Apollo 16 Geochemical X-ray Fluorescence Experiment: Preliminary Report

The lunar surface was mapped with respect to magnesium, aluminum, and silicon as aluminum/ silicon and magnesium/ silicon intensity ratios along the projected ground tracks swept out by the orbiting Apollo 16 spacecraft. The results confirm the observations made during the Apollo 15 flight and provide new data for a number of features not covered before. The data are consistent with the idea that the moon has a widespread differentiated crust (the highlands). The aluminum/ silicon and magnesium/ silicon concentration ratios correspond to those for anorthositic gabbros through gabbroic anorthosites or feldspathic basalts. The x-ray results suggest the occurrence of this premare crust or material similar to it at the Descartes landing site.     

硅钙钾镁肥对浙江省酸性水稻土壤的改良效果

为了明确新型土壤调理剂——硅钙钾镁肥对浙江省酸性水稻土的改良效果,通过连续3 a的田间小区试验,研究硅钙钾镁肥不同用量与化肥配施对水稻产量及土壤养分含量的影响。结果表明,与习惯施肥相比,施用硅钙钾镁肥水稻增产明显,以施用硅钙钾镁肥1 500 kg·hm^-2增产效果较好。在土壤改良方面,施用硅钙钾镁肥可以提高土壤pH值,降低土壤交换性氢和交换性铝含量,提高土壤有效硅和盐基离子含量。     

进水钙、铝离子共存对反渗透膜污染的影响效应分析

基于某生物制药企业膜生物反应器处理出水配置了不同Ca/Al配比的料液,以考察其对反渗透膜污染的结构、形貌、组成与特征的影响效应。结果表明：进水中共存的钙、铝成分结合有机物在膜面上形成了复合污染层,Ca/Al配比的变化导致差异显著的膜污染特性。在低铝含量、高Ca/Al比条件下,进水中铝盐与膜面有机官能团在强势极性作用力下优先结合,与进水中疏水性有机组分凝聚共沉于膜面,对膜污染的形成具有远大于Ca组分的作用。根据扩展杨氏方程计算得到系统总表面张力：低钙低铝,53.0 mJ/m²;低钙高铝,69.5 mJ/m²;高钙高铝,70.4 mJ/m²。这表明进水中铝含量变化主要影响进水溶液与膜面材料之间的极性作用力,钙含量变化几乎没有相应影响。膜清洗结果表明进水中钙铝成分引起的膜污染在空间结构上是分层的,铝通过与膜面分子间的极性力作用紧密结合在膜污染的底层,形成难以清洗的不可逆污染;Ca则主要存在于污染的滤饼层,极易通过化学清洗恢复。因此,精准控制前段混凝预处理阶段Al盐投加量对防止膜污染具有重要意义。     

X-ray line and continuum spectra of solar flares from 0.5 to 8.5 angstroms

Two crystal spectrometers aboard the orbiting solar observatory OSO-4 cover the wavelength ranges 0.5 to 3.9 angstroms and 1.0 to 8.5 angstroms. Within this range, there appear emission lines from hydrogen-like and helium-like states of calcium, sulfur, silicon, magnesium, and aluminum. The Mg XII Lyman-alpha is present strongly in all x-ray flares. The most intense flares (such as class 3) produce strong Si XIV Lyman-alpha and often S XVI Lyman-alpha. Emission, in the form of Ka lines of highly ionized states of calcium, iron, aluminum, and silicon is usually present. The continuum from 1 to 10 angstroms always dominates the line emission by more than an order of magnitude. Electron temperatures derived from the slope of the continuum spectrum are in the range of 10(7) to 10(8) degrees K, considerably higher than theoretical ionization equilibrium temperatures.     

含硅、钙土壤调酸剂应用于酸性水稻土的效果分析

连续两季施用含硅、钙土壤调酸剂,对湖北省水稻产区酸性水稻土基本理化性状和水稻产量进行评价。结果表明,施用不同量的含硅、钙土壤调酸剂对土壤的pH均有提高,提高值最高达0.29;土壤硅铝率提高0.23;对土壤阳离子交换量也有一定影响,增加幅度最高达1.90 cmol(+)/kg;对水稻结实率提高幅度达5.56%,千粒重增加0.73 g;对土壤容重及耕层有机质、全氮、碱解氮、有效磷等影响不大。表明在酸性较重土壤中施用含硅、钙土壤调酸剂可以改善土壤酸性、硅铝率和提高阳离子交换量,对土壤结构和其他养分含量影响不明显,对水稻增产效果明显。     

