摘要： In the paracortex of the lymph node (LN), T zone fibroblastic reticular cells (TRCs) orchestrate an immune response by guiding lymphocyte migration both physically, by creating three-dimensional (3D) cell networks, and chemically, by secreting the chemokines CCL19 and CCL21 that direct interactions between CCR7-expressing cells, including mature dendritic cells and naive T cells. TRCs also enwrap matrix-based conduits that transport fluid from the subcapsular sinus to high endothelial venules, and fluid flow through the draining LN rapidly increases upon tissue injury or inflammation. To determine whether fluid flow affects TRC organization or function within a 3D network, we regenerated the 3D LN T zone stromal network by culturing murine TRC clones within a macroporous polyurethane scaffold containing type I collagen and Matrigel and applying slow interstitial flow (1-23 mu m/min). We show that the 3D environment and slow interstitial How are important regulators of TRC morphology, organization, and CCL21 secretion. Without flow, CCL21 expression could not be detected. Furthermore, when flow through the LN was blocked in mice in vivo, CCL21 gene expression was down-regulated within 2 h. These results highlight the importance of lymph flow as a homeostatic regulator of constitutive TRC activity and introduce the concept that increased lymph flow may act as an early inflammatory cue to enhance CCL21 expression by TRCs, thereby ensuring efficient immune cell trafficking, lymph sampling, and immune response induction. The Journal of Immunology, 2009, 183: 4273-4283.

关键词： 超临界流体   萃取   化学反应   色谱   水氧化   环境保护  

摘要： 超临界流体技术是一种化工过程新技术,它利用超临界流体独特的物理化学性质,使常态流体中难以完成的化学化工过程得以实现。本文介绍了超临界流体的特性,超临界流体技术的历史发展、原理、优缺点,着重论述了超临界流体技术在环境保护中应用状况。

关键词： Sensors   Micro-fabrication   Total internal reflection   Diffraction gratings  

摘要： This work reports an enhancement of the diffraction efficiency of a grating upon total internal reflection, which is the main part in a recently developed integrated system for micro-fluidic analysis. Experimentally, a first order diffraction efficiency of 37% is obtained, by adjusting the thickness and/or the refractive index of a thin transparent layer, which seals and isolates the grid. The application of such an optimized grating to micro-fluidic sensing increases the accuracy of the whole system by a factor of two.

关键词： 地热流体   环境同位素   补给来源   年龄   水化学特征  

摘要： 天津境内在宝坻断裂以南的广大平原区,蕴藏着丰富的中低温地热资源。随着开采程度的加强,研究地热流体的补给和迳流条件显得日益重要。利用环境同位素技术确定了天津各热层储地热流体的补给来源和年龄。并结合地热流体的水化学特征,初步分析了各热储层之间的联系程度和迳流关系。

关键词： 环境物理学  

ISBN: (纸本)9787301154779

摘要： 本书系统地介绍了环境流体力学的基本知识。全书分为9章：主要内容包括：流体运动的基本概念和基本方程、旋转流体运动、分层流、不稳定性与湍流的发生等。

关键词： 微流体系统   微流量传感器   Lamb波  

摘要： 为提高微流体系统中的流量检测灵敏度,增大动态检测范围,实现温度补偿,提出了一种基于Lamb波的压差式微流量传感系统。该传感系统主要由两个Lamb波压力传感器和微通道组成,它利用Lamb波薄膜内应力的敏感特性,以频率计量的方式间接测量微通道两端的压力差;并采用双Lamb波压力传感器构成差动式测量结构进行温度补偿。对长20 mm,宽1 mm,高50μm的微通道进行了流量测试实验,结果表明:在流量测试范围内,微通道两端的频率差与流量基本呈线性变化,其线性相关系数为0.999 9;在微流量传感器未进行优化的前提下,最小检测量为0.627μL/s。

