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薄膜润滑 5

Cu(In 4

Ga)Se₂ 3

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Largely reduced cross-plane thermal conductivity of nanoporous In

Dongchao XU, Quan WANG, Xuewang WU, Jie ZHU, Hongbo ZHAO, Bo XIAO, Xiaojia WANG, Xiaoliang WANG, Qing HAO

《能源前沿（英文）》 2018年第12卷第1期页码 127-136 doi: 10.1007/s11708-018-0519-5

摘要： In recent year, nanoporous Si thin films have been widely studied for their potential applications in thermoelectrics, in which high thermoelectric performance can be obtained by combining both the dramatically reduced lattice thermal conductivity and bulk-like electrical properties. Along this line, a high thermoelectric figure of merit (ZT) is also anticipated for other nanoporous thin films, whose bulk counterparts possess superior electrical properties but also high lattice thermal conductivities. Numerous thermoelectric studies have been carried out on Si-based nanoporous thin films, whereas cost-effective nitrides and oxides are not systematically studied for similar thermoelectric benefits. In this work, the cross-plane thermal conductivities of nanoporous In Ga N thin films with varied porous patterns were measured with the time-domain thermoreflectance technique. These alloys are suggested to have better electrical properties than conventional Si Ge alloys; however, a high ZT is hindered by their intrinsically high lattice thermal conductivity, which can be addressed by introducing nanopores to scatter phonons. In contrast to previous studies using dry-etched nanopores with amorphous pore edges, the measured nanoporous thin films of this work are directly grown on a patterned sapphire substrate to minimize the structural damage by dry etching. This removes the uncertainty in the phonon transport analysis due to amorphous pore edges. Based on the measurement results, remarkable phonon size effects can be found for a thin film with periodic 300-nm-diameter pores of different patterns. This indicates that a significant amount of heat inside these alloys is still carried by phonons with ~300 nm or longer mean free paths. Our studies provide important guidance for ZT enhancement in alloys of nitrides and similar oxides.

关键词： nanoporous film thermoelectrics phonon mean free path diffusive scattering

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Preparation of adsorptive nanoporous membrane using powder activated carbon: Isotherm and thermodynamic

Majid Peyravi

《化学科学与工程前沿（英文）》 2020年第14卷第4期页码 673-687 doi: 10.1007/s11705-019-1800-9

摘要： Adsorptive polyethesulfone (PES) membranes were prepared by intercalation of powder activated carbon (PAC) with and without functionalization. Accordingly, PAC was aminated with 1,5-diamino-2-methylpentane, and the physicochemical properties of the functionalized PAC were analyzed. Intercalation of PAC within the PES scaffold changed the porosity and mean pore size of the aminated membrane (AC-NH ) from 52.6% to 92.5% and from 22.6 nm to 3.5 nm, respectively. The effect of temperature on the performance of the modified membranes was monitored by the flux and chemical oxygen demand (COD) removal of leachate. At ambient temperature, the COD removal of the neat, AC-containing, and AC-NH membranes was 47%, 52%, and 58.5%, respectively. A similar increment was obtained for the membrane flux, which was due to the synergistic effect of the high porosity and large number of hydrophilic functional groups. The experimental leachate adsorption data were analyzed by Langmuir, Freundlich, and Dubinin- Radushkevich isotherm models. For all membranes, the signiﬁcant thermodynamic parameters ( , , and ) were calculated and compared. The isosteric heat of adsorption was lower than 80 kJ∙mol , indicating that the interaction between the membranes and the leachate is mainly physical, involving weak van der Waals forces.

