陕西省兵工企业管理岗位人岗匹配研究

企业人力资源管理工作的核心就是人岗匹配.文中针对兵工企业行业特征,对员工与岗位进行保密与否区分.在保密管理者可匹配任意管理岗位,而普通管理者只能匹配普通管理岗位的假设下,以管理者的岗位满意度和企业效益最大为目标,建立双目标人岗匹配模型,并用遗传算法分析与求解.尝试探讨兵工企业管理岗位人岗匹配的途径.     

疲劳可靠度分析的概率密度演化方法

基于概率守恒原理,推导出疲劳损伤和随机参数联合概率密度函数服从的演化方程。据此计算的随机疲劳损伤概率密度曲面和累积概率分布函数等值线可以给出疲劳损伤概率结构的演化规律,并用以分析给定损伤阈值的疲劳可靠度。常幅疲劳可靠度的数值解与试验结果吻合良好。给定二级载荷各自的常幅疲劳寿命概率分布参数,根据Miner准则可以较好地预测二级低高加载变幅疲劳可靠度。     

型钢混凝土柱骨架曲线特征点计算方法研究

收集国内近年来关于型钢混凝土(SRC)柱低周循环加载下的84组试验数据,回归分析峰值位移和屈服位移之比、强化刚度、软化刚度与SRC柱构件主要设计参数(轴压比、配箍特征值、剪跨比、体积配箍率和混凝土强度)之间的关系,提出型钢混凝土柱骨架曲线特征点的计算方法。结果表明:峰值位移和屈服位移之比与体积配箍率、混凝土强度成正比,与轴压比、配箍特征值及剪跨比均成反比;强化刚度系数与配箍特征值、剪跨比成正比,与轴压比、体积配箍率及混凝土强度成反比;软化刚度系数与配箍特征值、剪跨比及混凝土强度成正比,与轴压比、体积配箍率成反比。该结果可为型钢混凝土组合结构的地震反应分析提供参考。     

Deterioration mechanism of sulfate attack on concrete under freeze-thaw cycles

The experiments of concrete attacked by sulfate solution under freeze-thaw cycles were investigated. The sulfate solution includes two types of 5% Na2SO4 and 5% MgSO4. Through the experiment, microstructural analyses such as SEM, XRD and TGA measurements were performed on the selected samples after freeze-thaw cycles. The corrosion products of the concrete were distinguished and quantitatively compared by the thermal analysis. Besides, the damage mechanism considering the dynamic modulus of elastically of concrete under the coupling effect was also investigated. The experimental results show that, under the action of freeze-thaw cycles and sulfate attack, the main attack products in concrete are ettringite and gypsum. The corrosion products exposed to MgSO4 solution are more than those to Na2SO4 solution. Furthermore, the content of gypsum in concrete is less than that of ettringite in test, and some of gypsum can be observed only after a certain corrosion extent. It is also shown that MgSO4 solution has a promoting effect to the damage of concrete under freeze-thaw cycles. Whereas for Na：SO4 solution, the damage of concrete has restrained before 300 freeze-thaw cycles, but the sulfate attack accelerates the deterioration process in its further test period.     

非溶剂水添加对PVDF超滤膜结构和性能的影响

以H2O/DMAc为共溶剂,相转化法制备了PVDF/PVP平板超滤膜,考察了非溶剂水添加量对相分离进程、膜结构参数、膜分离性能的影响规律,观察了膜的微观形貌。结果显示,随着体系中含水量由1%～5%变化时,相转化成膜固化时间缩短,膜表面孔数增多,支撑层逐渐疏松,膜断面大孔结构变化丰富,呈现不规律变化,但膜平均孔径相对稳定。含水量由0%变化至5%,膜纯水通量从850 L/(m2.h)上升到1 250 L/(m2.h),BSA截留率基本保持在85%以上,在3%时最高,5%时有所下降。     

CuSO4对氰化提金贫液中SCN-的沉淀效果以及对共存离子浓度的影响

针对氰化提金贫液循环利用过程SCN^-积累以及外排带来的环境污染问题,以CuSO₄作为沉淀剂处理某高浓度SCN^-贫液,考察了沉淀剂用量、沉淀时间及沉淀温度对SCN^-沉淀效果和对共存离子浓度的影响。结果表明,当在贫液中加入1.6倍化学反应计量的CuSO₄后于室温搅拌60 min,SCN^-的去除率达87.5%以上,体系中T_Cu、S₂O₃ ^2-和SO₃ ^2-浓度也大幅降低,同时得到纯度达97%以上的CuSCN产品。沉SCN^-后的贫液只需石灰中和并沉部分SO₄ ^2-后,其活性得到进一步恢复,可直接返回金精矿浸出工序充分利用其中的CN^-,实现提金贫液的循环利用。     

Hydroxyapatite/bioactive glass functionally graded materials (FGM) for bone tissue engineering

In this work, HA/bioactive glass Functionally Graded Materials (FGMs) are obtained for the first time by means of Spark Plasma Sintering (SPS). Two series of highly dense 5 layered products, namely FGMS1 and FGMS2, are prepared under optimized SPS conditions, i.e. 1000 °C/2 min/16 MPa and 800 °C/2 min/50 MPa, respectively, using a die with varying cross section.Results arising from XRD, SEM, mechanical and biological characterization in SBF, evidence that lower temperature and higher-pressure levels used for FGMS2 samples provide better materials in terms of microstructure, compactness, hardness, elastic modulus and in vitro bioactivity. Indeed, a fully sintered and crack-free microstructure with no crystallisation at the top layer (100% bioactive glass) is correspondingly produced.The obtainment of such FGMs is quite promising, since it permits to vary the relative volume fractions of the two constituents and, consequently, tailor the biological response for specific clinical applications.     

低阶煤热解条件对高炉喷吹半焦燃烧性能及动力学特性的影响

采用热重分析法研究了不同热解条件下半焦的燃烧性能和动力学特征,利用Ozawa法求取动力学参数。结果表明,热解温度越低、保温时间越短时,半焦的燃烧性能越好;热解升温速率对半焦燃烧过程的反应程度影响不大;粒度越大,燃烧性能差异性越明显。热解温度对半焦燃烧性能影响较大,550℃是本研究中制备高燃烧反应性半焦的适宜热解温度。两种不同粒度原煤制得的半焦均随转化率增大,活化能减小。1~3 mm原煤在热解温度为550℃时所得半焦在燃烧过程中符合反应级数模型,化学反应为限制性环节,反应最概然机理函数为f(α)=(1–α)2。     

2002～2011年我国RSM分析法研究文献分析

响应面分析法(简称RSM)是一种最优化方法,已在食品、生物、化工、机械等很多方面都有应用。本文运用文献计量学方法,以"RSM"为检索词,检索CNKI数据库,收集2002～2011年国内公开发表的有关RSM分析法的研究论文。从文献增长情况、文献基金、所登期刊、文献地区等方面,分析了RSM分析法的研究现状。     

酸热处理对累托石结构和吸附性能的影响

酸热活化是增强粘土吸附性能的一种有效手段。本文采用湖北钟祥产的累托石为原料,酸热活化后,结合XRD、SEM和BET等表征手段,分析酸热处理前后累托石的结构变化,并用亚甲基蓝溶液来测试酸热处理对累托石吸附性能的影响。结果表明酸热处理增大了累托石的比表面积和吸附能力,认为吸附能力提升的原因为:无机盐溶解和层间水脱除打开了内部孔道;可交换阳离子的溶出;水分脱除减小了表层和内部孔道中水膜产生的吸附阻力。