大宝山矿区多金属硫化物矿床中共生(伴生)元素的分布特点及综合利用前景分析

大宝山是一个大型的多金属复合矿床,并含多种共生(伴生)元素,综合利用价值很大.研究和分析多金属硫化物矿床中伴生元素的含量、赋存状态、嵌布特点、分布规律,是综合利用的前提.     

Single and complex effect of ammonia and hydrogen sulfide in the air on small laboratory animals (rats) under various environmental conditions 2. Effect of hydrogen sulfide alone and hydrogen sulfide with ammonia and dust

The maximum tolerable concentrations per animal position of hydrogen sulphide alone (5 ppm) and with ammonia (5 ppm H2S; 30 ppm NH3) were established by model experiments under defined environmental conditions. The normal values of the contaminant gas combination were found to be acceptable even with additional dust load on the experimental animals. TGL 29084 should stipulate 5 ppm hydrogen sulphide as the new maximum concentration per animal position.     

Distribution of alloying elements and impurities in the secondary zinc alloy after filtration

Influence of the ceramic foam filter composition on the microstructure and distribution of alloying elements (copper and aluminum) and impurities (iron and lead) in the secondary zinc alloy is investigated. The foam-ceramic filters (FCF) on the basis of corundum, cordierite and silicon carbide with ultradispersed active layers are investigated. By the methods of metallographic, X-ray diffraction and X-ray spectral analyses it is demonstrated that the filtration through the foam-ceramic filters allows one to obtain a homogeneous alloy with the uniform distribution of the alloying elements and impurities. It has been revealed that the highest effect on the microstructure and characteristics of the alloy exert the filters based on cordierite and silicon carbide with an ultradispersed layer including the elements of IV group of the Periodic System.     

Dissolution of hydrogen from the gas in steel at room temperature

The purpose of this paper is to show that embrittlement of steel deformed in a hydrogen atmosphere is caused by hydrogen entering the crystal lattice. Tensile tests are made under pure compressed hydrogen gas. It is shown that the hydrogen penetrates steel before any fissures develop. The penetration depends on the time of exposure of fresh surface produced by straining but does not depend directly on the strain rate. The hydrogen distribution vs depth was measured. It agrees with a transient distribution calculated with an apparent solubility (1 cu cm per 100 g at 150 kp per sq cm) and an apparent diffusivity (1.3·10^?7 sq cm per sec).     

Distribution of penicillin in the cornea, tears and aqueous humour at various times following a single intravenous injection

Bioassays performed by the disc diffusion technique on samples of blood, tears, aqueous humour and cornea from 30 rabbits killed 4 to 24 hours following a single intravenous injection of benzylpenicillin (40 mg/kg) showed that the penicillin content of these fluids and tissues progressively decreased with time. However, even after 24 hours the agent could be detected in the samples. The peripheral and central cornea contained similar amounts of penicillin up to 16 hours; thereafter, the peripheral cornea contained more of the agent.     

Single and complex effect of ammonia and hydrogen sulfide in the air on small laboratory animals (rats) under various environmental conditions. 1. Effect of ammonia

The maximum per-animal-position concentration of ammonia was studied under defined environmental conditions and with reference to basic stress on thermoregulation. The normal value of 30 ppm NH3, laid down in TGL 29084, was experimentally confirmed.     

Continuing bonds and adjustment at 5 years after the death of a spouse.

Thirty-nine bereaved individuals completed the Continuing Bonds Scale (CBS), assessing various aspects of the ongoing attachment to the deceased, at 60 months postloss in a longitudinal conjugal bereavement study. They also completed symptom measures at 6, 14, 25, and 60 months postloss. Higher CBS scores were associated with a more elevated grief-specific symptom pattern over the 5-year postloss period. Moreover, those who expressed greater helplessness and less blame toward the deceased during a monologue role-play involving their deceased spouse at 6 months postloss had higher CBS scores. Finally, greater satisfaction in the past relationship with the spouse was predictive of higher CBS scores. The results were discussed in relation to existing literature on the adaptiveness of continuing bonds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of the age and sex dependence of trace elements in hair by correspondence analysis

