膜法除硝技术与传统钡法技术的探讨

介绍了膜法冷冻除硝技术、传统钡法技术在处理盐水系统硫酸根方面的应用情况,并在环保以及经济效益方面做了比较。     

Influence of strain histories on liquefaction resistance of sand

The liquefaction resistance of sand increases with cyclic pre-shearing and pre-shaking as a result of earthquakes if the strain level in the pre-shearing is small. When larger shear strains are imposed, liquefaction resistance decreases. These complicated effects of pre-shearing histories on the liquefaction resistance are investigated in this study through a series of cyclic triaxial tests. Various combinations of cyclic stress amplitude and number of cycles of pre-shearing are examined. The tested sand is Toyoura Sand at 45% relative density, under a confining pressure of 50 kPa. Test results indicate that for the range of shear strain amplitude in pre-shearing smaller than 0.35%, the liquefaction resistance increases with pre-shearing. The increase in the liquefaction resistance depends strongly on the volumetric strain in the pre-shearing, and several effects of the shear stress amplitude and number of cycles can be negligible. Small volumetric strain of the order of 1% doubled the liquefaction resistance. Meanwhile, in the range of shear strain amplitude larger than 0.6%, the liquefaction resistance decreases. The liquefaction resistance decreases as the shear strain amplitude increases. Shear strain amplitude is one of the factors dominating this degrading effect, and the volumetric strain exerts beneficial effects to a certain extent. In this study, another series of tests are conducted to investigate the combined effects of small and large strain amplitude pre-shearing. It is observed that small shear strain pre-shearing cycles subsequent to large shear strain cycles erased the degrading effect of the latter. However, a large shear strain pre-shearing after small strain cycles degrades the beneficial effect of the small shear strain pre-shearing cycles previously applied to the specimens; however, the effects of the former small strain pre-shearing remains.     

煤制乙醇技术与应用

介绍了目前正在开发和推广应用的几种合成气制乙醇技术,分析了这几条技术路线的技术经济。     

考虑分界面的黏性泥石流下游演进数学模型研究

基于分界面理论,以泥石流屈服深度对应的面为分界面,将黏性泥石流分为理想流体和Bingham流体,建立了模拟黏性泥石流演进过程的数学模型和相应计算方法。该模型基于泥石流的运动特征,注重不同层间泥石流流速的差异,并可合理反映泥石流运动速度对其演进形态的影响机制;同时,全面考虑了黏性泥石流在演进过程中所呈现的"舌状体"和"龙头"由上向下翻落现象,因此可更准确描述黏性泥石流在演进过程中的运动状态。采用3组模型试验结果对建立的数学模型与计算方法进行了验证,结果表明:模型计算得出的泥石流泛滥范围和最大堆积厚度与模型试验结果误差在±5%以内,验证了模型的合理性。     

高校自主招生实施效果的实证研究——基于CQ大学自主招生学生与普通高考学生的跟踪与比较

从后期质量跟踪的角度,对自主招生学生进校后的情况进行了跟踪调研,通过学生问卷调查结合大量的客观数据统计,从能力素质方面及学习成绩、奖学金获得、参加科研情况等多角度分析、比较自主招生和普通高考两类学生入校后的差异,并在此基础上分析结论背后的原因,以此检验CQ大学自主招生效果,回答社会对自主招生的质疑,丰富相关研究领域成果。研究表明,自主招生学生能力素质均分及各项能力素质均显著高于普通高考学生;自主招生学生成绩略高于普通高考学生;自主招生学生综合素质表现(综合奖学金、五四评优、争先创优)显著高于普通高考学生;自2015年开始自主招生学生科创能力(科创项目立项)显著高于普通高考学生。     

云南薅坝地锡矿控矿因素及找矿方向

昌宁薅坝地锡矿是产于薅坝地断裂和水草洼断裂之间的中型矿床,该矿历经30多年的开采,当年查明的矿体已被开采殆尽,矿山已经步入危机矿山行列。在矿区深部及外围寻找新的接替资源,维持当前生产刻不容缓。文章通过对区内锡矿控矿因素的分析和找矿标志的拟定,圈定了3处找矿有利地段,即4号矿体的南东段沿F2的南西侧、F12断裂以南F1断裂以北的地段、F1与F2断裂交汇处T3分布的地段。     

胶东玲珑金矿田深部钻孔揭露招平断裂带及其意义

玲珑金矿田位于胶东隆起区,著名的招(远)—平(度)金成矿带的北端。文章以野外调查和已有资料为基础,重点剖析研究区深部钻孔资料,对比研究招平断裂带北段地质特征、蚀变带特征、控矿构造特征,取得了一定的新认识。最新研究成果表明:九曲蒋家断裂带和破头青断裂带属同期构造、同一性质成矿流体、壳幔混合的中低温热液矿床,均为招平断裂带北段的分支控矿断裂带;通过对比含矿碎裂岩带宽度和探获金资源量,证实九曲蒋家断裂带规模及含矿性均强于破头青断裂带,九曲蒋家断裂带为招平断裂带北段最主要控矿断裂。九曲蒋家断裂带深部是今后重点找矿方向,本文按地质可靠程度圈定了5处预测区,共预测Au金属量约1200t。     

河南嵩县双元沟铅锌矿地质特征及找矿方向

河南省嵩县双元沟铅锌矿位于华北陆块南缘外方山断隆带上,华北陆块南缘多金属成矿带的东段,黄庄—付店—土门钼铅锌银金成矿带内,矿体赋存于NE向或者与SW向构造带交汇处,呈脉状、透镜状;矿体形态、产状严格受断裂带控制,断裂交汇处为富厚矿体赋存的有利部位,矿床围岩蚀变较弱,铅锌矿以硅化、钾化为主,少量绿泥石化、褐铁矿化。钼铅矿以硅化、萤石矿化、碳酸盐化为主,次为锰矿化、黄铁矿化。为中—低温石英脉型铅锌矿床。     

针对表面粗糙度和刀具振幅的切削用量优化研究

对进给量、切削速度和轴向切深这3个切削参数对工件表面粗糙度和刀具振动幅度的影响进行试验研究。采用BBD响应面法对6061铝工件进行端铣加工试验,并通过数学建模对试验结果进行分析。提出一种基于遗传算法的多目标优化方法来同时减小工件表面粗糙度和刀具振动幅度。建立能预报表面粗糙度和刀具振动的径向基神经网络模型,并通过试验验证其准确性。