Microhardness and corrosion behavior in CrN/electroless Ni/mild steel complex coating

The electroless nickel–phosphorous (Ni–P) coating was chosen as an interlayer to improve the properties of the CrN/mild steel (MS) composite. A hypophosphite-reduced acid solution was used to first deposit electroless Ni–P onto MS substrates, and then the CrN overlayer was deposited by reactive r.f. magnetron sputtering onto the electroless Ni–P modified substrate. The electroless Ni–P layer crystallizes with the precipitation of a Ni₃P phase during r.f. sputtering, and thus a coating–substrate composite of CrN/Ni–Ni₃P/MS is formed. The electroless Ni–P coating increases the surface hardness of the steel substrate to more than three times. The surface hardness of the CrN coating modified by an electroless Ni–P interlayer exhibits a hardness higher than 2000 HK_0.015. The usual substrate effect on the microhardness of the coatings is nearly eliminated with the complex coating feature, and a significant enhancement of surface hardness in the coating assembly is achieved. The corrosion tests indicate that the Ni–Ni₃P/MS configuration exhibits a more positive E_corr value (i.e. less electronegative) than CrN/MS and the corresponding potential curve is shifted toward the low-current side, indicating a better anti-corrosion performance. Through comparison of the E_corr values and the polarization curves, it is demonstrated that the CrN/Ni–Ni₃P/MS composite exhibits significantly higher corrosion resistance than the Ni–Ni₃P/MS and CrN/MS coating configurations.     

基于铁素体轧制工艺低碳铝镇静钢板r值降低原因分析

某钢厂试开发基于铁素体轧制工艺的SPCC板,经热轧-冷轧-罩式退火工序后对样品进行性能检测,发现与传统奥氏体轧制工艺相比,该工艺路径下的产品各项力学性能指标均有不同程度下降,且r值有明显降低.对两种工艺路径的热轧板和冷轧退火成品板进行了组织和织构的对比分析,且提出了改进措施.结果表明:铁素体轧制工艺中热轧精轧温度过高,...     

紫外纳米压印抗蚀剂的研究进展

本文介绍了纳米压印技术的基本原理。总结了紫外纳米压印抗蚀剂的种类以及组分。具体包括丙烯酸酯体系、环氧树脂体系和乙烯基醚体系的配方组成及单体合成方法。比较了各个体系的优缺点。本文还分析了目前国内纳米压印抗蚀剂的研究现状并对其研究方向进行了分析与展望。     

渭河流域降水时空变化与干旱特征分析

以渭河流域14个典型气象站降水资料为基础,应用Mann-Kendall趋势检验法、频率分析法、差积曲线法以及游程分析法对研究区的降水变化规律及少水概率特征进行了研究。结果显示:40多年来渭河流域降水量呈明显减少趋势,以春、秋两季最为明显,这增加了区域发生干旱的可能性;流域降水过程呈丰枯交替的周期性现象,连丰或连枯较易发生,且存在干旱与洪涝并发现象;连枯年的概率比连丰年概率大,且少水期常持续2~3a,引发的干旱强度较大;1991年以后渭河流域干旱事件的频率、强度和烈度均有增加趋势,未来渭河流域的农业发展与水安全将面临更大的威胁,必须予以高度关注。     

关于黄河上游水电开发的若干构想

黄河上游龙羊峡至青铜峡河段（简称龙－青段）既有优良的工程建设自然条件，又有梯级连续开发的优势，且调节性能优越，水库淹没和移民少，技术经济指标优越。开发龙－青段水电资源，不但满足西北电网的需要，也是解决华北电网调峰困难的重要措施之一。西北华北联网具有调峰效益、错峰效益和降低备用容量效益。     

羧酸锂汽油抗爆剂的制备及应用

 利用羧酸和氢氧化锂制备了2种中长链的羧酸锂,并对合成的产品进行了红外光谱表征。在羧酸锂中加入高效增溶剂得到了异辛酸锂抗爆剂（A）和月桂酸锂抗爆剂（B）,将A和B分别加入3种不同的汽油中, 进行辛烷值机台架实验,并考察其对汽油的各项性能的影响。结果表明,3种不同的汽油对研制的羧酸锂抗爆剂均有一定的感受性。当抗爆剂A和抗爆剂B在催化裂化汽油中的添加质量分数均为2%时,可以使汽油的辛烷值（RON）分别提高3.2和1.5。同时,它们对汽油的各项使用性能基本没有不良影响,并且能够提高诱导期至 1400 min以上。     

Structural, morphological and electrochemical properties of nanocrystalline V2O5 thin films deposited by means of radiofrequency magnetron sputtering

Due to easiness of preparation and high energy density, V₂O₅ nanocrystalline thin films are particularly attractive as cathode materials for all-solid-state rechargeable lithium microbatteries. However, their electrochemical performances are strictly related to the film microstructure, which, in turn, is related to the nature and parameters of the deposition technique. For this reason, the preparation of thin films with reproducible electrochemical properties is still an open problem.Here, we report on the deposition of V₂O₅ crystalline thin films by means of reactive radiofrequency (r.f.) magnetron sputtering, using vanadium metal as the target. Different deposition times and substrate temperatures were adopted. X-ray powder diffraction (XRD) and atomic force microscopy were used to investigate the structural and morphological features of the films. In particular, XRD analysis revealed that the deposition parameters affect the crystallographic orientation of the films. A h 0 0 orientation is observed in case of thin samples (about 100 nm) prepared at 300 °C, whereas a 1 1 0 preferential growth is obtained for thicker films. Films deposited at 500 °C display a 0 0 1 orientation irrespective on the deposition time.Reversible Li intercalation/deintercalation processes and high specific capacity are observed for the h 0 0-oriented V₂O₅ thinner films, with the ab plane arranged perpendicular to the substrate. In this case, the cycling behaviour is very promising, and a stable capacity higher than 300 mAh g⁻¹ was delivered in the potential range 3.8-1.5 V at 1C rate over at least 70 cycles.     

荫营煤矿丈八煤综放工作面顶板顶煤运动规律研究

通过对荫营煤矿丈八煤1501盘区综放工作面现场矿压观测分析，结合所采煤层顶板实际运动情况，阐述了缓倾斜煤层综放开采顶板、顶煤的运动规律。     

基于GEO-SLOPE的土石坝应力场—渗流场耦合分析

运用GEO SLOPE的全耦合分析功能对瀑布沟水电站高土石坝应力场─渗流场进行了耦合分析,求解了坝体、坝基深厚覆盖层的水平及垂直向位移分布,同时给出了相应的渗流场分布,分析得到了孔隙水压力随时间的消散情况,最后预测了不同时段通过坝基的渗流量。     

西伯利亚地台腹部文德系及下寒武统含油气性预测

经过改进的含油气性预测方法，适用于结构复杂和油气藏形成期长的古老地层。这种含油气性预测方法是建立在综合地层、构造、岩性－岩相、地球化学和本文地质指标和对每种指标进行评价的基础上的。介绍了盐下陆源层和碳酸盐岩层（维柳依、下涅普斯克、上涅普斯克齐尔、下达尼洛夫、上达尼洛夫和乌索尔等储集层）的含油气性的详细预测结果。在它们的分布地区划分了不同含油气性的详细预测结果。在它们的分布地区划分了不同含油气远景区，油气聚集带和首批应进行石油普查的目标，预测了这些地区的主要圈闭类型、油藏数量和烃类组分。这些研究成果将能极大地提高石油普查的效果。