质量分离低能离子束外延超薄硅单晶的初步研究

采用质量分离的低能离子束外延(MALE-IBE)技术进行超薄硅外延生长,在600C下获得单晶硅外延层,厚度2000A,过渡区宽度小于500A。有较好的电学性质。

质量分离的双离子束沉积法生长CeO_2(111)/Si薄膜

利用一种全新的薄膜生长技术—质量分离的双离子束沉积技术 ,在较低温度 ( 40 0℃ )下对CeO2 ( 111) /Si( 10 0 )薄膜的生长进行了研究。两束离子的比例以及离子束的能量对薄膜的成分和晶体质量有很大影响 ,较高能量 ( 3 0 0eV)的离子束对薄膜有轰击作用 ,并有助于薄膜的择优取向生长。在 4 0 0℃时 ,制备了CeO2 ( 111) /Si( 10 0 )单晶薄膜。

CO_2团束的离化、加速及质量分离

设计并制造了ＣＯ２离化装置——由电子轰击对团束进行离化，由电极电位进行加速，由阻止势进行质量分离。通过实验确定了最佳参数，其中包括：离化电子电流和电压、加速电压、阻止电势、供气压力等。

论绩效管理中的质量不分离准则

世界是能量的,一部分能量转化为广义物质,剩下部分表现为力量与热量即力热形式。广义物质分为实物质即常规物质概念和方向、时空即虚物质范畴。力热、实物质、方向、时间、空间五个组成物体的构素,简称五构素。物体五构素中,力热、时空、实物质之量的概念突出,而方向之质的概念突出,可见质与量统一于物体,即质量具不可分离性质。

基于GASA混合算法的计算机辅助分子设计方法及其在质量分离剂选择上的应用

采用了改进的遗传模拟退火混合优化算法(GASA),避免了单种算法的缺陷,很好的解决了CAMD中的组合爆炸问题;通过采取新的基团分类方法,可以比较容易地判断分子的完整性和稳定性,从而解决了分子编码问题,且可实现直链烷烃和芳香烃的同时搜索;采用实际物系对本文提出的方法进行了检验,结果表明本文筛选出来的溶剂适应度在普遍高于文献中溶剂,表明本文提出的方法具有很好的准确性和实用性,并通过实用软件PROII进行了验证。

变质量物体的运动微分方程的研究

工科大学物理中,在介绍牛顿运动定律时,主要涉及的是定质量物体的运动情况,对于变质量物体的运动涉及的很少,本文先从动量定理出发推导出变质量物体的动力学方程的三个表达式,然后对这三个表达式分别进行了详细的讨论,最后通过具体实例能够使我们进一步加深对其的理解。

支管方向对T形管气液分离效果影响的数值模拟分析

应用计算流体动力学方法对T形管气、液分离器进行了数值模拟,采用标准k-ε模型为湍流计算模型,针对不同支管放置方向对T形管气、液分离效果的影响进行了模拟分析。分析表明,支管水平放置和竖直向上放置时支管均以气相采出占优;支管竖直向下放置时,分流率为临界值时气液两相均匀分流;支管竖直向上放置时,质量分离效率最高。

提高离心力卸料离心机离质量的一项简单有效措施

提高离心力卸料离心机离质量的一项简单有效措施郑州工学院王玉卿离心力卸料离心机不需要专门的卸料装置，利用物料受的离心力实现自动连续卸料，因此它具有结构简单、效率高、产量大、能耗低、制造容易、操作和维修费用低等特点。由于该机分离质量不稳定，它的应用范围受...

