酶膜反应—萃取技术及其应用

就酶膜反应－萃取技术的现状进行了综述，并对酶膜反应－－萃取技术的应用用领域做了扼要介绍。     

火试金法中银作用的探讨

本文探讨了银在火试金法的作用。按照火试金法,通过改变银与金的配比进行实验。通过实验数据可以得出银在火试金检测法的两个作用,一个是萃取剂的作用,将金从杂质中萃取出来;另一个是保护金的作用,减少检测过程中金的损耗。     

火试金法中银作用的探讨

本文探讨了银在火试金法的作用。按照火试金法,通过改变银与金的配比进行实验。通过实验数据可以得出银在火试金检测法的两个作用,一个是萃取剂的作用,将金从杂质中萃取出来;另一个是保护金的作用,减少检测过程中金的损耗。     

D_2EHPA与C_(5-7)羟肟酸自硫酸介质中协同萃取Ga~(3 )的液膜理论基础研究(Ⅰ)

研究了从硫酸介质中用二－（－２－乙基己基）－膦酸（Ｄ２ＥＨＰＡ）与Ｃ５－７羟肟酸协同萃取Ｇａ３＋及其机理,经斜率法和饱和容量法确定了其萃取Ｇａ３＋萃合物的组成,并计算了其表观平衡常数     

尼龙1010/HDPE-g-MAH共混体系界面形态及结晶行为的研究

通过Ｍｏｌａｕ实验、密度测定、二甲苯萃取物的ＩＲ分析以及ＤＳＣ、ＳＥＭ等手段，对尼龙１０１０／ＨＤＰＥ－ｇ－ＭＡＨ共混体系的界面形态和结晶行为进行了研究。结果表明，共混体系为热力学不相容体系；在熔融共混过程中，尼龙１０１０和ＨＤＰＥ－ｇ－ＭＡＨ发生化学反应，生成的接枝共聚物起到了共混体系相容剂的作用，分散和界面形态明显改善；共混体系中两相的结晶行为也受到影响，尼龙组分的熔融热焓明显下降。     

(甲基)丙烯酸-3-磺酸丙酯钠(钾)盐及自聚物的应用

本文研究了（甲基）丙烯酸－３－磺酸丙酯钠（钾）盐及其自聚物在无乳聚合反应中的乳化和胶体保护作用。实验表明,这类化合物在无乳聚合反应体系中无论以单体 是以自聚物形式使用,都具有较好的乳化分散作用和胶体保护作用。     

聚丙烯酸与聚乙二醇在浓溶液中的复合作用

研究了聚丙烯酸（ＰＡＡ）与聚乙二醇（ＰＥＧ）在浓溶液中的复合作用及影响因素，发现ＰＡＡ－ＰＥＧ在很宽的ＰＨ范围内都存在着复合作用。低ＰＨ时，通过氢键作用的形式进行复合，高ＰＨ时，则通过离子－偶极作用。对ＰＡＡ－ＰＥＧ－盐以及ＰＡＡ－盐复合膜进行了ＤＳＣ和Ｘ射线衍射分析，结果表明，ＰＡＡ与ＰＥＧ进行复合，可以破坏ＰＥＧ的结晶性能。     

D2EHPA与C5—7羟肟酸自硫酸介质中协同萃取Ga^3＋的液膜理论基础 …

研究了从硫酸介质中用二－（－２乙－乙基己基）－膦酸（Ｄ２ＥＨＰＡ）与Ｃ５－７羟肟酸协同萃取Ｇａ＾３＋及其机理,经斜率法和饱和容量法确定了其萃取Ｇａ＾３＋萃合物的组成,并计算了其表观平衡常数。     

一种提取辣椒素新方法的研究

本文提出一种提取辣椒素的新方法,对利用纤维素酶提取干红辣椒中辣椒素进行了酶解最佳条件的探讨。结果表明,在优化的酶解条件下(酶解温度为40℃,酶解液初始pH=5,酶解时间为3h,酶量为5mg/g辣椒),该提取方法较传统溶剂提取产量提高30%,具有萃取速度快、萃取效率高的优点,取得较好的效果。     

