Influence of solar heating and precipitation scavenging on the simulated lifetime of post--nuclear war smoke

The behavior of smoke injected into the atmosphere by massive fires that might follow a nuclear war was simulated. Studies with a three-dimensional global atmospheric circulation model showed that heating of the smoke by sunlight would be important and might produce several effects that would decrease the efficiency with which precipitation removes smoke from the atmosphere. The heating gives rise to vertical motions that carry smoke well above the original injection height. Heating of the smoke also causes the tropopause, which is initially above the smoke, to reform below the heated smoke layer. Smoke above the tropopause is physically isolated from precipitation below. Consequently, the atmospheric residence time of the remaining smoke is greatly increased over the prescribed residence times used in previous models of nuclear winter.     

微观结构对水合物浆液流动特性的影响研究现状

海底管道天然气/水合物浆液混输技术是近年来出现的一种新技术,有助于解决深海油气混输易发生水合物堵塞事故的难题。研究水合物浆液的流动特性是实现该管输技术大规模工业应用的重要基础,而浆液的微观结构是决定其流动特性的本质因素。介绍了现有文献中的几种关于颗粒聚集机理的解释以及两种测量微观性质的试验方法。     

Effects of aerosol from biomass burning on the global radiation budget

An analysis is made of the likely contribution of smoke particles from biomass burning to the global radiation balance. These particles act to reflect solar radiation directly; they also can act as cloud condensation nuclei, increasing the reflectivity of clouds. Together these effects, although uncertain, may add up globally to a cooling effect as large as 2 watts per square meter, comparable to the estimated contribution of sulfate aerosols. Anthropogenic increases of smoke emission thus may have helped weaken the net greenhouse warming from anthropogenic trace gases.     

云南4个烤烟品种物理和烟气指标的相关性分析

选择云南省11个烟区4个烤烟品种3个部位的烟叶,进行了12个物理指标与7个烟气指标的检测和相关性分析。结果表明,物理指标中CV较大的占41.67%,烟气指标中CV较大的占28.57%,说明物理指标相对于烟气指标波动大,稳定性较差。高度正相关的指标有总粒相物与烟气水分、总粒相物与烟气烟碱量、总粒相物与焦油量、烟气烟碱量与焦油量、烟气烟碱量与烟气pH、拉力与抗张强度;中度正相关的指标有总粒相物与叶片厚度、烟气水分与焦油量、烟气烟碱量与抽吸口数、烟气烟碱量与叶片厚度、含梗率与填充值、拉力与叶质重、叶片厚度与耐破度;中度负相关的指标有焦油量与长宽比、一氧化碳与长宽比、叶质重与填充值。说明各烟气指标间、各物理指标间相关性较大,物理指标与烟气指标间也存在一定的相关性。     

浅谈如何使用烟剂有效防治森林病虫害

烟剂是防治森林病虫害的主要手段之一,非常适用于树高、林密、交通不便、水源缺乏的林区。由于药剂转变成烟以后,颗粒变得非常小,能够到达茂密的树冠、叶子的正反面、树皮缝隙等处,大大提高了防治病虫害的效果,所以烟剂防治是一种很有前途的防治方法。     

卷烟主流烟气中单糖成分的分析研究

采用高效阴离子色谱法对卷烟主流烟气中单糖成份进行分析。用超声萃取卷烟烟气总粒相物,超滤后,以高效阴离子色谱法进行分离,采用2．0mmol／LNaOH和0．5mm01／LNaAc的混合水溶液淋洗,在METROSEPCarbl250分离柱（4．6×250mm,5μm）柱上检测单糖成分,检测出卷烟主流烟气总粒相物中含有果糖、葡萄糖、阿拉伯糖、甘露糖、半乳糖、木糖等6种单糖,其中半乳糖成分的检出在可查的文献未见报道,组分分离较完全,定性灵敏度高。此方法能同时对卷烟烟气中多种单糖成分进行定性、定量分析,为判断卷烟的感官品质提供了有效途径。     

