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NIPS法聚偏氟乙烯超滤膜的制备与应用

吕晓龙,武春瑞,张昊,赵丽华

《中国工程科学》 2014年 第16卷 第12期   页码 35-45

摘要:

非溶剂相分离(NIPS)制膜方法是20世纪60年代发明的一种高效的制膜方法。利用该法制备的不对称膜结构赋予膜优异的选择渗透性能,膜孔结构易于调控,已经成为当前聚合物分离膜研究及商业化生产中普遍采用的方法。聚偏氟乙烯(PVDF)具有优异的综合性能,成膜性能佳,可利用NIPS法制膜。NIPS法PVDF膜的研制、膜结构控制方法及应用研究受到国际膜研究者广泛关注,是分离膜领域热点之一。本文分别针对NIPS法PVDF超滤膜制备的相分离原理研究、膜结构控制方法及膜应用研究等关键研究进展作简要介绍。

关键词: 非溶剂致相分离     聚偏氟乙烯     超滤膜     相分离原理     膜结构与性能     膜应用    

Solvent-resistant porous membranes using poly(ether−ether ketone): preparation and application

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1536-1559 doi: 10.1007/s11705-022-2221-8

摘要: Poly(ether−ether ketone) (PEEK) is a linear aromatic macromolecule, which can form semi-crystalline aggregative status, allowing PEEK materials to have strong environment tolerance and excellent physicochemical properties. PEEK materials have become a promising alternative to fabricate particular membranes used in extreme conditions. In the past few decades, many researches and evolutions have emerged in membrane fabrication with PEEK materials and its applications for treating organic solvents and their mixtures; however, there are little systematic and comprehensive literature to summarize fabrication approaches, compile applications, and elaborate PEEK property-structure relationship. In this review, the main approaches to fabricate PEEK-based membranes are illustrated concretely, including conventional thermal-induced and non-solvent-induced phase separation, and novel chemical-induced crystallization; the representative applications in ultrafiltration, nanofiltration and membrane contactor containing organic solvents are demonstrated systematically. Meanwhile, the mechanism to tune PEEK solubility in solvents, which can be achieved by altering monomers in synthesis processes or changing membrane preparation routes, is deeply analyzed. Moreover, the existing problems and the future prospects are also discussed. This review provides positive guidance for designing and fabricating membranes using PEEK and its derivative materials for task-specific applications in harsh conditions.

关键词: PEEK     phase inversion     solvent-resistant membrane     nanofiltration     membrane contactor    

Polysulfone and zirconia composite separators for alkaline water electrolysis

Li XU, Wei LI, Yan YOU, Shaoxing ZHANG, Yingchun ZHAO

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 154-161 doi: 10.1007/s11705-013-1331-8

摘要: The novel composite separators composed of polysulfone and zirconia were prepared by phase inversion precipitation technique. This technique allows pre-evaporation time and extraction temperature to be varied in order to obtain optimal performances of the separators. In order to evaluate practical applicability of those composite separators, a small-scale electrolysis experimental apparatus was used to investigate the changes of cell voltage, gas purity and separator stability. The results revealed a decreased cell voltage compared to the conventional asbestos separators, and the gas purity and separator stability met the requirements for industrial use.

关键词: phase inversion     separator     alkaline water electrolysis     mechanical and chemical stability    

The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering emulsions and enhance oil recovery

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1101-1113 doi: 10.1007/s11705-021-2095-1