真空下激光烧蚀碳化钨铜多组分等离子体发射光谱的时空演化研究

激光诱导击穿光谱技术目前已用于国内大科学装置EAST托卡马克壁诊断。在真空环境下,如何提升LIBS定量分析准确性是其进一步发展的瓶颈问题之一。在真空中,激光诱导等离子体具有高度时空非均匀性,对等离子体时空演化行为的研究,理解各个物种的演化规律,是进一步改进LIBS定量分析准确性的重要内容。针对托卡马克第一壁和偏滤器的材料相关的不同元素,该工作在真空环境下利用波长为1 064 nm、脉宽5 ns、功率密度6.3 GW·cm-2的脉冲激光对三元合金-碳化钨铜((WC)70Cu30)进行烧蚀产生多组分等离子体,使用线性阵列光纤实现了对发射光谱的时空分辨测量。以三种元素CⅠ833.51 nm, CⅡ657.81 nm, CuⅠ515.32 nm, CuⅡ512.45 nm, WⅠ429.46 nm, WⅡ434.81 nm六条谱线为研究对象,研究了激光烧蚀等离子体不同辐射机制的时间尺度以及多组分等离子体在扩张过程中发生的元素“空间分离”现象和“离子加速”现象。根据连续背景和六条谱线的时间演化规律,观察到连续辐射主要发生在等离子体膨胀早期80 ns内,离子谱线在30~300 ns,原子谱线在100~1 000 ns。空间分辨实验研究发现,C、 Cu、 W元素对应原子及离子的空间分布均有所不同,即真空中激光烧蚀多组分等离子体在扩张过程中发生了元素“空间分离”现象。将六条谱线的峰值位置和时间进行线性拟合,获得了对应物种的扩张速度,其速度范围在4.2~34.9 km·s^(-1)。结果表明,相对原子质量越小,对应粒子的速度越快(CⅠ>CuⅠ>WⅠ, CⅡ>CuⅡ>WⅡ);对应元素的离子速度大于其原子速度(CⅡ>CⅠ,CuⅡ>CuⅠ,WⅡ>WⅠ)。利用元素“质量分离效应”和“瞬态鞘层加速”的物理机制,对激光等离子体元素“空间分离”以及“离子加速”现象进行了讨论和解释。该研究结果为LIBS理论模型建立提供了重要的实验数据参考,也为提高真空LIBS定量分析准确性提供了新思路。

Effects of Different Heavy Crude Oil Fractions on the Stability of Oil-in-water Emulsions —— Isolation of functional fractions from heavy crude oil and study of their properties

The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional fractions (saturates, aromatics, resins and asphaltenes) are also isolated from the heavy crude oil. These components have been characterized by spectroscopic methods (FT-IR), namely acid number, basic nitrogen number, ultimate analysis and molecular weight measurements using vapor pressure osmometry (VPO). The ion-exchange chromatography method based on separation by a functional group induces a little change on the nature of the crudes and reasonable mass balances can be easily obtained.

质量分离低能离子束沉积碳膜及离子轰击效应

用质量分离的低能离子束沉积技术得到了非晶碳薄膜 ,X射线衍射、Raman谱以及俄歇深度谱的线形表明 ,此种非晶碳膜中镶嵌着金刚石颗粒 .碳离子的浅注入是该碳膜SP3 形成的主要机理 .

白车身在线检测数据分析方法研究

介绍了工序质量的概念,把在线检测得到的综合质量数据分离成单工序质量,为进一步的装配故障诊断提供了实用数据。

Separation and Identification of Differentially Expressed Proteins in Pistillate Flowers between Different Mulberry Cultivars

[Objective] This study aimed to explore the proteins related to pistillate flower development in different mulberry cultivars. [Method] The total proteins of the pistillate flowers of two mulberry cultivars Dal0 （Morus atropurpurea Roxb.） and SG01 （Morus muIticaulis Perr.） were extracted, separated and detected through two- dimensional electrophoresis （2-DE） and mass spectrometry. [Result] There was sig- nificant difference in the expression of proteins from the pistillate flowers of different mulberry cultivars. From the 2-DE images of Dal0 and SG01, 445_＋17 and 425_＋12 protein spots were respectively detected. The expression levels of 75 protein spots differed significantly. Thirteen spots those were expressed at high levels and well separated were analyzed by mass spectrometry, and nine of them were identified successfully. The nine proteins are involved in the glycometabolism, protein and amino acid metabolism and defense responses during the development of mulberry pistillate flower after they were pollinated. [Conclusion] The findings will provide reference for further study on the molecular mechanism of mulberry pistillate flower de- velopment.

Extraction and Isolation of Type Ⅰ,Ⅲ and Ⅴ Collagens and Their SDS-PAGE Analyses

Type Ⅰ Ⅲ and Ⅴ collagens were extracted from bovine dermis and cornea by using pepsin treatment in acetic acid solution, followed by salt precipitation and dialysis, to purify and isolate each type of collagens. The preparation process was analyzed by using sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE）. A reducing agent, 2-mercaptoethanol, was used to remove disulfide bonds and analyze the structure of the bonds involved between α chains in some types of collagens. The use of delayed reducing methods resulted in the difference between α1 （Ⅲ） and α1 （ Ⅰ ） chains in a mixture containing type Ⅰ and Ⅲ collagens. The structure of disulfide bonds among α chains exists potentially in type V collagen prepared from the pepsin-treatment extraction at 4 ℃, which differs from type Ⅲ collagen in relation to the locations of disulfide bonds. Compared with pepsin-treated collagen at 4 ℃, the relative molecular weights of α1 （V） and α2 （V） chains treated at room temperature decrease by 4.6% and 6.0%, respectively. It is concluded that type Ⅰ Ⅲ and Ⅴ collagens can be prepared from bovine dermis and cornea by the use of pepsin treatment, salt precipitation and dialysis. The interchain disulfide bonds lie potentially near the edges of termini of type V collagen molecules in extracellular matrix, and a small number of interchain crosslinks exist in type V collagen.

