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Recovery of free volume in PIM-1 membranes through alcohol vapor treatment

Faiz Almansour, Monica Alberto, Rupesh S. Bhavsar, Xiaolei Fan, Peter M. Budd, Patricia Gorgojo

《化学科学与工程前沿（英文）》 2021年第15卷第4期页码 872-881 doi: 10.1007/s11705-020-2001-2

摘要： Physical aging is currently a major obstacle for the commercialization of PIM-1 membranes for gas separation applications. A well-known approach to reversing physical aging effects of PIM-1 membranes at laboratory scale is soaking them in lower alcohols, such as methanol and ethanol. However, this procedure does not seem applicable at industrial level, and other strategies must be investigated. In this work, a regeneration method with alcohol vapors (ethanol or methanol) was developed to recover permeability of aged PIM-1 membranes, in comparison with the conventional soaking-in-liquid approach. The gas permeability and separation performance, before and post the regeneration methods, were assessed using a binary mixture of CO and CH (1:1, v:v). Our results show that an 8-hour methanol vapor treatment was sufficient to recover the original gas permeability, reaching a CO permeability>7000 barrer.

关键词： polymer of intrinsic microporosity (PIM) PIM-1 physical aging gas separation vapor-phase regeneration

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无溶剂气相制备用于可持续分离过程的膜材料 Perspective

赵俊杰, Karen K. Gleason

《工程（英文）》 2020年第6卷第12期页码 1432-1442 doi: 10.1016/j.eng.2020.05.002

摘要：

可用于水净化、碳捕集、生物燃料生产、燃料电池运行以及节能工业分离操作的可持续化工过程亟待发展下一代膜材料。膜的无溶剂制备不仅消除了有机溶剂的潜在环境问题，而且解决了脆弱聚合物基材的膨胀问题。此外，采用无溶剂气相沉积方法可以减少合成微孔材料[如金属有机骨架（MOF）]所需的活化步骤。本文综述了几种真空沉积工艺，包括引发式化学气相沉积（iCVD）、引发式等离子体增强化学气相沉积（iPECVD）、无溶剂气相沉积原位聚合（SLIP）、原子层沉积（ALD）和分子层沉积（MLD）。这些无溶剂气相沉积方法在制备薄膜复合膜结构中的超薄选择层方面极具优势，而且能够保形地修饰纳米级孔道并精确调节孔径和孔内官能团。所制备的膜在气体分离、纳滤、海水淡化和水/油分离等方面表现出颇具应用潜力的性能。因此，开发新型膜材料、放大可用于无溶剂气相沉积的高通量反应器将对化学工业产生巨大影响。

关键词：膜分离化学气相沉积原子层沉积分子层沉积薄膜金属有机骨架聚合物先进制造

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Shock wave of vapor-liquid two-phase flow

ZHAO Liangju, GAO Hong, TANG Jingwen, YUAN Yuexiang, WANG Fei

《能源前沿（英文）》 2008年第2卷第3期页码 344-347 doi: 10.1007/s11708-008-0065-7

摘要： The shock wave of vapor-liquid two-phase flow in a pressure-gain steam injector is studied by building a mathematic model and making calculations. The results show that after the shock, the vapor is nearly completely condensed. The upstream Mach number and the volume ratio of vapor have a great effect on the shock. The pressure and Mach number of two-phase shock conform to the shock of ideal gas. The analysis of available energy shows that the shock is an irreversible process with entropy increase.

关键词： available mathematic conform vapor-liquid two-phase analysis

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Ultrafast solid-liquid-vapor phase change of a thin gold film irradiated by femtosecond laser pulses

Jing HUANG, Yuwen ZHANG, J. K. CHEN, Mo YANG

《能源前沿（英文）》 2012年第6卷第1期页码 1-11 doi: 10.1007/s11708-012-0179-9

摘要： Effects of different parameters on the melting, vaporization and resolidification processes of thin gold film irradiated by femtosecond pulses and pulse train were systematically studied. The classical two-temperature model was adopted to depict the non-equilibrium heat transfer in electrons and lattice. The melting and resolidification processes, which was characterized by the solid-liquid interfacial velocity, as well as elevated melting temperature and depressed solidification temperature, was obtained by considering the interfacial energy balance and nucleation dynamics. Vaporization process which leads to ablation was described by tracking the location of liquid-vapor interface with an iterative procedure based on energy balance and gas kinetics law. The parameters in discussion included film thickness, laser fluence, pulse duration, pulse number, repetition rate, pulse train number, etc. Their effects on the maximum lattice temperature, melting depth and ablation depth were discussed based on the simulation results.