摘要: Nanoparticles with high surface energy and chemical activity have drawn substantial attention in petroleum industry. Recently, Janus nanoparticles exhibited tremendous potential in enhanced oil recovery (EOR) due to their asymmetric structures and properties. In this study, a series of amphiphilic pseudo-Janus@OTAB (PJ@C18) nanoparticles with different concentrations of stearyltrimethylammoium bromide (OTAB) were successfully fabricated. The structures and properties of PJ@C18 were characterized by Fourier transform infrared spectroscopy and ζ-potential measurements. Based on the emulsification experimental results, the interaction models and the self-assembly behavior between hydrophilic nanoparticles (SiO2@NH2) and OTAB molecules at the oil/water interface were proposed, which was further confirmed via the measurements of the contact angle and dynamic interfacial tension. Interestingly, it was found that the change of pH value from 7.5 to 4.0 caused the type reversal of the PJ@C18-1000 stabilized Pickering emulsions. Furthermore, the PJ@C18-1000 stabilized Pickering emulsion system with excellent salt and temperature tolerances (10000 mg∙L–1, 90 °C) significantly improved the oil recovery in the single-tube (more than 17%) and double-tube (more than 25%) sand pack model flooding tests. The findings of this study could help to better understand the construction mechanism of pseudo-Janus silica/surfactant assembly and the potential application of PJ@C18-1000 stabilized Pickering emulsions for EOR.

关键词: Janus nanoparticles     surfactant     double phase inversion     self-assembly     enhanced oil recovery    

均质纤维素膜的制备及其正渗透性能研究

张兵涛,张林,黄和,侯立安

《中国工程科学》 2014年 第16卷 第7期   页码 57-61

摘要:

以纤维素(cellulose)为膜材料,离子液体1-乙基-3 甲基咪唑醋酸盐(EMIMAc)为溶剂,水为非溶剂,无纺布作为支撑层,通过相转化法制备了纤维素均质膜。采用红外、X-射线衍射和扫描电子显微镜表征了膜的结构及形貌,考察了该膜的正渗透性能。结果表明:纤维素溶解再生过程中没有发生化学变化,但晶型发生了转变;当原料液为0.6 mol/L 的氯化钠水溶液,汲取液为特制的营养液时,所制备的正渗透膜的水通量为3.534 L/(m2· h),截盐率达到99 %以上。

关键词: 正渗透     离子液体     纤维素膜     相转化     膜制备    

智能高分子开关膜的制备方法研究进展

谢锐,刘 壮,巨晓洁,汪 伟,褚良银

《中国工程科学》 2014年 第16卷 第12期   页码 94-101

摘要:

智能高分子开关膜是将智能高分子与非刺激响应型基材膜结合而成。由于智能高分子能够响应外界刺激发生亲疏水性转变和构象变化,智能高分子开关膜也能根据外部刺激改变自身的表面/界面特性、渗透通量或选择透过性。智能高分子膜被用作抗污染滤膜、亲和分离、酶反应的起/停控制以及控制释放等。智能高分子开关膜的制备方法直接影响其环境刺激响应特性、稳定性和可重复制备性等。因此,系统介绍了基材膜修饰法、基材修饰成膜法和共混成膜法等3种智能高分子开关膜制备方法的定义、分类、机理和研究进展,并对比了3种方法的优缺点。基材膜修饰法研究最多,而共混成膜法最有望用于大规模制备智能高分子膜。本文以期为高效制备具有稳定、优良响应特性的智能高分子开关膜提供指导和参考。

关键词: 智能高分子膜     智能凝胶     智能线性高分子     制备方法     相转化法    

Kinematical synthesis of an inversion of the double linked fourbar for morphing wing applications

J. AGUIRREBEITIA, R. AVILéS, I. FERNáNDEZ, M. ABASOLO

《机械工程前沿(英文)》 2013年 第8卷 第1期   页码 17-32 doi: 10.1007/s11465-013-0364-5

摘要:

This paper presents the kinematical features of an inversion of the double linked fourbar for morphing wing purposes. The structure of the mechanism is obtained using structural synthesis concepts, from an initial conceptual schematic. Then, kinematic characteristics as instant center of rotation, lock positions, dead point positions and uncertainty positions are derived for this mechanism in order to face the last step, the dimensional synthesis; in this sense, two kinds of dimensional synthesis are arranged to guide the wing along two positions, and to fulfill with the second one some aerodynamic and minimum actuation energy related issues.

