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膜分离 5

绿色化工 4

反渗透 3

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Fouling mechanisms in the early stage of an enhanced coagulation-ultrafiltration process

Haiqing CHANG,Baicang LIU,Wanshen LUO,Guibai LI

《环境科学与工程前沿（英文）》 2015年第9卷第1期页码 73-83 doi: 10.1007/s11783-014-0692-7

摘要： We investigated the fouling performances of ultrafiltration (UF) membrane for treating in-line coagulated water in an enhanced coagulation-UF hybrid process. Then we analyzed the fouling mechanisms in the early stage of UF using mathematical models and microscopy observation methods. Finally, we discussed the impact of aeration on membrane fouling in this paper. The results showed that a two-stage of trans-membrane pressure (TMP) profile during the operation of enhanced coagulation-UF membrane was observed, and the relationship between permeability and operation time fitted well with a logarithmic curve. Membrane pores blocking and cake filtration were confirmed as main membrane fouling mechanisms using the mathematical models. The two stages of membrane fouling mechanisms were further deduced, namely, the membrane pore narrowing followed by the formation of cake layer. Membrane autopsy analysis using scanning electron microscopy (SEM) images of the membrane surface sampled from different filtration cycles also confirmed the mechanisms of pores blocking and cake filtration. Moreover, according to the variations of the permeability and membrane fouling resistance, aeration was able to mitigate and control the membrane fouling to a certain extent, but the optimization of aeration conditions still needs to be studied.

关键词： coagulation-UF trans-membrane pressure (TMP) permeability membrane fouling resistance scanning electron microscopy (SEM)

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Selective pseudosolubilization capability of

Fei HUA, Hongqi WANG

《环境科学与工程前沿（英文）》 2013年第7卷第4期页码 539-551 doi: 10.1007/s11783-013-0498-z

摘要： Pseudosolubilized ability of sp. DG17 on -alkanes, role of biosurfactants in -octadecane uptake and trans-membrane transport mechanism of -octadecane were studied by analyzing amount of pseudosolubilized oil components in water phase, and the fraction of radiolabeled C -octadecane in the broth and cell pellet. GC-MS results showed that pseudosolubilized oil components were mainly C to C of -alkanes. In -octadecane broth, pseudosolubilized -octadecane could be accumulated as long as pseudosolubilized rate was faster than mineralization rate of substrate, and the maximum concentration of pseudosolubilized -octadecane achieved to 45.37 mg·L . All of these results showed that sp. DG17 mainly utilized alkanes by directly contacting with pseudosolubilized small oil droplets in the water phase. Analysis of C amount in cell pellet revealed that an energy-dependent system mainly controlled the trans-membrane transport of -octadecane.

关键词： Pseudomonas alkane uptake pseudosolubilization trans-membrane transport

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Ionic strength directed self-assembled polyelectrolyte single-bilayer membrane for low-pressure nanofiltration

《化学科学与工程前沿（英文）》 2022年第16卷第5期页码 699-708 doi: 10.1007/s11705-021-2093-3

摘要： Layer-by-layer assembly is a versatile technique for fabricating nanofiltration membranes, where multiple layers of polyelectrolytes are usually required to achieve reasonable separation performance. In this work, an ionic strength directed self-assembly procedure is described for the preparation of nanofiltration membranes consisting of only a single bilayer of poly(diallyldimethylammoniumchloride) and poly(sodium-4-styrenesulfoate). The influence of background ionic strength as well as membrane substrate properties on the formation of single-bilayer membranes are systematically evaluated. Such a simplified polyelectrolyte deposition procedure results in membranes having outstanding separation performance with permeating flux of 14.2 ± 1.5 L∙m^–2∙h^–1∙bar^–1 and Na₂SO₄ rejection of 97.1% ± 0.8% under a low applied pressure of 1 bar. These results surpass the ones for conventional multilayered polyelectrolyte membranes. This work encompasses an investigation of ionic strength induced coiling of the polyelectrolyte chains and emphasizes the interplay between-polyelectrolyte chain configuration and substrate pore profile. It thus introduces a new concept on the control of membrane fabrication process toward high performance nanofiltration.

