化学镀镍磷合金工艺中问题与探讨

从化学镀镍磷合金生产工艺、镀层性能的各种影响因素、镀液中离子浓度的测定方法等三个方面论述了化学镀镍磷合金工艺中的主要问题和研究方向.     

青海硫化物工艺矿物学研究

研究对象为属硫铁铅锌原生硫化矿矿石,通过化学分析及岩矿鉴定的方法对该矿石的工艺矿物学特征进行了研究,查明了矿石的化学组成、主要矿物组成、金属矿物的嵌布特征及影响选矿回收的因素。为选矿工艺制定提供了理论依据。     

重型机械产品焊接质量剖析

本文着重从生产技术角度对重型机械产品焊接结构中带普遍性的质量问题进行了分析。较系统地论述了产品设计、工艺制造等对大型焊接结构件接头质量的影响因素,并提出了一些建议。可供参考。     

压力管道的焊接质量控制

通过分析石油化工装置中影响压力管道焊接质量的重要因素,从焊接工艺评定与焊接工艺、焊接材料、焊工培训、施焊过程、焊后检验、焊缝返修等六方面进行了论述,提出了保证焊接质量应采取的工艺措施,对提高压力管道焊接质量具有指导作用。     

直齿圆柱齿轮精密塑性成形技术研究现状与发展趋势

从成形方法、理论研究、工艺设计等几个方面论述了国内外直齿圆柱齿轮精密塑性成形技术研究的现状,并对其发展趋势进行了探讨.     

碳质金矿生物预氧化研究进展

碳质金矿是一种难处理金矿,当原生矿石中有机碳含量大于0.2%时,会严重干扰氰化提金,进而发生"劫金效应"。生物预氧化法以其条件温和、工艺简便、能耗低、环境友好等优点在难处理金矿预处理方面发展较快。难处理碳质金矿生物预氧化法目前还处于研究阶段,要实现工业化需要从新型添加剂以及开发构建既能氧化硫砷又能氧化碳的新型细菌等方面进行研究。     

混凝土的细菌腐蚀

从混凝土细菌腐蚀的发生、腐蚀的影响因素、腐蚀的破坏形态以及腐蚀的防护等方面总结了近年来混凝土细菌腐蚀的研究进展。认为虽然对混凝土细菌腐蚀的研究取得了一些进展，但该领域在国内尚属起步研究阶段，在研究的广度和深度、腐蚀程度的评价、预测模型的建立、腐蚀的预防措施等方面的研究还很欠缺，希望尽快加强这些方面的研究。     

浅析汽车车身冲压件材料利用率提升方法

对汽车车身冲压件材料利用率的影响因素进行了分析,并从产品设计、工艺、新技术新材料等方面详细介绍了提升冲压件材料利用率的方法.     

直齿圆柱齿轮精锻工艺研究

直齿圆柱齿轮精锻工艺正日益受到国内外业界的重视。但由于零件的几何形状复杂,影响因素多,成形难度大,直齿圆柱齿轮精锻成形规律的研究比较薄弱。本文从精锻成形工艺、研究方法、数值模拟研究等几个方面综合论述了直齿圆柱齿轮精锻工艺研究的发展现状与趋势。     

采用生物技术提高铝土矿质量

论述了用于铝土矿生物浸出的硅酸盐细菌及其浸矿机理．介绍了不同细菌微生物用于铝土矿浸出提高矿石铝硅比及降低钙铁等杂质含量的试验研究结果，用超声波等外界物化手段可以提高微生物活性，强化浸出效果。     