2-2压电复合材料面板的压力放大作用

２－２压电复合材料应用普遍。材料中聚合物对压电陶瓷的应力作用，使性能得到施工改善。在复合材料两电极面上复盖薄面板，由于板的应力传递作用会使使接收国和辐射力产生放大效应，从而提高了接收灵敏度和发射响应。     

Effect of ultrasound irradiation on some freezing parameters of ultrasound-assisted immersion freezing of strawberries

In this study, the effect of ultrasound irradiation temperature and ultrasound intensity on the freezing and nucleation in strawberry samples was studied. The application of ultrasound irradiation at different temperatures was able to induce nucleation at lower degree of supercooling compared to the control samples. The achieved degree of supercooling in the ultrasound irradiated strawberries was linearly correlated to the ultrasound irradiation temperature. At the ultrasound irradiation temperature of −1.6 °C, the characteristic freezing time (CFT) was significantly shorter than that in the control sample (p < 0.05). The application of ultrasound at higher intensities was found to effectively shorten the CFT. The degree of supercooling in ultrasound irradiated samples was not linearly correlated to ultrasound intensity. In conclusion, the combination of ultrasound irradiation temperature and intensity can be effective in controlling nucleation and freezing processes of perishable fruits such as strawberry.     

超声辐照对HepG2细胞存活率影响的实验研究

为探讨超声辐照对体外培养的HepG<,2>细胞存活力的影响,采用正交设计方法,选定声强、占空比和辐照时间3因素,每因素5水平的参数条件设计正交表,对贴壁培养的HepG<,2>细胞进行超声辐照,之后继续培养24h后行MTT(噻唑蓝)实验检测细胞存活率,期间光学显微镜观察培养板内的细胞生长状况及形态.结果表明:当超声声强大...     

B超图像的计算机实时成像研究

早在50年代前期，超声就被研究并作为医学上的一种诊断工具。随着超声诊断技术的发展，超声医学诊断成为一门专门的医学诊断技术，并形成一个独立的分支。B超图像是由医学B型超声扫描仪(Ultrasound—B-mode Scanner)采用脉冲回波法对被测物体进行扫描，通过对所得的回波数据重建而形成的一类医学图像，它的主要成像原理是运用超声在人体组织中传播特性(速度、反射率、吸收率等)的不同，将其转化为一定的可显信号，在显示器上反映出来。文章对该类图像在计算机上重建的算法进行了研究，对各种算法分析、比较，最后提出比较合理的适应于计算机上实时重建B超图像的算法。     

用锥面靶测量大口径聚焦换能器声功率的计算讨论

辐射压力法是超声功率测量中常采用的方法，用辐射压力法测量声动功率中对于不同反射靶面的功率与压力之间的换算关系是非常重要的。文章从能量守恒基础出发，推导了大口径聚焦换能器声场作用于锥面反射靶的功率与压力的换算关系，并将结果应用于凹锥面反射靶计算。     

An Experimental Data Acquisition System for Ultrasound Imaging

An experimental digital data acquisition system for computerized ultrasound imaging studies is developed. The system requirements for the digital reconstruction of tomographic images from the envelope of ultrasound signals of several megahertz are described. To effectively digitize ultrasound signals, a new digital averager is implemented. Several consecutive ultrasound signals are averaged on a real-time base to enhance the signal-to-noise ratio, to reduce the volume of the data, and to achieve a match of data flow rates between the ultrasound signals and the usual computer input devices. The positions of the ultrasound transducers and the target are controlled by a microprocessor controller. These positions are sensed and also digitized by the averager. The averager transfers the digitized data, both the ultrasound signals and position signals, to a general-purpose computer for further data processing. Experimental data on reconstructing the cross section of a simple target from the ultrasound signals acquired by this system will be presented as an illustration.     