关键词： melting evaporation nucleation dynamics nanoscale heat transfer

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catalyst for the selective hydroamination of cyclohexene with cyclohexylamine to dicyclohexylamine in the vaporphase

Jingbin Wen, Kuiyi You, Minjuan Chen, Jian Jian, Fangfang Zhao, Pingle Liu, Qiuhong Ai, He’an Luo

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 654-665 doi: 10.1007/s11705-020-1973-2

摘要： In this work, a new mesoporous silicon sulfonic acid catalyst derived from silicic acid has been successfully prepared by the chemical bonding method. The physicochemical properties of mesoporous silicon sulfonic acid catalysts have been systematically characterized using various techniques. The results demonstrate that sulfonic acid groups have been grafted on silicic acid by forming a new chemical bond (Si–O–S). The mesoporous silicon sulfonic acid exhibits excellent catalytic performance and stability in the vapor phase hydroamination reaction of cyclohexene with cyclohexylamine. Cyclohexene conversion of 61% and 97% selectivity to dicyclohexylamine was maintained after running the reaction for over 350 h at 280 °C. The developed mesoporous silicon sulfonic acid catalyst shows advantages of low cost, superior acid site accessibility, and long term reactivity stability. Moreover, a possible catalytic hydroamination reaction mechanism over silicon sulfonic acid was suggested. It has been demonstrated that the sulfonic acid groups of the catalyst play an important role in the hydroamination. The present work provides a simple, efficient, and environmentally friendly method for the hydroamination of cyclohexene to valuable dicyclohexylamine, which also shows important industrial application prospects.

关键词： mesoporous silicon sulfonic acid catalytic hydroamination cyclohexene dicyclohexylamine vapor phase

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Development of new transient liquid phase system Au-Sn-Au for microsystem technology

Kirsten BOBZIN, Nazlim BAGCIVAN, Lidong ZHAO, Stefania FERRARA, Jan PERNE

《机械工程前沿（英文）》 2010年第5卷第4期页码 370-375 doi: 10.1007/s11465-010-0107-9

摘要： In the last decade, microsystems evolved to decisive technology in many technical applications. With increasing requirements on the performance of microsystems, more and more dissimilar materials are used in the same assembly. Correspondingly, suitable joining methods are required to fulfil the requirements on good properties of joints. In this study, a new transient liquid phase (TLP) system Au-Sn-Au was developed for potential medical applications in hybrid microsystems. The high and low melting phases Au and Sn were deposited onto diverse substrates by magnetron-sputter-ion plating. The coated substrates were soldered in a microsoldering station under different conditions. The influence of soldering conditions on the microstructure and properties of the joints was investigated. Results show that the developed solder led to high-quality joints that can be used in microsystems for medical applications.

关键词： transient liquid phase microtechnology soldering diffusion physical vapor deposition (PVD)

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Influence of Na

Rumin YANG, Fanhui MENG, Xiao WANG, Yaquan WANG

《化学科学与工程前沿（英文）》 2011年第5卷第4期页码 401-408 doi: 10.1007/s11705-011-1129-5

摘要： Silicalite-1 was hydrothermally synthesized in the presence of different concentrations of Na using tetrapropylammonium hydroxide (TPAOH) as a template. The synthesis was followed by a base treatment. The silicalite-1samples were characterized using X-ray diffraction, scanning electron microscopy, N adsorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and NH temperature-programmed desorption. The samples were used as catalysts for the vapor phase Beckmann rearrangement of cyclohexanone oxime. During the synthesis, the sodium ions were incorporated onto the silicalite-1 crystals, but were then removed by the base treatment. All the catalysts exhibited nearly complete conversion of cyclohexanone oxime to ?-caprolactam with selectivities grater than 95%. Addition of less than 2.5 mol-% Na (relative to TPAOH) did not influence the catalytic properties. However, for Na concentrations≥5 mol-%, the particle sizes of silicalite-1 increased and the catalytic activities decreased, which can be attributed to carbon deposition. The results in this work are of great importance for the polymer industry.