关键词： amine functionality nanoporous membrane adsorption isotherm thermodynamic parameters landfill leachate

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纳米多孔储气材料的物理吸附特性研究进展 Review

Katie A. Cychosz,Matthias Thommes

《工程（英文）》 2018年第4卷第4期页码 559-566 doi: 10.1016/j.eng.2018.06.001

摘要：

评估纳米多孔材料的吸附性能并确定它们的结构表征，对于将这类材料用于包括气体储存在内的许多应用至关重要。气体吸附法可用于此表征，因为它可以评估从微孔到中孔的各种孔径。在过去的20 年中，关于有序纳米多孔材料中流体的吸附和相行为的知识以及基于统计力学的最先进的方法的创新和发展，如分子模拟和密度泛函理论，都取得了重大进展。再结合高分辨率的亚临界和超临界流体吸附实验程序，使物理吸附结构表征取得了显著进步。笔者不仅讨论了流体在具有明确孔隙结构的各种纳米多孔材料中基础吸附机理的一些重要和中心特征，还讨论了这些特征对促进物理吸附表征和储存气体应用的重要性。

关键词：吸附表征高压吸附纳米多孔材料

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纳米多孔介质中的流体流动

Weiyao Zhu,Bin Pan,Zhen Chen,Wengang Bu,Qipeng Ma,Kai Liu,Ming Yue

《工程（英文）》 2024年第32卷第1期页码 139-152 doi: 10.1016/j.eng.2023.05.014

摘要：

Fluid flow at nanoscale is closely related to many areas in nature and technology, e.g., unconventional hydrocarbon recovery, carbon dioxide geo-storage, underground hydrocarbon storage, fuel cells, ocean desalination and biomedicine. At nanoscale, interfacial forces dominate over bulk forces, and nonlinear effects are important, which significantly deviate from conventional theory. During the past decades, a series of experiments, theory and simulations have been performed to investigate fluid flow at nanoscale, which has advanced our fundamental knowledge of this topic. However, a critical review is still lacking, which has seriously limited the basic understanding of this area. Therefore herein, we systematically review experimental, theoretical and simulation works on single- and multi- phases fluid flow at nanoscale. We also clearly point out the current research gaps and future outlook. These insights will promote the significant development of nonlinear flow physics at nanoscale and will provide crucial guidance on the relevant areas.

关键词： Transport in nanoporous media Multi-phase fluid dynamics Nonlinear flow mechanisms Nonlinear flow conservation equations Interfacial forces Molecular dynamics simulation

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葡萄糖辅助构建用于脱盐的高稳定超薄纳米多孔膜 Article

张艳秋, 杨帆, 孙红光, 白永平, 李松伟, 邵路

《工程（英文）》 2022年第16卷第9期页码 247-255 doi: 10.1016/j.eng.2020.06.033

摘要：

尽管纳米多孔膜在海水淡化中引起了人们的广泛关注，但构建具有较高截留率和高渗透性的纳米多孔膜以实现高效的海水淡化过程仍然具有挑战性。本研究中，高渗透性的纳米多孔膜在葡萄糖和多巴胺的多种功能的辅助下，通过与1,3,5-苯三甲酰三氯（TMC）的界面反应来制备。葡萄糖的小分子（0.66 nm）具有高亲水性，可以扩散到膜内部进行有效反应，确保结构完整性。本文中新型超薄（44 nm）纳滤（NF）膜在5 bar（1 bar = 10⁵ Pa）的压力下具有超高的Na₂SO₄通量及优异的 Na₂SO₄（66.5 L∙m⁻²∙h⁻¹, 97.3%）和MgSO₄（63.0 L∙m⁻²∙h⁻¹, 92.1%）截留率，其性能远优于基于天然产物的NF膜的性能。该膜表现出优异的长期稳定性，以及卓越的酸碱稳定性和抗污染能力。这项基于膜材料和结构的设计为超越现有膜材料分离膜打开了新的大门。

关键词：纳米多空膜可再生资源纳滤脱盐葡萄糖

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Numerical simulation of liquid falling film on horizontal circular tubes

