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Analytical evaluation of steady-state solute distribution in through- diffusion and membrane behavior test under non-perfectly flushing boundary conditions
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作者 Guannian Chen Yuchao Li +1 位作者 Kristin MSample-Lord Shan Tong 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期258-267,共10页
The through-diffusion and membrane behavior testing procedure using a closed-system apparatus has been widely used for concurrent measurement of diffusion and membrane efficiency coefficients of low-permeability clay-... The through-diffusion and membrane behavior testing procedure using a closed-system apparatus has been widely used for concurrent measurement of diffusion and membrane efficiency coefficients of low-permeability clay-based barrier materials.However,the common assumption of perfectly flushing conditions at the specimen boundaries could induce errors in analyses of the diffusion coefficients and membrane efficiencies.In this study,an innovative pseudo three-dimensional(3D)analytical method was proposed to evaluate solute distribution along the boundary surfaces of the soil-porous disks system,considering the non-perfectly flushing conditions.The results were consistent with numerical models under two scenarios considering different inflow/outflow positions.The proposed model has been demonstrated to be an accurate and reliable method to estimate solute distributions along the bound-aries.The calculated membrane efficiency coefficient and diffusion coefficient based on the proposed analytical method are more accurate,resulting in up to 50%less relative error than the traditional approach that adopts the arithmetic mean value of the influent and effluent concentrations.The retar-dation factor of the clay specimen also can be calculated with a revised cumulative mass approach.Finally,the simulated transient solute transport matched with experimental data from a multi-stage through-diffusion and membrane behavior test,validating the accuracy of the proposed method. 展开更多
关键词 Diffusion testing membrane behavior Coupled transport Clay barrier Transport modeling
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Monitoring of polymeric membrane fouling in hollow fiber module using ultrasonic nondestructive testing 被引量:1
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作者 刘景霞 李建新 +1 位作者 陈雪梅 张玉忠 《中国有色金属学会会刊:英文版》 CSCD 2006年第B02期845-848,共4页
This study describes the development of novel protocols extending the real-time ultrasonic reflectometry(UTDR) for the detection of membrane fouling in hollow fiber module during ultrafiltration(UF) of oily water trea... This study describes the development of novel protocols extending the real-time ultrasonic reflectometry(UTDR) for the detection of membrane fouling in hollow fiber module during ultrafiltration(UF) of oily water treatment. A specially designed acoustic sensor with a frequency of 2.5 MHz was used. The hollow fiber membranes used were polysulphone(PSf) UF membranes with MWCO 40 kDa. The wastewaters with three different oily concentrations of 100, 500 and 1 000 mg/L were investigated. Diesel oil was utilized as the primary foulant. The results show that the permeate flux declines with operation time and its value becomes lower with the increase of the oily concentration in wastewater. It is found that ultrasonic measurement can detect the fouling and cleaning processes. A new signal analysis protocol-ultrasonic reflected energy was developed. Ultrasonic reflected energy obtained indicates the deposition of oily layer as a function of operation time and its removal after cleaning. The overall flux decline is reasonably correlated with the changes in ultrasonic reflected energy. This research provides the evidence that the ultrasonic reflectometry technique is capable of monitoring membrane fouling and cleaning in hollow fiber modules. 展开更多
关键词 空心纤维组件 聚合物膜 膜附着 超声波 非破坏性试验 监测 超滤膜
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Cryodamage to plasma membrane integrity in head and tail regions of human sperm 被引量:13
