MC68HC908QY4单片机在炉温控制系统中的应用

本文介绍了MC68HC908QY4单片机控制的炉温控制系统，对系统的基本构成与工作原理进行了研究，并对数学模型与算法进行了分析，设计了软硬件．同时给出了部分硬件电路图与软件流程图。     

光谱分析的微机测试

介绍了一种用光电倍增管将光信号转换为电信号,再将此信号放大经模数转换后输入到微机、打印机等设备的一套光谱分析的微机处理方法,此种方法与传统的干板照像法进行比较,在进行光谱分析时省时、省力、误差小,实现了光谱分析的微机化。     

林区环境因素与CORS测量精度的相关性分析

在林区环境下的碎部测量中存在一定的障碍物对CORS信号进行干扰,影响CORS信号的站间传播。为研究林区环境因素与CORS测量精度之间的关系,通过获取林区优势树种的叶面积指数(LAI)和CORS测量精度等要素,利用SPSS软件分析其相关性。结果表明：不同优势树种的LAI值与CORS测量精度秩相关系数r_s>0.8,在p<0.01下呈强相关性,树冠投影面积与CORS测量精度的秩相关系数r_s>0.5,在p<0.01下呈现中等相关,而树冠高度和地形与CORS测量精度未得出相关性。     

Recovery of indium and lead from lead bullion

Lead and indium were recovered by electrolysis and nonequilibrium solvent extraction process from lead bullion.The effects of current density,electrolytic period and circle amnant of electrolyte on the electrochemical dissolution of lead and indium were investigated.The effects of extraction phase ratio and mixing time on solvent extraction of indium and striping phase ratio and stripping stage on the loaded organic phase stripping were also investigated.The experimental results indicate that under optimum conditions,the purity of lead deposited on cathode is 98.5% and the deposit rate of lead is 99.9%,the dissolution rate of indium is 94.28%,the extraction rate of indium is 98.69%,the stripping rate of indium is almost 100%,and the impurity elements,such as Zn,Fe and Sn can be removed.     

基于软件无线电通信平台的高效信道化MSK系统

为了解决软件无线电平台中的数字上下变频技术,包括频谱的搬移和抽样率的转换,克服现有专用器件在实现这些功能中的不是,在分析高效宽频带变频系统的基础上把变频部分与MSK调制方式灵活地结合在一起,有利于在实际中进一步推广到各类调制方式中,从而实现软件无线电的高效数字变频调制解调．     

小方坯连铸中间包内型优化试验

通过水力学模型试验 ,研究了中间包内的温度和浓度变化。研究表明 :现场中间包内型结构欠合理 ;设置横挡墙和“V”字型挡墙均可改善中间包内的流场 ;开口度为130mm×100mm横型挡墙和开口度为150mm×80mm“V”字型挡墙效果最好 ,它们均可保证在正常浇注条件下 ,使1 ,2流平均温差1℃左右。     

Radiation synthesis of PVP/CMC hydrogels as wound dressing

Carboxymethyl cellulose (CMC) and poly(N-vinyl pyrrolidone) (PVP) were blended to synthesize hydrogels by ⁶⁰Co γ-ray irradiation. A series of hydrogels were prepared with three compositions, i.e. PVP:CMC = 5:5, 6:4 and 7:3. The properties of the hydrogels such as gel fraction, gel strength, swelling behavior and moisture retention were investigated. Compared with pure PVP and CMC hydrogels, PVP/CMC blend hydrogels possessed improved gel strength, flexibility and transparency. As the content of PVP in PVP/CMC blend hydrogels increased, the gel fraction increased while the swelling rate decreased. The hydrogels with optimal properties were obtained in a composition of PVP/CMC = 6/4 with sterilization dose (25 kGy) and further characterized by FT-IR and SEM. Properties concerning the application of wound dressing were performed by comparison with a commercial hydrogel wound dressing to find a similar moisture retention capability and improved swelling rate. The improved properties as well as the cheapness of the materials suggest that PVP/CMC blend hydrogel can be good candidate as wound dressing.     

喷淋液滴在空气环境下的运动特性

本文以喷淋液滴在空气环境下运动特性为工程背景,建立单个液滴在常温、常压空气环境中的动量方程,分析液滴沉降特性、追赶特性及运动轨迹行为。计算结果表明,不同喷淋液滴初始条件下,短时间内存在重力大于曳力和重力小于曳力两种情况,但最终减速液滴均会达到受力平衡状态;液滴离开喷淋头后,垂向位移均迅速增大,液滴粒径越大、初始速度越大,垂向位移增长的速率也越大,达到相同位移的用时越短;液滴尺寸、初始速度相差越大,液滴追赶所用的时间越短,追赶位移越小,液滴尺寸、初始速度越接近,液滴追赶所用的时间越长,追赶位移越大;液滴初始速度越大、初始直径越大、喷射角度越大,横向速度消失越慢,达到的横向位移越大,喷射液滴覆盖的面积也越大。计算结果有助于优化工程实际中喷淋系统的设计与布置。     

A ctivation measurement of neutron distribution in intermediate energy heavy ion target area

The distribution of neutrons produced by the reaction of 50MeV/u ^12C-ion on a thick Cu target are studied.The neutrons are measured with threshold activation detectors.Al.F,C,Al and In activation samples were used to measure neutrons with energy greater than 7,11,20,50MeV and thermal neutrons,respectively,The fluence rate,energy and angular distributions of neutrons,total neutron yield of 12C-ion and the emission rate in the forward direction of neutrons over 11 and 20MeV were obtained.