Fengdan SUN, Songlin XU, Yongchuan GAO

《化学科学与工程前沿（英文）》 2012年第6卷第3期页码 322-328 doi: 10.1007/s11705-012-1296-z

摘要： The objective of this study is to investigate numerically the flow characteristics of falling film on horizontal circular tubes. Numerical simulations are performed using FLUENT for 2D configurations with one and two cylinders. The volume of fluid method is used to track the motion of liquid falling film and the gas-liquid interface. The effect of flow characteristics on heat and transfer coefficient may be remarkable, although it has been neglected in previous studies. The velocity distribution and the film thickness characteristics on the top tube, some special flow characteristics on the bottom tube, intertube flow modes and effect of liquid feeder height on flow characteristics have been studied. Our simulations indicate that 1) the velocity distributions of the upper and lower parts of the tube are not strictly symmetric and non-uniform, 2) the film thickness depends on flow rate and angular distributions, 3) the flow characteristics of the top tube are different from those of the bottom tube, 4) three principal and two intermediate transition modes are distinguished, and 5) the liquid feed height plays an important role on the formation of falling film. The numerical results are in a good agreement with the theoretical values by the Nusselt model and the reported results.

关键词： falling film horizontal tube flow characteristics film thickness liquid feeder height

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Experiment and optimal design of a collection device for a residual plastic film baler

Qi NIU,Xuegeng CHEN,Chao JI,Jie WU

《农业科学与工程前沿（英文）》 2015年第2卷第4期页码 347-354 doi: 10.15302/J-FASE-2015077

摘要： It is imperative to carry out research on residual plastic film collection technology to solve the serious problem of farmland pollution. The residual plastic film baler was designed as a package for film strip collection, cleaning and baling. The collection device is a core component of the baler. Response surface analysis was used in this study to optimize the structure and working parameters for improving the collection efficiency of residual film and the impurity of film package. The results show that the factors affecting the collection rate of residual film and the impurity of the film package are the speed ratio ( ) between the trash removal roller and eccentric collection mechanism, the number ( ) and the mounting angle ( ) of spring teeth in the same revolution plane. For the collection rate, the importance of the three factors are in the order, . Meanwhile, for the impurity, the importance of three factors are in the order, . When the speed ratio, the mounting angle and the number of spring teeth was set at 1.6°, 45°, and 8°, respectively, the collection rate of residual film was 88.9% and the impurity of residual film package was 14.2% for the baler.

关键词： residual film collection device collection rate of residual film impurity of film package optimization baler

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薄膜润滑研究的回顾与展望

雒建斌,张朝辉,温诗铸

《中国工程科学》 2003年第5卷第7期页码 84-89

摘要：

薄膜润滑是20世纪90年代以来广泛研究的新型润滑状态。它是界于弹流润滑和边界润滑之间的一种过渡润滑状态，有着自己独特的润滑规律。文章回顾了薄膜润滑的研究历史，包括薄膜润滑概念的提出、测试技术的发展、薄膜润滑的膜厚特性、润滑机理探索以及计算理论等方面的研究成果与主要进展。

关键词：薄膜润滑有序膜膜厚测量微结构

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Thin-liquid-film evaporation at contact line

Hao WANG, Zhenai PAN, Zhao CHEN

《能源前沿（英文）》 2009年第3卷第2期页码 141-151 doi: 10.1007/s11708-009-0020-2

摘要： When a liquid wets a solid wall, the extended meniscus near the contact line may be divided into three regions: a nonevaporating region, where the liquid is adsorbed on the wall; a transition region or thin-film region, where effects of long-range molecular forces (disjoining pressure) are felt; and an intrinsic meniscus region, where capillary forces dominate. The thin liquid film, with thickness from nanometers up to micrometers, covering the transition region and part of intrinsic meniscus, is gaining interest due to its high heat transfer rates. In this paper, a review was made of the researches on thin-liquid-film evaporation. The major characteristics of thin film, thin-film modeling based on continuum theory, simulations based on molecular dynamics, and thin-film profile and temperature measurements were summarized.