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作者 Wei-Jie ZHU Xue-Gao LIU Center for Reproductive Immunology Research, Jinan University, Guangzhou 510632, China 《Asian Journal of Andrology》 SCIE CAS CSCD 2000年第2期135-138,共4页
Aim: To investigate the effect of cryopreservation on the plasma membrane integrity in the head and tail regions ofindividual sperm, and the relationship between intact cryopreserved sperm and its motility and zona-fr... Aim: To investigate the effect of cryopreservation on the plasma membrane integrity in the head and tail regions ofindividual sperm, and the relationship between intact cryopreserved sperm and its motility and zona-free hamster oocytepenetration rate. Methods: The eosin Y exclusion and the hypoosmotic swelling tests were combined to form a sin-gle test (HOS-EY test) to identify the spermatozoa with four types of membrane integrity. Results: After cryop-reservation, there was a marked decline in the percentage of spermatozoa with Type Ⅳ membrane integrity (head mem-brane intact/tail membrane intact), and a significant increase in those with Type Ⅰ (head membrane damaged/tail mem-brane damaged) and Type Ⅲ (head membrane damaged/tail membrane intact) membrane integrity (n = 50, P <0.01). The value of Type Ⅲ integrity had a wide range of variability, whereas Type Ⅱ (head membrane intact/tailmembrane damaged) was uncommon after thawing. A high correlation was observed between the percentage of Type Ⅳintegrity and sperm motility ( n = 50, r = 0.74, P < 0.01 ). However, the values of Type Ⅳ integrity were usuallylower than those of post-thaw motility in most cryopreserved samples. The value of Type Ⅳ integrity did not correlatewith the sperm penetration rate ( n = 25, r = 0.22, P > 0.05). Conclusion: (1) The HOS-EY test has the advan-tage of showing four patterns of membrane integrity in individual spermatozoon; (2) Cryopreservation causes a signifi-cant membrane rupture in the head and tail regions of spermatozoa; Type Ⅲ is the main transitional state of membranecryodamage; (3) Cryodamage to head and tail membrane may occur independently; the presence of an intact tail mem-brane does not necessarily indicate the intacmess of head membrane. (4) Intact membranes are closely related to post-thaw motility, but do not reflect the fertilizing potential. 展开更多
关键词 SPERMATOZOA CRYOPRESERVATION cell membrane supravital staining hypoosmotic swelling test
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Experimental Study and Model Analysis of the Performance of IPMC Membranes with Various Thickness 被引量:13
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作者 Qingsong He Min Yu +3 位作者 Linlin Song Haitao Ding Xiaoqing Zhang Zhendong Dai 《Journal of Bionic Engineering》 SCIE EI CSCD 2011年第1期77-85,共9页
Ionic Polymer-Metal Composite (IPMC) is a new electro-active polymer, which has the advantages of light weight, flexibility, and large stroke with low driving voltage. Because of these features, IPMC can be applied ... Ionic Polymer-Metal Composite (IPMC) is a new electro-active polymer, which has the advantages of light weight, flexibility, and large stroke with low driving voltage. Because of these features, IPMC can be applied to bionic robotic actuators, artificial muscles, as well as dynamic sensors. However, IPMC has the major drawback of low generative blocking force. In this paper, in order to enhance the blocking force, the Nation membranes with thickness of 0.22 mm, 0.32 mm, 0.42 mm, 0.64 mm and 0.8 mm were prepared by casting from liquid solution. By employing these Nation membranes, IPMCs with varying thickness were fabricated by electroless plating. The elastic modulus of the casted Nation membranes were obtained by a nano-indenter, and the current, the displacement and the blocking force were respectively measured by the apparatus for actuation test. Finally, the effects of the thickness on the performance of IPMC were analyzed with an electromechanical model. Experimental study and theory analysis indicate that as the thickness increases, the elastic modulus of Nation membrane and the blocking force of IPMC increase, however, the current and the displacement decrease. 展开更多
关键词 IPMC Nation membranes electroless plating actuation test model analysis
