测距仪在检测制丝线贮柜存料量中的应用

贮柜是制丝生产线上的物料存贮设备,及时准确地掌握其存料量对于合理安排生产、及时调整生产计划等具有重要作用,但是对于寻堆布料贮柜存料量的检测,一直以来是一个技术难题。分析了储柜物料检测定位的现状,介绍了激光对扫描测距的结构、原理及功能,提出了采用激光测距仪间接检测此类贮柜存料量的方法,并结合实际使用情况说明了三类激光测距的应用。最后对新出现的扫描式漫反射激光测距仪的应用方式进行了介绍。

一种旋转锥体床的颗粒混合与输运规律

采用带竖立环壁的旋转锥体床,并在环壁上设置溢流口,在锥体内设置固定搅拌器.研究颗粒在这种新型的旋转锥体内的混合和输运规律,探讨锥体旋转速率、颗粒给料速率、溢流口面积等参数对锥体内的颗粒混合、动态存料量以及停留时间的影响.结果表明,通过增设竖立环壁将大大延长颗粒在锥体的停留时间,而搅拌器的设置对于保证颗粒在锥体内的充分混合起着关键作用.在设置搅拌器的情况下,锥体内的动态存料量与给料速率成正比,而与锥体旋转速率成反比;停留时间与锥体旋转速率和给料速率成反比.增加溢流口面积,将缩短颗粒停留时间和降低锥体内的存料量.研究结果对于设计耦合旋转锥体床的煤热解气化炉具有一定的参考价值.

旋转锥体床内颗粒传输规律的实验研究

该实验针对旋转锥体床,研究颗粒在锥体内的输运规律。探讨锥体旋转速率、颗粒给料速率、锥体溢流口数量等参数变化时,对颗粒在锥体内的动态存料量以及停留时间的影响。结果表明,旋转锥体床具有控制物料输送和调节停留时间的可操作性,增设竖立环壁将大大延长颗粒在锥体的停留时间,而搅拌器的设置对于保证颗粒在锥体内的充分混合起着关键作用。在设置竖立环壁和搅拌器的情况下,锥体内的动态存料量与给料速率成正比,而与锥体旋转速率反比;停留时间与锥体旋转速率和给料速率成反比。增加溢流口面积,将缩短颗粒停留时间和降低锥体内的存料量。研究结果对于设计新颖的煤热解气化炉以及开发以固体热载体热解气化为基础的多联产技术具有一定的参考价值。

新型附着式料位—荷重指示器主要误差分析及其实测结果

新型专利产品FWZ型料位—荷重指示器能连续显示料仓内的存料量,具有较高的检测精度。某工地200t料仓的存料量实测结果表明,FWZ-Ⅰ型和FWZ-Ⅱ型指示器综合显示误差分别为2.55％和0.65％。

Enhanced Methane Adsorption in Catenated Metal-organic Frameworks： A Molecular Simulation Study

A systematic molecular simulation study was performed to investigate the effect of catenation on methane adsorption in metal-organic frameworks(MOFs).Four pairs of isoreticular MOFs(IRMOFs)with and without catenation were adopted and their capacities for methane adsorption were compared at room temperature.The present work showed that catenation could greatly enhance the storage capacity of methane in MOFs,due to the formation of additional small pores and adsorption sites formed by the catenation of frameworks.In addition,the simulation results obtained at 298K and 3.5MPa showed that catenated MOFs could easily meet the requirement for methane storage in porous materials.

Optimum blending of iron ore from Choghart stockpiles by using goal programming

Iron and steel industry is an important sector of Iran's economy.Choghart iron ore mine is an important iron ore producer of Iran steel industry.Phosphorous contained in the iron ore concentrates of Choghart mine has a detrimental effect on the steel making process,whereby this causes cracks to form in the refractory lining of blast furnaces.In the past,about 1.43 Mt of low-grade and 4.53 Mt of high-phosphorous materials had been transported to low grade and high phosphorous stockpiles,respectively,for future beneficiation.As a result of the progressive depletion of high-grade ore and establishment of beneficiation plant in Choghart,exploitation of these two stockpiles in this mine became an important issue.In this work,a linear goal programming(GP) model was developed in order to determine the optimum iron ore blend in terms of quality from low grade and high phosphorous stockpiles of Choghart mine.The model was solved by the SOLVER V.9 program.Results show that feeding with acceptable quality(w(Fe)≥50% and w(P)≤1.2%,mass fraction) materials can be blended from stockpiles that satisfy the needs of the Choghart processing line.