基于经验模态分解的聚焦超声非线性声场检测

为精确检测聚焦超声声场中的谐波成分并得到谐波分布规律,开展了对聚焦超声非线性声场检测的研究,提出基于经验模态分解的聚焦超声谐波检测方法。首先对声场信号进行经验模态分解;然后利用噪声判断准则判断出固有模态函数（IMF）中的噪声分量,滤除噪声分量后将剩余的IMF分量予以重新组合;最后对新信号进行傅里叶变换,得到各次谐波的幅值。结果表明:它能较好地抑制噪声,相比于传统的检测方法可获得更平滑的谐波分布;该方法对开展谐波成像、医学超声检测具有重要意义。     

超声弹性成像与常规超声诊断100例乳腺良恶性的应用价值

目的:探究超声弹性成像及常规超声在诊断乳腺肿瘤定性中的效果及应用价值,为后期临床诊断提供参考。方法:选取我院2012年4月-2014年4月期间收治的102例乳腺肿瘤患者的临床资料进行回顾性分析。患者行常规超声及超声弹性成像,并经病理学检验确诊。结果:检验结果显示,超声弹性成像诊断阳性肿瘤79例,阴性21例,误诊5例;常规超声成像诊断阳性75例,阴性25例,误诊13例。两种检验方式在准确率与误诊率比较,差异具有统计学意义(P0.05)。结论:乳腺肿瘤采用超声弹性成像诊断的效果显著,尤其在常规超声诊断的基础上使用,效果更佳。     

A system for simultaneously measuring contact force, ultrasound, and position information for use in force-based correction of freehand scanning

During freehand ultrasound imaging, the sonographer places the ultrasound probe on the patient's skin. This paper describes a system that simultaneously records the position of the probe, the contact force between the probe and skin, and the ultrasound image. The system consists of an ultrasound machine, a probe, a force sensor, an optical localizer, and a host computer. Two new calibration methods are demonstrated: a temporal calibration to determine the time delay between force and position measurements, and a gravitational calibration to remove the effect of gravity on the recorded force. Measurements made with the system showed good agreement with those obtained from a standard materials testing machine. The system's uses include three-dimensional (3-D) ultrasound imaging, force-based deformation correction of ultrasound images, and indentation testing.     

A single FPGA-based portable ultrasound imaging system for point-of-care applications

We present a cost-effective portable ultrasound system based on a single field-programmable gate array (FPGA) for point-of-care applications. In the portable ultrasound system developed, all the ultrasound signal and image processing modules, including an effective 32-channel receive beamformer with pseudo-dynamic focusing, are embedded in an FPGA chip. For overall system control, a mobile processor running Linux at 667 MHz is used. The scan-converted ultrasound image data from the FPGA are directly transferred to the system controller via external direct memory access without a video processing unit. The potable ultrasound system developed can provide real-time B-mode imaging with a maximum frame rate of 30, and it has a battery life of approximately 1.5 h. These results indicate that the single FPGA-based portable ultrasound system developed is able to meet the processing requirements in medical ultrasound imaging while providing improved flexibility for adapting to emerging POC applications.     

Ultrasound velocity and absorption in BeO,Al<Subscript>2</Subscript>O<Subscript>3</Subscript>, ZrO<Subscript>2</Subscript>, and SiO<Subscript>2</Subscript> ceramics

We have measured the ultrasound velocity and absorption in BeO, Al₂O₃, ZrO₂, and SiO₂ ceramics. The results indicate that the ultrasound velocity in oxide ceramics depends on the nature of the basic oxide component, the density of the material, and the preferential alignment of the grains. The ultrasound velocity in ceramics is shown to correlate with their thermal conductivity: with increasing thermal conductivity, the ultrasound velocity increases. The ultrasound absorption in oxide ceramics decreases with decreasing temperature, and vice versa, with increasing temperature, the ultrasound attenuation coefficient increases.