关键词: morphing wing     structural synthesis     dimensional synthesis     geometrical kinematics    

Meshless numerical method based on tensor product

SUN Haitao, WANG Yuanhan, MIAO Yu

《结构与土木工程前沿(英文)》 2008年 第2卷 第2期   页码 166-171 doi: 10.1007/s11709-008-0021-y

摘要: A normalized space constructed by tensor product is used in field function approach to give a special case of moving least squares (MLS) interpolation scheme. In the regular domain, the field function which meets homogenous boundary conditions is constructed by spanning base space to make the MLS interpolation scheme simpler and more efficient. Owing to expanded basis functions selection, some drawbacks in general MLS method, for example repeated inversion, low calculation efficiency, and complex criterions, can be avoided completely. Numerical examples illustrate that the proposed method is characterized by simple mathematical concept, convenient repeat calculations with high accuracy, good continuity, less computation and rapid convergence.

关键词: mathematical     continuity     inversion     selection     efficient    

基于频率域全波形反演的隧道超前探测研究 Article

于明羽, 程飞, 刘江平, 彭代诚, 田志坚

《工程(英文)》 2022年 第18卷 第11期   页码 197-206 doi: 10.1016/j.eng.2021.06.018

摘要:

地震超前探测方法是获取隧道前方复杂地质体结构的重要手段,对隧道工程的安全建设和灾害防治极为重要。针对目前隧道地震超前探测方法在获取掌子面前方地质体结构和物性参数时存在精度不足的问题,本文将高分辨率成像的声波频率域全波形反演方法应用于地震隧道超前探测,并研究了频率组选择策略以及观测系统对反演效果的影响,实现了隧道前方不良地质体的结构成像与物性反演。研究结果显示:本文基于常规频率域声波全波形反演的频率组选择策略,提出的覆盖垂直波数和抗混叠相结合的频率组选择策略,能够有效获得隧道前方地质体的空间结构和物性参数,并提高反演分辨率;本文通过线性增加隧道观测系统侧边长度,讨论不同隧道双边观测系统长度对反演成像的影响,得出侧边长度近似于掌子面宽度5 倍时反演效果最佳,超过该范围后继续增加侧边观测长度对反演结果影响可忽略;最后采用研究结果对复杂的多地层模型进行反演,得出掌子面前方复杂地层的准确结构形态和物性参数,验证了本文方法的可行性。

关键词: 隧道超前探测     全波形反演     频率选择策略     观测系统设计    

基于HY-2高度计波形数据的高分辨率有效波高反演算法研究

王桂忠,张杰,苗洪利,李国强,王鑫

《中国工程科学》 2014年 第16卷 第6期   页码 60-64

摘要:

有效波高是描述海况的重要参量之一,利用高度计遥感获取有效波高已在海洋研究中获得广泛应用。本文基于海洋二号(HY-2)卫星高度计波形数据,发展了一种高分辨率有效波高反演算法,采用中误差对反演得到的20 Hz有效波高进行筛选,有效提高了测量精度。通过该方法对1 个轨的波形数据进行有效波高反演,统计结果表明:与针对1 s 回波反演的有效波高比较,利用该方法可将有效波高观测分辨率提高约15 倍,精度约为0.44 m;利用HY-2 高度计20 Hz 波形数据反演的有效波高精度可靠,可用其进行高分辨率的相关海洋研究。

关键词: HY-2     有效波高     反演算法     高分辨率    

Microfluidic production of liposomes through liquid–liquid phase separation in ternary droplets

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 1017-1022 doi: 10.1007/s11705-021-2118-y

摘要: Liposomes, the self-assembled phospholipid vesicles, have been extensively used in various fields such as artificial cells, drug delivery systems, biosensors and cosmetics. However, current microfluidic routes to liposomes mostly rely on water-in-oil-in-water double emulsion droplets as templates, and require complex fabrication of microfluidic devices, and tedious manipulation of multiphase fluids. Here we present a simple microfluidic approach to preparing monodisperse liposomes from oil-in-water droplets. For demonstration, we used butyl acetate-water-ethanol ternary mixtures as inner phase and an aqueous solution of surfactants as outer phase to make oil-in-water droplets, which can evolve into water-in-oil-in-water double emulsion droplets by liquid–liquid phase separation of ternary mixtures. Subsequently, the resultant water-in-oil-in-water droplets underwent a dewetting transition to form separated monodisperse liposomes and residual oil droplets, with the assistance of surfactants. The method is simple, does not require complex microfluidic devices and tedious manipulation, and provides a new platform for controllable preparation of liposomes.

