Superheated ice: true compression fractures and fast internal melting

Internal melt figures can be nucleated in ice without the presence of a vapor bubble. Their form and growth are fracture-like, different from the normal Tyndall stars, which do contain vapor bubbles. Normal Tyndall figures that grow rapidly are not oriented in the basal plane, and very rapid internal melting gives a peculiar, systematic growth of clouds of Tyndall figures.     

Ozone- and photon-enhanced atmospheric sulfidation of copper

The sulfidation of materials upon exposure to the atmosphere has traditionally been attributed entirely to reactions with sulfur-containing gases and water vapor. New laboratory results demonstrate that the sulfidation of polycrystalline copper can be markedly enhanced both by solar radiation and by the ubiquitous atmospheric ozone, thus indicating that the high rates of corrosion in urban areas are a result of a complex sequence of multicomponent photochemical processes.     

Mars: occurrence of liquid water

In the absence of juvenile liquid water, condensation of water vapor to ice and subsequent melting of ice are the only means of producing liquid water on the martian surface. However, the evaporation rate is so high that the available heat sources cannot melt pure ice. Liquid water is therefore limited to concentrated solutions of strongly deliquescent salts.     

Melt inclusions in veins: linking magmas and porphyry Cu deposits

At a porphyry copper-gold deposit in Bajo de la Alumbrera, Argentina, silicate-melt inclusions coexist with hypersaline liquid- and vapor-rich inclusions in the earliest magmatic-hydrothermal quartz veins. Copper concentrations of the hypersaline liquid and vapor inclusions reached maxima of 10.0 weight % (wt %) and 4.5 wt %, respectively. These unusually copper-rich inclusions are considered to be the most primitive ore fluid found thus far. Their preservation with coexisting melt allows for the direct quantification of important oreforming processes, including determination of bulk partition coefficients of metals from magma into ore-forming magmatic volatile phases.     

Crystalline ribulose 1,5-bisphosphate carboxylase-oxygenase from spinach

Spinach fraction I protein (ribulose 1,5-bisphosphate carboxylase-oxy genase, E.C. 4.1.1.39) was crystallized on both an analytical and a preparative scale by vapor diffusion with polyethylene glycol (molecular weight, 6000) used as the precipitant. The identity of the crystalline material with fraction I protein was shown by gel electrophoresis in the presence of sodium dodecyl sulfate and immunological properties. The carboxylase and oxygenase activities copurify during crystallization, and the crystalline enzyme lacks copper and iron.     

Emplacement of cretaceous-tertiary boundary shocked quartz from chicxulub crater

Observations on shocked quartz in Cretaceous-Tertiary (K-T) boundary sediments compellingly tied to Chicxulub crater raise three problems. First, in North America shocked quartz occurs above the main K-T ejecta layer. Second, shocked quartz is more abundant west than east of Chicxulub. Third, shocked quartz reached distances requiring initial velocities up to 8 kilometers per second, corresponding to shock pressures that would produce melt, not the moderate-pressure shock lamellae observed. Shock devolatilization and the expansion of carbon dioxide and water from impacted wet carbonate, producing a warm, accelerating fireball after the initial hot fireball of silicate vapor, may explain all three problems.     

原油管道油气爆炸实验与数值模拟

为研究油气体积分数对爆炸的影响,采用实验研究与数值模拟相结合的方法,对输油管道油气爆炸发展机理进行研究。结果表明:油气体积分数是影响油气爆炸强烈程度的重要因素,原油油气爆炸的最大压力与初始体积分数有关。当油气体积分数为5.51%～7.06%时,体积分数越大,爆炸压力越大;当油气体积分数为7.06%时,爆炸压力达到最大值;当油气体积分数超过7.06%时,随着油气体积分数增大,爆炸最大压力反而变小。研究结果对揭示原油管道油气爆炸传播规律,减少管道爆炸事故具有指导意义。     

Pb isotopic variability in melt inclusions from oceanic island basalts, polynesia

Previous studies have suggested that melting processes are responsible for the trace element variability observed in olivine-hosted basaltic melt inclusions. Melt inclusions from three individual lava samples (two from Mangaia, Cook Islands, and one from Tahaa, Society Islands) have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. The range of Pb isotopic compositions from individual melt inclusions spans 50 percent of the worldwide range observed for ocean island basalts. The melt inclusion data can be explained by two-component mixing for each island. Our data imply that magmas with different isotopic compositions existed in the volcanic plumbing system before or during melt aggregation.     

Oscillatory zoning in plagioclase feldspar

A kinetic mathematical model of crystal growth from the melt is used to describe quantitatively the phenomenon of oscillatory zoning in plagioclase feldspar. In this model, the functional dependence of crystal growth rate on both melt and crystal surface composition and the transport of material within the melt are explicitly considered. Oscillatory zoning is found to develop for a wide variety of such functional dependence and to be sensitive to the initial composition of the melt.     

Microtomography of partially molten rocks: three-dimensional melt distribution in mantle peridotite

The permeability of the upper mantle controls melt segregation beneath spreading centers. Reconciling contradictory geochemical and geophysical observations at ocean ridges requires a better understanding of transport properties in partially molten rocks. Using x-ray synchrotron microtomography, we obtained three-dimensional data on melt distribution for mantle peridotite with various melt fractions. At melt fractions as low as 0.02, triple junctions along grain edges dominated the melt network; there was no evidence of an abrupt change in the fundamental character of melt extraction as melt fraction increased to 0.2. The porosity of the partially molten region beneath ocean ridges is therefore controlled by a balance between viscous compaction and melting rate, not by a change in melt topology.     