关键词： meniscus thin film contact line disjoining pressure evaporation

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Surface-tailoring chlorine resistant materials and strategies for polyamide thin film composite reverse

《化学科学与工程前沿（英文）》 2022年第16卷第5期页码 564-591 doi: 10.1007/s11705-021-2109-z

摘要： Polyamide thin film composite membranes have dominated current reverse osmosis market on account of their excellent separation performances compared to the integrally skinned counterparts. Despite their very promising separation performance, chlorine-induced degradation resulted from the susceptibility of polyamide toward chlorine attack has been regarded as the Achilles’s heel of polyamide thin film composite. The free chlorine species present during chlorine treatment can impair membrane performance through chlorination and depolymerization of the polyamide selective layer. From material point of view, a chemically stable membrane is crucial for the sustainable application of membrane separation process as it warrants a longer membrane lifespan and reduces the cost involved in membrane replacement. Various strategies, particularly those involved membrane material optimization and surface modifications, have been established to address this issue. This review discusses membrane degradation by free chlorine attack and its correlation with the surface chemistry of polyamide. The advancement in the development of chlorine resistant polyamide thin film composite membranes is reviewed based on the state-of-the-art surface modifications and tailoring approaches which include the in situ and post-fabrication membrane modifications using a broad range of functional materials. The challenges and future directions in this field are also highlighted.

关键词： reverse osmosis polyamide thin film composite membranes chlorine resistance surface modification

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Piezoelectric film-actuated motion platform with high resolution

HUA Shunming, ZHANG Hongzhuang, CHENG Guangming, FAN Zunqiang, LIU Jianfang

《机械工程前沿（英文）》 2008年第3卷第3期页码 265-269 doi: 10.1007/s11465-008-0041-2

摘要： A piezoelectric film-actuated motion platform with high resolution, which can run in two directions within a horizontal plane, is presented. On the basis of the analysis of the working principle of a stick-slip mechanism, a mathematical model describing its dynamic behavior is set up and simulated. Experiments of the motion performance and carrying ability on the prototype are conducted. Results show that this type of platform has advantages including a simple structure, small volume, light weight, stable step length, and large traveling range. When the driving voltage is less than 30 V, step error is less than 0.5 ?m. The carrying ability of the platform is terrific and about 7–8 times its weight.

关键词： mathematical stick-slip mechanism piezoelectric film-actuated analysis terrific

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Overcoming oral insulin delivery barriers: application of cell penetrating peptide and silica-based nanoporous

Huining HE, Junxiao YE, Jianyong SHENG, Jianxin WANG, Yongzhuo HUANG, Guanyi CHEN, Jingkang WANG, Victor C YANG

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 9-19 doi: 10.1007/s11705-013-1306-9

摘要： Oral insulin delivery has received the most attention in insulin formulations due to its high patient compliance and, more importantly, to its potential to mimic the physiologic insulin secretion seen in non-diabetic individuals. However, oral insulin delivery has two major limitations: the enzymatic barrier that leads to rapid insulin degradation, and the mucosal barrier that limits insulin’s bioavailability. Several approaches have been actively pursued to circumvent the enzyme barrier, with some of them receiving promising results. Yet, thus far there has been no major success in overcoming the mucosal barrier, which is the main cause in undercutting insulin’s oral bioavailability. In this review of our group’s research, an innovative silica-based, mucoadhesive oral insulin formulation with encapsulated-insulin/cell penetrating peptide (CPP) to overcome both enzyme and mucosal barriers is discussed, and the preliminary and convincing results to confirm the plausibility of this oral insulin delivery system are reviewed. In vitro studies demonstrated that the CPP-insulin conjugates could facilitate cellular uptake of insulin while keeping insulin’s biologic functions intact. It was also confirmed that low molecular weight protamine (LMWP) behaves like a CPP peptide, with a cell translocation potency equivalent to that of the widely studied TAT. The mucoadhesive properties of the produced silica-chitosan composites could be controlled by varying both the pH and composition; the composite consisting of chitosan (25 wt-%) and silica (75 wt-%) exhibited the greatest mucoadhesion at gastric pH. Furthermore, drug release from the composite network could also be regulated by altering the chitosan content. Overall, the universal applicability of those technologies could lead to development of a generic platform for oral delivery of many other bioactive compounds, especially for peptide or protein drugs which inevitably encounter the poor bioavailability issues.

