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Transparent exopolymer particles (TEPs)-associated protobiofilm: A neglected contributor to biofouling

《环境科学与工程前沿（英文）》 2021年第15卷第4期 doi: 10.1007/s11783-020-1361-7

摘要：

• Bacteria could easily and quickly attached onto TEP to form protobiofilms.

关键词： Transparent exopolymer particles (TEPs) TEP-protobiofilm Bacteria attachment Biofouling of membrane

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Preparation of transparent BaSO

Le Fang, Qian Sun, Yong-Hong Duan, Jing Zhai, Dan Wang, Jie-Xin Wang

《化学科学与工程前沿（英文）》 2021年第15卷第4期页码 902-912 doi: 10.1007/s11705-020-1985-y

摘要： BaSO nanoparticles as important functional materials have attracted considerable research interests, due to their X-rays barrier and absorption properties. However, most of BaSO nanoparticles prepared by traditional technology are nanopowders with broad size distribution and poor dispersibility, which may greatly limit their applications. To the best of our knowledge, the synthesis of transparent BaSO nanodispersions was rarely reported. Here, we firstly present a novel and efficient method to prepare transparent and stable BaSO nanodispersions with a relatively small particle size around 10 to 17 nm using a precipitation method in a rotating packed bed (RPB), followed by a modification treatment using stearic acid. Compared with the BaSO prepared in a traditional stirred tank, the product prepared using an RPB has much smaller particle size and narrower size distribution. More importantly, by using RPB, the reaction time can be significantly decreased from 20 min to 18 s. Furthermore, the transparent BaSO -polyvinyl butyral nanocomposite films with good X-ray shielding performance can be easily fabricated. We believe that the stable BaSO nanodispersions may have a wide range of applications for transparent composite materials and coatings with X-ray shielding performance for future research.

关键词： BaSO₄ nanoparticles rotating packed bed transparent nanodispersions BaSO₄-PVB films X-ray shielding

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Model test and discrete element method simulation of shield tunneling face stability in transparent clay

Huayang LEI, Yajie ZHANG, Yao HU, Yingnan LIU

《结构与土木工程前沿（英文）》 2021年第15卷第1期页码 147-166 doi: 10.1007/s11709-020-0704-6

摘要： The stability of the shield tunneling face is an extremely important factor affecting the safety of tunnel construction. In this study, a transparent clay with properties similar to those of Tianjin clay is prepared and a new transparent clay model test apparatus is developed to overcome the “black box” problem in the traditional model test. The stability of the shield tunneling face (failure mode, influence range, support force, and surface settlement) is investigated in transparent clay under active failure. A series of transparent clay model tests is performed to investigate the active failure mode, influence range, and support force of the shield tunneling face under different burial depth conditions, whereas particle flow code three-dimensional numerical simulations are conducted to verify the failure mode of the shield tunneling face and surface settlement along the transverse section under different burial depth conditions. The results show that the engineering characteristics of transparent clay are similar to those of soft clay in Binhai, Tianjin and satisfy visibility requirements. Two types of failure modes are obtained: the overall failure mode (cover/diameter: / ≤1.0) and local failure mode ( / ≥2.0). The influence range of the transverse section is wider than that of the longitudinal section when / ≥2.0. Additionally, the normalized thresholds of the relative displacement and support force ratio are 3%–6% and 0.2–0.4, respectively. Owing to the cushioning effect of the clay layer, the surface settlement is significantly reduced as the tunnel burial depth increases.

关键词： shield tunneling face stability transparent clay model test numerical simulation

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ImgFS: a transparent cryptography for stored images using a filesystem in userspace