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Feasibility and simulation model of a pilot scale membrane bioreactor for wastewater treatment and reuse from Chinese traditional medicine 被引量:4
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作者 REN Nan-qi YAN Xian-feng +3 位作者 CHEN Zhao-bo HU Dong-xue GONG Man-li GUO Wan-qian 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第2期129-134,共6页
The lack and pollution of water resource make wastewater reuse necessary. The pilot scale long-term tests for submerged membrane bioreactor were conducted to treat the effluents of anaerobic or aerobic treatment proce... The lack and pollution of water resource make wastewater reuse necessary. The pilot scale long-term tests for submerged membrane bioreactor were conducted to treat the effluents of anaerobic or aerobic treatment process for the high-strength Chinese traditional medicine wastewater. This article was focused on the feasibility of the wastewater treatment and reuse at shorter hydraulic retention time (HRT) of 5.0, 3.2 and 2.13 h. MLSS growth, membrane flux, vacuum values and chemical cleaning periods were also investigated. The experimental results of treating two-phase anaerobic treatment effluent demonstrated that the CODfilt was less than 100 mg/L when the influent COD was between 500-10000 mg/L at HRT of 5.0 h, which could satisfy the normal discharged standard in China. The experimental results to treat cross flow aerobic reactor effluent demonstrated that the average value of CODfilt was 17.28 mg/L when the average value of influent COD was 192.84 mg/L at HRT of 2.13 h during 106 d, which could completely meet the normal standard for water reuse. The maximum MLSS and MLVSS reached 24000 and 14500 mg/L at HRT of 3.2 h respectively. Membrane flux had maximal resume degrees of 94.7% at vacuum value of 0.02 MPa after cleaning. Chemical cleaning periods of membrane module were 150 d. A simulation model of operational parameters was also established based on the theory of back propagation neural network and linear regression of traditional mathematical model. The simulation model showed that the optimum operational parameters were suggested as follows: HRT was 5.0 h, SRT was 100 d, the range of COD loading rate was between 10.664-20.451 kg/(m3.d), the range of MLSS was between 7543-13694 mg/L. 展开更多
关键词 submerged membrane bioreactor (SMBR) Chinese traditional medicine wastewater hydraulic retention time (HRT) simulation model pilot scale test
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Influence of enterococci on human sperm membrane in vitro 被引量:2
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作者 Hua Qiang Ming-Sen Jiang +1 位作者 Jian-Yin Lin Wei-Min He 《Asian Journal of Andrology》 SCIE CAS CSCD 2007年第1期77-81,共5页
Aim: To study the influence of enterococci on human sperm membrane in vitro. Methods: Ejaculated human sperm were artificially infected with β-hemolytic or non-β-hemolytic enterococci at the bacteria: sperm ratio... Aim: To study the influence of enterococci on human sperm membrane in vitro. Methods: Ejaculated human sperm were artificially infected with β-hemolytic or non-β-hemolytic enterococci at the bacteria: sperm ratio of 50:1 at 37℃. Sperm membrane integrity was examined after incubation for 1, 3 and 5 h by hypoosmotic swelling (HOS) test and electron microscopy. Results: Sperm infected with β-hemolytic enterococci had lower HOS scores compared with non-β-hemolytic strains or uninfected control (P 〈 0.01). The HOS test scores of sperm infected with β-hemolytic enterococci increased in the presence of phosphatidylcholine, an inhibitor of hemolysin. Non-β-hemolytic strains showed no significant difference in swelling rate, compared with the control group (P 〉 0.05). It was shown by electron microscopy that β-hemolytic enterococci caused significant rupture of human sperm membrane. Conclusion: β-hemolytic enterococci caused human sperm membrane injury, and might be mediated by the hemolysin of enterococci. 展开更多
关键词 ENTEROCOCCI SPERM sperm membrane hypoosmotic swelling test ULTRASTRUCTURE
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Preparation and Optimization of Porous Membrane Electrodes via Gradient Coating in Hydrogen Fuel Cell 被引量:2