关键词: microfluidics     liposomes     ternary droplets     phase separation    

Construction and Application of a Regional Kilometer-Scale Carbon Source and Sink Assimilation Inversion

Lifeng Guo,Xiaoye Zhang,Junting Zhong,Deying Wang,Changhong Miao,Licheng Zhao,Zijiang Zhou,Jie Liao,Bo Hu,Lingyun Zhu,Yan Chen,

《工程(英文)》 doi: 10.1016/j.eng.2023.02.017

摘要: CO2 is one of the most important greenhouse gases (GHGs) in the earth’s atmosphere. Since the industrial era, anthropogenic activities have emitted excessive quantities of GHGs into the atmosphere, resulting in climate warming since the 1950s and leading to an increased frequency of extreme weather and climate events. In 2020, China committed to striving for carbon neutrality by 2060. This commitment and China’s consequent actions will result in significant changes in global and regional anthropogenic carbon emissions and therefore require timely, comprehensive, and objective monitoring and verification support (MVS) systems. The MVS approach relies on the top-down assimilation and inversion of atmospheric CO2 concentrations, as recommended by the Intergovernmental Panel on Climate Change (IPCC) Inventory Guidelines in 2019. However, the regional high-resolution assimilation and inversion method is still in its initial stage of development. Here, we have constructed an inverse system for carbon sources and sinks at the kilometer level by coupling proper orthogonal decomposition (POD) with four-dimensional variational (4DVar) data assimilation based on the weather research and forecasting–greenhouse gas (WRF–GHG) model. Our China Carbon Monitoring and Verification Support at the Regional level (CCMVS-R) system can continuously assimilate information on atmospheric CO2 and other related information and realize the inversion of regional and local anthropogenic carbon emissions and natural terrestrial ecosystem carbon exchange. Atmospheric CO2 data were collected from six ground-based monitoring sites in Shanxi to verify the inversion effect of regional anthropogenic carbon emissions by setting ideal and real experiments using a two-layer nesting method (at 27 km and 9 km). The uncertainty of the simulated atmospheric CO2 decreased significantly, with a root-mean-square error of CO2 concentration values between the ideal value and the simulated after assimilation was close to 0. The total anthropogenic carbon emissions in Shanxi Province in 2019 from the assimilated inversions were approximately 28.6% (17%–38%) higher than the mean of five emission inventories using the bottom-up method, showing that the top-down CCMVS-R system can obtain more comprehensive information on anthropogenic carbon emissions.

关键词: CCMVS-R     Regional carbon assimilation system     Anthropogenic carbon emissions     CO2     POD 4DVar    

Advances and perspectives in catalysts for liquid-phase oxidation of cyclohexane

Hui LI, Yuanbin SHE, Tao WANG

《化学科学与工程前沿(英文)》 2012年 第6卷 第3期   页码 356-368 doi: 10.1007/s11705-012-0903-3

摘要: The latest progress and developments in catalysts for the oxidation of cyclohexane are reviewed. Catalytic systems for the oxidation of cyclohexane including metal supported, metal oxides, molecular sieves, metal substituted polyoxometalates, photocatalysts, organocatalysts, Gif systems, metal-organic catalysts and metalloporphyrins are discussed with a particular emphasis on metalloporphyrin catalytic systems. The advantages and disadvantages of these methods are summarized and analyzed. Finally, the development trends in the oxidation technology of cyclohexane are examined.