关键词： 地层流体   地层水   天然气   沉积环境   松辽盆地   地球化学特征   油气成藏  

摘要： 沉积盆地中流体-岩石-油气之间相互作用对油气成藏产生深远的影响，国际地学界已将油、气、成矿溶液和地下水作为地质流体的重要组成部分。由于地下水直接参与了沉积盆地中物质和能量的运动和变换，其水化学成分与同位素特征能够提供流体的成因、来源、流动及水-岩反应等信息。这一研究对于丰富同位素示踪、水-岩相互作用等基础理论具有重要的研究意义，同时也为深入研究储层性质、成岩作用、油气运移等提供了依据。\n 本文主要分析研究松辽盆地北部天然气与地层水的地球化学特征，通过分析天然气的组成和同位素分布特征，分析、判识天然气的来源、成因类型；通过分析地层水的无机离子成分、微量元素、同位素组成、有机质分布，并结合地层水化学特征参数揭示油田水系统的演化和水文地质条件的封闭性，分析可能的水-岩石反应；最后运用元素地球化学分析手段重建松辽盆地北部生油岩沉积环境，探讨湖盆古气候、古沉积环境变化和湖盆演化过程。获得的主要结论与认识包括以下几个方面：\n 1、松辽盆地北部天然气组分特征表明：天然气总体上以烃类为主，CO2、N2等非烃气体含量甚低。烃类气体以甲烷为主，重烃气体含量较低，主要特征为干气。CO2含量非常低，多是与烷烃气伴生的有机CO2气；与烷烃气伴生的N2大多数为有机成因。\n 2、松辽盆地北部天然气同位素特征表明：嫩江组、姚家组和青山口组天然气各组分的碳同位素值总体上是：δ13C1＜δ13C2＜δ13C3＜δ13C4，基本呈正序列，说明天然气均为有机成因的烷烃气；其它层位天然气碳同位素序列普遍具有异常排列现象，甚至有部分样品碳同位素序列为完全“倒转”。嫩江组、姚家组和青山口组的碳同位素组成相似，泉头组、登娄库组、营城组和侏罗系的碳同位素组成相似，上部与下部地层的碳同位素存在一定差异；松辽盆地北部上部地层天然气大多属于油型气，在下部地层存在部分煤成气；营城组天然气为无机成因烷烃气；松辽盆地北部上部地层(K2n、K2y、K2qn)天然气中的烃类物质绝大多数为有机成因，而不属于无机成因；而松辽盆地下部地层中，泉头组和登娄库组、侏罗系天然气以煤成气为主。其中，下部地层生成的油型气只能来自深部。\n 由氦、氩稀有气体同位素分析得出：大庆长垣和龙虎泊阶地的嫩江组和姚家组，以及三肇凹陷的登娄库组天然气中的氦来源于壳源物质；三肇凹陷的营城组天然气中的氦来源于幔源物质；朝阳沟阶地的姚家组和泉头组、泰康隆起带的青山口组以及长春岭背斜的泉头组的天然气中氦同位素组成变化较大，反映出天然气为非单一气源的特征。\n 3、通过对松辽盆地北部天然气气源研究得出：嫩江组的天然气为腐泥气(油型气)的成熟和高熟气，还有部分为浅层混合气、后期浅层混合气；姚家组和青山口组天然气以油型气为主；泉头组和登娄库组天然气以煤成气为主，混入了油型气、无机成因和有机裂解气；营城组天然气为无机成因烷烃气；侏罗系天然气以煤成气为主，混入少量无机成因气。\n 4、松辽盆地地层水大多数为NaHCO3型水，仅有少数的CaCl2、Na2SO4型水；阳离子组成均以K+Na+占优势(绝大多数＞80％)，Ca2+次之，Mg2+含量最小；而阴离子含量组成在不同地区不同层位的分布差异性较大；Na+和、Na++K+、Cl-和HCO3-浓度浓度随总矿化度增大而增大，而Ca2+、Mg2+、CO32-和SO42-浓度与总矿化度呈散点关系。\n 5、地层水同位素分析结果表明，位于盆地西部地区地层水明显受到古大气降水的影响，HCO3-的来源可能是碳酸盐的溶解，中央凹陷地区δ18O正偏移可能是由水岩作用加强引起的，而HCO3-的来源明显受到有机物的影响。较轻的δD值反映出原始沉积属陆相沉积水。\n 地下水中Sr的浓度随TDS的增加而增加，表明地下水中Sr来源于地下水对岩石的溶解作用。地层水的形成，应主要以地表水(大气降水)为主，通过深大断裂循环，淋滤溶解地表以及地下各种岩石、矿物，发生水-岩相互作用，形成高87Sr/86Sr值流体与深部来源的低87Sr/86Sr值地质流体(火山-地热水)混合而成。\n 6、盆地不同层位地层水中有机酸含量有较大差异，地层水中有机酸含量的高值分布层位也是该区域油气分布层位；地层水中有机酸分布的格局与该区油气藏的分布有一定的关系；地层水中酚含量高值区主要分布在含油气层位，酚含量垂向分布特征与有机酸的垂向分布特征相似，深部地层水中酚含量很高，反映了煤系地层水的特点。\n 7、地层水化学特征参数分析表明：研究区上部地层水钠氯系数在1左右，脱硫系数达到10以上，明显受到地表水的渗入淡化影响。下部地层CaCl2型地层水分布区属于交替停滞带，地下水处于还原环境，发生浓缩和强烈的脱硫作用，变质程度较高，发生了强烈的水-岩相互作用，对油气藏保存是一种有利条件。盆地地层