Osama A. KHASHAN,Abdullah M. ZIN,Elankovan A. SUNDARARAJAN

《信息与电子工程前沿（英文）》 2015年第16卷第1期页码 28-42 doi: 10.1631/FITEE.1400133

摘要： Real-time encryption and decryption of digital images stored on end-user devices is a challenging task due to the inherent features of the images. Traditional software encryption applications generally suffered from the expense of user convenience, performance efficiency, and the level of security provided. To overcome these limitations, the concept of transparent encryption has been proposed. This type of encryption mechanism can be implemented most efficiently with kernel file systems. However, this approach has some disadvantages since developing a new file system and attaching it in the kernel level requires a deep understanding of the kernel internal data structure. A filesystem in userspace (FUSE) can be used to bridge the gap. Nevertheless, current implementations of cryptographic FUSE-based file systems suffered from several weaknesses that make them less than ideal for deployment. This paper describes the design and implementation of ImgFS, a fully transparent cryptographic file system that resides on user space. ImgFS can provide a sophisticated way to access, manage, and monitor all encryption and key management operations for image files stored on the local disk without any interaction from the user. The development of ImgFS has managed to solve weaknesses that have been identified on cryptographic FUSE-based implementations. Experiments were carried out to measure the performance of ImgFS over image files’ read and write against the cryptographic service, and the results indicated that while ImgFS has managed to provide higher level of security and transparency, its performance was competitive with other established cryptographic FUSE-based schemes of high performance.

关键词： Storage image security Cryptographic file system Filesystem in userspace (FUSE) Transparent encryption

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Utilizing transparent and conductive SnO

Jing Gu, Hongtao Yu, Xie Quan, Shuo Chen, Junfeng Niu

《环境科学与工程前沿（英文）》 2020年第14卷第4期 doi: 10.1007/s11783-020-1251-z

摘要： Abstract • A novel Z-scheme Si-SnO2-TiOx with SnO2 as electron mediator is first constructed. • Transparent and conductive SnO2 can pass light through and promote charge transport. • VO from SnO2 and TiOx improve photoelectrochemical performances. • Efficient photocatalytic degradations originate from the Z scheme construction. Z-scheme photocatalysts, with strong redox ability, have a great potential for pollutants degradation. However, it is challenging to construct efficient Z-scheme photocatalysts because of their poor interfacial charge separation. Herein, by employing transparent and conductive SnO2 as electron mediator to pass light through and promote interfacial charge transportation, a novel Z-scheme photocatalyst Si-SnO2-TiOx (1

关键词： Z-scheme photocatalyst Tin oxide Electron mediator Organic pollutant

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从资源共享到服务共享：透明计算的机遇与挑战

张尧学,周悦芝

《中国工程科学》 2009年第11卷第8期页码 10-17

摘要：

随着计算机和网络技术以及应用的不断快速发展，计算模式从最初的以主机计算为主，发展到以桌面(PC)计算为主，再发展到现在的以网络计算为主，乃至普适计算。然而，迄今为止的计算模式还是遵循以单机或单机联合为基础的单机思维模式，因此，目前的计算模式还是一种以“资源共享”为主要特征的计算。在网络和普适计算的新时代，用户关心的主要是服务和服务共享，计算机也将从以“资源共享”为特征的计算过渡到以“服务共享”为特征的计算。笔者提出一种适应于“服务共享”的计算模式——透明计算，并对其概念、体系结构及相关关键技术进行介绍。此外，还对透明计算的未来发展及影响进行展望。

关键词：普适计算资源共享服务共享透明计算

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Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

《能源前沿（英文）》 2013年第7卷第4期页码 506-510 doi: 10.1007/s11708-013-0275-5

摘要： The collision frequency function for aerosol particles has already been calculated for the free molecule regime and for the continuum range. The present work, taking into account the influence of internal force fields such as magnetic force, electric force and molecular forces, created by particles themselves, recalculated the collision frequency in the case of particles much smaller than the mean free path of the gas (free molecule regime). Attractive forces increase naturally the collision frequency, while repulsive forces decrease it. The calculation was performed for all types of central forces deriving from a potential, including Coulomb forces and Van der Waals forces.

关键词： aerosol particles collision frequency function coagulation

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Polymer-nanoinorganic particles composite membranes: a brief overview

Zhen-liang XU, Li-yun YU, Ling-feng HAN

《化学科学与工程前沿（英文）》 2009年第3卷第3期页码 318-329 doi: 10.1007/s11705-009-0199-0

摘要： Polymer-nanoinorganic particles composite membranes present an interesting approach for improving the physical and chemical, as well as separation properties of polymer membranes, because they possess characteristics of both organic and inorganic membranes such as good permeability, selectivity, mechanical strength, thermal stability and so on. The preparations and structures of polymer-nanoinorganic particles composite membranes and their unique properties are reviewed.

