假如我们能够活上一百万年

正大大延长人类寿命将会带来各种各样的机会,然而也有令人畏惧的风险……最近,科学家们发现了超过一亿年的细菌埋藏在海底,而且它们还活着。假如我们仅仅能够生存一百万年,将会发生怎样的变化呢?两个想法立刻涌上心头。首先,必须要限制学术界的任期。     

浅谈中小企业人力资源面临的问题及对策

人力资源管理是企业生存与发展的根本，尤其对于中小企业而言显得尤为重要，因为中小企业在我国的国民经济中占有十分重要的作用，对经济的发展起着决定性的作用。而人力资源作为企业管理的关键，也越来越受到企业管理者的重视。但是，由于目前我国的中小企业还没有形成完善、科学的人力资源管理系统，在人力资源规划认知以及技术人才方面还存在不少的问题，那么如何处理好企业目前面临的这种问题，加强人力资源管理，促进中小企业经济发展，是摆在我们面前的首要任务，本文就此展开探讨。     

基于分形理论的红层软岩填料缩尺料制备方法

采用分形理论研究了在室内采用球磨机制备与现场填料具有相同分形维的缩尺料的方法.基于对模拟现场重复破碎机制的考虑,选用球磨机作为破碎岩块制备缩尺料的设备.通过正交试验,研究了岩块初始粒径、球磨机转数、钢球数等参数对分形模型拟合优度、颗粒分形维的影响.在此基础上,通过中三轴制样试验进一步研究了试样制作过程对缩尺料二次破碎的影响.研究结果表明,对于红层软岩,采用破碎参数:球磨机转数100转,钢球数9个、岩块初始粒径20 mm,可以制备得到与现场原料相同分形维的中三轴试样缩尺料.     

Single-componentchemicallyamplifiedi-linemolecularglassphotoresistbased on calix[4]resorcinarenes

Calix[4]resorcinarene, prepared by the acid- catalyzed condensation of resorcinol and paraldehyde, was used as the core of the molecular glass compound. The hydroxyl groups of calix[4]resorcinarene were partly pro- tected by tert-butoxycarbonyl （t-BOC） and then esterified with 2-diazo-l-naphthoquinone-4-sulfonyl chloride （2,1,4- DNQ-C1）. Upon irradiation to 365 nm light, the 2,1,4-DNQ groups undergo photolysis to generate a small quantity of sulfonic acid other than indene carboxylic acid. The gen- erated sulfonic acid can further catalyze the deprotection of the t-BOC group. So, a new type of single-component chemically amplified i-line positive photoresist can be formed by the molecular glass compounds. The litho- graphic performance of the resist was evaluated with high resolution and photosensitivity with an i-line stepper.     

基于改进蚁群算法的多目标路径规划研究

传统蚁群算法因在复杂环境中容易产生死锁，导致部分蚂蚁失效，造成效率低下，迭代次数增多。为此，提出了一种利用环境信息引入环境因子来调整启发函数的方法从而降低死锁情况的发生，增加了有效蚂蚁的数量，从整体上提高了蚁群的搜索速度，扩大了搜索范围。同时，传统蚁群算法在路径规划中仅在理想地域内寻求最短路径，而多因素环境中最短路径往往并非最优解。为解决此问题通过在不同环境中对转移概率进行加权优化在追求路径最短的基础上提出多目标路径规划，丰富了蚁群算法的实用性和现实意义。最后经仿真实验对优化算法进行验证，证明了上述优化的可行性。     

Influence of alumina on mineralogy and environmental properties of zinc-copper smelting slags

An iron-silicate slag, from a zinc-copper smelting process, and mixtures of this slag with 5wt%, 10wt%, and 15wt% alumina addition were re-melted, semi-rapidly solidified, and characterized using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction. The FactSageTM6.2 thermodynamic package was applied to compare the stable phases at equilibrium conditions with experimental characterization. A standard European leaching test was also carried out for all samples to investigate the changes in leaching behaviour because of the addition of alumina. Results show that the commonly reported phases for slags from copper and zinc production processes (olivine, pyroxene, and spinel) are the major constituents of the current samples. A correlation can be seen between mineralogical characteristics and leaching behaviours. The sample with 10wt% alumina addition, which contains high amounts of spinels and lower amounts of the other soluble phases, shows the lowest leachabilities for most of the elements.     

