阿司匹林的合成条件研究

以水杨酸和醋酐为原料经O-酰化反应合成阿司匹林，比较了三氯化铝、三氯化铋和无水碳酸钠三种不同催化剂以及反应条件对合成的影响，找到了最佳催化剂和最佳反应务件，即以三氯化铝为催化剂，其用量为水杨酸的2％，水杨酸与醋酐的摩尔比为1：2，反应时间为30min，回流温度为85℃左右，阿司匹林产率可迭72．6％。实验表明该催化剂催化效果好．不污染环境，是一种环境友好的催化剂。同时，本法简单、快速、经济、无污染，产品质量好，适于工业化生产。     

Petrography and geochemistry of eclogites from the Mir kimberlite,Yakutia, Russia

 Diamond-bearing eclogites are an important component of the xenoliths that occur in the Mir kimberlite, Siberian platform, Russia. We have studied 16 of these eclogite xenoliths, which are characterized by coarse-grained, equigranular garnet and omphacite. On the basis of compositional variations in garnet and clinopyroxene, this suite of eclogites can be divided into at least two groups: a high-Ca group and a low-Ca group. The high-Ca group consists of high-Ca garnets in equilibrium with pyroxenes that have high Ca-ratios [Ca/(Ca+Fe+Mg)] and high jadeite contents. These high-Ca group samples have high modal% garnet, and garnet grains often are zoned. Garnet patches along rims and along amphibole- and phlogopite-filled veins have higher Mg and lower Ca contents compared to homogeneous cores. The low-Ca group consists of eclogites with low-Ca garnets in equilibrium with pyroxenes with a low Ca-ratio, but variable jadeite contents. These low-Ca group samples typically have low modal% of garnet, and garnets are rarely compositionally zoned. Three samples have mineralogic compositions and modes transitional to the high- and low-Ca groups. We have arbitrarily designated these samples as the intermediate-Ca group. The rare-earth-element (REE) contents of garnet and clinopyroxene have been determined by ion microprobe. Garnets from the low-Ca group have low LREE contents and typically have [Dy/Yb]_n < 1. The high-Ca group garnets have higher LREE contents and typically have [Dy/Yb]_n > 1. Garnets from the intermediate-Ca group have REE contents between the high- and low-Ca groups. Clinopyroxenes from the low-Ca group have convex-upward REE patterns with relatively high REE contents (ten times chondrite), whereas those from the high-Ca group have similar convex-upward shapes, but lower REE contents, approximately chondritic. Reconstructed bulk-rock REE patterns for the low-Ca group eclogites are relatively flat at approximately ten times chondrite. In contrast, the high-Ca group samples typically have LREE-depleted patterns and lower REE contents. The δ¹⁸O values measured for garnet separates range from 7.2 to 3.1‰. Although there is a broad overlap of δ¹⁸O between the low-Ca and high-Ca groups, the low-Ca group samples range from mantle-like to high δ¹⁸O values (4.9 to 7.2‰), and the high-Ca group garnets range from mantle-like to low δ¹⁸O values (5.3 to 3.1‰). The oxygen isotopic compositions of two of the five high-Ca group samples and four of the eight low-Ca group eclogites are consistent with seawater alteration of basaltic crust, with the low-Ca group eclogites representative of low-temperature alteration, and the high-Ca group samples representative of high-temperature hydrothermal seawater alteration. We interpret the differences between the low- and high-Ca group samples to be primarily a result of differences in the protoliths of these samples. The high-Ca group eclogites are interpreted to have protoliths similar to the mid to lower sections of an ophiolite complex. This section of oceanic crust would be dominated by rocks which have a significant cumulate component and would have experienced high-temperature seawater alteration. Such cumulate rocks probably would be LREE-depleted, and can be Ca-rich because of plagioclase or clinopyroxene accumulation. The protoliths of the low-Ca group eclogites are interpreted to be the upper section of an ophiolite complex. This section of oceanic crust would consist mainly of extrusive basalts that would have been altered by seawater at low temperatures. These basaltic lavas would probably have relatively flat REE patterns, as seen for the low-Ca group eclogites. Received: 10 July 1995 / Accepted: 17 May 1996     