海南岛火山岩砖红壤铁质风化壳主量元素特征[1]

通过对海南岛西北部火山岩砖红壤铁质风化壳剖面样品进行X荧光光谱法检测、风化特征指数及质量迁移系数的计算,揭示海南岛新生代火山岩砖红壤铁质风化壳的主量元素分布、风化强度和迁移特征。风化壳主量元素以Fe2O3、Al2O3、SiO2为主,K、Na、Ca、Mg等易溶组分较低;Fe2O3、Al2O3富集、SiO2淋失的热带地区风化特征。风化层CIA指数高达95%以上、Fe2O3/Al2O3上升,BA值较低, SiO2/Al2O3、SiO2/R2O3、BA下降;以Zr为参比元素,铁、铝迁移系数大于1,最大可达4.029,钠、钾、钙、镁、硅、锰迁移系数小于1,可低至-0.996。研究认为海南岛西北部火山岩风化壳表现为典型的脱硅富铁,铁质元素强烈富集,其它元素淋失明显,且铁铝元素发生了的分异,是比较成熟的风化壳。     

吉富罗非鱼饲料钙磷比研究

【目的】探讨饲料钙磷比(质量比)对吉富罗非鱼生长、饲料利用、磷表观消化率、体成分、骨组织无机物含量、血清生化指标的影响,确定吉富罗非鱼饲料中适宜的钙磷比。【方法】以磷酸二氢钾为磷源、氯化钙为钙源,分别配制等磷（总磷为9～10 g/kg）、等氮、等能、钙磷比理论值分别为2∶1,1.5∶1,1∶1,1∶1.5,1∶2和1∶3（实测值分别为1.8∶1,1.3∶1,1∶1.1,1∶1.5,1∶2.5和1∶2.9）的6组纯化饲料,用之饲养吉富罗非鱼（初始体质量为(46.03±2.14) g/尾）8周,每组设3个重复,测定其体质量增加率、饲料系数、磷表观消化率、体成分、骨组织无机物含量、血清生化指标等。用折线模型分别对供试罗非鱼的特定生长率、全鱼磷含量、脊椎骨磷含量和血清磷含量与饲料钙磷比水平进行相关分析,确定饲料中钙磷比的适宜水平。【结果】钙磷比为1∶1.1～1∶2.9的试验组鱼体质量增加率和特定生长率均显著高于钙磷比1.8∶1组(P＜0.05);钙磷比1∶2.5组的饲料系数显著低于1.8∶1组(P＜0.05),但与其他各组间无显著差异(P＞0.05);钙磷比1∶2.5组的磷表观消化率显著高于1.8∶1组、1.3∶1组和1∶2.9组(P＜0.05),但与1∶1.1组和1∶1.5组无显著差异(P＞0.05);饲料钙磷比对吉富罗非鱼的脏体比、肝体比、肥满度及成活率均无显著影响(P＞0.05)。随着饲料钙磷比的下降（钙水平的降低）,全鱼和脊椎骨的钙、磷含量均呈先升高后降低的趋势(P＜0.05),肌肉的粗脂肪含量呈升高趋势(P＜0.05),而全鱼和脊椎骨的粗灰分含量及Ca/P值均无显著变化(P＞0.05)。血清磷含量随饲料钙磷比的下降呈升高的趋势(P＜0.05),饲料钙磷比对血清钙含量无显著影响(P＞0.05);血清碱性磷酸酶活力和甲状旁腺激素含量均随饲料钙磷比的下降呈先升高后降低的趋势(P＜0.05),血清总胆固醇和甘油三酯的含量随饲料钙磷比的下降均呈先降低后升高的趋势(P＜0.05)。【结论】吉富罗非鱼要获得最大的特定生长率、全鱼磷含量、脊椎骨磷含量和血清磷含量,其饲料中最适钙磷比分别应为1∶1.5,1∶1.1,1∶1.1和1∶2.4,据此建议在饲料总磷水平为9～10 g/kg时,吉富罗非鱼饲料中钙磷比的适宜水平为1∶1.1～1∶1.5。     

Enceladus' varying imprint on the magnetosphere of Saturn

The bombardment of Saturn's moon Enceladus by >20-kiloelectron volt magnetospheric particles causes particle flux depletions in regions magnetically connected to its orbit. Irrespective of magnetospheric activity, proton depletions are persistent, whereas electron depletions are quickly erased by magnetospheric processes. Observations of these signatures by Cassini's Magnetospheric Imaging Instrument allow remote monitoring of Enceladus' gas and dust environments. This reveals substantial outgassing variability at the moon and suggests increased dust concentrations at its Lagrange points. The characteristics of the particle depletions additionally provide key radial diffusion coefficients for energetic electrons and an independent measure of the inner magnetosphere's rotation velocity.     

