主动式冷梁性能对房间气流组织影响模拟研究

以某主动式冷梁送风房间为模型，利用计算流体力学（CFD）软件模拟了主动式冷梁性能对房间气流组织的影响，并将模拟值和实测值进行了对比，验证了模型的准确性。利用该模型研究了主动式冷梁出风速度、出风温度、出风角度、出风高度以及回风口位置对房间气流组织的影响。结果表明：若仅改变出风速度，当出风速度从1 m·s⁻¹增大到4 m·s⁻¹时，预期平均通感P_M下降，不适人员比例P_D先降后升，出风速度为2 m·s⁻¹时，P_D最小，为9%，此时人员对环境的满意度最高；若仅改变出风角度，当出风角度为45°时房间气流组织分布最佳；若仅改变出风高度，当出风高度为2.33 m时房间气流组织分布最佳。在出风温度为20 °C、出风速度为4 m·s⁻¹时，比较不同回风口位置（上部、中部、底部）时距离地面高度Y=1.2 m截面的气流组织变化，发现回风口位于底部时该截面温度最高，空气速度最小，空气龄最大，P_D最小，为28%，此时人体冷热感觉较舒适。     

铁钴修饰镍基复合载氧体化学链重整制氢研究

采用浸渍法制备Fe₂O₃−NiO−CeO₂/γ−Al₂O₃和CoO−NiO−CeO₂/γ−Al₂O₃复合载氧体，研究了不同复合载氧体对化学链重整制氢反应性能的影响。固定床活性测试实验表明，在镍铈载氧体中加入质量分数为5%的Fe₂O₃复合载氧体（5%Fe−Ni−Ce）的H₂选择性和H₂体积分数最大；在镍铈载氧体中加入CoO后，其复合载氧体的反应性能下降。循环实验表明，5%Fe−Ni−Ce复合载氧体在经过20次循环后仍保持高活性。X射线衍射（XRD）结果表明，5%Fe−Ni−Ce复合载氧体中有固溶体形成，进一步的XRD分析发现5%Fe−Ni−Ce晶粒粒径较小。扫描电子显微镜分析发现，反应前5%Fe−Ni−Ce复合载氧体的颗粒分散度最优，在经过20次循环后复合载氧体仍能保持较好的形貌。进一步的固定床实验研究表明，5%Fe−Ni−Ce复合载氧体在低温下性能良好。     

CNs−Bi12O17Cl2复合体系制备及光催化降解性能研究

采用简易水解法制备了一系列CNs−Bi₁₂O₁₇Cl₂复合半导体材料并对其物相、光学性质和光催化降解性能进行了分析表征。X射线衍射光谱表明复合体系衍射峰与四方晶相Bi₁₂O₁₇Cl₂一致,紫外可见漫反射光谱证明复合材料在可见区域具有较强的光吸收能力,由此可提高光催化活性。在可见光照射下,复合体系相对于纯Bi₁₂O₁₇Cl₂对亚甲基蓝具有更高的降解效率,特别是具有合适组分的样品CB50可以在180 min后完全去除20 mg·L⁻¹的亚甲基蓝分子,这主要是由于CNs的引入抑制了光生载流子的复合,使复合体系表现出更高的光催化降解性能。最后,提出了可能的光催化机理。     

金属纤维悬浮液中天然气水合物生成特性实验研究

水合物缓慢的生成速率已经成为水合物储运天然气技术应用的一大障碍。基于静态强化水合物生成技术,以含悬浮金属纤维的表面活性剂溶液作为水合储气介质,研究4.0～7.0 MPa下天然气水合物在悬浮溶液中的生成动力学特性。研究结果表明,金属纤维优良的导热性能够促进水合物快速生成,同时纤维的粗糙表面可促进水合物成核,水合物在金属纤维悬浮体系中的储气量与储气速率均明显高于表面活性剂溶液中的水合特性。在实验压力下,悬浮体系中水合物成核诱导时间明显降低,同时储气量可以达到87.3～129.6 m³·m^-3,比表面活性剂溶液中的增加了5.0%～23.4%;储气速率达到4.4～25.1 m³·（m³·min）^-1,比表面活性剂溶液中的提高了1.1%～39.8%。研究结果可为水合物储气技术在天然气储运方面的应用提供技术参考。     