卷烟抽吸过程中香线滤棒内含致香成分逐口转移的研究

为了探索香线滤棒中致香成分在卷烟燃烧过程中随主流烟气的转移情况,采用了气相色谱-质谱联用法(GC-MS)分析技术,对卷烟前7口主流烟气总粒相物中的薄荷醇及苯乙醇进行了定量分析。结果表明,试验所建立的检测方法具有较好的准确性,线性相关系数大于0.999,回收率为98%~104%。随着卷烟的抽吸口数增加,除第一口卷烟刚点燃释放量较低外,剩下6口均以一定的线性关系呈上升趋势。     

Preparation of submicroscopic spider threads for particle studies

Many small spiders produce threads of different diameters, some of which are submicroscopic. When the threads are subjected to an environment of tobacco smoke and then examined microscopically, the invisible threads are manifested as particles in a line with no visible connection. These threads are used to support microscopic water droplets in single-particle scattering experiments.     

Tobacco mosaic virus: purifying and sorting associated particles accordig to length

End-to-end aggregation of tobacco mosaic virus and associated particles during extraction and purification may be prevented by transfer of the virus to 0.001M buffer solution of ethylenediaminetetraacetic acid, pH 7.5, as rapidly as practicable. Colored components were removed with charcoal and diatomaceous earth, and salts by rapid passage through a column of granulated 8 percent agar gel. The virus particles were sorted according to length by passage through a 1 percent granulated agar-gel column to isolate the 300- and 200-mmicro fractions and through a 5 percent agar gel to isolate the shorter particles.     

不同装烟方式对烟叶色泽·酚类物质及抗氧化能力的影响

[目的]考察不同装烟方式对烟叶品质的影响。[方法]采用烟篦、烟夹和烟筐3种装烟方式进行烤烟,对烟叶的色泽、酚类物质和抗氧化能力进行了比较研究。[结果]研究表明,烟夹和烟篦装烟方式下的烟叶L*、a*、b*值均高于烟筐烤烟,3种装烟方式的烟叶a*、b*值之间没有显著性的差异,L*值则有显著性差异(P0.05),h值中烟夹和烟筐装烟方式显著低于烟篦装烟。烟篦烤烟的总酚、绿原酸含量最高,烟夹烤烟次之,烟筐烤烟的最低,且有显著性的差异(P0.05),而芸香苷含量差别不大。3种装烟方式的抗氧化能力顺序(DPPH自由基清除能力和还原能力)为烟篦烟夹烟筐,且与总酚含量和绿原酸含量之间存在一定的正相关性。[结论]从烟叶品质和抗氧化能力考虑,3种装烟方式中,烟篦装烟是比较好的选择。     

Proteins and disulfide groups in the aggregation of dissociated cells of sea sponges

A sponge extract that produced specific aggregation of dissociated cells was treated with various enzyme preparations to determine which enzymes would destroy its aggregating properties. The results indicate that proteins play a key role in the aggregating effect of the extract on dissociated, glutaraldehyde-fixed sponge cells. Further studies confirm the necessity of calcium for the aggregation and indicate the necessity of intact disulfide groups.     

林业应用系统本体聚合研究综述

通过对本体聚合的现状研究,结合林业应用系统本身特征,制定出林业应用系统本体聚合的方法,为林业应用系统的升级找到一种能节约费用的新方法,可让现有林业应用系统能更灵活地服务于林业职能部门。     

卷烟多点生产质量稳定性研究

利用方差分析对不同厂家生产的同一品牌卷烟的质量稳定性进行研究,结果表明:不同厂家生产的卷烟在包装与卷制、主流烟气及感官质量上没有差异性,可为产品的多点生产提供理论依据。     

Isopycnic separation of subcellular components from poliovirus-infected and normal HeLa cells

A rapid method for determining the density of ribonucleoprotein particles and complexes has been developed. The method involves glutaraldehyde fixation of sucrose gradient fractions and immediate centrifugation for 5 hours through preformed cesium chloride gradients. There is little or no aggregation of particles, so that components which co-sediment in sucrose gradients are resolved by the cesium chloride gradient. By this method the densities of HeLa cell ribosomes, polyribosomes, and subribosomal particles have been determined. Furthermore, the poliovirus replication complex has been separated from polyribosomes and its density has been found to be unaffected by treatment with ethylene-diaminetetraacetic acid.     

