Enhanced temperature stability in the O–T phase boundary of (K,Na)NbO3-based ceramics

In order to obtain excellent electrical properties and its temperature stability of KNN-based ceramics to meet the practical applications, a new lead-free material system of (1−x)K_0.5Na_0.5Nb_0.96Sb_0.04O₃-xBi_0.5Na_0.5Zr_0.8Sn_0.2O₃ (KNNS-xBNZS, 0 ≤ x ≤ 0.060) was designed, and the enhanced electrical properties (eg, d₃₃ ~ 465 pC/N, ε_r ~ 3318, S_uni ~ 0.133%) is obtained in the ceramics with x = 0.04. The physical origin of enhanced electric properties should be ascribed to the phase instability of R-T, resulting in a low-energy barrier, which can greatly facilitate the polarization switching. Moreover, the temperature stable of piezoelectric constant (d₃₃ or d₃₃*) is measured by three distinctive methods in different phase boundaries (O, O-T, R-T) at the temperature range 20°C-180°C, revealing that the O-T phase boundary has a relatively good temperature stability. A mode is used to show how to effectively modified the piezoelectric constant (d₃₃ or d₃₃*) and its temperature stability, we believe that such a strategy may further improve the temperature stability of d₃₃ or d₃₃* value in KNN-based ceramics.     

关于建设自然资源专业档案目录中心的探讨

自然资源专业档案包括矿业权档案、油气类档案、土地管理类档案等,是地质、找矿工作中重要的组成部分,在数据集中管理及政务信息公开的现状背景下,做好自然资源专业档案管理、利用和开发工作对未来发展大有裨益,建设目录中心可以安全有效地推进自然资源专业档案的开发利用,以信息共享的形式将档案中蕴含的海量信息有机的结合起来,从而更好地为政务及社会公众提供服务。本文结合自然资源专业档案管理现状,探讨了目录中心建设的必要性、建设目标等内容。提出了自然资源专业档案目录中心两级体系、五层架构的建设设想,并从标准研制、数据库建设、平台搭建、目录服务几个方面阐述了建设的具体路线。     

巴基斯坦山达克铜金矿露天边坡稳定性与参数优化研究

为了得到巴基斯坦山达克铜金矿露天边坡最优参数,选取了8个工程地质剖面,通过极限平衡分析了A～H剖面在三种工况下的安全系数。基于设计参数,对8个边坡剖面进行计算分析,得出了边坡各剖面最优边坡角结构参数,并根据工程地质分区,推荐各分区边坡结构参数如下:1)A、B、C、E、F、G剖面整体边坡角为46°,即Ⅰ区、Ⅲ区边坡整体边坡角46°;2)D、H剖面整体边坡角为45°,即Ⅱ区、Ⅳ区边坡整体边坡角45°。     

外来文化对日本家具发展的影响

日本是一个靠不断吸收外来优秀文化来塑造本民族文化的国家。本文探讨了中国和西方文化在不同时期对日本的家具产生的巨大影响,分析了日本把这些影响有选择地逐渐吸收并融入到自身文化的一部分,并最终形成其独具特色的家具风格的过程。     

Synthesis and characterization of β-cyclodextrin inclusion complexes of thymol and thyme oil for antimicrobial delivery applications

Microencapsulation with β-cyclodextrin (β-CD) as a delivery platform offers a promising application for natural antimicrobial delivery for food safety. Hence, this study aimed to characterize inclusion complexes of thymol and thyme essential oil with β-CD and their resulting antimicrobial activities. Inclusion complexes were prepared by kneading (KN) and freeze-drying (FD) methods. The entrapment efficiencies ranged from 71 to 83 g/100 g with higher (P < 0.05) values for thymol and FD particles. All particles showed irregular shapes and sharp edges with significant differences in size distribution and strong tendency to agglomerate. FD produced higher (P < 0.05) particle sizes than KN method. Differential Scanning Calorimetry (DSC) analysis confirmed inclusion complexes formation between β-CD and both compounds. Phase solubility tests indicated B_S-type complexes formation between thymol and β-CD. All compounds effectively inhibited bacterial growth within the concentration range tested. Free thyme oil showed higher (P < 0.05) antimicrobial activity than thymol, and FD β-CD inclusion complexes were able to inhibit Escherichia coli K12 at lower (P < 0.05) active compound concentrations than corresponding free oils. Antimicrobial activities of β-CD inclusion complexes against total viable counts in pork meat system throughout storage were observed. The FD method showed to be the best encapsulation method with enhanced antimicrobial activity for both compounds.     

Rapid fabrication of microstructure on PMMA substrate by the plate to plate Transition‐Spanning isothermal hot embossing method nearby glass transition temperature

Generally, the hot embossing cycle time for fabricating microfeatures on the surface of polymer takes no <10 min because the mold needs to be firstly heated to 10–40°C above T_g and then cooled to temperature below T_g after certain time of holding pressing force. In this article, the Plate to Plate (P2P) Transition‐Spanning Isothermal Hot Embossing method was proposed, specific of which was relatively short embossing cycle time of 15–60 s by setting and holding constant mold temperature in a narrow temperature interval around T_g in whole cycle of embossing substrate of PMMA. The experiment hot embossing device satisfied the needs of isothermal embossing process was designed and built up, on which the micro V‐cut array with a pitch of 49 µm was successfully fabricated on the PMMA substrate. The experiments gave a confirmation of possibility for fabricating microfeatures by P2P Transition‐Spanning Isothermal Hot Embossing method. POLYM. ENG. SCI., 57:268–274, 2017. © 2016 Society of Plastics Engineers     

不同炼胶工艺对半钢轮胎磨耗性能的影响

分析对比不同生产工艺条件下轮胎胎面胶的各项性能,可以看出SSM混炼工艺生产的胎面胶白炭黑和炭黑分散度提升,胶料流动性向好,成品轮胎外观缺陷(花纹圆角、胎冠缺胶等)出现的几率降低;轮胎胎面的疲劳磨耗、胎面的磨损磨耗降低;胎面胶的磨耗体积量,SSM混炼工艺较传统法工艺整体有大幅度降低,相比传统法提升量大于50%。     

走出盒子——开放式国际工作坊的教学理念与实践

通过对麻省理工学院建筑系简·沃泊勒教授开放式教学理念与模式的介绍,用实例说明国际工作坊教学实践及其所取得的成就,着重分析建筑系学生从中学到的人文设计思想与方法,进一步思考开放式教学理念对当代建筑学教育和未来建筑师培养所产生的重要影响。     

天然野樱桃果酒的酿造及香气成分分析

以天然野樱桃为主要原料,发酵酿造野樱桃果酒,并对成品酒进行感官、理化和微生物指标的评价分析。结果表明,该野樱桃果酒澄清透明,酒香浓馥幽郁,风味极佳;果酒酒精度（11.9%vol）,总糖含量（11.8 g/L）,挥发酸（0.41 g/L）等理化指标均符合国家相关标准;采用顶空固相微萃取（HS-SPME）和气相色谱-质谱联用（GC-MS）法共鉴定出野樱桃果酒中有52种香气成分,其中酯类18种、醇类4种、酸类3种、苯及其衍生物19种、萜烯类6种、呋喃类2种。香气成分中,苯甲酸乙酯相对含量最高,为31.12%,其次是苯甲醇为14.71%,苯乙醇为5.64%,这几种物质初步确定为构成天然野樱桃果酒的重要香气成分。