Mechanical properties of directionally solidified lead-antimony alloys

The Pb-17wt% Sb alloy was directionally solidified under two solidification conditions: with different temperature gradients (G=0.93–3.67 K/mm) at a constant growth rate (V=17.50 μm/s) and with different growth rates (V=8.3–497 μm/s) at a constant temperature gradient (G=3.67 K/mm) in a Bridgman furnace. Microstructure parameters, such as primary dendrite arm spacing (λ₁), secondary dendrite arm spacing (λ₂), and dendrite tip radius (R), were measured. The microhardness (Hv) and ultimate tensile strength (σ) of the directional solidification samples were also measured. The influences of solidification and microstructure parameters on Hv and σ were investigated. The results obtained in this work were compared with similar experimental researches in literatures. It is shown that the Hv and σ values increase with the increase of G and V, but decrease with the increase of λ₁, λ₂, and R.     

Optical properties of cobalt xanthate films on different substrates

Cobalt isopropyl xanthate thin films (CXTFs) were deposited via chemical bath deposition onto different substrates: commercial glass (CG), indium tin oxide (ITO), and poly(methyl methacrylate) (PMM). Isopropyl xanthate was synthesized according to a method described in the literature. The cobalt nitrate and isopropyl xanthate were mixed in a beaker, which allowed the thin films to be deposited via a simple ion-ion mechanism. The transmission, reflectivity, refractive index, dielectric constant, and optical conductivity were investigated for various thin films coated onto different substrates. An ultraviolet-visible spectrophotometer was used to measure the optical properties of the thin films. The lowest value of the transmission and the highest value of the refractive index were observed for the thin films deposited onto PMM. The structure of the cobalt xanthate was characterized by Fourier transform infrared (FTIR) spectroscopy, which was measured using a Perkin-Elmer Spectrum 400 spectrometer. The stretching vibration of the Co-S bonds was observed at 359 cm-1 in the FTIR spectrum of the CXTFs.     

低矿化度水驱技术增产机理与适用条件

针对最新提出的注入水低矿化度提高原油采收率问题,展开了对低矿化度水驱技术全方位研究。通过对文献 调研、实验和油田试验数据对比分析,表明低矿化度水驱增产的主要原因是黏土微粒迁移储层微观改造和润湿性转 变,其机理包括微粒迁移、多官能团离子交换、阳离子交换、高价阳离子桥接、双电层离子扩散、pH 值变化、低界面张 力、降低油水流度比、盐溶作用和胶结物溶解等,各种机理相互协同作用增加原油采收率,由于储层条件不同,会出现 某种机理缺失或者某种机理占主导的情况。如果油田具备低矿化度水驱的必备条件,那么控制好注入水的矿化度便 能够提升5%~20% 的原油产量。低矿化度水驱技术不仅成本低、油田施工步骤相对简单和环境污染小,还可以用于开 发海上油田,充分展现了该技术在未来油田开发的潜在价值和广阔空间。     

基于质量预测的飞机装配动态调度问题研究

为提高飞机装配调度计划应对装配质量不合格的能力,首先以两阶段近似动态决策为框架,研究装配质量与相关因素的映射关系和不确定性因素在不同决策周期的表现形式,并以最小化基于场景的项目工期期望值为目标函数建立整数规划模型;然后基于构建的飞机装配质量预测模型,设计了多层循环迭代搜索算法,算法第一层基于任务列表的编码方式优化任务执行顺序,第二层通过装配人员分配列表优化人员配置,第三层根据人员配置结果求解目标函数. 数值实验结果显示在工件质量预测值与实际值不一致的情况下,多层循环迭代搜索算法在任务开始时间偏差能够保持在2以下,表明该算法能够适应不确定性因素的变化,满足构建飞机装配动态调度计划的需求.