原油在不同温度下的饱和蒸气压及其经验公式

国内外一直使用测定汽油饱和蒸气压的雷德法来测定原油的饱和蒸气压，测量误差较大。利用雷德法的测量大批量及所用仪器，研究出测定原油饱和蒸气压的新方法－－参比法，比国内外现在所用方法具有更高的精密度，已被批准为国家标准。通过对测试数据的分析，发现在储存和管输温度范围内，原油的饱和蒸气压与温度有线性关系，可用克拉帕龙－克劳修斯经验公式ｌｎＰ＋Ｂ＋Ａ／Ｔ表示。并指出对不同时间所取油样，测得的饱和蒸气压有一定     

基于模糊聚类的冰雪融冻期交通流状态分析

在收集大量冰雪融冻期和非冰雪期速度和密度数据的基础上,提出采用模糊c均值的算法对这两个时期的交通流状态进行聚类分析。分别将冰雪融冻期和非冰雪期的交通流状态分为了3类、4类和6类,通过比较分析发现冰雪融冻期的交通流状态比非冰雪期的规律性更强,基本上4类足以描述冰雪融冻期的各种交通流状态。     

油气含量测定方法的研究

研究了单体烃及油气色谱分析条件,建立了一套简单、便宜、准确的油气含量测定方法,研究了单体烃或油气-空气混合气中油气含量与色谱峰面积的关系、单体烃之间及其与油气之间的换算关系,并推导或回归出了相应的计算式。油气含量测定既可以油气总烃的标准谱图来换算,也可参照某单体烃标准谱图来换算。试验获得的基础数据及标定方法可供相关研究及管理部门作参考。     

菠菜和油菜对铜的吸收及化学结合形态研究

以菠菜和油菜为供试材料，采用盆栽试验的方法，研究菠菜和油菜对微量元素铜的吸收规律及其体内铜的不同化学结合形态的差异。结果表明：在铜处理浓度不超过160mg／kg土时，随铜处理浓度的增加，菠菜对铜的吸收呈先升后降的趋势．而油菜对铜的吸收却随铜处理浓度的升高而一直保持增加的趋势。在菠菜和油菜的不同生长时期，均以中期对铜的吸收量大于收获期的吸收量。铜在菠菜和油菜体内的化学结合形态，菠菜是以活性较高的水溶态为主，油菜则以活性较低的残余态为主。     

反刍动物铜营养代谢病研究进展

铜是反刍动物必需的微量元素,适量的铜可刺激动物生长,当动物机体摄入过量的铜时就会引发铜中毒,而铜不足则会造成动物生产机能下降.文章从反刍动物对微量元素铜的需要量及影响因素、铜缺乏和铜中毒对动物机体的影响、铜营养代谢病的诊断、监测及防治等方面介绍了反刍动物微量元素铜营养代谢病的研究进展,提出加强对反刍动物的肝铜测定、加强改善口服铜制剂适口性、提高铜制剂生物利用率、降低生产成本等方面研究的建议.     

铜在青菜体内的分布与存在形式研究

用溶液培养的方法研究了青菜对铜的吸收、分布 ,以及铜在青菜体内的存在形式。结果表明 :青菜根系铜含量远大于地上部 ,随着铜处理浓度的升高 ,根系和地上部的铜含量显著增加。青菜根系中的铜主要与小分子物质结合 ,但这些物质并不是由铜诱导产生的。     

Vapor pressure of water at its triple point: highly accurate value

The vapor pressure of water at its triple point was measured with greatly increased accuracy. The triple point was realized with newly designed equipment that enhanced the stability of the pressure and permitted any air released from solution to be removed by pumping. A diaphragm pressure transducer separated the water vapor from the helium used to transmit the pressure to the manometer. The pressure was measured with the National Bureau of Standards precision mercury manometer. The vapor pressure at the triple point was found to be 611.657 pascals with random uncertainties at the 99 percent confidence level of +/- 0.010 pascal. The systematic errors are estimated to be relatively insignificant.     

Flotation of diamond in mantle melt at high pressure

Experiments show that diamond floats in a primitive mantle melt at around 20 gigapascals and 2360 degrees C and in a melt formed by partial melting of the transition zone at about 16 gigapascals and 2270 degrees C. These observations constrain magma densities at high pressure. Diamond precipitated or trapped in a silicate melt at the base of the transition zone or the lower mantle floats and has been accumulating in the transition zone since early in Earth's history. Thus, the transition zone could be a reservoir of diamond.     

铜对烤烟生长及产质量的影响研究

研究不同施铜量对烤烟生长、产量及养分吸收的影响。结果表明:施铜能提高烟叶的产量、产值、均价和上等烟比例,且与对照之间的差异达到显著水平,以1.35 kg/hm2处理最高。在0.45～1.35 kg/hm2施铜水平范围内可改善烟叶的品质。施铜对烟叶中铜含量有显著的影响,当施铜水平为0.45~0.90 kg/hm2时,烟叶中铜含量为最佳。因此,从烤烟的农艺性状、经济性状、品质和养分吸收方面综合考虑,建议云南省滇中优质烤烟合理的施铜水平以0.45～0.90 kg/hm2为宜。     

静态混合原理在松脂熔解过程中的应用

松脂熔解过程实际上是一个传热、反应及萃取同时存在的综合过程。过程进行的好坏与各物料间的分散混合及其在熔解器中的停留时间密切相关。在连续熔解器中设置静态混合元件可以促进物料在熔解器径向的分散和混合,强化熔解过程;另一方面,混合元件可抑制物料在熔解器轴向的大幅度混合,从而使各部分松脂在熔解器中的实际停留时间均较接近所计算的表观停留时间,提高熔解过程的总体效果。