几种稀土化合物成冰性能的实验结果

在人工影响天气工作中,国内外广泛地使用着碘化银,为了克服实用播种中碘化银气溶胶的某些缺点(如阳光引起活性衰减),也有采用水溶胶形式播种的,例如,我国内蒙近年来采用碘化银水溶胶播种。然而,两者都要消耗大量白银。为了寻找新的经济而有效的成冰催化剂,多年来各国不少研究者对许多无机和有机化合物的成冰性能作了实验研究。 七十年代初期,Matsubara曾报道七种稀土元素氧化物的成冰性能,并认为它们的     

二十四种有机化合物成冰性能的实验研究

1.实验方法 本文测定有机化合物的成冰性能,主要指成冰阈温和成核率。实验在容积为24升的圆柱型近似恒温的云室中进行,药品颗粒的分散发生,采用气流分散法和升华法。成冰阈温的测定为,云室由某一低温开始,然后逐渐增温,通过反复实验,确定出药品出冰晶的最高温度,即得之。成核率的测定包括,通过云室测定出不同温度区间下,药     

沈抚污灌区结冻土壤中微生物群落及石油烃优势降解菌的筛选

针对已有50余年污水灌溉历史的沈抚污灌区石油污染结冻土壤中微生物种群及石油优势降解菌株进行了分离、筛选及初步鉴定。结果表明:石油污染土壤中的细菌总数是未污染土壤的100倍左右,其真菌和放线菌数量也明显超过未污染土壤。通过筛选,共得到17株石油烃优势降解细菌和11株真菌,其中,降解性能较强的细菌为12号,石油烃降解率为30.54%,初步鉴定为芽孢杆菌属(Bacillus);降解性能较强的真菌为22号真菌,石油烃降解率为34.21%,初步鉴定为常现青霉(Penicil-liam freguentans Westling)。     

黑龙江省雷电灾害调查及案例分析

1引言雷电是一种大自然释放电现象。雷电引起森林火灾,点燃爆炸物,导致输电线路与电力系统故障,扰乱控制系统的电子设备,对人民生产、生活造成很大影响。2雷电灾害调查的意义雷电灾害调查是在雷电事故产生后,对雷电事故发生现场情况、发生地勘察、现场取证、事故鉴定、评估事故损失并整理出事故发生原因。通过雷电灾害调查及鉴定可以预防同类事故发生可能性,从而为气象部门处理同类事故做出理论依据,同时气象部门对雷电灾害防御工作具有管理权,也为政府制定防灾减灾工作方向。     

温度标准探空仪研制成功

大气探测研究所承担的重点课题:“温度标准探空仪”已完成了性能样机的研制,并取得了现场施放试验的成功。4月6日由国家气象局科技教育司主持通过了验收鉴定 温度标准探空仪采用12μm镀金钨铼丝作温度敏感元件,强度高、线性度好,辐射误差和滞后误差小,技术性能优于国外其它金属丝测温元件,达     

内蒙古自治区人工影响天气重点实验室首次承担催化剂配方的国家级鉴定实验

2008年7月1—7日。中国气象科学研究院人影中心2位专家在内蒙古自治区人工影响天气重点实验室云室对江西、齐齐哈尔等厂家的多个催化剂新配方进行了成冰性能的鉴定实验。催化剂配方的成冰性能的鉴定实验一直以来都由中国云雾物理重点实验室云室独家承担完成。属于权威性鉴定实验。此次因中国云雾物理重点实验室正在装修改造,内蒙古自治区人工影响天气重点实验室云室便成为该项鉴定的首选实验去室。     

雷电灾害调查与鉴定技术

对雷电灾害调查与鉴定方法进行了论述。以雷电灾害调查与鉴定实践经验为基础,详细论述了雷电灾害调查与鉴定的基本原理、具体程序、灾害现场调查的详细内容、调查记录的整理要求、雷电灾害调查与鉴定报告的内容以及存档资料要求。将雷击灾害现场分为3类:原始现场、变动现场和伪造现场;将雷电的破坏类型分为直接破坏和间接破坏2种;指出了雷电的7种破坏方式;讨论和介绍了9种雷电灾害的鉴定技术方法以及鉴定过程中的注意事项。     

WR-1B型增雨防雹火箭性能介绍

由航天部第四研究院41研究所设计研制的我国新一代WR－1B型增雨防雹火箭于今年7月15～18日在西安通过国家级鉴定，并将投入批量生产，经专家鉴定认为：WR－IB型增雨防雹火箭性能已达到国外同类产品的国际水平。现将该火箭的结构、性能及特点简要介绍如下：WR－IB型增雨防雹火箭由火箭弹和发射架两部分组成。火箭弹由发动机、碘化根烟炉和降落伞安全着陆装置等部分组成。发射架由多联导向轨、俯仰方向机构、周角方向机构、电路检测发火控制器和固定底座等部分组成。WR－IB型增雨防雹火箭的主要技术性能指标列于附表。由表可以看出，＊…     