关键词： layer-by-layer self-assembly single bilayer nanofiltration membrane desalination

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Effects of pressure and temperature on fixed-site carrier membrane for CO 2 separation from natural gas

Meng WANG, Dongxiao YANG, Zhi WANG, Jixiao WANG, Shichang WANG,

《化学科学与工程前沿（英文）》 2010年第4卷第2期页码 127-132 doi: 10.1007/s11705-009-0231-4

摘要： In this paper, the effect of testing temperature on the performance of fixed carrier membrane for CO separation were studied. The blend composite membranes were developed respectively with a blend of PEI-PVA (polyetheleneimine-polyvinyl alcohol) as separation layer and PS (polysulfone) ultrafiltration membranes as the substrates. The permselectivity of the membranes was measured with CO/CH mixed gas. The effect of testing temperature on membrane separation performance was investigated. The results showed that both the permeances of CO and CH decreased with the increase of temperature, and the permeances decreased more quickly under low pressure than those under high pressure. At the feed pressure of 0.11MPa, the CO/ CH selectivity of PEI-PVA/PS blend composite membrane reduced along with temperature increment. Under the feed pressure of 0.21MPa, as well as 1.11MPa, the selectivity decreased with the increase of temperature.

关键词： temperature increment high pressure permselectivity separation performance temperature

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Pilot study for the treatment of sodium and fluoride-contaminated groundwater by using high-pressuremembrane systems

Xiaomao WANG,Hongwei YANG,Zhenyu LI,Shaoxia YANG,Yuefeng XIE

《环境科学与工程前沿（英文）》 2015年第9卷第1期页码 155-163 doi: 10.1007/s11783-014-0740-3

摘要： High-pressure membrane process is one of the cost-effective technologies for the treatment of groundwater containing excessive dissolved solids. This paper reports a pilot study in treating a typical groundwater in Huaibei Plain containing excessive sodium, sulfate and fluoride ions. Three membrane systems were set up and two brands of reverse osmosis (RO), four low-pressure RO (LPRO) and one tight nanofiltration (NF) membranes were tested under this pilot study. An apparent recovery rate at about 75% was adopted. Cartridge filtration, in combination with dosing antiscalent, was not sufficient to reduce the fouling potential of the raw water. All RO and LPRO systems (except for the two severely affected by membrane fouling) demonstrated similar rejection ratios of the conductivity (~98.5%), sodium (~98.5%) and fluoride (~99%). Membrane fouling substantially reduced the rejection performance of the fouled membranes. The tight NF membrane also had a good rejection on conductivity (95%), sodium (94%) and fluoride (95%). All membranes rejected sulfate ion almost completely (more than 99%). The electricity consumptions for the RO, LPRO and NF systems were 1.74, 1.10 and 0.72 kWh?m treated water, respectively. The estimated treatment costs by using typical RO, LPRO and tight NF membrane systems were 1.21, 0.98 and 0.96 CNY?m finished water, respectively. A treatment process consisting of either LPRO or tight NF facilities following multi-media filtration was suggested.

关键词： reverse osmosis (RO) nanofiltration (NF) water quality standards sodium fluoride cost estimation

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Pressure swing adsorption/membrane hybrid processes for hydrogen purification with a high recovery

Baojun Li,Gaohong He,Xiaobin Jiang,Yan Dai,Xuehua Ruan

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 255-264 doi: 10.1007/s11705-016-1567-1

摘要： Hydrogen was recovered and purified from coal gasification-produced syngas using two kinds of hybrid processes: a pressure swing adsorption (PSA)-membrane system (a PSA unit followed by a membrane separation unit) and a membrane-PSA system (a membrane separation unit followed by a PSA unit). The PSA operational parameters were adjusted to control the product purity and the membrane operational parameters were adjusted to control the hydrogen recovery so that both a pure hydrogen product (>99.9%) and a high recovery (>90%) were obtained simultaneously. The hybrid hydrogen purification processes were simulated using HYSYS and the processes were evaluated in terms of hydrogen product purity and hydrogen recovery. For comparison, a PSA process and a membrane separation process were also used individually for hydrogen purification. Neither process alone produced high purity hydrogen with a high recovery. The PSA-membrane hybrid process produced hydrogen that was 99.98% pure with a recovery of 91.71%, whereas the membrane-PSA hybrid process produced hydrogen that was 99.99% pure with a recovery of 91.71%. The PSA-membrane hybrid process achieved higher total H recoveries than the membrane-PSA hybrid process under the same H recovery of membrane separation unit. Meanwhile, the membrane-PSA hybrid process achieved a higher total H recovery (97.06%) than PSA-membrane hybrid process (94.35%) at the same H concentration of PSA feed gas (62.57%).