关键词: cyclohexane     liquid-phase oxidation     catalysis    

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

《结构与土木工程前沿(英文)》 2015年 第9卷 第2期   页码 114-120 doi: 10.1007/s11709-014-0267-5

摘要: The accurate and efficient simulation of random heterogeneous media is important in the framework of modeling and design of complex materials across multiple length scales. It is usually assumed that the morphology of a random microstructure can be described as a non-Gaussian random field that is completely defined by its multivariate distribution. A particular kind of non-Gaussian random fields with great practical importance is that of translation fields resulting from a simple memory-less transformation of an underlying Gaussian field with known second-order statistics. This paper provides a critical examination of existing random field models of heterogeneous two-phase media with emphasis on level-cut random fields which are a special case of translation fields. The case of random level sets, often used to represent the geometry of physical systems, is also examined. Two numerical examples are provided to illustrate the basic features of the different approaches.

关键词: microstructure     random fields     level sets     shape recovery     two-phase media    

Phase transition regulation and caloric effect

《能源前沿(英文)》 2023年 第17卷 第4期   页码 463-477 doi: 10.1007/s11708-023-0860-1

摘要: Solid state refrigeration based on caloric effect is regarded as a potential candidate for replacing vapor-compression refrigeration. Numerous methods have been proposed to optimize the refrigeration properties of caloric materials, of which single field tuning as a relatively simple way has been systemically studied. However, single field tuning with few tunable parameters usually obtains an excellent performance in one specific aspect at the cost of worsening the performance in other aspects, like attaining a large caloric effect with narrowing the transition temperature range and introducing hysteresis. Because of the shortcomings of the caloric effect driven by a single field, multifield tuning on multicaloric materials that have a coupling between different ferro-orders came into view. This review mainly focuses on recent studies that apply this method to improve the cooling performance of materials, consisting of enlarging caloric effects, reducing hysteresis losses, adjusting transition temperatures, and widening transition temperature spans, which indicate that further progress can be made in the application of this method. Furthermore, research on the sign of lattice and spin contributions to the magnetocaloric effect found new phonon evolution mechanisms, calling for more attention on multicaloric effects. Other progress including improving cyclability of FeRh alloys by introducing second phases and realizing a large reversible barocaloric effect by hybridizing carbon chains and inorganic groups is described in brief.

关键词: phase transition regulation     caloric effect     solid state refrigeration    

标题 作者 时间 类型 操作

NIPS法聚偏氟乙烯超滤膜的制备与应用

吕晓龙,武春瑞,张昊,赵丽华

期刊论文

Solvent-resistant porous membranes using poly(ether−ether ketone): preparation and application

期刊论文

Polysulfone and zirconia composite separators for alkaline water electrolysis

Li XU, Wei LI, Yan YOU, Shaoxing ZHANG, Yingchun ZHAO

期刊论文

The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering emulsions and enhance oil recovery

期刊论文

均质纤维素膜的制备及其正渗透性能研究

张兵涛,张林,黄和,侯立安

期刊论文

智能高分子开关膜的制备方法研究进展

谢锐,刘 壮,巨晓洁,汪 伟,褚良银

期刊论文

Kinematical synthesis of an inversion of the double linked fourbar for morphing wing applications

J. AGUIRREBEITIA, R. AVILéS, I. FERNáNDEZ, M. ABASOLO

期刊论文

Meshless numerical method based on tensor product

SUN Haitao, WANG Yuanhan, MIAO Yu

期刊论文

基于频率域全波形反演的隧道超前探测研究

于明羽, 程飞, 刘江平, 彭代诚, 田志坚

期刊论文

基于HY-2高度计波形数据的高分辨率有效波高反演算法研究

王桂忠,张杰,苗洪利,李国强,王鑫

期刊论文

Microfluidic production of liposomes through liquid–liquid phase separation in ternary droplets

期刊论文

Construction and Application of a Regional Kilometer-Scale Carbon Source and Sink Assimilation Inversion

Lifeng Guo,Xiaoye Zhang,Junting Zhong,Deying Wang,Changhong Miao,Licheng Zhao,Zijiang Zhou,Jie Liao,Bo Hu,Lingyun Zhu,Yan Chen,

期刊论文

Advances and perspectives in catalysts for liquid-phase oxidation of cyclohexane

Hui LI, Yuanbin SHE, Tao WANG

期刊论文

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

期刊论文

Phase transition regulation and caloric effect

期刊论文