Spherical bilayer vesicles of fullerene-based surfactants in water: a laser light scattering study

The low solubility of fullerenes in aqueous solution limits their applications in biology. By appropriate substitution, the fullerenes can be transformed into stabilized anions that are water soluble and can form large aggregated structures. A laser light scattering study of the association behavior of the potassium salt of pentaphenyl fullerene (Ph5C60K) in water revealed that the hydrocarbon anions Ph5C60- associate into bilayers, forming stable spherical vesicles with an average hydrodynamic radius and a radius of gyration of about 17 nanometers at a very low critical aggregation concentration of less than 10(-7) moles per liter. The average aggregation number of associated particles in these large spherical vesicles is about 1.2 x 10(4).     

长江河口内溢油轨迹的数值模拟研究

构建了海洋与溢油模型相耦合的长江河口的溢油轨迹预报系统,海洋模型能较好模拟该海域的表层流场;溢油模型采用拉格朗日和随机游走的油粒子追踪法,可快速预测油粒子的漂移扩散轨迹和扫海面积。研究表明,大潮时溢油的油粒子的分布范围和扫海面积均比小潮时刻大,在南支溢出的油粒子会漂移到南、北港和南、北槽,对生态环境危害最大,会影响陈行和青草沙两大水库取水口,并对中华鲟和九段沙湿地保护区产生潜在的生态危害;在北支溢出的油粒子主要分布在北支水道和两岸,如果溢油点位于上段会倒灌进南支水道,将会产生较大的生态危害;在南港溢出的油粒子会漂移到南北槽,不会对两大水库和中华鲟保护区产生危害,但会对九段沙保护区造成潜在的危害;在北港溢出的油粒子则会漂移到崇明岛外海,且扩散范围很大,只对中华鲟保护区造成危害。     

Tenuous structures from disorderly growth processes

Colloidal aggregation and other random growth processes produce structures that behave differently from ordinary bulk matter. Much of this behavior can be described in terms of the invariance of the aggregates under changes of spatial length scale: they appear to be fractals. There are two types of basic mechanisms for producing fractal aggregates. Those in which aggregation proceeds cluster by cluster can be understood qualitatively in terms of a solvable schematic model. The diffusion-limited aggregation or deposition of individual particles to make a large cluster is not as well understood. It is closely related to several irreversible processes in other areas of physics, such as two-fluid displacement in porous materials and the dielectric breakdown of insulators. More generally, disorderly growth mechanisms provide structures having unique properties, many of which can be understood by using simple statistical principles.     

磁场对土壤理化性质的影响

 研究了磁场对土壤理化性质的影响。结果表明，在磁场作用下，土壤胶体ξ电位降低，电荷密度有所提高，土壤持水力，膨胀量下降;土壤微团聚化作用增强，＜0.01毫米粒径的微团聚体数量减少，0.01-0.05毫米粒径的微团聚体数量增加；土壤比表面减少，土壤粘结力降低，土壤物理性质得到改善。     

Significance of individual components of organic matter in the formation of the water-stable structure of light gray forest soils of the northern forest steppe

The effect of humus, readily decomposable organic matter, and carbohydrates of a nonspecific nature on the formation of water-stable aggregates in field rotation members has been studied. It has been established that the degree of effect of organic matter on aggregation of particles is determined by the character of use of the plots and crop being grown.     

Chemical signatures for superheavy elementary particles

Models of unified fundamental interactions suggest the existence of many particles in the mass range 10 x 10(9) to 100 x 10(12) electron volts. Among these may be charged particles, X(+/-), that are stable or nearly so. The X(+,)s would form superheavy hydrogen, while the X(-,)s would bind to nuclei. Chemical isolation of naturally occurring technetium, promethium, actinium, protactinium, neptunium, or americium would indicate the presence of superheavy particles in the forms RuX(-), SmX(-), (232)ThX(-), (235,236,238)UX(-), (244)PuX(-), or (247)CmX(-). Other substances worth searching for include superheavy elements with the chemical properties of boron, fluorine, manganese, beryllium, scandium, vanadium, lithium, neon, and thallium.