关键词： hydrogen purification PSA membrane separation hybrid process

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长江越江通道工程应实行桥隧并举

钱七虎,何益寿

《中国工程科学》 2001年第3卷第5期页码 32-34

摘要：

长江越江交通通道工程对我国21世纪经济的稳定发展作用巨大，因此在越江交通通道工程方案的选择上不能唯桥是举，而要因地制宜和恰到好处地发挥桥梁和水下隧道各自的优势，总体上实行桥隧并举。

关键词：长江越江交通通道工程桥梁水下隧道

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Roles of integrin β3 cytoplasmic tail in bidirectional signal transduction in a trans-dominant inhibition

null

《医学前沿（英文）》 2016年第10卷第3期页码 311-319 doi: 10.1007/s11684-016-0460-0

摘要：

We evaluated the roles of calpain cleavage-related mutations of the integrin β3 cytoplasmic tail in integrin αIIbβ3 bidirectional signaling using a trans-dominant inhibition model. Chimeric Tac-β3 proteins (i.e., Tac-β3, Tac-β3D741, Tac-β3D747, Tac-β3D754, Tac-β3D759, and Tac-β3DNITY) consisting of the extracellular and transmembrane domains of human IL-2 receptor (Tac) and the human integrin β3 cytoplasmic domain were stably expressed in the 123 CHO cells harboring human glycoprotein Ib-IX and wild-type integrin αIIbβ3. The different cells were assayed for stable adhesion and spreading on immobilized fibrinogen, and for binding soluble fibrinogen representing outside-in and inside-out signaling events, respectively. The chimeric protein Tac-β3 inhibited, and Tac-β3DNITY partially attenuated stable adhesion and spreading. Tac-β3, Tac-β3D759, Tac-β3DNITY, and Tac-β3D754, but not Tac-β3D747 or Tac-β3D741, impaired the soluble fibrinogen binding. Results indicated that the bidirectional signaling was significantly inhibited by Tac-β3 and Tac-β3DNITY, albeit to a much lesser extent. Moreover, only inside-out signaling was impaired in the 123/Tac-β3D759 and 123/Tac-β3D754 cells in contrast to an intact bidirectional signaling in the 123/Tac-β3D747 and 123/Tac-β3D741 cells. In conclusion, the calpain cleavage of integrin β3 resulted in the regulatory effects on signaling by interrupting its interaction with cytoplasmic proteins rather than altering its conformation, and may thus regulate platelet function.

关键词： integrin β3 signal transduction trans-dominant inhibition model

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计算流体力学在水处理膜过程中的应用

张雅琴,张林,侯立安

《中国工程科学》 2014年第16卷第7期页码 47-52

摘要：

本文介绍了计算流体力学（CFD）在膜分离过程模拟中的基本原理，对CFD在压力膜驱动过程组件设计、传质和膜污染过程研究方面的应用和CFD在具有相变膜过程（渗透汽化、膜蒸馏）以及其他膜过程中的应用分别进行了综述，最后对CFD在膜分离技术研究中的应用前景进行了展望。

关键词：计算流体力学膜分离压力驱动渗透汽化膜蒸馏

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opportunities in improving left ventricular remodelling and clinical outcome following surgical and trans-catheter

《医学前沿（英文）》 2021年第15卷第3期页码 416-437 doi: 10.1007/s11684-021-0852-7

摘要： Over the last half century, surgical aortic valve replacement (SAVR) has evolved to offer a durable and efficient valve haemodynamically, with low procedural complications that allows favourable remodelling of left ventricular (LV) structure and function. The latter has become more challenging among elderly patients, particularly following trans-catheter aortic valve implantation (TAVI). Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss, valvular-vascular impedance to myocardial activation, force-velocity relationship, and myocardial strain. LV hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this endeavour. Early intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient outcome. Physiological pacing via the His-Purkinje system for conduction abnormalities, further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression, LV coordinate contraction, and global vascular function. TAVI leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary interventions. Until comparable long-term durability and the resolution of TAVI related complications become available, SAVR remains the first choice for lower risk younger patients.