垃圾焚烧电厂热电联产的经济性分析

合理利用垃圾资源进行热电联产,是节能减排、改善环境的有力措施。以某2×750 t·d^-1垃圾焚烧电厂为例,通过模型研究发现热电联产可以减少垃圾焚烧电厂的冷源损失,提高全厂热效率;利用一抽蒸汽进行热电联产可实现蒸汽品质的梯级利用,获得较高的经济效益;供热量为30 t·h^-1,垃圾热值由4185.9 kJ·kg^-1增加至8371.7 kJ·kg^-1时,发电量越多,供热能力越强,年热电联产经济效益由7822.76万元增加到14641.07万元;垃圾热值为8371.7 kJ·kg^-1,供热量从10 t·h^-1增加到60 t·h^-1时,垃圾焚烧电厂热效率从28.96%增加到48.50%,年经济效益从13602.74万元增加到15455.66万元。当该地区垃圾热值较高并具备供热条件时,实现垃圾热电联产具有较高的收益。     

农村生活与生产综合污水生物处理的A/O工艺启动策略与特性研究

为实现新时期各类典型性农村综合污水的治理,选择了一种农村生活与生产综合污水作为研究对象,研究了利用兼氧/好氧（A/O）工艺处理农村生活和生产综合污水的启动过程。结果表明：采用逐步递增生产废水和污泥接种培养的启动策略能够实现处理工艺的快速启动;pH、化学需氧量（COD）、氨氮（NH₄⁺−N）、总磷（TP）以及色度在启动过程中各阶段的变化情况的分析结果表明,A/O工艺能够通过兼氧池和好氧池的协同配合达到理想的污水处理效果。     

新能源制氢及氢能应用浅述

氢能作为一种清洁、可储存的能源,是世界新能源和可再生能源领域正在积极开发的二次能源。氢能具有巨大的发展潜力,因此氢能在全球范围内获得了极大的关注和发展。简述了氢能环境分级和常规的氢能制取方法,介绍了新能源制取“绿色氢气”的基本原理和系统组成。以容量为5 000 Nm³·h^-1和20 000 Nm³·h^-1的制氢系统为例,分析了制氢系统的占地面积、投资构成和影响新能源制氢成本的因素,结果表明电价和制氢系统年运行小时数是影响新能源制氢成本的两个关键因素。最后讨论了氢能作为原料和动力燃料的应用途径。     

g-C3N4/TiO2可见光催化降解磺胺甲恶唑的研究

以TiO₂颗粒和三聚氰胺为原料,采用高温煅烧法制备g-C₃N₄/TiO₂复合光催化材料,研究其对仿生生态系统中磺胺类抗生素的去除效果。利用扫描电子显微镜（SEM）、X射线衍射仪(XRD)、傅里叶变换红外光谱仪（FTIR）、紫外可见分光光度计（UV-vis DRS）对g-C₃N₄/TiO₂进行表征,并研究在可见光条件下g-C₃N₄/TiO₂对溶液中磺胺甲恶唑（SMX）的光催化降解效果。结果表明,g-C₃N₄/TiO₂具有良好的光催化活性,在可见光照射下,当g-C₃N₄/TiO₂投加量为0.2 g·L^-1时,对初始质量浓度为200 μg·L^-1的SMX的去除率可达84.3%。在相同条件下,而g-C₃N₄和TiO₂只能分别去除21.0%和16.0%的SMX,同时在仿生系统中12.37 g·m^-2 g-C₃N₄/TiO₂可以去除95.35%的SMX。通过质谱分析推测,SMX可能的降解路径分别为S—N键断裂、C—N键断裂、S—C键断裂、SMX的羟基化和SMX上氨基的硝化反应,两种可能的中间产物分别为对氨基苯磺酰胺和3-氨基-5-甲基异恶唑。     

