低品位重晶石的浮选特性研究

重晶石的用途非常广泛,对BaSO_4的含量要求85％～90％以上。但我国重晶石矿山贫矿多,富矿少,需进行选矿。因此,本文进行了低品位重晶石的浮选特性研究。结果确定了低品位重晶石浮选的最佳条件,并获得了品位98.2％,回收率82.3％的能生产高品位钡化合物的重晶石精矿,为今后重晶石选矿发展具有实用价值。     

单耗分析的理论和实施

《单耗分析》是在(火用)和(火用)经济学的基础上所设计的能量系统分析的理论和方法,以产品单耗做为降耗节能的主要指标,分析单耗的构成及其分布和变化,为节能降耗技术提供实用的理论依据。     

露天矿开采计划CAD系统的研究

本文结合哈尔滨水泥厂新明矿的实际情况,开发了露天矿开采计划CAD系统软件包。主要包括系统分析,矿床地质模型处理,现状数组形成,开采屏幕模拟,台阶边界线搜索,坡面线处理,图纸输出等。     

Atomic snapshots using lattice agreement

Summary Thesnapshot object is an important tool for constructing wait-free asynchronous algorithms. We relate the snapshot object to thelattice agreement decision problem. It is shown that any algorithm for solving lattice agreement can be transformed into an implementation of a snapshot object. The overhead cost of this transformation is only a linear number of read and write operations on atomic single-writer multi-reader registers. The transformation uses an unbounded amount of shared memory. We present a deterministic algorithm for lattice agreement that usedO (log² n) operations on 2-processorTest & Set registers, plusO (n) operations on atomic single-writer multi-reader registers. The shared objects are used by the algorithm in adynamic mode, that is, the identity of the processors that access each of the shared objects is determined dynamically during the execution of the algorithm. By a randomized implementation of 2-processorsTest & Set registers from atomic registers, this algorithm implies a randomized algorthm for lattice agreement that uses an expected number ofO (n) operations on (dynamic) atomic single-writer multi-reader registers. Combined with our transformation this yields implementations of atomic snapshots with the same complexity.Cambridge Research Laboratory, Digital Equipment Corporation Hagit Attiya received the B.Sc. degreeiin Mathematics and Computer Science from the Hebrew University of Jerusalem, in 1981, the M.Sc. and Ph.D. degrees in Computer Science from the Hebrew University of Jerusalem, in 1983 and 1987, respectively. She is presently a senior lecturer at the departtment of Computer Science at the Technion, Israel Institute of Technology. Prior to this, she has been a post-doctoral research associate at the Laboratory for Computer Science at M.I.T. Her general research interests are distributed computation and theoretical computer science. More specific interests include fault-tolerance, timing-based and asynchronous algorithms. Maurice Herlihy received the A.B. degree in Mathematics from Harvard University, and the M.S. and the Ph.D. degrees in Computer Science from M.I.T. From 1984 to 1989 he was a faculty member in the Computer Science Department at Carnegie Mellon University in Pittsburgh, PA. In 1989 he joined the research staff at the Digital Equipment Corporation's Cambridge Research Laboratory in Cambridge MA. Since 1994, he has been on the faculty at the Computer Science Department at Brown University. Dr. Herlihy's research interests encompass practical and theoretical aspects of distributed and concurrent computation. Ophir achman received a B.A. in computer science from the Technion, Haifa, Israel in 1989 and M.Sc. in computer science from the Technion, Haifa, Israel, in 1992. He is now studying for a D.Sc. in computer science at the Technion. His currentarea of research is distributed computing, and in particular, asynchronous shared memory systems.This work appeared in preliminary form in proceedings ofthe 6th International Workshop on Distributed Algorithms [12]. This research was partially supported by grant No. 92-0233 from the United States-Israel Binational Science Foundation (BSF), Jerusalem, Technion V.P.R. funds — B. and G. Greenberg Research Fund (Ottawa), and the fund for the promotion of research in the TechnionPart of the work of this author was performed while visiting DEC Cambridge Research Laboratory     

A systolic array for the longest common subsequence problem

We introduce a linear systolic array for the Longest Common Subsequence (LCS, for short) problem. We first present an array of m identical cells which computes the length of an LCS of two strings of length m and n, respectively, in linear time (i.e., in time proportional to m + n). Then we show that, by extending any cell with the systolic stack introduced by Guibas and Liang (1982), a new array can be designed to recover an LCS in linear time.     

