System performance and economic analysis of solar-assisted cooling/heating system

The long-term system simulation and economic analysis of solar-assisted cooling/heating system (SACH-2) was carried out in order to find an economical design. The solar heat driven ejector cooling system (ECS) is used to provide part of the cooling load to reduce the energy consumption of the air conditioner installed as the base-load cooler. A standard SACH-2 system for cooling load 3.5 kW (1 RT) and daily cooling time 10 h is used for case study. The cooling performance is assumed only in summer seasons from May to October. In winter season from November to April, only heat is supplied. Two installation locations (Taipei and Tainan) were examined.It was found from the cooling performance simulation that in order to save 50% energy of the air conditioner, the required solar collector area is 40 m² in Taipei and 31 m² in Tainan, for COP_j = 0.2. If the solar collector area is designed as 20 m², the solar ejector cooling system will supply about 17–26% cooling load in Taipei in summer season and about 21–27% cooling load in Tainan. Simulation for long-term performance including cooling in summer (May–October) and hot water supply in winter (November–April) was carried out to determine the monthly-average energy savings. The corresponding daily hot water supply (with 40 °C temperature rise of water) for 20 m² solar collector area is 616–858 L/day in Tainan and 304–533 L/day in Taipei.The economic analysis shows that the payback time of SACH-2 decreases with increasing cooling capacity. The payback time is 4.8 years in Tainan and 6.2 years in Taipei when the cooling capacity >10 RT. If the ECS is treated as an additional device used as a protective equipment to avoid overheating of solar collectors and to convert the excess solar heat in summer into cooling to reduce the energy consumption of air conditioner, the payback time is less than 3 years for cooling capacity larger than 3 RT.     

朝鲜某地硫化铜镍矿浮选试验研究

为了给开发朝鲜某地硫化铜镍矿石提供依据,在工艺矿物学研究的基础上,对该矿石进行了浮选试验。试验结果表明,在-0.074 mm占75%的磨矿细度下,经过1次粗选、3次精选、4次扫选,可以得到适合电炉熔炼的合格铜镍混合精矿,精矿镍品位为5.16%,镍回收率为92.13%,铜品位为1.94%,铜回收率为97.47%。     

Weighted least-square estimation of demand product mix and its applications to semiconductor demand

Estimation of demand product mix is important for effective production plans. Unlike most research in the literature where the product mix is either given or treated as a decision variable in optimization of the production efficiency, this paper focuses on the product mix itself and how to estimate it from the market demand. With more accurate information on the demand product mix, aggregate production plans for product families can be disaggregated into quality detailed plans for individual product items. In this paper, least-square estimates of demand product-mix proportions are first derived. To take into account the effect of the product life cycle, dynamic weighting schemes are then developed to improve the accuracy of the product-mix estimates. For applications, we concentrate particularly on semiconductor demand where new generations of semiconductor products emerge at the pace of every six months, as manifested by the celebrated Moore's laws. The proposed methodologies will be tested with simulated DRAM demands and actual semiconductor demands of different technology generations.     

Graphene decoration with metal nanoparticles: towards easy integration for sensing applications

A simple and versatile method for the decoration of CVD grown graphene with metal nanoparticles is presented. The mechanism of nanoparticle formation is galvanic displacement resulting in physically adsorbed clusters. The single layer graphene obtained by this method can be easily transferred. Integration onto a gas sensing transducer is presented as proof of concept.     

Study on the Interaction between Talc and Perfluoropolyethers under Tribological Contact

Particle contamination at the head–disk interface (HDI) is a major concern for the long-term reliability of hard disk drives. In the current study, it is shown that, surprisingly, soft and lubricious talc particles have a significant damaging effect on the friction performance of media lubricants, nanometer-thick perfluoropolyethers. Thermogravimetric analysis (TGA) and the adsorption studies indicate that two mechanisms, Lewis acid–catalyzed decomposition and surface adsorption, are responsible for the observed tribological degradation. The potential impacts of the findings here on the design of next-generation media lubricant have been discussed.     

基于FPGA的穆斯堡尔谱仪数据采集卡

FPGA(Field Programmable Gate Array)是一种可编程器件,有着强大的逻辑运算和时序控制能力,尤其擅长于时序信号的采集和处理.基于FPGA的穆斯堡尔谱仪数据采集卡,改变了传统的使用单片机的方法,运算速度明显提高,仪器体积显著减小.通过Quartus Ⅱ开发系统,选用Altera公司Cyclone系列的EP1C6T144C8芯片实现穆斯堡尔谱仪的计数器、存储器及串行通信功能.EP1C6T144C8芯片的逻辑单元为5980个,存储空间为92160位,丰富的逻辑资源可以很好的满足穆斯堡尔谱仪数据采集卡的要求,并且可以实现功能和参数修改.     

Calibration in 1976 and 1983 of didymium glass filters issued as NBS standard reference materials

In 1983, a new supply of didymium glass filters was prepared since the stock calibrated in 1976 has been very useful for wavelength calibration and the inventory has been depleted. Results for representative samples of the new filters are presented. The new supply of glass has been calibrated by the batch mode and will be designated Standard Reference Materials (SRM) 2009A and 2010A. During the latter part of 1976, research was begun to characterize didymium glass filters for use with visible spectrophotometers with bandwidth in the range 1.5 to 10.5 nm. These filters were found to produce a smaller wavelength uncertainty than previously issued filters. Also, it was found that points of inflection in the transmittance curve could be used to supplement the data for transmittance minima. The results of that research were SRM 2009, 2010, 2013, and 2014. The same techniques were applied in 1983. Also, the results from 1983 and 1976 for one of the Master filters are compared.     

Calibrating a multi-manipulator robotic system

A simple, but effective, method of calibrating a multimanipulator robotic system is introduced. The algorithm uses precisely machined calibration plates which are inexpensive to manufacture and require no measuring instrumentation. The method is tested on a dual-arm system which resulted in an order of magnitude reduction in the pose error. Coordinated dual-arm manipulation experiments are conducted using the calibrated kinematic model to validate the usefulness of the calibration process     

An optimal receiver using a time-dependent adaptive filter

The optimal time-dependent receiver (OTDR) is presented and its performance is compared to that of the matched filter receiver. The OTDR, a time-dependent adaptive filter, is shown through simulation to be superior to the matched filter for signals corrupted by cyclostationary interference because it exploits statistical periodicities of the interference