Studies on the feasibility of electrochemical recovery of palladium from high-level liquid waste

The electrochemical behavior of palladium (II) in nitric acid medium has been studied at platinum and stainless steel electrodes by cyclic voltammetry. The cyclic voltammogram consisted of a surge in cathodic current occurring at platinum electrode at a potential of −0.1 V (vs. Pd), which culminates in a peak at −0.3 V was due to the reduction of Pd(II) to Pd. This was accompanied by a broad scant anodic peak at 0.25 V during scan reversal. Reduction of Pd(II) was irreversible and the diffusion coefficient was found to be 2.35 × 10⁻⁸ cm²/s at 298 K. At stainless steel electrode, a surge in the cathodic current occurring at −0.4 V (vs. Pd) was due to palladium deposition, which was immediately followed by a steep increase in cathodic current at −0.66 V due to H⁺ reduction. Electrolysis of palladium nitrate from 1 M to 4 M nitric acid medium at stainless steel electrode resulted in complete recovery of palladium with reasonably high Faradaic efficiency depending upon nitric acid concentration. However, the recovery and Faradaic efficiency were significantly lowered (to 40%) in the case of electrolysis from simulated high-level liquid waste due to other interfering competitive reactions.     

电子产品的可靠性设计

针对电子产品易受干扰的特点,提出了设计电子产品可靠性应遵循的基本原则.重点给了提高电子产品可靠性常用的三种设计方法,说明了提高电子产品的可靠性对机电设备的可靠和安全运行具有重要意义.     

Nature Inspired Small Molecules for Chemical Biology

Chemical biology and drug discovery are instrumental sciences to address unmet medical needs and to gain a deeper understanding of normal and disease state biology in mammalian systems. Unlike most genetic tools, the small molecule modulation of biology is reversible, controllable in space, time and quantity, avoids the removal of gene products from cellular systems and thus enables perturbation of biology in its native state. Natural products, their derivatives as well as small molecules based on the core‐scaffolds of natural products including natural product fragments allow targeting unique, biologically relevant fractions of chemical space that may deliver quality tool compounds. In this essay, we discuss various synthesis approaches inspired by natural products to deliver biologically active small molecules. We argue and provide evidence that inspiration by natural product structure remains a powerful guiding principle for the development of novel approaches to the study biology by means of novel bioactive small molecules.     

床类家具模块化设计的研究

本文根据床类家具的使用功能将其分为支撑围合构件、承接构件、辅助装饰构件三大模块.其中支撑围合构件中的床屏模块是最主要的造型和使用模块,其变化和功能最为丰富,结构也最复杂.因此,本文将床屏模块又细分为框架和装饰两大构件,分别建立相应的模块库,再按照分类组合原则组合成丰富多样的产品,实现产品的多样化.这样,只需不断充实与更...     

基于模糊评价的薄壁件产品可制造性复杂程度实现

传统的设计过程偏重于强调产品的功能性,不能适应现代产品的快速设计及制造的迫切需求。针对这一问题,提出了考虑产品可制造性的产品智能设计模型,并结合薄壁圆筒件的冲压成型可制造过程构建了其决策分析方法。分析讨论了平面制件的结构要素与工艺决策、规则形状拉伸件的结构要素与工艺决策,拉伸力和压边力的计算等关键问题,以此发展了基于模糊数学理论的冲压工艺决策中存在的不确定因素分析模型;并以一类薄壁冲压零部件的可制造性分析作为一个分析实例,确定了每一制造因素评判标准的因素等级,得到了其隶属度的函数关系。     

文化传承视域下西夏博物馆文创产品开发策略

西夏博物馆作为承载着诸多西夏历史文化的旅游胜地,对于旅游产业的深入发展有着较高的文化价值。从方法论的角度对西夏博物馆的文创产品设计开发进行分析,将博物馆的文化特色归纳总结,从图形、符号、色彩等3个方面进行重点阐释,丰富博物馆文创产品的开发策略,从而通过文创产品对文物特色进行弘扬与推广,深入挖掘西夏历史文化,带动西夏旅游产业的发展。     

建筑元素在匈牙利旅游文创产品设计中的应用

近年来,随着旅游市场的快速发展,匈牙利旅游产品的消费需求也日渐增大。在文化创意产业与旅游产业融合发展的背景下,文章解析了建筑元素如何为匈牙利旅游文创产品设计提供新的创作思路。阐述了匈牙利旅游文化的发展现状与特色建筑,对匈牙利建筑元素展开信息收集与整理分析,将其风格、造型、颜色等特征进行提取设计与创意转换。提出建筑元素应用于匈牙利旅游文创产品的具体方法,为提高匈牙利旅游文创产品在市场中的竞争力提供参考方向。     

The Electrochemistry of the FPL (Forest Products Laboratory) Process and its Relationship to the Durability of Structural Adhesive Bonds

The FPL (Forest Products Laboratories) Process for preparing aluminum for structural adhesive bonding has been used in the aerospace industry since the early 1950's. Problems were encountered with the use of the process when the industry changed from phenolic to epoxy adhesives. In-service disbonds followed by corrosion were observed. This review article describes an investigation of the electrochemistry of the FPL etch process. Through a combination of electrochemical polarization measurements, surface chemical and surface morphological investigations and a thorough application of the Boeing wedge test, we are able to provide a mechanism of action of the FPL etch process. An oscillating electrochemical reaction was observed for low alloy aluminum which was ascribed to the dissolution and redeposition of copper on the aluminum during the etching process. A spatial variation in wedge test performance was found in that edge specimens demonstrated lower crack extensions than center specimens when using a low alloy aluminum that was etched in an FPL etch bath that was low in copper. These results are positioned in a historical perspective providing some insight into possible reasons for the irreproducibility of durability of structural adhesive bonds made with low alloy aluminum adherends that were prepared in a low copper content FPL etch bath.     

Strength and microscopic characteristics of alkali-activated fly ash-cement

The effects of different activator concentration, liquid/fly ash ratio, and curing temperature and time on the compressive strength of specimens prepared from low-calcium fly ash activated with sodium hydroxide without the use of Portland cement were investigated. SEM, XRD and mercury intrusion porosimetry (MIP) were used to observed the structural feature, reaction products, and porosity and pore-size distribution of the specimens from alkaliactivated fly ash, respectively. It was found that the degree of reactivity, as shown by the compressive strength, the activator concentration and the ratio of liquid/fly ash, and the curing temperature always result to be significative factors. The 7, 14, and 28-day compressive strengths of specimens prepared from alkali-activated fly ash by 5M NaOH solution at 50 °C are 152, 219, and 263 kgf/cm², while those from 6M solution are 184, 225, and 267 kgf/cm², respectively. In SEM observation, the fly ash activated by the 5M NaOH solution shows a more continuous matrix with solid and non porous due to subsequent gel restructuring by amorphous alkaline aluminosilicate produced from alkali-activated fly ash.     

Ozonation of Several Organic Compounds Having Low Molecular Weight under Ultraviolet Irradiation

Ozonation of several low molecular weight organic compounds under ultraviolet irradiation was studied. Nine compounds were identified as reaction products of the ozonation of phenol which was promoted by the simultaneous use of ozone and ultraviolet irradiation. In the case of several organic compounds having carbon numbers from one to six, the removal of total organic carbon (TOC) by this simultaneous use was higher than by either the ozone oxidation method or the ultraviolet irradiation method for all the compounds.