A High-K, Mantle Derived Plutonic Suite from 'Linga', near Arequipa (Peru)

The Linga Group consists of a suite of Cretaceous high-K calc-alkalinerocks intruded into 2?0 Ga old basement in S.E. Peru. The rocksrange in composition from gabbros, through diorites and grandioritesto granites. Microprobe, major and trace element and isotopedata suggest the suite evolved by fractional crystallization,with plagioclase as the dominant phase and with surprisinglylittle interaction with the pre-existing crust. The rocks yieldan Rb/Sr whole rock isochron of 68 ? 3 Ma with an initial Sr-isotoperatio 0.70516 ? 8, and from three Nd-isotope analyses initialNd = – 1?4 to – 2?0. ¹⁸ O increases from 5?0 permil in a gabbro to 7?0 per mil in a granite, and models arepresented which suggest that the suite evolved from parentalmagmas which had ¹⁸O = 5?8 to 6?0 per mil, 1.5 per cent K₂O,63 p.p.m. Rb, 582 p.p.m. Sr, 35 p.p.m. Ce, 0.38 p.p.m. Ta, ⁸⁷Sr/⁸⁶Sr= 0.7052, and ¹⁴³Nd/¹⁴⁴Nd = 0.51247. Trace element considerationsimply that these magmas contain contributions from incompatibleelement enriched upper mantle material and from a componentassociated with subduction. The latter is thought to reflectthe preferential mobilization of alkali and alkaline earth elementsby H₂O-rich fluids from the subducted slab, and preliminarycalculations indicate that it was responsible for {small tilde}45 per cent of the Sr and {small tilde} 80 per cent of the Kin the more primitive Linga rocks. However, the isotope datasuggest that while the fluids may be from the subducted slab,the elements in this component may also have been mobilizedfrom the overlying mantle wedge.     

Biological and Physical Attenuation of Endocrine Disruptors and Pharmaceuticals: Implications for Water Reuse

A select group of endocrine disrupters, pharmaceuticals, and personal care products was studied to determine the degree of biological attenuation in water reuse applications. Laboratory investigations involved both batch reactors using biologically active sand and continuous flow simulated aquifer storage and recovery experiments. All laboratory experiments were conducted using Colorado River water spiked with various target compounds at concentrations between 10 and 100 ng/L. Field studies were also conducted to determine the occurrence and attenuation of target compounds in water reuse applications. Two golf courses irrigated with reuse water were studied to determine if turf applications led to contamination of nearby ground water. A waste water treatment facility that uses rapid infiltration basins seasonally was also tested to determine the degree of attenuation of detectable target compounds along a subsurface flowpath. A qualitative structural activity relationship model was applied to the target compounds to predict the general rate of aerobic biological degradation. Significant attenuation of many target compounds was observed in both laboratory and field experiments. Conversely, several compounds displayed limited removal during these studies. Field experiments were limited to detectable compounds and various nonbiological removal or concentration effects that may impact data interpretations, which are discussed in this paper. The predictive model was found to be moderately accurate within the confines of the project scope.     

The gravitational field of a disk

This note gives the gravitational potential of the disk {(x, y, z):x ² +y ² p ² , z=0} and the gravitational field at the point (x, y, z). Formulas for a ring can be obtained as the difference of our results for two different values ofp. Results are obtained in terms of elliptic integrals and we indicate how these functions can be computed efficiently. Formulas necessary for the computation of partial derivatives are also given.This paper presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract NAS7-100, sponsored by the National Aeronautics and Space Administration.     