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作者 Gu Xianrui Wu Yuchao +1 位作者 Wang Houpeng Rong Junfeng 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2020年第3期1-8,共8页
Fuel cells are considered to be one of the ideal alternatives to traditional fossil energy conversion devices.Membrane electrodes are the core components in the hydrogen fuel cells.Our work reported the synthesis of t... Fuel cells are considered to be one of the ideal alternatives to traditional fossil energy conversion devices.Membrane electrodes are the core components in the hydrogen fuel cells.Our work reported the synthesis of the Pt/C catalysts with different Pt loading,and by changing the Nafion content,hot pressing temperature and hot pressing pressure,the catalyst coated membrane(CCM)spraying process was optimized.Moreover,the three-dimensional structure model of the single battery membrane electrode was studied quantitatively,and the porous membrane electrode with gradient distribution was fabricated under optimized processing conditions,with excellent electrical performance. 展开更多
关键词 hydrogen fuel cell membrane electrode Pt/C catalyst polarization curve power density single cell test
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Graphene/carbon structured catalyst layer to enhance the performance and durability of the high-temperature proton exchange membrane fuel cells 被引量:1
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作者 Zhaoqi Ji Jianuo Chen +7 位作者 Zunmin Guo Ziyu Zhao Rongsheng Cai Maxwell T.P.Rigby Sarah J.Haigh Maria Perez-Page Yitao Shen Stuart M.Holmes 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第12期399-407,I0011,共10页
In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature ... In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature PEMFCs with lower Pt loading.On the one hand,Pt/Nr EGO_(2)-CB_(3)with the strong interaction between the Pt and nitrogen(N)prevent agglomeration of Pt particles and Pt particles is 5.46±1.46 nm,which is smaller than that of 6.78±1.34 nm in Pt/C.Meanwhile,ECSA of Pt/Nr EGO_(2)-CB_(3)decrease 13.65%after AST,which is much lower than that of 97.99%in Pt/C.On the other hand,the Nr EGO flakes in MEAac act as a barrier to mitigate phosphoric acid redistribution,which improves the formation of triple-phase boundaries(TPBs)and gives stable operation of the MEAacwith a lower decay rate of 0.02 mV h^(-1)within100 h.After steady-state operation,the maximum power density of Pt/Nr EGO_(2)-CB_(3)(0.411 W cm^(-2))is three times higher than that of conventional Pt/C(0.134 W cm^(-2))in high-temperature PEMFCs.After AST,the mass transfer resistance of Pt/Nr EGO_(2)-CB_(3)electrode(0.560Ωcm^(2))is lower than that in Pt/C(0.728Ωcm^(2)). 展开更多
关键词 High-temperature proton exchange membrane fuel cell Phosphoric acid loss Pt catalyst degradation Accelerated stress test DURABILITY
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Controlling Pore Size and its Distribution of γ-Al_2O_3 Nanofiltration Membranes
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作者 Rong Chun XIONG, Xiao Dong LEI, Gang WEI Beijing University of Chemical technology, Beijing 100029 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第9期969-972,共4页
The preparation process of γ-A12O3 nanofiltration membranes were studied by N2 absorption and desorption test and retention rate vs thickness gradient curve method. It was found that template and thermal treatment we... The preparation process of γ-A12O3 nanofiltration membranes were studied by N2 absorption and desorption test and retention rate vs thickness gradient curve method. It was found that template and thermal treatment were key factors for controlling pore size and its distribution. Under the optimized experimental conditions, the BJH (Barret-Joyner-Halenda) desorption average pore diameter, BJH desorption cumulative volume of pores and BET (Brunauer-Emmett-Teller) surface area of obtained membranes were about 3.9 nm, 0.33 cm3/g and 245 m2/g respectively, the pore size distribution was very narrow. Pore size decreased with the increasing of thickness and no evident change after the dense top layer was formed. The optimum thickness can be controlled by retention rate vs thickness gradient curve method. 展开更多
关键词 NANOFILTRATION γ-Al2O3 membrane membrane pore size N2 absorption-desorption test.
