难处理金精矿加压氧化-氰化提金工艺研究

对新疆阿希难浸金精矿进行了酸性加压氧化-氰化浸金试验研究，考察了各种因素对加压氧化和氰化浸金效果的影响。在适宜条件下，金浸出率达到97％以上。     

碱性热压氧化预处理浑江金精矿提金工艺试验研究

热压氧化预处理提金工艺已被成功地用于难处理矿石中金的回收.特别是酸性热压氧化法应用较多,自1985年以来,先后被美国的Mclanglin金矿,巴西的Sao.Be-nto金矿和美国的Getchell金矿等用来处理难浸金矿,而用于难处理金矿的碱性热压氧化法的报道较少,美国的Mercur金矿是其中之一.无论酸性还是碱性热压氧化其主要目的都是通过适当地破坏对金形成包裹的矿物的晶格结构,使金解离暴露出来,以便用常规氰化法提金.实际应用中要根据矿     

某难处理金精矿生物氧化--炭浸提金试验研究

针对某难处理金精矿进行了单因素及连续生物预氧化-炭浸提金试验,研究了矿石粒度、矿浆浓度、氧化时间、pH值及充气量等因素对难处理金精矿生物氧化及氧化渣炭浸提金的影响。结果表明,矿浆浓度、氧化时间和充气速率是难处理金精矿生物氧化及氧化渣炭浸的主要影响因素。在磨矿细度为-0.034 mm占75%、温度为45℃、矿浆浓度为14%和充气速率为0.25~35 m3/h·L-1的条件下,经生物氧化7~8 d,单因素和连续生物氧化的硫氧化率和氧化渣炭浸提金浸出率均＞95%。     

康家湾含砷金硫精矿提金工艺的研究进展与评述

介绍了康家湾含砷金硫精矿的矿物特征与几种提金工艺的研究进展,评述了各方案的优、缺点,指出了采用焙烧法和生物预氧化提金工艺的应用前景。     

某难处理硫化金精矿加压氧化一氰化浸金试验研究

对云南某难处理硫化金精矿进行加压氧化一氰化浸金试验研究,考察了加压氧化各因素对氰化浸金的影响。加压氧化最优条件为：固液比1：4,木质素磺酸钠5g／t,硫酸初始质量浓度10g/L,温度190℃,压力2．0MPa,反应时间4h,搅拌转速450r／min。金精矿经加压氧化一氰化浸出获得了97．55％的较高金浸出率。     

生物提金技术

本文从生物提金原理和方法两方面阐述了生物提金技术，并简介了生物提金实践例子。     

康家湾含砷金硫精旷提金工艺的研究进展与评述

介绍了康家湾含砷金硫精矿的矿物特征与几种提金工艺的研究进展，评述了各方案的优缺点，指出了采用焙烧法和生物预氧化提金工艺的应用前景。     

细菌氧化—氰化浸金工艺试验研究

主要介绍了对其含砷浮选金精矿进行的１００ｋｇ／ｄ细菌氧化－氰化浸金连续扩大试验所取得的成果；并对试验结果进行了分析与评价；同时指出了今后细菌氧化－氰化浸金的研究方向。     

难处理金精矿生物氧化-氰化炭浸法提金试验

针对某难处理金精矿含砷、高碳的特点,采用生物氧化-氰化炭浸提金工艺,考察了矿浆浓度、氧化时间、溶氧量、搅拌速度、培养基用量等因素对Fe、As、S脱除率、硫化物氧化率及金浸出率的影响。氰化炭浸试验结果表明,金的浸出率由直接氰化炭浸时的15.53%提高到95.82%,同时分析了氧化过程Eh、pH变化及Fe的行为。     

金精矿中氰化物的测定

在细菌氧化过程中,金精矿含有氰化物,会对细菌起到毒害作用,严重地影响细菌氧化处理,因此实际生产时对金精矿中的氰化物含量提出了严格的要求。为了准确测定金精矿中氰化物舍量,文中分别实验了固体称样量及预蒸馏时蒸馏试剂的选择等测定条件,最终总结出针对金精矿中氰化物含量切实可行的测定方法。     

Experimental studies of the effects of atmospheric pollutants]