Total Phenolic Content and Antioxidative Activity in Seasoning Protein Hydrolysate as Affected by Pasteurization and Storage

Protein hydrolysate prepared from fish and shrimp by-products were used to prepare a seasoning protein hydrolysate （SPH）. The effects of pasteurization and storage on total phenolic content （TPC）, DPPH radical scavenging activity, reducing power, and color of the SPH were investigated. Pasteurization at 90 ℃ for 10 minutes led to a reduction of TPC and DPPH radical scavenging activity and an increase of reducing power of solid fraction of SPH by about 30%, 99%, and 100%, respectively. Consequently it increased TPC DPPH radical scavenging activity, and reducing power of the liquid phase by about 32%, 600%, and 100%, respectively. Storage at 28, 35, or 45 ℃ for 12 weeks altered color values and increased brownness intensity （OD420）. The storage led to an apparent increase of the TPC and antioxidative activity of the product. The results indicate the possibility of producing healthy appetizers from protein hydrolysate prepared from by-products of the seafood industry.

Evaluation of Selected Quality Degradation Indices for Palestinian Extra Virgin Olive Oil Bottled in Different Packaging Materials upon Storage under Different Lighting Conditions

The effect of packaging materials and lighting conditions on quality of extra virgin olive oil （EVOO） was investigated during six months. The results highlighted an influence of light and type of packaging material on EVOO-quality with storage time. At shelf, all packages maintained EVOO at the end of storage in terms of acidity, peroxide value, K232, while K270 exceeded limit of EVOO in glass and PET-stored oil. Loss of phenols was the highest in glass-stored oil and the lowest in high-density polyethylene （HDPE）-stored oil. In terms of sensory evaluation, glass-stored oil lost EVOO grade after three months and its edible compliance after six months, while HDPE-stored oil maintained EVOO grade 90 days and was virgin after six months. In extended lighting, acidity, peroxide value and K232 did not exceed EVOO grade, while K270 exceeded EVOO grade after 30 days in glass and polyethylene terephthalate （PET）-stored oil and after 90 days in HDPE. The loss of phenols was the largest in glass and smallest in HDPE-stored oil. Glass stored-oil lost organoleptic edible compliance before 90 days, while that in PET was virgin at 90 days and that in HDPE maintained EVOO quality 90 days. At the end of experiment, oils in all packages were not edible. In dark, all packages maintained oil in EVOO quality in terms of all indices. The loss of phenols was marginal but was the least in glass and the highest in HDPE. It was concluded that HDPE bottles conserve stored olive oil at shelf or illumination better than PET or glass, while in dark, glass was superior over plastic.

Issues of Access, Equity, and Quality in Early Childhood Development Programmes in Zimbabwe

The paper sought to explore issues of access, equity, and quality in the early childhood development （ECD） sub-sector in Zimbabwe. The massive expansion of ECD services prompted the author to undertake the study. Data were collected using focus group discussions, individual interviews, document analysis, and observations. Information from literature, research reports, policies, and practices was also analyzed in order to establish the state of affairs in the provision of ECD. The data were analyzed using theme identification methods to solicit emerging issues. Generally, it was found that on issues of access, equity, and quality in ECD in Zimbabwe, there is a quality-quantity dilemma with qualitative progress less conspicuous than quantitative progress. The resultant specific challenges include： large teacher-child ratio; lack of parental involvement, lack of trained ECD specialists with expertise in using a play-based curriculum; and shortage of equipment, material resources, and age appropriate infrastructure. In most ECD settings, there were inadequate health and nutrition provisions. Water, sanitation and health （WASH） facilities were found to be insufficient in most centres. The study recommended that there is need for： equal access to quality early childhood education; provision of infrastructure, provision of ability and age appropriate resources; and health, sanitation, and nutrition services especially in rural settings. Overall, ECD programmes in Zimbabwe should strive to attain quality more than quantity services. The need to train more early childhood specialists who would drive the ECD sub-sector is emphasized.