导尿管抑菌涂层的研究进展

由导尿管引发的尿路感染(CAUTI)是医院常见的感染,在各种院内感染中的占比高达20%~30%,极大地影响了病人的生命健康。目前,基于导尿管表面生物膜生成及无机盐沉积等问题,研究人员提出了多种方法来预防或改善,以实现导尿管的抗菌和抗阻塞性能,如导尿管表面涂层构建、改进导尿管的结构设计、缩短临床使用时间等。综述了近年来导尿管表面抗菌涂层的研究进展,主要从物理改性和化学改性等方面展开。物理改性方法一般通过将聚乙二醇、聚两性离子、抑菌酶等沉积在导管表面,或在导管表面进行仿生微纳结构修饰等,以达到润滑和降低细菌黏附的效果。化学改性方法主要通过将可直接作用于细菌的药物或者因子(包括分子泵抑制剂、抗生素、一氧化氮、抗菌肽等)附着在导尿管表面,以达到抑菌、延长导管堵塞时间等目的。在此基础上,通过对当前导尿管研究趋势的总结及思考,对未来导尿管的功能、抑菌机制及验证等方面进行展望,以期为导尿管抑菌材料的选择和设计提供一定的指导。     

Effect of biological pretreatment on flotation recovery of pyrolusite

Bacillus mucilaginosus was used in pretreatment of pyrolusite to facilitate the flotation removal of quartz from pyrolusite minerals. Quartz was activated by B. mucilaginosus, whereas pyrolusite was unaffected at pH 7 with laurylamine as collector. Flotation recovery of pyrolusite with B. mucilaginosus pretreatment is 73.62%, slightly lower than that of the process without biopretreament, namely 74.70%. The grade of concentrate of recovered pyrolusite is 19.44%, 2.18% higher than that of the recovered pyrolusite without B. mucilaginosus pretreatment (17.26%). The results of FTIR and SEM showed that no bacteria were adsorbed on the surface of quartz or pyrolusite, indicating that the better selectivity and collectability of flotation resulted from bacterial byproducts. And interaction of bacterial byproducts such as extracellular bacterial polysaccharide, extracellular bacterial protein and acetic acid, on minerals were studied by FTIR and adsorption.     

Influence of a dual-species biofilm on the corrosion of mild steel

The effect of a dual-species biofilm on the corrosion of carbon steel was examined using two bacterial species: the iron-reducer, Shewanella oneidensis (MR-1), and the sulfate-reducer, Desulfovibrio desulfuricans (G20). These experiments exploit the fact that the products of their metabolism (ferrous iron or sulfide) affect the corrosion rate of carbon steel in opposite ways. Electrochemical impedance spectroscopy (EIS) shows that over a short time period, co-cultures of MR-1 and G20 protect steel from corrosion. The fact that an iron-reducing bacterium can inhibit corrosion when a corrosion-enhancing bacterium is present warrants future study with respect to its potential applicability to the design of biological corrosion-control measures.     

Electron-induced surface modification of hydroxyapatite-coated implant

Here, the authors report on surface free energy modulation of a hydroxyapatite-coated titanium femoral implant that is performed by a newly-developed method using a low-energy electron irradiation. They observe pronounced increase of hydrophobicity of irradiated samples that occurs in several stages and is characterized by various mechanisms. Bacterial adhesion on electron modified hydroxyapatite samples is studied, by considering different approaches. The authors show that bacterial adherence is selective and depends on the surface free energy components, which were determined from detailed surface free energy analysis. The selective bacterial adhesion, together with the ability to define the surface energy properties, suggests that this newly-developed method opens an avenue for protection of implants from bacterial infections.     

Valence variation of arsenic in bioleaching process of arsenic-bearing gold ore

The concentration and variational trend of As3+ and As5+, the bacterial resistance for the As3+ and As5+ and converting conditions from As3+ to As5+ were analyzed. The additive was used to prompt the bacterial leaching efficiency by changing valence state of arsenic. The results show that the concentration of As3+ is larger than that of As5+ in the lag phase. The concentration of As3+ decreases in the log phase, and is lower than that of As5+. HQ-0211 typed bacteria express better resistance for As3+ and As5+ and remain growing when the concentrations of As3+ and As5+ are above 6.0 g/L and 12.0 g/L, respectively. It is found that Fe3+ cannot oxidize As3+ singly as strong oxidant in the leaching system, but can cooperate with pyrite or chalcopyrite to do that. The oxidation of As3+ is prompted with addition of H2O2. The bacterial activity is improved in favor of bacterial leaching efficiency. NaClO restrains the bacterial growth to depress leaching efficiency because of the chloric compounds affecting bacterial activity.     