高分子薄膜电容式湿敏元件研制成功

由国家气象局气象科学研究院大气探测所丁碧君等同志研制的高分子薄膜电容式湿敏元件,于1987年10月30日在北京召开的鉴定会上通过了科研成果鉴定。会议由国家气象局科教司主持,鉴定组由局内外专家10人组成,易仕明任组长,刘余滨、许梓秀任付组长。参加会议的有局科教司、业务发展司、仪器设备司、气象科学研究院及航天部5院501设计部等单位的有关专家与代表共27人。 会议听取了大气探测所的研制工作报告、试验报告、鉴定测试组的测试报告以及用户的使用报告。并参观了研制的元件和现场试验样机。 自1982年开展研制工作以来,该元件先后经气象台站及航天部等单位的实际考验及性能测试,证实其技术性能指标已达到了芬兰和美国同类产品的     

云室在云雾物理学研究中的应用进展

云室是云雾降水物理学的实验室装置,在云物理实验研究方面一直有着广泛的应用。本文介绍了目前国内几种主要云室的构造和基本性能,以及它们在大气冰核浓度的观测与研究、高效碘化银焰剂及其成冰性能的研究、液氮（LN）消雾成冰性能的实验研究、稀土化合物成冰性能的实验研究、冰雪晶碰并勾连增长的实验与观测分析中的应用,并着重介绍了这几方面试验研究目前在国内的进展情况。     

一个用于人工冰核研究的2m3等温云室

本文介绍了一个以研究人工冰核为主要目的的2m~3等温云宝及其结构、测量仪器、实验程序及性能特点。井用对三种不同配方发生的碘化银气溶胶成核率检测结果与国外同类云室的结果进行了比较。已进行的各种试验表明,云室性能稳定,重复性好,是进行人工冰核研究的有效的专用设备。     

A 2M~3 ISOTHERMAL CLOUD CHAMBER FOR THE STUDY OF ARTIFICIAL ICE NUCLEI

A 2m~3 isothermal cloud chamber mainly for ice nucleation research is described in this paper.Its structure,attached instruments and experimental procedures are also presented.The experiments of determining the icenuclei effectiveness for the Agl-containing aerosols produced by three formulations have been conducted andthe results have been compared with those of the CSU 960-liter isothermal cloud chamber.All experimentalresults show that the chamber has advantages of stable performance and reproducibility.It would be expectedto become a useful experimental facility for ice nucleation research.     

一个用于催化剂成冰性能检测的新型等温云室

云雾物理实验是我国大气科学研究需要加强的一个方面, 文中介绍了中国气象科学研究院新建用于人工冰核催化剂成冰性能研究的1 m3等温云室。阐述了该云室主要结构组成、 性能特点、 附属设备和实验程序, 以及所开展的催化剂成冰效率的初步检测研究。实验结果表明, 该云室在原建系列云室基础上, 对制冷及保温性能有很大的改进和优化, 更适合催化剂成冰性能检测和研究, 为今后我国开展云雾、 降水微物理实验研究和提高人工影响天气催化技术水平提供了一个有用的综合研究平台。     

On Mechanisms of Nucleation of Ice Crystals by Aerodynamic Cooling

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Relative importance of acid coating on ice nuclei in the deposition and contact modes for wintertime Arctic clouds and radiation

Aerosols emitted from volcanic activities and polluted mid-latitudes regions are efficiently transported over the Arctic during winter by the large-scale atmospheric circulation. These aerosols are highly acidic. The acid coating on ice nuclei, which are present among these aerosols, alters their ability to nucleate ice crystals. In this research, the effect of acid coating on deposition and contact ice nuclei on the Arctic cloud and radiation is evaluated for January 2007 using a regional climate model. Results show that the suppression of contact freezing by acid coating on ice nuclei leads to small changes of the cloud microstructure and has no significant effect on the cloud radiative forcing (CRF) at the top of the atmosphere when compared with the effect of the alteration of deposition ice nucleation by acid coating on deposition ice nuclei. There is a negative feedback by which the suppression of contact freezing leads to an increase of the ice crystal nucleation rate by deposition ice nucleation. As a result, the suppression of contact freezing leads to an increase of the cloud ice crystal concentration. Changes in the cloud liquid and ice water contents remain small and the CRF is not significantly modified. The alteration of deposition ice nucleation by acid coating on ice nuclei is dominant over the alteration of contact freezing.     