关键词： multiphase flows   microfluidics   polymer chips   gas-liquid two-phase flow   liquid-liquid segmented flow  

摘要： Continuous delivery of segmented reagents using pressure-driven multiphase flow in microchannels is a promising technology for high throughput microfluidic bioassays. Separation and encapsulation of the target reagents with another inert fluid provide many advantages over single phase flow in microfluidic applications of biotechnology. In order to achieve these advantages and control these multiphase flows, it is necessary to understand their generation and transport characteristics as influenced by geometrical miniaturization, channel wall properties, the effects of surfactants and operating conditions. For gas-liquid two-phase flow, dry air and deionized water were driven into hot embossed PMMA microchannels with 200 μm square test microchannels. Flow regimes, flow maps and the lengths of the gas bubbles and liquid plugs in terms of the liquid volumetric flow ratio (βL) were determined. Continuous generation of regular segmented flow was also discussed. Three sub-regimes of the Segmented flow were identified based on the statistical phase length scales observed over a substantial test channel length. For the liquid-liquid segmented flow, deionized water and perfluorocarbon with a surfactant were used as test fluids in the hot embossed polycarbonate microchannels. The effects of three expansion ratios from the injection to the test channels of 2, 4, and 16 were investigated comparing the flow regimes, transitions and maps in terms of a fixed carrier fluid volumetric flow ratio. The length of the dispersed fluids and the distance between consecutive droplets or plugs in terms of the carrier fluid volumetric flow ratio (βC) were determined. Velocities of the dispersed droplets and plugs were measured using double-pulsed laser illumination and were found to be 1.46 ± 0.08 and 1.25 ± 0.05 times faster than the superficial velocity of the segmented flow, respectively. The multiphase flow pressure drops were measured for all of the flow regimes in gas-liquid two-phase an

关键词： .Tweezers   yeast cells   Ashkin   Optical Trapping   polystyrene spheres   uidic chip   Integration of plasmonic   plasmonic structures   lab–on chip  

摘要： Near field generated by plasmonic structures has recently been proposed to trap small objects. We report the first integration of plasmonic trapping with microfluidics for lab-on-a-chip applications. A three-layer plasmo-microfluidic chip is used to demonstrate the trapping of polystyrene spheres and yeast cells. This technique enables cell immobilization without the complex optics required for conventional optical tweezers. The benefits of such devices are optical simplicity, low power consumption and compactness;they have great potential for implementing novel functionalities for advanced manipulations and analytics in lab-on-a-chip applications. (C) 2009 Optical Society of America

关键词： 微流体系统   资助   国土安全   科技委员会   小批量生产   自动系统   探测器   网络式  

摘要： 微流体系统公司（MFSI）宣布已获得了微流体一生物侦探自动网络式探测器（M-BAND）制作的3X阶段合同。这项合同是DHS科学和科技委员会自2003年起资助的阶段系列之四。资助将持续到2009年3月，实现自动系统的小批量生产以用于美国关键地区扩展领域的实验。MFSI是接受这项资助的主要承包商，