Experimental studies in man are an indispensable complement to epidemiological studies and experimental studies on animals. They aim at understanding the mechanisms of action of the main pollutants and at knowing their thresholds of triggering of the acute effects on the respiratory system. The studies made in man involve controlled exposure to different atmospheric pollutants, with measurement of the functional respiratory repercussions, studies of modification of the cells in broncho-alveolar lavage, as well as experimental protocols that combine inhalation of allergen and exposure to atmospheric pollutants by allergic subjects. The main results that are available are reported to distinguish those from normal subjects and those who are allergic. More recent protocols are based on exposure to concentrations that are close to atmospheric concentrations or those that are met in work places. The main data in the literature are reported in this journal and concern SO2 acid aerosols, dioxides of nitrogen, ozone and diesel particles. Pathogenic hypotheses concerning the undesirable effects of atmospheric pollutants on the respiratory system are considered.     

Assessment of Time of Concentration Formulas for Overland Flow

Despite the importance of overland time of concentration on the design discharge, engineers are often bewildered by the array of formulas available in the literature without knowing the accuracy of each formula. This assessment covers nine formulas published between 1946 and 1993, which are intended for overland flow only that is subjected to uniform rain. The assessment compares the estimates from the formulas with experimental values that are derived under the same conditions for two surfaces: concrete and grass. The assessment shows that formulas that do not account for the rainfall intensity are only valid for a limited range of rainfall intensities. The formulas that account for the rainfall intensity generally show better agreement with the experimental data. Finally, the assessment gives two rankings of the formulas for the two surfaces in accordance to their accuracy as compared to the experimental data. The formula that has the best accuracy for both surfaces is the Chen and Wong formula.     

Eysenck's treatment of the personality of communists.

The data, presented by Eysenck (see 30: 909), concerned with the notion that communists and fascists are similar in being "tough-minded" and "authoritarian" are critically examined. A detailed treatment of the sampling and measurement techniques employed to obtain the revelant data are presented. The author concludes that: (1) "The samples studied are not representative of the present population, and that generalizations drawn from these samples are therefore unwarranted; (2) the 'tough-mindedness' scale leads to misleading comparisons among members of various political parties because of biases built into the scoring system." In addition, the author concludes that the communists and fascists did differ from one another in many "crucial aspects." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

晶内铁素体及其组织控制技术研究概况

介绍了晶内铁素体的组织特点以及晶内铁素体组织对钢材力学性能的影响,得出晶内铁素体能显著提高钢的冲击韧性。详细阐述了晶内铁素体的形核机理,分析表明目前晶内铁素体形核机理仍不够完善,尚未形成统一的机制。同时介绍了钛氧化物、MnS、稀土氧化物等促进晶内铁素体形核的夹杂物,指出含Ti复合夹杂物是理想的晶内铁素体形核核心。最后分析了夹杂物尺寸、冷却速度对晶内铁素体形核的影响,并简述了一些晶内铁素体组织控制技术,结果表明Ti-B 处理、Ti-Mg处理效果优于单独的Ti处理。     

The effect of the reduction of colloid oncotic pressure, with and without reduction of osmolality, on post-traumatic cerebral edema

The fact that centrally acting analgesics have abuse potential commensurate with their analgesic activity raises the question of whether these effects are related. The abuse potential of drugs depends on their ability to produce reinforcing effects, which are mediated by a neural system that includes the ventral tegmental dopamine cells and their connections with the ventral striatum. Morphine and amphetamine are both powerful analgesics and have high abuse potential. Their analgesic and reinforcing effects are mediated by similar receptors, similar sites of action, and overlapping neural substrates. These coincidences suggest that reinforcers may produce analgesia by transforming the aversive affective state evoked by pain into a more positive affective state. The implications of this hypothesis and its relation to other known mechanisms of analgesia are discussed. The hypothesis predicts that drugs with reinforcing effects should produce analgesia. A survey of drugs acting through 21 classes of receptors reveals that in 13 classes there is evidence for both analgesic and reinforcing effects that are approximately equipotent. The GABA(A) agonists were found to be the only drugs with confirmed abuse potential that lack analgesic activity. The interpretation of this and several other anomalous cases is discussed.     