关键词： surgical aortic valve replacement trans-catheter aortic valve implantation left ventricular hypertrophy and fibrosis myocardial force-velocity relationship His-Purkinje pacing renin-angiotensin system inhibitors coronary access impairment

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跨海大桥健康监测的关键技术分析

郭健

《中国工程科学》 2010年第12卷第7期页码 90-95

摘要：

以舟山大陆连岛工程为背景，阐述和讨论了在跨海大桥中开展健康监测的重要性和研究现状，并分析了跨海大桥健康监测和损伤识别所面临的关键技术问题和研究趋势，提出了考虑非线性效应和荷载激励特征来开展复杂结构损伤识别的研究思路，以提升通过大型健康监测系统来实现桥梁损伤评估的能力。

关键词：跨海大桥舟山大陆连岛工程健康监测损伤识别

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Current treatment strategy of acute promyelocytic leukemia

Jianqing Mi

《医学前沿（英文）》 2011年第5卷第4期页码 341-347 doi: 10.1007/s11684-011-0169-z

摘要： Acute promyelocytic leukemia (APL) is a unique subtype of acute myeloid leukemia (AML). The prognosis of APL has changed from the worst among the AMLs to currently the best. The application of all- retinoic acid (ATRA) in the induction therapy of APL decreases the high mortality of newly diagnosed patients, thereby significantly improving the response rate. ATRA combined with anthracycline-based chemotherapy is the current standard treatment, and for high-risk patients, high doses cytarabine have a beneficial effect on relapse prevention. In recent years, the indications of arsenic trioxide (ATO) therapy for APL have been extended from the salvage therapy for relapse patients to the first-line treatment of APL. The introduction of both ATRA and ATO represents great achievements in translational medicine. In this review article, we discuss the therapeutic strategies for this disease, including the initial approaches to newly diagnosed patients, prevention, and treatment of side effects and relapse to ensure the best and timely treatment for each newly diagnosed APL patient.

关键词： acute promyelocytic leukemia all-trans retinoic acid arsenic trioxide

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Deviation correction strategy for the earth pressure balance shield based on shield–soil interactions

《机械工程前沿（英文）》 2022年第17卷第2期 doi: 10.1007/s11465-022-0676-4

摘要： The control system presently used in shield posture rectification is based on driver experience, which is marginally reliable. The study of the related theory is flawed. Therefore, a decision-making approach for the deviation correction trajectory and posture rectification load for an earth pressure balance (EPB) shield is proposed. A calculation model of posture rectification load of an EPB shield is developed by considering the interactions among the cutter head, shield shell, and ground. The additional position change during the shield attitude correction is highlighted. The posture rectification loads and shield behaviors results can be solved by the proposed method. The influences of the stratum distribution (i.e., bedrock height in the upper-soft and lower-hard strata) on shield behaviors and posture rectification loads are analyzed. Results indicated that the increase of pitch angle in the upper-soft and lower-hard strata causes a sharp rise in vertical displacement. The bedrock height increases the magnitudes of the required posture rectification moments when h_r/D > 0.5. For a tunnel with h_r/D ≤ 0.5, the variation of h_r/D has little effect on the posture rectification moments. Finally, the posture rectifying curves based on the theoretical model are compared with the target ones based on the double circular arc interpolation method. The required results can be obtained regardless of the soil–rock compound stratum distribution. The maximum rectification moment in the rock layer is almost 12.6 times that in the soil layer. Overall, this study provides a valuable reference for moment determination and the trajectory prediction of posture rectification in compound strata.

关键词： additional position change deviation correction trajectory earth pressure balance shield mechanical model posture rectification

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Membrane fouling control by ultrasound in an anaerobic membrane bioreactor

SUI Pengzhe, WEN Xianghua, HUANG Xia

《环境科学与工程前沿（英文）》 2007年第1卷第3期页码 362-367 doi: 10.1007/s11783-007-0062-9

摘要： In this study, ultrasound was used to control the membrane fouling online in an anaerobic membrane bioreactor (AMBR). Short-term running experiments were carried out under different operating conditions to explore feasible ultrasonic parameters. The experimental results indicated that when the crossflow velocity was more than 1.0 m/s, membrane fouling could be controlled effectively only by hydrodynamic methods without ultrasound. When ultrasound was applied, an ultrasonic power range of 60–150 W was suitable for the membrane fouling control in the experimental system. The experimental results showed that the membrane fouling was controlled so well that membrane filtration resistance (Σ) could stay at 5 × 10 m for more than a week with the crossflow velocity of 0.75 m/s, which equaled the effect of crossflow velocity of more than 1.0 m/s without ultrasound.

关键词： membrane filtration filtration resistance different feasible ultrasonic anaerobic membrane