湿式冷却塔进风口加装导风板的优化设计

基于两相流传热传质理论,利用Fluent软件模拟300 MW机组冷却塔填料区使用多孔介质时的通风率,采用离散相模型（DPM）在配水区上表面加入热水,模拟研究新型旋流型叶片导风板的优化能力,给定不同弧度及安装角,分别在0、3和7 m·s^-1风速下计算冷却塔出塔水温,并分析侧风对冷却塔冷却性能的影响。研究结果表明：加装导风板可以降低侧风引起的不利影响,导风板数量为50块时效果最好,旋流型叶片导风板的最佳安装角为20°,此时旋流型叶片的最佳弧度为15°,最大温降可达0.787 4 K。研究结果为火电厂选择导风板提供了依据。     

基于能耗监管平台的现有医院空调系统运行节能优化

基于上海某医院能耗监管平台数据,利用EnergyPlus软件建立了该医院门诊楼建筑模型和空调系统模型,并验证了该模型的准确性。对该医院集中式空调系统运行策略进行优化分析,结果表明：当室内负荷低于冷水机组总额定制冷量80%时,负荷分配优化运行方案节能率最高,达到9.7%;当室内负荷高于冷水机组总额定制冷量80%时,机组联合运行并采用负荷平均分配时比一台机组满负荷运行另一台机组部分负荷运行时节能,节能率为1.5%～3.7%。分析了冷却水变流量对冷水机组和冷却水系统的影响及节能效果。结果表明,离心机组变流量运行时节能率达到17%,而螺杆机组在定流量45.13 kg·s⁻¹运行时比较合理和节能。     

A study of pulsatile blood flow modeled as a power law fluid in a constricted tube

A mathematical model for the pulsatile blood flow in a small vessel in the cardiovascular system with a mild stenosis is analyzed. Blood is modeled as a power law fluid and the differential approximation for the heat flux is invoked in the energy equation. The effect of heat transfer on the velocity is computed and discussed.     

Non-Newtonian blood flow with magnetic nanoparticles in a W-shaped stenosed arterial segment: A numerical study

Flow of blood, infused with magnetic nanoparticles, in a W-shaped stenosed human arterial segment is studied numerically using a realistic non-Newtonian blood rheology model. It is observed that the Newtonian model predicts less time to reach a steady state than the non-Newtonian blood rheology model. An increased drug retention time at the target site with an increase in nanoparticle concentration is predicted. Detailed simulations further reveal that the skin friction coefficient does not increase significantly with the increase in nanoparticle concentration. Hence, it is anticipated from our study that the infusion of drug-carrying nanoparticles in blood flow does not excessively enhance wall shear stress that may lead to arterial wall damage. An overall increase in heat transfer rates and wall shear stress at the stenosed section is seen with an increase in Reynolds number. The present study provides valuable information for designing computer-assisted drug delivery systems.     

Effect of physiology on the temperature distribution of a layered head with external convection

To improve the existing thermal models of the human head, we incorporate the effect of the temperature over the metabolic heat generation, the regulatory processes that control the cerebral blood perfusion and their dependence on physiological parameters like, the mean arterial blood pressure, the partial pressure of oxygen, the partial pressure of carbon dioxide, and the cerebral metabolic rate of oxygen consumption.The introduction of these parameters in a thermal model gives information about how specific conditions, such as brain edema, hypoxia, hypercapnia, or hypotension, affect the temperature distribution within the brain. Our work, on a layered head model, shows that variations of the physiological parameters have profound effect on the temperature gradients within the head.     

小型离心血液泵内流动特性的数值研究

采用数值求解Reynolds—Averaged Navier—Stokes方程技术，研究分析了小型离心血液泵内三维流动特性和水力性能。计算得到的不同流量条件下血液泵的水力性能与试验数据吻合良好，验证了计算方法的可靠性。分析了在设计流量、小流量和大流量条件下血液为工质的离心泵内流动形态。研究结果表明：在3种流量条件下，离心血液泵的出口流场均匀，满足设计要求。对血液泵内涡流产生及其容易产生溶血的位置进行了初步探讨，为改进血液泵结构设计提供参考。     

A Surface Heat Disturbance Method for Measuring Local Tissue Blood Perfusion Rate

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Intracellular trehalose improves the survival of human red blood cells by freeze-drying