Physical Modeling of Compressive Behaviors of Anchored Rock Masses

The mechanical characteristics of rock masses anchored with bolts play a critical role in anchored slope and underground buildings. In this study, the components and their mixing ratios of similar materials, such as rock masses, are simulated. The materials similar to the anchored bolts and cement are selected. The physical and mechanic properties of these materials are tested. Based on these, an experimental model and a method are designed with a focus on a uniaxial compression test on anchored rock masses. A series of tests on the anchored specimens’ uniaxial compression strength are conducted under the conditions of varying numbers and installations of anchor bolts. The results reveal that compared with the specimens without anchor bolts, the peak strength, elastic modulus, and shear strength of the specimens with both perpendicular and horizontal bolts are improved. Furthermore, it is indicated that the improvement attributable to the horizontal bolts is slightly lower than that with vertical bolts. This suggests that the uniaxial compression strength is heterogeneous in different directions.     

Machining of Machine Elements Made of Polymer Composite Materials

The machining of the machine elements that are made of polymer composite materials (PCMs) or are repaired using them is considered. Turning, milling, and drilling are shown to be most widely used among all methods of cutting PCMs. Cutting conditions for the machining of PCMs are presented. The factors that most strongly affect the roughness parameters and the accuracy of cutting PCMs are considered.     

Orientation of the peptidoglycan chains in the sacculus of Escherichia coli

The organization of chains of oligopeptidoglycan in the saccular wall is of critical importance in the study of the mechanism and physiology of prokaryotic wall growth. The electron microphotographs of De Pedro et al. present new findings and can be used to negate or at least raise questions about the previously accepted conclusion that the glycan chains are oriented transversely to the axis of rod-shaped Escherichia coli. This suggests caution in assuming that the glycan chains in the murein structure are parallel to each other and are perpendicular to the axis of the cell. These results should reopen the question of not only the orientation of the peptidoglycan chains, but the possibility of variability in orientation. Three classes of hypotheses about wall growth are reconsidered and problems with them are presented. The new results from De Pedro's laboratory and the experimental glycan chain length distribution argue against proposed systematic models. These include models that postulate belts or hoops stretched around the circumference of the cell and mechanisms that insert new chains of the length of presumptive "docking" strands in the stress-bearing wall. They are consistent, however, with the surface stress theory that proposes that random enzyme action together with physical forces are involved in the elongation of the rod-shaped Gram-negative wall.     

New Relation for the Computation of Settling Velocities and Diameters of Spheres

Single relations that can be used to calculate both the terminal settling velocities of spheres and the equivalent diameter of particles from their settling velocities are developed. The literature going back to Newton is reviewed and the relations developed tabulated. It is shown how the standard drag curve has developed into the dimensionless velocity versus dimensionless diameter curve. No relations that cover the full range that can conveniently be used for both velocity and diameter calculation were found, however a relation by Concha and Almendra covers most of the range.

The standard drag curve data are constructed by utilizing 535 data points available in the literature in a Reynolds number range of 2.4 × 10^?5 to 2 × 10⁵. The settling velocities are corrected for experiments in finite width columns that do not satisfy the infinite medium dimensions. The data are converted to the dimensionless diameter and dimensionless velocity terms, which is more convenient for calculation purposes.

The data are analyzed using piecewise cubic functions. Data from sources with excessive scatter and a few outliers are removed leaving 443 data points. The resulting piecewise cubic can be used to obtain velocity from diameter or diameter from velocity. To give an algebraic expression a hyperbola is fitted to the data giving an expression that can be solved to give explicit relations for both dimensionless velocity and dimensionless diameter. This provides an accuracy that compares well with expressions given in the literature.     

On the practice of dichotomization of quantitative variables.

The authors examine the practice of dichotomization of quantitative measures, wherein relationships among variables are examined after 1 or more variables have been converted to dichotomous variables by splitting the sample at some point on the scale(s) of measurement. A common form of dichotomization is the median split, where the independent variable is split at the median to form high and low groups, which are then compared with respect to their means on the dependent variable. The consequences of dichotomization for measurement and statistical analyses are illustrated and discussed. The use of dichotomization in practice is described, and justifications that are offered for such usage are examined. The authors present the case that dichotomization is rarely defensible and often will yield misleading results. (PsycINFO Database Record (c) 2011 APA, all rights reserved)