Branched Co3O4/Fe2O3 nanowires as high capacity lithium-ion battery anodes

We report a facile, two-step hydrothermal synthesis of a novel Co304/a-Fe2O3 branched nanowire heterostructure, which can serve as a good candidate for lithium-ion battery anodes with high Li＋ storage capacity and stability. The single-crystalline, primary C0304 nanowire trunk arrays directly grown on Ti substrates allow for efficient electrical and ionic transport. The secondary a-Fe2O3 branches provide enhanced surface area and high theoretical Li＋ storage capacity, and can also serve as volume spacers between neighboring Co3O4 NW arrays to maintain electrolyte penetration as well as reduce the aggregation during Li＋ intercalation, thus leading to improved electrochemical energy storage performance.

Exploration and progress of high-energy supercapacitors and related electrode materials

As one of new electrical energy storage systems, supercapacitors possess higher energy density than conventional capacitors and larger power density than batteries, integrating substantial merits with high energy, large power delivery, long cycle life, obvious safety, and low cost. However, the unsatisfying energy density is the inhabiting issue for the wide commercial applications. As the energy density(E, W h kg?1) is directly proportional to specific capacitance(C, F g?1) and the square of operating voltage(V, V), in this review, we summarize the recent progress in two sections: the exploration of high-performance electrode materials to achieve high specific capacitance and the construction of high-voltage supercapacitor systems for high working voltage. The progressive explorations and developments in supercapacitors could guide the future research towards high-performance, low-cost, and safe energy storage devices.

Stimulus-responsive polymers for safe batteries and smart electronics

Stimulus-responsive energy storage devices,which can respond to external stimuli,such as heat,pH,moisture,pressure,or electric field,have recently attracted intensive attention,aiming at the ever-increasing demand for safe batteries and smart electronics.The most typical stimulus-responsive materials are polymers that can change their conformation by forming and destroying secondary forces,including hydrogen bonds and electrostatic interactions in response to external stimuli,accompanied by changes in the intrinsic properties such as conductivity and hydrophobicity.Although the applications of stimulus-responsive functions in rechargeable batteries are still in the early stage because of the complexity and compatibility of battery architectures,many new concepts of regulating the polymer structures upon applications of stimuli have already been developed.In this review,we discuss the recent progress of stimulus-responsive polymers on energy storage devices featuring thermal protection and intelligent scenarios,with a focus on the detailed structural transformations of polymers under a given stimulus and the corresponding changes in battery performance.Finally,we present perspectives on the current limitations and future research directions of stimulus-responsive polymers for energy storage devices.

The strategies of advanced cathode composites for lithium-sulfur batteries

Lithium-sulfur batteries have been widely nominated as one of the most promising next-generation electrochemical storage systems due to its low cost, high capacity and energy density. However, its practical application is still hindered by poor cycling lifetime, low Coulombic efficiency, instability and small scales. In the last decade, the electrochemical performances of the lithium-sulfur batteries have been improved by developing various novel nanoarchitectures as qualified hosts, and enhancing the sulfur loading with effective encapsulating strategies. The review summarizes the major sulfur cooperating strategies of cathodes based on background and latest progress of the lithium-sulfur batteries. The novel cooperating strategies of physical techniques and chemical synthesis techniques are discussed in detail. Based on the rich chemistry of sulfur, we paid more attention to the highlights of sulfur encapsulating strategies. Furthermore, the critical research directions in the coming future are proposed in the conclusion and outlook section.

Coherent Mn3O4-carbon nanocomposites with enhanced energy-storage capacitance

Nanostructured Mn3O4 was introduced to activated C （AC） by a novel sonochemical reaction, and the resulting nanocomposites were examined as supercapacitor electrodes. The sonication not only catalyzed the redox reaction but also promoted the diffusion of the precursors, causing the formation of coherent nanocomposites with Mn3O4 nanoparticles grown and uniformly distributed inside the mesopores of the AC. In addition, the extreme local condition in the sonochemical synthesis yielded an excessive amount of divalent manganese ions and oxygen vacancies. This novel microstructure endowed the sample with a superior performance, including a specific capacitance of 150 F/g compared with the value of 93 F/g for AC at a charge/discharge rate of 100 mA/g. A Li-ion capacitor delivered an energy density of 68 Wh/kg, compared with 41 Wh/kg for the AC capacitor at a power density of 210 W/kg.