诱变对新菌株Leptospirillum ferriphilum YXW及浸出金矿的影响

通过稀释分离方法从江西德兴铜矿矿山废水中富集而来的混合菌中分离得到菌株 Leptospirillum ferriphilum YXW,再利用超声波、紫外线和微波对其进行诱变,筛选出更高效的细菌用于金矿的浸出。生理生化特性实验显示,菌株YXW为极端化能自养型细菌,最佳的生长条件为温度40°C,pH=1.5。诱变后,细菌浓度分别可达到9×109(超声波)、8.4×109(紫外线)和4.3×108 mL?1(微波),与原始菌相比,分别提高了291%、265%和87%。微波和紫外诱变后,细菌总蛋白活性升高,而超声诱变后,细菌总蛋白活性降低。诱变对细菌浸出金矿的影响由大到小的排列顺序是微波、紫外线、超声波。在金矿浸出过程中,微波诱变后的细菌具有最好的浸出效果。浸出10 d后,As和Fe的浸出率分别高出原始菌19.6%和17.7%。结果表明,诱变对细菌浸出金矿效果的提高,可能不在于细菌浓度的增大,而是取决于细菌总蛋白活性的提高。     

肝脏巨噬细胞及其在肝损伤和修复中的作用

肝脏巨噬细胞在肝脏损伤和修复过程中具有重要调节作用,根据不同的来源和表型,肝脏巨噬细胞分别具有清除细菌病原体、呈递抗原、促进或者抑制肝脏炎症反应的能力,直接参与肝脏疾病的发生发展和损伤修复。本文就肝脏巨噬细胞的功能及其在肝脏损伤和修复中的调节作用进行综述,并总结治疗肝脏疾病的潜在巨噬细胞靶点。     

Chemical behaviors of different arsenic-bearing sulphides bio-oxidated by thermophilic bacteria

1INTRODUCTION Arsenic bearinggoldoreiswidelydistributedinprovincesofYunnan,Guizhou,Sichuan,Guan gxi,Guangdong,Hunan,Jiangxi,Liaoning,Jilin,Hebei,Shanxi,Gansu,Qinghai,Xinjiang,etc.Withtheprocessdevelopmentofbacteriummetal lurgy[1,2],suchgoldoreresourcemaybereasona blyutilized,however,arsenicintheseoresishigh lytoxictotheleachingbacteriaandbecomesthe researchfocus.Arsenicisacomplexandvitalele mentofarsenic bearingmineralswiththeelectronconfigurationof4s34p3[3].WhenAslosesthree electro…     

生物浸铀中影响嗜酸氧化亚铁硫杆菌活性的氟毒物活性形态(英文)

为了确定浸矿菌耐氟的机制,在氟化物存在的条件下,驯化铀矿浸出菌嗜酸氧化亚铁硫杆菌ATCC23270,研究溶液中含不同氟浓度、不同pH值时铀矿浸出菌的活性变化,以及有无蛋白酶K处理时铀矿浸出菌细胞内氟浓度的变化情况。采用铂电极和Ag/AgCl参比电极测量氧化还原电位,以作为细菌不同活性的参照指标,采用氟离子选择性电极测定细胞内的氟浓度。结果表明,真正影响铀矿浸出菌活性的是HF,溶液pH值增加以及溶液中与氟有较强络合能力的离子浓度的变化,也会引起耐氟菌假象的出现。浸矿菌的耐氟能力可能与细胞壁和细胞膜上的一些蛋白密切相关。     

骨植入物纳米多层结构抗菌涂层研究进展

骨植入物表面负载纳米多层结构抗菌涂层具备多重优势,可以有效地提高材料抗菌率,避免使用抗生素产生细菌耐药性的问题。相较于单层结构涂层,纳米多层结构抗菌涂层同时具有骨植入物材料所需的多种性能,促进骨细胞的增殖与分化,有效降低细胞毒性所引起的不良反应,是目前骨植入物表面涂层研究的重点。本文综述了纳米多层结构抗菌涂层的研究进展,包括涂层的性能、制备方法及抗菌机制,讨论了纳米多层结构抗菌涂层的发展方向,有望进一步解决细菌感染和骨整合等问题。