大气冰核:研究进展与挑战

大气冰核参与初始冰晶的异质形成,影响冰云的微物理过程和辐射性质.阐明大气冰核浓度、来源、性质及活化成冰的微观机制,是深入认识气溶胶与云相互作用的关键.本文梳理了近年来国内外在冰核测量技术、冰核活化机制、外场观测及其参数化方案等几个方面取得的进展,明晰了冰核研究存在的挑战.此外,本文也指出了我国加强大气冰核研究的必要性和...     

一次降雹过程的AgI系列催化模拟研究

云数值模拟是研究降雹过程和人工防雹试验的重要手段。利用三维冰雹云AgI催化模式,对北京1996年6月10日的一次降雹过程进行AgI不同催化高度、催化剂量和催化时间的系列催化模拟试验,并优选催化方案,为外场防雹设计和作业提供依据。在催化系列模拟中发现,不同催化高度的催化剂均在上升到-5℃高度后开始核化。在2.1~4.9 km高度范围内催化,AgI成核率比较高,防雹效果较好。核化的人工冰晶有效弥补了该高度上自然冰晶的不足。小剂量催化,可在减雹的同时增加部分降雨量,而大剂量催化,在减雹的同时会减少降雨。在催化时间、剂量和高度的系列催化试验中得出,采用在模拟的第15分钟在5 km高度附近播撒AgI,连续4次以5×106 kg-1的催化剂量进行催化,催化效果较好,可减少降雹量约60%,同时可避免降雨量的大幅减少。     

Theoretical Modeling of the Size-Dependent Influence of Surface Tension on the Absorptive Partitioning of Semi-Volatile Organic Compounds

The influence of surface tension on the formation of secondary organic aerosol (SOA) is investigated in this study using a size-dependent absorptive partitioning model. A theoretical framework is offered to estimate the surface tension of multi-component aerosols consisting of organic compounds and water. The size-dependent influence of surface tension on the absorptive partitioning of semi-volatile organic compounds is examined via numerical simulations of systems of representative pre-existing aerosol (PA) components and semi-volatile organic compounds that have been observed to constitute SOA. Results indicate that if nonpolar organic species constitute a significant fraction of the PA, the Kelvin effect on SOA formation may be negligible. However, if PA is dominated by polar organic compounds, the Kelvin effect on SOA formation is significant when the PA initial diameter is smaller than approximately 200 nm. If the PA is an aqueous aerosol, the Kelvin effect on SOA formation is most important. A simplified computational scheme for estimation of the Kelvin effect is developed in this study and feasibly could be coupled into three-dimensional air quality models that simulate SOA formation. Available observations also suggest that future modeling and analysis of SOA formation may need to consider the Kelvin effect. Concrete testing of the purely theoretical model presented here requires carefully designed observations that examine the phase distribution of secondary organic compounds between the gas phase and aerosol particles small enough to be affected by surface tension.     

Changes of cloud microphysical properties during the transition from supercooled to mixed-phase conditions during CIME

A ground-based seeding experiment using carbon dioxide and propane sprayed from pressurized bottles was carried out under supercooled cloud conditions on a small spatial and short time scale. Water vapor deposition on the artificially generated dry ice and propane ice germs as the main ice formation process (nucleation and growth) is consistent with the experimental results. After nucleation, diffusional growth of the ice particles, partly at the expense of evaporating small droplets, was identified during the mixing of the seeding line with the ambient supercooled cloud. Within the seeding plume, ice water contents up to 80% of the total condensed water are observed, although the size of the formed ice particles did not exceed 25 μm. From the changes of the ice and supercooled liquid phase with time under mixed-phase conditions, liquid water content (LWC) evaporation, ice water content (IWC) formation, and ice crystal growth rates are estimated, which are not affected by the artificial nucleation process. Thus, these rates are assessed to be applicable for a growing ice phase of small ice particles in a young mixed-phase cloud, where other growth mechanisms, like riming or aggregation, are negligible.     

Thunderstorm charging: Laboratory experiments clarified

Further laboratory experiments of thunderstorm charging by ice crystal collisions with riming graupel pellets have led to results that may help account for a major difference between two independent studies reported earlier. The problem concerns values of the cloud liquid water content required to change the sign of graupel charging. The present work has noted and investigated differences in the techniques of cloud nucleation used in the two studies. In one set of measurements by Takahashi, ice crystals are nucleated continuously in a supercooled water droplet cloud, while in the other experiments by Jayaratne et al. and Saunders et al., the droplet cloud is nucleated only briefly. These two nucleation methods lead to differences in the mass of cloud particles collected on a sampling probe used to determine the liquid water content of the cloud. In the continuous nucleation case, the probe collects sufficient numbers of ice crystals to lead to a substantial overestimate of the cloud liquid water content.