Chemical analysis of the moon at the surveyor v landing site

The chemical composition of the lunar surface material at a maria landing site has been determined by the alpha-scattering technique. Oxygen, silicon, and aluminum have been identified in the preliminary evaluation of the data. The general chemical composition is similar to that of a silicate of a basaltic type.     

Radio science results during the NEAR-shoemaker spacecraft rendezvous with eros

We determined the mass of asteroid 433 Eros, its lower order gravitational harmonics, and rotation state, using ground-based Doppler and range tracking of the Near Earth Asteroid Rendezvous (NEAR)-Shoemaker spacecraft and images of the asteroid's surface landmarks. The mass of Eros is (6.687 +/- 0.003) x 10(18) grams, which, coupled with our volume estimate, implies a bulk density of 2. 67 +/- 0.03 grams per cubic centimeter. The asteroid appears to have a uniform density distribution. The right ascension and declination of the rotation pole are 11.37 +/- 0.05 and 17.22 +/- 0.05 degrees, respectively, and at least over the short term, the rotation state of Eros is stable with no measurable free precession of the spin pole. Escape velocities on the surface vary from 3.1 to 17.2 meters per second. The dynamical environment of Eros suggests that it is covered with regolith and that one might expect material transport toward the deepest potential wells in the saddle and 5.5-kilometer crater regions.     

Obsidian hydration profiles measured by sputter-induced optical emission

The variation of concentrations of hydrogen, sodium, potassium, lithium, calcium, magnesium, silicon, and aluminum as a function of depth in the hydration layer of obsidian artifacts has been determined by sputter-induced optical emission. The surface hydration is accompanied by dealkalization, and there is a buildup of alkaline earths, calcium and magnesium in the outermost layers. These results have clarified the phenomena underlying the obsidian hydration dating technique.     

Hydrogen in stishovite, with implications for mantle water content

Stishovite, the highest pressure polymorph of silicon dioxide, may be an important mineral in some regions of the Earth's mantle. Fourier transform infrared spectroscopy has been used to determine the hydrogen content of synthetic stishovite. The concentration of hydrogen depends on the aluminum content of the sample and reaches a maximum of 549 +/- 23 hydrogen atoms per 10(6) silicon atoms for an Al(2)O(3) content of 1.51 percent by weight. Stishovite could be a storage site for water in deep subducting slabs and in regions of the mantle that are too hot for hydrous minerals to be stable.     

Type II Supernova Matter in a Silicon Carbide Grain from the Murchison Meteorite

The circumstellar silicon carbide (SiC) grain X57 from the Murchison meteorite contains large amounts of radiogenic calcium-44 (20 times its solar system abundance) and has an anomalous silicon isotopic composition, different from other circumstellar SiC grains. Its inferred initial 44Ti/Si and 44Ti/48Ti ratios are 1.6 x 10(-4) and 0.37. In addition, it contains radiogenic magnesium-26; the inferred initial 26Al/27Al ratio is 0.11. The isotopic and elemental data of X57 can be explained by selective mixing of matter from different zones of a typical type II supernova of 25 solar masses during its explosion. The high 44Ti/Si ratio requires contributions from the innermost nickel zone of the supernova to the SiC condensation site, as similarly suggested by astronomical observations.     

女贞子中微量元素的分析研究

采用一种套筒电极和分段曝光新技术,在一米平面光栅摄谱测得女贞子样品中含有27种微量元素。本研究为女贞子药效提供科学依据,也给其它中草药微量元素提供一个切实可行的测试方法。     

Fine particles in the soufriere eruption plume

The size distributions of fine particles measured at tropospheric altitudes in the periphery of the eruption plume formed during the 17 April 1979 eruption of Soufriere Volcano and in the low-level effluents on 15 May 1979 were found to be bimodal, having peak concentrations at geometric mean diameters of 1.1 and 0.23 micrometers. Scanning electron microscopy and energy-dispersive x-ray analysis of the samples revealed an abundance of aluminum and silicon and traces of sodium, magnesium, chlorine, potassium, calcium, and iron in the large-particle mode. The submicrometer-sized particles were covered with liquid containing sulfur, assumed to be in the form of liquid sulfuric acid.     