关键词： silicalite-1 cyclohexanone oxime vapor phase Beckmann rearrangement ?-caprolactam

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Flow boiling heat transfer in circulating fluidized bed

Xiaoguang REN , Jiangdong ZHENG , Sefiane KHELLIl , Arumemi-Ikhide MICHAEL ,

《能源前沿（英文）》 2009年第3卷第1期页码 85-89 doi: 10.1007/s11708-008-0067-5

摘要： In order to enhance heat transfer and mitigate contamination in the boiling processes, a new type of vapor-liquid-solid (3-phase) circulating fluidized bed boiling system has been designed, combining a circulating fluidized bed with boiling heat transfer. Experimental results show an enhancement of the boiling curve. Flow visualization studies concerning flow hydrodynamics within the riser column are also conducted whose results are presented and discussed.

关键词： vapor-liquid-solid three phase flow boiling heat transfer circulating fluidized bed

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Heat transfer characteristics of high heat flux vapor chamber

Dongchuan MO, Shushen LU, Haoliang ZHENG, Chite CHIN,

《能源前沿（英文）》 2010年第4卷第2期页码 166-170 doi: 10.1007/s11708-009-0076-z

摘要： To meet the challenge of heat spreading in electronic products, highly efficient high heat flux heat transfer vapor chambers have been manufactured and their heat transfer characteristics have been studied by a fast test system. A solid copper block with the same shape as the vapor chamber is used to compare the performance of the vapor chamber. The result shows that, it will take about 5min to achieve a steady state in the fast test system. The heat transfer characteristics of the vapor chamber are more superior to those of the copper block. In this paper, total thermal resistance of the test system is used to evaluate the heat transfer characteristics of the vapor chamber, because it has already been used to consider both the spreading thermal resistance and the flatness of the vapor chamber.

关键词： high heat flux vapor chamber (VC) heat transfer characteristics fast test

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Migration of manganese and iron during the adsorption-regeneration cycles for arsenic removal

Fangfang CHANG, Jiuhui QU, Xu ZHAO, Wenjun LIU, Kun WU

《环境科学与工程前沿（英文）》 2011年第5卷第4期页码 512-518 doi: 10.1007/s11783-011-0372-9

摘要： Fe-Mn binary oxide incorporated into porous diatomite (FMBO-diatomite) was prepared in situ and regenerated in a fixed-bed column for arsenite [As(III)] and arsenate [As(V)] removal. Four consecutive adsorption cycles were operated under the following conditions: Initial arsenic concentration of 0.1 mg·L , empty bed contact time of 5 min, and pH 7.0. About 3000, 3300, 3800, and 4500 bed volumes of eligible effluent (arsenic concentration≤0.01 mg·L ) were obtained in four As(III) adsorption cycles; while about 2000, 2300, 2500, and 3100 bed volumes of eligible effluent were obtained in four As(V) adsorption cycles. The dissection results of FMBO-diatomite fixed-bed exhibited that small amounts of manganese and iron were transferred from the top of the fixed-bed to the bottom of the fixed-bed during As(III) removal process. Compared to the extremely low concentration of iron (<0.01 mg·L ), the fluctuation concentration of Mn in effluent of the As(III) removal column was in a range of 0.01–0.08 mg·L . The release of manganese suggested that manganese oxides played an important role in As(III) oxidation. Determined with the US EPA toxicity characteristic leaching procedure (TCLP), the leaching risk of As(III) on exhausted FMBO-diatomite was lower than that of As(V).

关键词： arsenic adsorption filtration regeneration fixed-bed

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New refrigeration system using CO vapor-solid as refrigerant

HUANG Dongping, DING Guoliang, QUACK Hans

《能源前沿（英文）》 2008年第2卷第4期页码 494-498 doi: 10.1007/s11708-008-0070-x

摘要： A refrigerant must be in the vapor-liquid phase in a vapor-compression refrigeration system, therefore, CO cannot be used as a refrigerant for temperatures lower than -56°C because solid CO will form under the triple point temperature of -56°C. A refrigeration system with CO vapor-solid particles as refrigerant is put forward, by which a temperature lower than the triple point is achieved. An adjustable nozzle, a sublimator, a high-pressure regulating valve and a low-pressure regulating valve are used to replace the conventional evaporator. Theoretical cycle analysis of the refrigeration system shows that its COP can be 50% higher than that of the conventional one.