关键词： polymer nanoinorganic particles composite membranes

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纤维膜在机械压力下由不透明到透明的转变 Article

王超, 赵景, 刘柳, 张鹏, 王先锋, 俞建勇, 丁彬

《工程（英文）》 2022年第19卷第12期页码 84-92 doi: 10.1016/j.eng.2021.02.018

摘要：

智能可穿戴设备、电子皮肤、空气过滤和组织工程等领域，对透明薄膜材料或基材的需求很大。传统透明材料，如玻璃、塑料等，由于缺乏相互连通的孔道、不理想的孔隙率和柔性，不能满足这些新兴领域的要求。静电纺丝纤维膜因其具有小孔径、高孔隙率和良好的柔性等优点可以弥补传统材料的不足，因此，开发透明的静电纺丝纤维膜具有重大的价值。本文报道了一种简单有效的方法，在不使用任何其他添加剂的情况下，通过机械压力，直接将静电纺丝纤维膜制备成柔性的、有孔的透明纤维膜材料。同时，首次总结了压制后聚合物的透明度性能与分子结构之间的关系。经过机械压力处理后，纤维膜仍可以保持纤维形态、微米级孔道和一定的孔隙率。以聚苯乙烯静电纺丝纤维膜为例，所制备的透明聚苯乙烯纤维膜具有优异的光学性能和机械性能。透明纤维膜可实现高透光率（≈89%，可见光波长在550 nm处）、大孔隙率（10%~30%）和强的机械拉伸强度（≈148 MPa），该拉伸强度约为初始静电纺丝纤维膜的78倍。此外，本文基于透明纤维膜，利用真空辅助抽滤银纳米线和机械压力作用，制备出透明的导电纤维膜材料。与氧化铟锡导电薄膜相比，我们所制备的透明导电纤维膜展示出良好的导电性（9 Ω·sq^-1，78%的透光率）和优异的机械性能（可承受大量的弯曲应力）。

关键词：透明静电纺丝纤维膜孔道结构机械压力导电

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Dynamic characteristics of molten droplets and hot particles falling in liquid pool

Liangxing LI, Weimin MA, Huixiong LI, Tingkuan CHEN,

《能源前沿（英文）》 2010年第4卷第2期页码 246-251 doi: 10.1007/s11708-009-0077-y

摘要： The dynamic characteristics of molten droplets and hot particles at the very beginning of their fall into coolant pools are presented. The falling course of a single droplet or a single hot particle was recorded by a high-speed camera and a curve of velocity . time was obtained. Emphasis was placed on the effects of the droplet’s size and temperature, the coolant’s temperature and properties, and the droplet’s physical properties on the moving behavior. The results for the all cases showed that the velocity of a falling droplet/particle decreased rapidly but rebounded shortly, at the beginning of droplet/particle falling in the coolant. Following such a V-shaped evolution in velocity, the droplet/particle slows down gradually to a comparatively steady velocity. An increase in either coolant temperature or droplet temperature results in a larger velocity variation in the “J-region”, but a smaller deceleration when it moves out of the “J-region”. The elevated volatility of a coolant leads to a steeper deceleration in the “J-region” and beyond. The bigger size of a particle leads to a greater velocity variation in the “J-region” and terminal velocity. A high melting point and thermal conductivity as well as lower heat capacity contribute to dramatic variation in the “J-region” and low terminal velocity.

关键词： dynamic characteristics molten droplets high-temperature particles fuel and coolant interactions

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Selective removal of phenol by spherical particles of