A New Model for the Simulation of Distillation Column

A new computational mass transfer model is proposed for simulating the distillation process by solving the fluctuating mass flux u^＇ic^＇ for the closure of turbulent mass transfer equation in order to obtain the concentration profile and the separation efficiency of distillation column. The feather of the proposed model is to abandon the conventional way of introducing the turbulent mass transfer diffusivity （dispersion coefficient） to the turbulent mass transfer equation. To verify the validity of the proposed model, a commercial scale packed column and a sieve tray column were simulated and compared with published experimental data. The simulated results were satisfactorily confirmed in both concentration distribution and senaration efficiency.

Mathematical Model of Gas Permeation Through PTFE Porous Membrane and the Effect of Membrane Pore Structure

Membrane-based separation processes are new technology combined membrane separation with conventional separation. Hydrophobic porous membranes are often used in these processes. The structure of hydrophobic porous membrane has significant effect on mass transfer process. The permeabilities of five kinds of gas, He, N2, O2, CO2 and water vapor, across six polytetrafluoroethylene(PTFE) flat membranes were tested experimentally. Results indicated that the greater the membrane mean pore size and the wider the pore size distribution are, the higher the gas permeability. A gas permeation model, including the effects of membrane structure parameter and gas properties, was established. A comprehensive characteristic parameter (including porosity, thickness and tortuosity) was found more effective to express the influence of membrane structure in gas permeation process. The predicted permeation coefficients were in good agreement with experimental data.

Characterization of a newly Isolated Bacterium Pandoraea sp.B-6 capable of degrading kraft Lignin

A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegradation experiment was carried out in mineral salt medium, containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30℃. Under these conditions, significant reduction in color and lignin content by the strain was observed after incubation for 5 d. The strain attains maximum reduction capability in color （44.6%） and lignin content （39.9%） within 5 d of incubation, and reduced chemical oxygen demand（COD） from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day. The total ion chromatograph （TIC） of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments, indicating a strong destruction in the lignin structure.

A Pilot-scale Demonstration of Reverse Osmosis Unit for Treatment of Coal-bed Methane Co-produced Water and Its Modeling

This study presents the first demonstration project in China for treatment of coal-bed methane(CBM) co-produced water and recycling.The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water.The reverse osmosis(RO) unit is applied to the treatment of CBM co-produced water.The results indicate that system operation is stable,the removal efficiency of the total dissolved solids(TDS) is as high as 97.98%,and Fe,Mn,and F-are almost completely removed.There is no suspended solids(SS) detected in the treated water.Furthermore,a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities-membrane length,flow velocity,salt concentration,driving pressure and water recovery rate,and the water recovery restriction equation based on mass balance is developed.This model provides a theoretical support for the RO system design and optimization.The TDS in the CBM co-produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water,irrigation water,and livestock watering.In addition,the cost for treatment of CBM co-produced water is assessed,and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

A Reynolds mass flux model for gas separation process simulation:Ⅰ. Modeling and validation

Separation process undertaken in packed columns often displays anisotropic turbulent mass diffusion. The anisotropic turbulent mass diffusion can be characterized rigorously by using the Reynolds mass flux(RMF) model.With the RMF model, the concentration and temperature as well as the velocity distributions can be simulated numerically. The modeled Reynolds mass flux equation is adopted to close the turbulent mass transfer equation,while the modeled Reynolds heat flux and Reynolds stress equations are used to close the turbulent heat and momentum transfer equations, so that the Boussinesq postulate and the isotropic assumption are abandoned. To validate the presented RMF model, simulation is carried out for CO2 absorption into aqueous Na OH solutions in a packed column(0.1 m id, packed with 12.7 mm Berl saddles up to a height of 6.55 m). The simulated results are compared with the experimental data and satisfactory agreement is found both in concentration and temperature distributions. The sequel Part II extends the model application to the simulation of an unsteady state adsorption process in a packed column.