关键词： refrigerant adjustable temperature vapor-compression refrigeration sublimator

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biomaterial transplantation and genetic enhancement of intrinsic growth capacities to promote CNS axon regeneration

Bin Yu, Xiaosong Gu

《医学前沿（英文）》 2019年第13卷第2期页码 131-137 doi: 10.1007/s11684-018-0642-z

摘要： The inhibitory environment that surrounds the lesion site and the lack of intrinsic regenerative capacity of the adult mammalian central nervous system (CNS) impede the regrowth of injured axons and thereby the reestablishment of neural circuits required for functional recovery after spinal cord injuries (SCI). To circumvent these barriers, biomaterial scaffolds are applied to bridge the lesion gaps for the regrowing axons to follow, and, often by combining stem cell transplantation, to enable the local environment in the growth-supportive direction. Manipulations, such as the modulation of PTEN/mTOR pathways, can also enhance intrinsic CNS axon regrowth after injury. Given the complex pathophysiology of SCI, combining biomaterial scaffolds and genetic manipulation may provide synergistic effects and promote maximal axonal regrowth. Future directions will primarily focus on the translatability of these approaches and promote therapeutic avenues toward the functional rehabilitation of patients with SCIs.

关键词： spinal cord injury biomaterial extrinsic barrier intrinsic regeneration capacity

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Bone regeneration by stem cell and tissue engineering in oral and maxillofacial region

Zhiyuan Zhang

《医学前沿（英文）》 2011年第5卷第4期页码 401-413 doi: 10.1007/s11684-011-0161-7

摘要： Clinical imperatives for the reconstruction of jaw bone defects or resorbed alveolar ridge require new therapies or procedures instead of autologous/allogeneic bone grafts. Regenerative medicine, based on stem cell science and tissue engineering technology, is considered as an ideal alternative strategy for bone regeneration. In this paper, we review the current choices of cell source and strategies on directing the osteogenic differentiation of stem cells. The preclinical animal models for bone regeneration and the key translational points to clinical success in oral and maxillofacial region are also discussed. We propose comprehensive strategies based on stem cell and tissue engineering researches, allowing for clinical application in oral and maxillofacial region.

关键词： bone regeneration animal models translational strategies oral and maxillofacial region

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Investigation on regeneration and energy storage characteristics of a solar liquid desiccant air-conditioning

SHI Mingheng, DU Bin, ZHAO Yun

《能源前沿（英文）》 2007年第1卷第1期页码 85-90 doi: 10.1007/s11708-007-0008-8

摘要： Solar liquid desiccant air-conditioner is a new air-conditioning system in which liquid desiccant can be regenerated by solar energy and energy can be stored in the form of chemical energy in the liquid desiccant. In this paper regeneration and energy storage characteristics were studied theoretically and experimentally. Two criterion equations for heat and mass transfer in the regeneration process were obtained. The main factors that influence the regeneration process were analyzed. A principal solar liquid desiccant air-conditioning system under energy storage operating mode is proposed.

关键词： desiccant air-conditioning regeneration process air-conditioning system energy regeneration

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Evaluation of power regeneration in primary suspension for a railway vehicle

Ruichen WANG, Zhiwei WANG

《机械工程前沿（英文）》 2020年第15卷第2期页码 265-278 doi: 10.1007/s11465-019-0571-9

摘要： To improve the fuel economy of rail vehicles, this study presents the feasibility of using power regenerating dampers (PRDs) in the primary suspension systems of railway vehicles and evaluates the potential and recoverable power that can be obtained. PRDs are configured as hydraulic electromagnetic-based railway primary vertical dampers and evaluated in parallel and series modes (with and without a viscous damper). Hydraulic configuration converts the linear behavior of the track into a unidirectional rotation of the generator, and the electromagnetic configuration provides a controllable damping force to the primary suspension system. In several case studies, generic railway vehicle primary suspension systems that are configured to include a PRD in the two configuration modes are modeled using computer simulations. The simulations are performed on measured tracks with typical irregularities for a generic UK passenger route. The performance of the modified vehicle is evaluated with respect to key performance indicators, including regenerated power, ride comfort, and running safety. Results indicate that PRDs can simultaneously replace conventional primary vertical dampers, regenerate power, and exhibit desirable dynamic performance. A peak power efficiency of 79.87% is theoretically obtained in series mode on a top-quality German Intercity Express track (Track 270) at a vehicle speed of 160 mile/h (~257 km/h).

关键词： railway vehicle primary damper power regeneration ride comfort running safety