Nondialyzable Maillard reaction products (MRPs) were recovered from three different coffee brew extracts (i.e., brewed, boiled, instant) to evaluate the efficacy of MRPs in modulating in vitro metal-induced cytotoxicity in C3H/10T1/2 mouse embryo fibroblast cells, cultured in the presence of Fe2+, Fe3+, or Cu2+ ions. Preliminary experiments were performed in an vitro linoleic acid emulsion model system to characterize the anti- or pro-oxidant activity of coffee MRPs. Cytotoxicity experimental protocols involved both the direct application of metal ions and coffee MRPs to fibroblast cells, and the premixing of metal ions with coffee MRPs at room temperature prior to incubating with fibroblast cells. Fe2+ and Cu2+ significantly lowered the colonization efficiency (CE) of cells at all three concentrations (i.e., 0.1, 10, 50 microM) used. Similar Fe3+ activity was observed only at 50 microM concentration. None of the coffee MRPs alone or together with 0.1 and 10 microM of Fe2+ or Fe3+ produced cytotoxic effects during direct application. The premixing step, however, significantly enhanced the CE of cells compared to the control, denoting cytoprotection, only in the presence of Fe2+. In addition, the application of MRPs with 0.1 or 10 microM of Cu2+ significantly lowered the CE of cells than the control, but enhanced the CE of cells than the Cu2+ added control. These results corresponded directly with the results of model linoleic acid emulsion test, thereby demonstrating that lipid hydroperoxide generation is the source for fibroblast cell toxicity when MRPs are added to cells together with metal ions. These results further indicate that coffee MRPs can suppress in vitro metal-induced cytotoxicity to a certain extent when Fe2+, Cu2+, or Fe3+ ions are present below a concentration of 50 microM, possibly by chelating the metal ions. Ionic reducing capacity of coffee MRPs, albeit small, may explain the potential for increased cytotoxicity at higher coffee MRP concentrations.     

广东某铜矿尾矿有价金属回收工艺流程

由于历史技术原因,广东某铜矿的开采利用是单一的,矿石中可利用金属铜、铁只开发利用了铜,铜的利用也不彻底,导致尾矿中仍含有可回收的Cu、Fe等有价元素.随着选冶科学技术的发展,特别是现代铜湿法冶金技术的发展和创新,使以前认为是不可用的铜矿资源由呆矿变成巨大的财富.采用浸出-萃取-电解化学处理方法提取铜,浸出渣用磁选方法选...     

Pathophysiology of the neuroregulation of growth hormone secretion in experimental animals and the human

During the last decade, the GH axis has become the compelling focus of remarkably active and broad-ranging basic and clinical research. Molecular and genetic models, the discovery of human GHRH and its receptor, the cloning of the GHRP receptor, and the clinical availability of recombinant GH and IGF-I have allowed surprisingly rapid advances in our knowledge of the neuroregulation of the GH-IGF-I axis in many pathophysiological contexts. The complexity of the GHRH/somatostatin-GH-IGF-I axis thus commends itself to more formalized modeling (154, 155), since the multivalent feedback-control activities are difficult to assimilate fully on an intuitive scale. Understanding the dynamic neuroendocrine mechanisms that direct the pulsatile secretion of this fundamental growth-promoting and metabolic hormone remains a critical goal, the realization of which is challenged by the exponentially accumulating matrix of experimental and clinical data in this arena. To the above end, we review here the pathophysiology of the GHRH somatostatin-GH-IGF-I feedback axis consisting of corresponding key neurotransmitters, neuromodulators, and metabolic effectors, and their cloned receptors and signaling pathways. We propose that this system is best viewed as a multivalent feedback network that is exquisitely sensitive to an array of neuroregulators and environmental stressors and genetic restraints. Feedback and feedforward mechanisms acting within the intact somatotropic axis mediate homeostatic control throughout the human lifetime and are disrupted in disease. Novel effectors of the GH axis, such as GHRPs, also offer promise as investigative probes and possible therapeutic agents. Further understanding of the mechanisms of GH neuroregulation will likely allow development of progressively more specific molecular and clinical tools for the diagnosis and treatment of various conditions in which GH secretion is regulated abnormally. Thus, we predict that unexpected and enriching insights in the domain of the neuroendocrine pathophysiology of the GH axis are likely be achieved in the succeeding decades of basic and clinical research.