Nano Sized Copper Selenide Thin Film Pre-Cursor by A Liquid Phase Chemical Growth Process

The deposition of copper selenide(CuSe)thin films was carried out using liquid phase chemical bath deposition process at the optimized growth parameters as:60℃deposition temperature,90 minutes deposition time,pH equal to 10.5±0.1 and 72±2 r/min speed of mechanical rotation.The as-grown deposits exhibited excellent uniformity and physical adherency with the substrate surface and are smooth and diffusely reflecting with colour changing from yellowish orange to dark chocolate during deposition.The layer is of the order of 300 nm thick.The EDS analysis technique gave film composition to be nearly stoichiometric(Cu=47.89%,Se=52.11%).An X-ray diffraction analysis showed CuSe to be polycrystalline hexagonal with a good match of d-values and intensities of reflections.The crystallite size is in the nanorange(50-60 nm).The as-deposited CuSe exhibited a high coefficient of absorption(α=105cm-1)with a direct optical band gap of 1.81 eV.Compared to other chalcogenides,CuSe films exhibit low resistance;room temperature electrical resistivity being 1.55×103?cm.The electrical conductivity decreased with increase in temperature up to 473 K;showing totally unusual behaviour from that of the semiconducting property.The thermo probe measurements showed n-type conduction of the samples.     

我国太阳热水器产业发展现状与对策

经过近２０年的研究和科技成果转化,太阳热水器技术已趋成熟。随着改革开放,人民生活质量不断提高,生活热水正在成为现代文明生活中不可缺少的需求。太阳热水器市场不断扩大,太阳热水器产业迅速发展。据不完统计,全国已有 １０００多家企业,从事研制、生产、销售和安装服务业务。太阳热水器已成为太阳能热利用产业的主流。１太阳热水器产业发展现状 我国市场上销售的太阳热水器基本上可分为三大类型产品,即闷晒热水器、平板热水器和真空管（包括热管）热水器。其中间晒热水器的生产主要以中小型企业为主。 平板热水器的核心部分是平…     

On-site treatment of a motorway service area wastewater using a package sequencing batch reactor (SBR).

A sequencing batch reactor (SBR) treating the effluent of a motorway service station in the south of England situated on a major tourist route was investigated. Wastewater from the kitchens, toilets and washrooms facilities was collected from the areas on each side of the motorway for treatment on-site. The SBR was designed for a population equivalent (p.e.) of 500, assuming an average flow of 100 m3/d, influent biochemical oxygen demand (BOD) of 300 mg/l, and influent suspended solids (SS) of 300 mg/l. Influent monitoring over 8 weeks revealed that the average flow was only 65 m3/d and the average influent BOD and SS were 480 mg/l and 473 mg/l respectively. This corresponded to a high sludge loading rate (F:M) of 0.42 d(-1) which accounted for poor performance. Therefore the cycle times were extended from 6 h to 7 h and effluent BOD improved from 79 to 27 mg/l.     

Effect of gamma-irradiation on flavour 5′-nucleotides,tyrosine, and phenylalanine in mushrooms (Agaricus bisporus)

The impact of gamma-irradiation on 5′-nucleotides and on the free amino acids tyrosine and phenylalanine in fresh mushrooms was studied. After irradiation the samples were freeze-dried to avoid enzyme induced chemical changes. Three 5′-nucleotides could be detected using HPLC–UV and LC–ESI-MS: adenosine 5′-monophosphate (AMP), guanosine 5′-monophosphate (GMP) and guanosine 5′-diphosphate (GDP). Irradiation significantly reduced (p = 0.05) the GDP concentration (22%). AMP showed a marked reduction (46%) only at 5 kGy. GMP, tyrosine, and phenylalanine were not affected by gamma-irradiation.     

铝基牺牲阳极材料合金化研究进展

铝基牺牲阳极合金具有理论电容量大、电位适中、原料丰富等优点而普遍受到人们的重视。本文概述了近年来的铝基牺牲阳极材料的发展,总结了其合金化理论的发展变化,在分析铝阳极合金化活化规律及研究手段的基础上,讨论了几种被广泛接受的活化机理,并提出多种活化机制联合作用是活化机理的研究方向。     

Optical and electrical properties of porous silicon layer formed on the textured surface by electrochemical etching

Porous silicon(PS) layers were formed on textured crystalline silicon by electrochemical etching in HF-based electrolyte.Optical and electrical properties of the TMAH textured surfaces with PS formation are studied. Moreover,the influences of the initial structures and the anodizing time on the optical and electrical properties of the surfaces after PS formation are investigated.The results show that the TMAH textured surfaces with PS formation present a dramatic decrease in reflectance.The longer the anodizing time is,the lower the reflectance.Moreover,an initial surface with bigger pyramids achieved lower reflectance in a short wavelength range.A minimum reflectance of 3.86%at 460 nm is achieved for a short anodizing time of 2 min.Furthermore,the reflectance spectrum of the sample,which was etched in 3 vol.%TMAH for 25 min and then anodized for 20 min,is extremely flat and lies between 3.67%and 6.15%in the wavelength range from 400 to 1040 nm.In addition,for a short anodizing time,a slight increase in the effective carrier lifetime is observed.Our results indicate that PS layers formed on a TMAH textured surface for a short anodization treatment can be used as both broadband antireflection coatings and passivation layers for the application in solar cells.     

SPICE compatible analytical electron mobility model for biaxial strained-Si-MOSFETs

This paper describes an analytical model for bulk electron mobility in strained-Si layers as a function of strain.Phonon scattering,columbic scattering and surface roughness scattering are included to analyze the full mobility model.Analytical explicit calculations of all of the parameters to accurately estimate the electron mobility have been made.The results predict an increase in the electron mobility with the application of biaxial strain as also predicted from the basic theory of strain physics of metal oxide semiconductor(MOS) devices.The results have also been compared with numerically reported results and show good agreement.     

Three-dimensional ultrasound evaluation of fetal tooth germs

Thirty children have had percutaneous endoscopic gastrostomy (PEG) inserted for feeding purposes. During a follow-up period of 5-45 months (mean 24 months), complications were recorded in 13 patients. Some patients had more than one complication. Complications included colocutaneous fistula, gastro-oesophageal reflux, wound infection, granulation tissue formation, tube leakage, tube blockage and bleeding. The authors present a retrospective review of the results and discuss the management of these complications.