关键词： insulin cell penetrating peptide mucoadhesive composites oral delivery

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Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

《能源前沿（英文）》 2011年第5卷第4期页码 358-366 doi: 10.1007/s11708-011-0161-y

摘要： To investigate the performance of heat and mass transfer of ammonia-water during the process of falling film evaporation in vertical tube evaporator, a mathematical model of evaporation process was presented, the solution of which that needed a coordinate transformation was based on stream function. The computational results from the mathematical model were validated with experimental data. Subsequently, a series of parameters, such as velocity, film thickness and concentration, etc., were obtained from the mathematical model. Calculated results show that the average velocity and the film thickness change dramatically at the entrance region when <100 mm, while they vary slightly with the tube length in the fully developed region when >100 mm. The average concentration of the solution reduces along the tube length because of evaporation, but the reducing tendency becomes slow. It can be concluded that there is an optimalβrelationship between the tube length and the electricity generated. The reason for the bigger concentration gradient in the direction is that the smooth tube is chosen in the calculation. It is suggested that the roll-worked enhanced tube or other enhanced tube can reduce the concentration gradient in the film thickness direction and enhance the heat and mass transfer rate.

关键词： falling film evaporation ammonia-water heat and mass transfer

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Dynamic analysis of free-surface thin film flows driven by gravity over undulated substrate

Zhaomiao LIU, Xin LIU, Guobin WANG, Hong LIAO,

《机械工程前沿（英文）》 2010年第5卷第2期页码 219-225 doi: 10.1007/s11465-010-0010-4

摘要： This paper studies thin film flows with free surfaces driven by gravity through two types of undulated planes: periodically sinusoidal plane and triangle. The substrate plane is fixed and inclined to a certain angle and the flow with a free surface. Through finite element method (FEM), commenced from Navier-Stokes equations and continuity equation, the exact numerical results of free-surface film flows are obtained through discretization solution to finite equations in flowing areas. Based on the numerical calculations, the streamlines and wall shearing stress during the flowing process are visualized via post-proceeding, and the streamlines separation, the onset and evolution of vortex near the substrate boundary during the flow are also analyzed. The influences from the waviness of the substrate planes profile, height of the triangle plane, and change of the film height on film flow dynamics properties are shown.

关键词： waviness triangle height film thickness streamlines separation vortex

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Improved film evaporator for mechanistic understanding of microwave-induced separation process

Xin Gao, Dandan Shu, Xingang Li, Hong Li

《化学科学与工程前沿（英文）》 2019年第13卷第4期页码 759-771 doi: 10.1007/s11705-019-1816-1

摘要： Microwave-induced film evaporation separation process has been reported recently to separate the polar/nonpolar mixture. However, the efficiency of the separation is still too low for practical applications, which requires further enhancement via different strategies such as optimization design of evaporator structure. In addition the depth understanding of the separation mechanisms is great importance for better utilization of the microwave-induced separation process. To carry out these investigations, a novel microwave-induced falling film evaporation instrument was developed in this paper. The improvement of the enhancement effect of microwave-induced separation was observed based on the improved film evaporator. The systematic experiments on microwave-induced separation with different binary azeotropic mixtures (ethanol-ethyl acetate system and dimethyl carbonate (DMC)-H O system) were conducted based on the new evaporator. For the ethanol-ethyl acetate system, microwave irradiation shift the direction of evaporation separation at higher ethanol content in the starting liquid mixture. Moreover, for DMC-H O system microwave-induced separation process broke through the limitations of the traditional distillation process. The results clearly demonstrated the microwave-induced evaporation separation process could be commendably applied to the separation of binary azeotrope with different dielectric properties. Effects of operating parameters are also investigated to trigger further mechanism understanding on the microwave-induced separation process.

关键词： process intensification microwave falling film evaporation separation azeotrope