The modulation by neurosteroids of the scopolamine-induced learning impairment in mice involves an interaction with sigma1 (sigma1) receptors

Pulmonary tuberculosis: primary tuberculosis, usually asymptomatic, represents the first infection and is shown by a parenchymal mostly mid-pulmonary focus and satellite lymphadenopathy. Postprimary pulmonary tuberculosis, mostly located in the upper fields may be caused by endogenous reinfection for reactivation of a hematogenous focus formed during primary infection or from exogenous reinfection. Extrapulmonary tuberculosis: it includes numerous forms mostly from hematogenous spread. Miliary tuberculosis may involve a number of organs and apparatus besides the lung. Tuberculous meningitis predominantly involves the base of the skull, the fluid is clear with hypoglycorrhachia and lymphocyte pleocytosis. Lymph node tuberculosis is generally unilateral and cervical. Tuberculous pleuritis is exudative or dry. Other forms of tuberculous serositis are pericarditis and peritonitis. Renal tuberculosis involves the medullaris and intestinal tuberculosis the ileocecum; tuberculous spondilitis (Pott's disease) involves the last dorsal vertebrae. Other forms are osteoarthritis, genital tract tuberculosis, pancreatitis, laryngitis, otitis.     

Edge dislocation climb over non-deformable circular inclusions

Edge dislocation climb over non-deformable circular inclusions is studied as a possible rate limiting mechanism for creep of dispersion strengthened metals. The inclusion and matrix are assumed to exhibit no misfit and to be elastically isotropic, with the inclusion, more rigid than the matrix. The climb motion of the dislocation is assumed to be diffusion controlled and very much slower than glide. We calculate the path taken by the dislocation as it climbs past the inclusion. Special attention is given to the equilibrium separation distance between the dislocation and inclusion, the total climb distance required to pass the inclusion and the total lag time imposed on the dislocation motion by the presence of the inclusion. We discuss the results of these calculations and their implications in connection with the problem of creep of dispersion strengthened metals.     

Phase diagram and lattice parameter data for the GaAsySb1−y system

Ingots of GaAs_ySb_1−y alloys have been prepared by various directional freezing techniques, the rate of freezing being kept sufficiently small (e.g. ∼ 0.5cm/day) that equilibrium conditions were obtained in cross-sectional slices. Samples from these slices have then been investigated by powder X-ray photographs and an X-ray fluorescence technique to determine the variation of lattice parameter with composition and the range of single phase solid solution. The results show that this system has a solid miscibility gap of maximum range 0.38 < y < 0.61 and that this corresponds to a peritectic reaction. In the range 0 < y < 0.38 the lattice parameter a_o follows the Vegard line, but for 0.61 < y < 1.00 a_o lies below this line. By annealing samples in the liquid-solid two phase fields, data have also been obtained on the solidus curve and the peritectic temperature has been shown to be 745 ± 5C.     

Rupture of Valsalva''s sinus of subacute development

In this study, the effects of forearm static exercise were determined on local blood flow and oxygen consumption in 15 normal individuals (NL) and their responses were compared with ten patients in congestive heart failure (CHF). Forearm blood flow was determined by a plethysmographic technique before and during 15% of maximum voluntary contraction of the forearm. Regional arterial and venous oxygen contents were sampled and forearm oxygen consumption calculated by the Fick principle. At rest, forearm blood flow was less in patients with heart failure than in normal individuals; however, this was compensated for by an increased oxygen extraction, thus maintaining forearm oxygen consumption at a normal level. In contrast, during static exercise, forearm blood flow failed to rise normally with heart failure (NL 9.31; CHF 4.35 ml/min-100 ml, P less than 0.001) and the increased oxygen extraction was not sufficient to maintain a normal forearm oxygen consumption (NL .82; CHF .44 ml/min-100 ml, P less than 0.01). Therefore, patients with congestive heart failure demonstrate regional circulatory and metabolic abnormalities during static exercise that are comparable to those present during dynamic exercise. Because of a limited ability of their skeletal muscle resistance vessels to respond to dilator stimuli, they have an attenuation of their exercise hyperemia which leads to an earlier shift to anaerobic metabolism.