The dynamics of the stratospheric polar vortex and its relation to springtime ozone depletions

Dramatic springtime depletions of ozone in polar regions require that polar stratospheric air has a high degree of dynamical isolation and extremely cold temperatures necessary for the formation of polar stratospheric clouds. Both of these conditions are produced within the stratospheric winter polar vortex. Recent aircraft missions have provided new information about the structure of polar vortices during winter and their relation to polar ozone depletions. The aircraft data show that gradients of potential vorticity and the concentration of conservative trace species are large at the transition from mid-latitude to polar air. The presence of such sharp gradients at the boundary of polar air implies that the inward mixing of heat and constituents is strongly inhibited and that the perturbed polar stratospheric chemistry associated with the ozone hole is isolated from the rest of the stratosphere until the vortex breaks up in late spring. The overall size of the polar vortex thus limits the maximum areal coverage of the annual polar ozone depletions. Because it appears that this limit has not been reached for the Antarctic depletions, the possibility of future increases in the size of the Antarctic ozone hole is left open. In the Northern Hemisphere, the smaller vortex and the more restricted region of cold temperatures suggest that this region has a smaller theoretical maximum for column ozone depletion, about 40 percent of the currently observed change in the Antarctic ozone column in spring.     

Glacial silicic acid concentrations in the Southern Ocean

Reconstruction of nutrient concentrations in the deep Southern Ocean has produced conflicting results. The cadmium/calcium (Cd/Ca) data set suggests little change in nutrient concentrations during the last glacial period, whereas the carbon isotope data set suggests that nutrient concentrations were higher. We determined the silicon isotope composition of sponge spicules from the Atlantic and Pacific sectors of the Southern Ocean and found higher silicic acid concentrations in the Pacific sector during the last glacial period. We propose that this increase results from changes in the stoichiometric uptake of silicic acid relative to nitrate and phosphate by diatoms, thus facilitating a redistribution of nutrients across the Pacific and Southern Oceans. Our results are consistent with the global Cd/Ca data set and support the silicic acid leakage hypothesis.     

Helicoidal crack propagation in aluminous orthoamphiboles

Sodie and alluolminous orthoamphiboles from metamorphosed volcanic rocks develop helicoidal fractures upon cooling, due to elastic strain gradients radical to the c-axis. This condition may arise, fromradial composition gradients involving subastitution of tetrahedral silicon by aluminum in the double chain structure or from intergranular boundary constraints with adjacent quartz.     

Mass and local topography measurements of Itokawa by Hayabusa

The ranging instrument aboard the Hayabusa spacecraft measured the surface topography of asteroid 25143 Itokawa and its mass. A typical rough area is similar in roughness to debris located on the interior wall of a large crater on asteroid 433 Eros, which suggests a surface structure on Itokawa similar to crater ejecta on Eros. The mass of Itokawa was estimated as (3.58 +/- 0.18) x 10(10) kilograms, implying a bulk density of (1.95 +/- 0.14) grams per cubic centimeter for a volume of (1.84 +/- 0.09) x 10(7) cubic meters and a bulk porosity of approximately 40%, which is similar to that of angular sands, when assuming an LL (low iron chondritic) meteorite composition. Combined with surface observations, these data indicate that Itokawa is the first subkilometer-sized small asteroid showing a rubble-pile body rather than a solid monolithic asteroid.     

外源钙对铝胁迫下辣椒植株几个生理指标的影响

[目的]为了解辣椒的耐铝机理提供参考依据.[方法]研究了不同浓度钙处理对同一浓度铝胁迫下辣椒植株生理特性的差异,解析在几种不等钙浓度状态下辣椒植株生理生化特性和形态的改变.[结果]在200 μmol/L铝胁迫下,辣椒植株生长明显受到影响;加入不同浓度的钙,可有效地减轻铝对辣椒幼苗的胁迫,随钙溶液处理浓度的增加,辣椒植株叶片的叶绿素含量变化幅度较小;净光合速率呈先上升后下降的趋势;细胞间隙二氧化碳浓度表现出递增式下降;辣椒植株的根长随钙浓度增加而增长.[结论]1 mmo/L钙离子对辣椒植株的铝胁迫缓解达到最佳生理状态.