Qingchuan CHEN, Yicun WEN, Yu CANG, Li LI, Xuhong GUO, Rui ZHANG

《化学科学与工程前沿（英文）》 2013年第7卷第2期页码 162-169 doi: 10.1007/s11705-013-1318-5

摘要： Spherical particles of -, - and -cyclodextrin (CD) polymers to efficiently remove phenol from waste water were prepared by reverse suspension polymerization with epichlorohydrin as crosslinker in liquid paraffin. By controlling the amounts of crosslinker and water, well-defined spherical polymer particles with controllable size were obtained. Due to the selective inclusion associations between CD groups and phenol, these CD spherical polymer particles were demonstrated to be ideal candidates for removal of phenol. Among them -CD polymer particles showed the best performance. The kinetics and isothermal equilibrium models were used to fit the experimental data of phenol removal from aqueous solution using these CD polymer particles. It was found that the kinetics followed the Ho and Mckay equation, suggesting that the adsorption process of phenol was controlled by diffusion and the host-guest interaction between CD and phenol. Equilibrium isothermal data can be well fitted by the Freundlich equation. The negative free energy change indicated the spontaneous nature of adsorption of phenol by -, - and -CD spherical polymer particles, while the lowest free energy for -CD polymer reflected its best adsorption ability, compared to - and -CD polymer particles.

关键词： cyclodextrin polymer particles phenol kinetic models adsorption isotherm equilibrium models

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Characteristics and mixing state of S-rich particles in haze episodes in Beijing

Jun Hu, Fengkui Duan, Kebin He, Yongliang Ma, Shuping Dong, Xiande Liu

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0861-y

摘要： Four types of S-rich particles are identified by SEM/FESEM-EDX With on-line observation, characteristics of S-rich particles are discovered Intensities of formation of S-rich particles are seasonally different Direct individual analysis using Scanning Electron Microscopy combined with online observation was conducted to examine the S-rich particles in PM of two typical polluted haze episodes in summer and winter from 2014 to 2015 in Beijing. Four major types of S-rich particles, including secondary CaSO particles (mainly observed in summer), S-rich mineral particles (SRM), S-rich water droplets (SRW) and (C, O, S)-rich particles (COS) were identified. We found the different typical morphologies and element distributions of S-rich particles and considered that (C, O, S)-rich particles had two major mixing states in different seasons. On the basis of the S-rich particles’ relative abundances, S concentrations and their relationships with PM as well as the seasonal comparison, we revealed that the S-participated formation degrees of SRM and SRW would enhance with increasing PM concentration. Moreover, C-rich matter and sulfate had seasonally different but significant impacts on the formation of COS.

关键词： S-rich particles Morphology Element distribution Mixing state

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Fundamental influences of particles on stirred and unstirred venting processes of foaming systems

Henrik LEIMEISTER,Jörg STEINBACH

《化学科学与工程前沿（英文）》 2014年第8卷第2期页码 141-148 doi: 10.1007/s11705-014-1423-0

摘要： Venting is the common safety measure to protect plant equipment against excessive overpressure. So far, scenarios in which particles were part of the system and should have been accounted for did ignore their presence; the scenarios were treated like a two-phase system. Current research shows that particles can have a major influence on the venting behaviour. Experimental results indicate that particles affect level swell and relief flow especially of foamy systems. Based on those results four different layers of influence of the particle have been identified and are presented in a first model. Based on this model recommendations for the development of new and more complex models are given.

关键词： venting multi-phase

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Hygroscopicity of ambient submicron particles in urban Hangzhou, China

Jiachen ZHANG, Lin WANG, Jianmin CHEN, Shengmao FENG, Jiandong SHEN, Li JIAO

《环境科学与工程前沿（英文）》 2011年第5卷第3期页码 342-347 doi: 10.1007/s11783-011-0358-7

摘要： In this study, hygroscopicity of size-segregated ambient submicron particles in urban Hangzhou was studied from 28th December 2009 to 18th January 2010, using a hygroscopicity-tandem differential mobility analyzer (H-TDMA). The submicron particles in Hangzhou showed a minor hygroscopic growth at 73% relative humidity (RH), and then grew significantly between 77% and 82% RH. Monomodal distribution accounted for 90% for 30 nm particles, 17% for 50 nm particles, and less than 7% for particles larger than 50 nm at 82% RH. Deconvolution of the bimodal distribution indicated a less hygroscopic group and a more hygroscopic group, with the fraction of the more hygroscopic group increasing with the initial dry particle size and then remaining almost constant for accumulation mode particles. Our results imply that submicron particles in urban Hangzhou were almost entirely externally mixed, and the hygroscopic properties of ambient particles in urban Hangzhou were mainly a function of their size and chemical composition.

关键词： hygroscopicity hygroscopic tandem differential mobility analyzer (H-TDMA) submicron ambient particles Hangzhou