出34.7%和286.0%,同时其膜表面的生物量增加速度最快;DOPA/GMA和DEA/GMA混合单体改性膜表面的微生物亲和性相近,且高于BA/GMA混合单体改性膜;Lys/GMA混合单体改性复合膜的最大氧传质系数为1.17 m/d（操作压力为35 kPa）,显著高于未改性PTFE膜的0.48 m/d（操作压力为11 kPa）.研究显示,两步等离子体法接枝聚合的混合单体改性能够同时改善PTFE膜的微生物亲和性和氧传质性能,更适合于制备MABR复合膜,可为开发MABR专用膜材料提供理论基础和技术支持.      

行为矫正法在建筑火灾安全中的应用研究

随着建筑物防火性能化的发展以及人行为机理的复杂性 ,要求应用更多的学科研究建筑物火灾中人的行为与安全疏散理论。行为矫正学是一门基于过去经验与实验研究的学科 ,笔者在阐述其基本原理和特点的基础上 ,提出了在灾害事故中应用此方法的模式 ,然后结合高层建筑物火灾疏散的特点 ,对高层居民建筑物发生火灾时 ,如何矫正人的一些不正确F行为和提高火灾安全进行了探讨。分析了矫正模式的功能和干预的措施。     

A NEW CHALLENGE FOR WESTERN WATER SUPPLIES1

ABSTRACT: In many of the limited water resource areas of the western United States most water supplies have been put to beneficial uses. Energy, a fast expanding high-priority water use, is making challenging demands for these limited supplies. Can water supplies be stretched, supplemented, or redirected so that present uses can be maintained and energy water needs satisfied? The Bureau of Reclamation is investigating innovative methods of water management, reregulation, and use to meet these demands. Related programs under study include potentials for: development of additional hydroelectric power, installation of low-head turbines in western water courses, utilization of pumped storage and underground storage, use of geo-thermal heat, extension of water supplies through more efficient irrigation systems and practices, and weather modification.     

A Social Contract for Biotechnology: Shared Visions for Risky Technologies?

Future technological developmentsconcerning food, agriculture, and theenvironment face a gulf of social legitimationfrom a skeptical public and media, in the wakeof the crises of BSE, GM food, and foot andmouth disease in the UK (House of Lords, 2000). Keyethical issues were ignored by the bioindustry,regulators, and the Government, leaving alegacy of distrust. The paper examinesagricultural biotechnology in terms of a socialcontract, whose conditions would have to be fulfilled togain acceptance of novel applications. Variouscurrent and future GM applications areevaluated against these conditions. Successwould depend critically on how far a sharedvision can be found with the public. Tore-establish trust, significant changes areidentified in the planning and pursuit ofbiotechnology.     

阳离子改性粘土对活性染料的脱色作用

金属离子改性的凹凸棒石和膨润土对水中活性艳红染料Ｋ－２ＢＰ的吸附脱色作用符合Ｆｒｅｕｎｄｌｉｃｈ吸附等温式并呈现一级反应动力学的特征，吸附的最佳ＰＨ范围分别为〈５和〈６，其中以改性凹凸棒石的吸附性能较好，光照检验表明，改性膨润土还具有一定的光化学催化降解作用。     

聚丙烯酰胺的改性及在废水处理中的应用研究

聚丙烯酰胺是一种使用范围广、处理效果好的高分子絮凝剂,具有良好的水溶性、优良的絮凝性能和吸附性能.文章总结了聚丙烯酰胺阴离子化、阳离子化、单体共聚的常见改性方法.列举了其改性产物在废水处理中的应用和取得的良好效果.对聚丙烯酰胺改性研究的必要性和有效性进行了说明.表明:聚丙烯酰胺经过改性后可提高使用效果、拓宽使用范围、减少投药量等优点.最后对聚丙烯酰胺改性的发展方向做了展望,改善现有絮凝剂性能和发展高品质絮凝剂是将来研究的重点.