Origin and history of waters associated with coalbed methane: I, Cl, and stable isotope results from the Fruitland Formation, CO and NM

The Fruitland Formation of the San Juan Basin was deposited during the late Cretaceous and is associated with significant reservoirs of coalbed methane (CBM). The purpose of this study is to determine the origin and history of waters associated with the formation, using long-lived cosmogenic and stable isotope systems. Ratios of ¹²⁹I/I and stable isotope values (δD and δ¹⁸O) were determined in waters from close to 100 wells, ³⁶Cl/Cl ratios for a subset of these samples. A significant group of samples has ¹²⁹I/I ratios between 100 × 10⁻¹⁵ and 200 × 10⁻¹⁵, indicating minimum iodine ages close to 60 Ma. If these ages are corrected for the addition of fissiogenic ¹²⁹I, they are compatible with the depositional age of the Fruitland Formation (Late Cretaceous).Several sets of waters are clearly present within the data. A group dominated by infiltration of recent surface waters is restricted to the uplifted basin margins, with a lateral extent of less than 5 km from outcrop, and is characterized by ¹²⁹I/I ratios in excess of 1500 × 10⁻¹⁵ and meteoric δD, δ¹⁸O, and ³⁶Cl/Cl signatures. The rest of the basin is characterized by several subsets of formation waters which have undergone variable degrees of iodine enrichment through diagenesis as well as variable degrees of dilution. The first subgroup is found in coals of relatively low vitrinite reflectance and moderate enrichment of iodine. This subgroup predominantly consists of entrapped pore fluids, although it may also contain waters which infiltrated the coals at the time of the Laramide uplift, between 25 and 30 Ma. A second subgroup consists of formation waters associated with coals of high vitrinite reflectance. Despite subsequent uplift, the high iodine concentrations and low ¹²⁹I/I ratios of this subgroup, as well as a moderate depletion of deuterium relative to ¹⁸O, suggest that these waters were not significantly altered since the time when diagenetic reactions occurred in the deepest portion of the basin. A third subgroup, with higher δD and δ¹⁸O values as well as higher ¹²⁹I/I ratios, extends roughly west to east at the New Mexico-Colorado state line and corresponds to a region of extensive fracturing of the coalbeds. In this case, the higher ¹²⁹I/I ratios are probably due to contributions of fissiogenic ¹²⁹I through fracture flow, perhaps from deeper formation waters. Our results do not support models of subsequent basin-wide groundwater migration in the Fruitland Formation. The combined use of ¹²⁹I and ³⁶Cl with stable isotope studies provides valuable information as to the hydrologic history of coalbed methane deposits, as well as their potential for commercial exploitation.     

A Chemical and Multi-Isotope Study of the Western Cape Olivine Melilitite Province, South Africa: Implications for the Sources of Kimberlites and the Origin of the HIMU Signature in Africa

We present major and trace element and Sr–Nd–Pb–Hf–Osisotopic data for the 76–58 Ma Western Cape melilititeprovince, an age-progressive magmatic lineation in which primitiveolivine melilitite intrusives and alkali basalt lavas have beenemplaced on the southwestern margin of South Africa. The magmasrange from alkali basalts with strong HIMU isotopic and traceelement affinities on the continental shelf to melilitites withkimberlite-like incompatible element compositions and EM 1 isotopicaffinities on thick Proterozoic lithosphere (i.e. ⁸⁷Sr/⁸⁶Sr_i= 0·7029–0·7043,     

三维激光点云数据在既有地下人防工程BIM模型重建中的应用

BIM模型的创建是实现BIM技术应用的第一步,常见的基于CAD图纸的BIM模型创建方法存在建模效率低、空间表现不直观的缺点、本丈以某地下人防工程的B1M模型重建为例,结合=维激光扫描技术,详细阐述了基于维激光点云数据的BIM模型重建过程,主要步骤为:①利用FARO Focus3DX330获取海量点云数据;②利用FARO SCENE软件完成点云数据的配准拼接,滤波去噪.贴图输出;③按目标对象几何形状和功能特征的差异,利用Autodesk Revil分别完成线性类、构件连接类、单体目标类点云对象的B1M模型制作.研究表明,利用三维激光扫描技术可以很好地完成BIM模型的重建.而且具有建模精度高、现场还原度好的优势.