BP神经网络预测混凝土抗渗性能的研究

综合考虑了双掺矿物、掺合料混凝土抗渗性能的各种影响因素，选取了双掺矿粉、粉煤灰混凝土配料中7个主要因素作为输入量，混凝土28d抗渗系数为输出量，建立了混凝土抗渗性能预测的BP网络模型，进而对双掺矿粉、粉煤灰混凝土配合比抗渗性能试验数据进行分析．结果表明此模型的可靠度高，可用于混凝土渗透性的虚拟化设计．     

TMS天目丝有机肥在红皮云杉育苗中的应用

应用Tms天目丝有机肥进行红皮云杉育苗,最佳质量浓度是1000mg/L,浸根6h,与常规育苗相比,高生长平均增加23.66%,地径生长平均增加14.89%.     

Densification behavior of mechanically milled Cu–8 at% Cr alloy and its mechanical and electrical properties

Synthesis and consolidation behavior of Cu–8 at%Cr alloy powders made by mechanical alloying with elemental Cu and Cr powders,and subsequently,compressive and electrical properties of the consolidated alloys were studied.Solid solubility of Cr in Cu during milling,and subsequent phase transformations during sintering and heat treatment of sintered components were analyzed using X-ray diffraction,scanning electron microscopy and transmission electron microscopy.The milled powders were compacted applying three different pressures(200 MPa,400 MPa and 600 MPa)and sintered in H2atmosphere at 900 1C for 30 min and at 1000 1C for 1 h and 2 h.The maximum densification(92.8%)was achieved for the sample compacted at 600 MPa and sintered for 1000 1C for 2 h.Hardness and densification behavior further increased for the compacts sintered at 900 1C for 30 min after rolling and annealing process.TEM investigation of the sintered compacts revealed the bimodal distribution of Cu grains with nano-sized Cr and Cr2O3precipitation along the grain boundary as well as in grain interior.Pinning of grain boundaries by the precipitates stabilized the fine grain structure in bimodal distribution.     

采油封隔器整体卡瓦材质及热处理工艺研究

本文在对美制ＵＮＩ——６型封隔器整体卡瓦的化学成分、力学性能、金相组织和失效形式进行分析的基础上，对照我国材料，选择了４０ＣｒＭｎＭｏ钢作为代用材料，同时采用正火→调质→高频表面淬火→低温回火的热处理工艺，获得了满意效果，为批量生产奠定了技术基础     

Structural, electrical, dielectric and magnetic properties of Mn-Nd substituted CoFeO3 nano sized multiferroics

A series of Mn x Co_(1-x) Fe_(1-y) Nd_yO_3(where x=0.0–1.0 y=0.0–0.1) multiferroic nanocrystals was synthesized via sol-gel auto-combustion technique. The structure was confirmed by X-ray diffraction(XRD)while morphology was investigated by scanning electron microscopy(SEM). The electrical resistivity was observed to increase from 2.14 * 10~7 to 8.77 * 10~9 Ω-cm and activation energy was found to increase from 0.64 to 0.75 e V, while the drift mobility decreased from 4.75 * 10~(-13) to 1.27 * 10~(-15)cm~2V~(-1)S~(-1) by the substitution of Mn and Nd contents. The dielectric constant, dielectric loss and dielectric loss factor decrease with frequency and Mn-Nd contents. The saturation magnetization was increased from 34 to 70 emu g~(-1) while the coercivity decreased from 705 to 262 Oe with the increase of substituents.The increase in electrical resistivity and saturation magnetization while decrease in dielectric parameters and coercivity make these nanomaterials suitable for applications in microwave devices and longitudinal magnetic recording media.     

以锌粉为前驱物合成纯ZnO纳米粉体材料

过去人们主要是以锌基化合物为前驱物，通过湿化学方法来大量合成纯氧化锌（ZnO）纳米粉体，这不仅使得制备成本增加，也会导致目标产物里面不可避免地含有杂质元素。在本研究中，我们以锌粉为前驱物，通过锌粉和水蒸汽在一定温度下直接反应，便大量、低廉地制备得到氧化锌纳米粉体。以XRD、SEM、EDX和Uv—vis等对获得的样品进行表征，结果表明所制得的氧化锌粉体为六方相纳米结构，不含杂质元素，在紫外光照射下具有很强的吸光度。我们所制得的ZnO纳米粉体作为一种好的光催化剂，在环境治理方面具有广阔的应用前帚。     

中国富勒烯的研究进展

阐述富勒烯的制备和分离、理论计算、化学修饰以及富勒烯在电、磁、光材料和生物中的应用等方面的研究现状，并展望富勒烯及富勒烯衍生物的应用前景。     

热镀55A1-Zn合金镀层钢板及其在工业建筑中的应用

介绍了助镀剂法热镀５５Ａｌ－Ｚｎ合金镀层钢板的生产工艺及其耐蚀性能,并就其在工业建筑领域中的应用做了探讨。     

Nanostructured thermoelectric materials: Current research and future challenge

The field of thermoelectrics has long been recognized as a potentially transformative power generation technology and the field is now growing steadily due to their ability to convert heat directly into electricity and to develop cost-effective, pollution-free forms of energy conversion. Of various types of thermoelectric materials, nanostructured materials have shown the most promise for commercial use because of their extraordinary thermoelectric performances. This article aims to summarize the present progress of nanostructured thermoelectrics and intends to understand and explain the underpinnings of the innovative breakthroughs in the last decade or so. We believed that recent achievements will augur the possibility for thermoelectric power generation and cooling, and discuss several future directions which could lead to new exciting next generation of nanostructured thermoelectrics.     

Hot corrosion behavior of nanostructured Gd2O3 doped YSZ thermal barrier coating in presence of Na2SO4 + V 2O5 molten salts

Nickel-based superalloy DZ125 was first sprayed with a NiCrAlY bond coat and followed with a nanostructured 2 mol% Gd_2O_3-4.5 mol% Y_2 O_3-ZrO_2(2 GdYSZ) topcoat using air plasma spraying(APS). Hot corrosion behavior of the as-sprayed thermal barrier coatings(TBCs) were investigated in the presence of 50 wt%Na_2SO_4 + 50 wt% V_2O_5 as the corrosive molten salt at 900 ℃ for 100 h. The analysis results indicate that Gd doped YVO_4 and m-ZrO_2 crystals were formed as corrosion products due to the reaction of the corrosive salts with stabilizers(Y_2O_3, Gd_2O_3) of zirconia. Cross-section morphology shows that a thin layer called TGO was formed at the bond coat/topcoat interface. After hot corrosion test, the proportion of m-ZrO_2 phase in nanostructured 2GdYSZ coating is lower than that of nano-YSZ coating. The result reveals that nanostructured 2GdYSZ coating exhibits a better hot corrosion resistance than nano-YSZ coating.