Freeze-drying of human red blood cells has a potential important application for blood transfusion. The aim of this study was to investigate the effects of intracellular trehalose on the survival of red blood cells after freeze-drying and rehydration. Fresh red blood cells were incubated in trehalose solutions of various concentrations at 37°C for 7 h following freeze-drying. Polyvinylpyrrolidone, Trehalose, sodium citrate, and human serum albumin were used as extracellular protective agents for the freeze-drying of red blood cells. The results indicated that the intracellular trehalose concentration was increased with increasing concentration of extracellular trehalose solution, and the maximum concentration of intracellular trehalose reached 35 mmol/L. The viability of freeze-dried red blood cells increased with the increment of intracellular trehalose concentration. Translated from Journal of Refrigeration, 2005, 27(3): 41–44 [译自: 制冷学报]     

Thermodynamic Significance of Human Basal Metabolism

The human basal state, a non-equilibrium steady state, is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its distinction to the dissipation function and exergy loss are identified. The analysis demonstrates the correct expression of the effects of the blood flow on the heat balance in a human-body bio-heat model and the relationship between the basal metabolic rate and the blood perfusion.     

Constructal design of an arterial bypass graft

Arterial bypass grafts tend to fail after some years due to intimal hyperplasia—an abnormal proliferation of smooth muscle cells that leads to stenosis and graft occlusion. In this regard and on the basis of the constructal design method, this study seeks to investigate the effect of geometric parameters—stenosis degree, junction angle, and diameter ratio—on the flow through a bypass graft circumventing an idealized, partially stenosed coronary artery. The computational model assumes a steady-state Newtonian fluid flow through an artery stenosis degree from 25% to 75%. A computational fluid dynamics model and a response surface methodology were employed to assess the effects of the project parameters on pressure drop. As diameter ratio increases to 1 and the junction angle decreases to 30°, the pressure drop decreases and there is a considerable dependence of pressure drop on the stenosis degree. The effects of the diameter ratio are more pronounced than those of junction angle on the velocity field and wall shear stress. The application of the constructal design method in hemodynamics might be a good alternative to provide configurations with enhanced performance and to provide valuable results to the understanding of biological flows.     

Modeling pulsatile blood flow within a homogeneous porous bed in the presence of a uniform magnetic field and time-dependent suction

The study models pulsatile blood flow in the cardiovascular system employing the Navier–Stokes equation. Resulting partial differential equations are solved approximately for the flow field. Solutions obtained which compare favourably with previously reported studies, show an increase in the wall shear stress when the porosity of the medium is increased.     

Fractional analysis of radiative blood transport through a porous channel containing multishaped cobalt nanoparticles: An application to hemodynamics

In this work, impacts of dispersing nonspherical shaped cobalt nanoparticles in the blood are analyzed for magnetohydrodynamic radiative transport of blood inside a vertical porous channel. An Oldroyd-B model is used to feature flow characteristics of blood along with Fourier's principle of heat transmission for the mathematical modeling of the problem. A fractional system is constructed by employing the idea of the Caputo–Fabrizio derivative on subsequent differential equations. The Laplace transform method is adopted to solve the fractional flow and energy equations subject to generalized boundary conditions, which involve time-dependent functions $h\left(\tau \right)$ and $g\left(\tau \right)$, respectively. Instead of promoting the analytic velocity and energy expressions, Zakian's numerical algorithm is operated to achieve the reverse transformation purpose of Laplace domain functions. To certify the obtained solutions, two additional numerical algorithms named Stehfest's algorithm and Durbin's algorithm are inculcated in this study, and comparative illustrations are drawn. For the extensive investigation of shear stress and heat transfer phenomenon, numerical simulations for the coefficient of skin friction and Nusselt number are performed, and outcomes are communicated through various tables. The impacts of shape-dependent viscosity and other significant parameters on flow patterns are investigated through graphs for multiple motion types of the left channel wall. Meanwhile, the thermal performance of nanofluid is examined for platelet, brick, cylinder, and blade shape nanoparticles, along with other thermal parameters. In addition, some recently reported results and flow profiles for Maxwell, second-grade, and viscous fluids are deduced graphically as special cases of the current study.