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Synthesis, Characterization and Biological Activities of Novel Water-soluble Metalloporphyrins
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作者 Li, ZY Zhang, YN +2 位作者 Gao, ZT Liu, Y Zhu, XJ 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第12期1085-1088,共4页
The synthesis, characterization, and biological activities of a series of metal porphyrins were described. The complexes 3a similar to 3e were prepared from the reaction of compound 2 with M(OAc)(2) in CHCl3, and the ... The synthesis, characterization, and biological activities of a series of metal porphyrins were described. The complexes 3a similar to 3e were prepared from the reaction of compound 2 with M(OAc)(2) in CHCl3, and the treatment of 3a similar to 3f with pyridine gave corresponding complexes 4a similar to 4f. These new compounds were identified by absorption spectroscopies, H-1 NMR and elemental analysis. The results of biological activity,testing revealed that 4a and 4c had stronger inhibiting action for Escherichia coli (CCTCC AB91115). 展开更多
关键词 water-soluble metalloporphyrin SYNTHESIS structure characterization biological activity testing
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Ex situ aging effect on sulfonated poly(ether ether ketone) membrane:Hydration-dehydration cycling and hydrothermal treatment
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作者 Seung-Young Choi Kyeong Sik Jin 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第7期583-592,I0014,共11页
Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation ... Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation provides incremental proton conductivity to the membranes, whereas mechanical degradation drastically reduces device stability. On this basis, we describe here the effects of two different ex situ aging processes on sulfonated poly(ether ether ketone) membranes: hydrationdehydration cycling and prolonged hydrothermal treatment. Both aged membranes exhibited enhanced phase separation under the hydrated conditions, as characterized by small angle X-ray scattering.However, when the aged membranes were dried again, the nanostructure of the membranes aged via the hydration-dehydration cycling was recoverable, whereas that of the membranes aged via prolonged hydrothermal treatment was irreversible. Furthermore, the two differently aged membranes showed clear differences in thermal, mechanical, and electrochemical properties. Finally, we implemented both aged membranes in fuel cell application. The sample aged via hydration-dehydration cycling maintained its improved cell performance, whereas the sample aged via hydrothermal treatment showed drastically reduced cell performance after durability test for 50 h. 展开更多
关键词 Sulfonated poly(ether ether ketone) Humidity cycle test Ex situ aging Proton exchange membrane Fuel cell
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Peritoneal Membrane Transport Characteristics in Uni-PET with Preceding Icodextrin Dwell as Compared to Classic PET with Preceding Glucose Dwell: A Prospective Study
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作者 Gaurav Vohra 《Open Journal of Nephrology》 2021年第4期516-522,共7页
<strong>Background:</strong> In subjects on CAPD who use icodextrin for long night dwell, it has been recommended that nocturnal exchange be replaced by dextrose dwell whenever PET is to be performed as pr... <strong>Background:</strong> In subjects on CAPD who use icodextrin for long night dwell, it has been recommended that nocturnal exchange be replaced by dextrose dwell whenever PET is to be performed as preceding exchange with icodextrin temporarily increases peritoneal membrane permeability and therefore, gives high D/PCr and low D/D<sub>0</sub> glucose values. Whether this temporary change is also seen with use of Uni-PET (which involves one hour dwell of 1.5% dextrose followed by 4-hour dwell of 4.25% dextrose) is not known. <strong>Methods:</strong> In this self, controlled study, subjects on CAPD, who were using icodextrin for long nocturnal dwell for at least 3 months, were screened for enrolment. Pregnancy or lactation, history of any PD related infectious complication in the past one month, present or past malignancy, and poor functional status were exclusion criteria. Enrolled subjects underwent classic PET with preceding 2.5% dextrose long nocturnal dwell on day 1 followed by Uni-PET with preceding 7.5% icodextrin long nocturnal dwell on day 2. Difference in D/PCr and D/D0 glucose between the two PETs was primary objectives. The study was approved by Institute Ethics Committee. <strong>Results:</strong> 15 out of 26 screened subjects were enrolled over a period of 18 months (July 2015-December 2016). The mean (±SD) age of study population was 60.8±9.1 years. Majority were males and diabetes was the most common cause of CKD. Mean D/PCr were 0.68 ± 0.11 and 0.64 ± 0.08 in classic PET and Uni-PET, respectively. The difference between the two values was not significant [mean difference between D/PCr (classic PET-Uni-PET): 0.040 ± 0.86;95% CI (-0.007 to 0.088);p = 0.09]. Similarly, D/D<sub>0</sub> glucose between classic PET and Uni-PET was also similar [mean difference between D/D0 glucose (classic PET-Uni-PET): -0.02 ± 0.09;95% CI (-0.06 to 0.03);p = 0.448]. <strong>Conclusion:</strong> Peritoneal membrane small solute transport characteristics in Uni-PET with preceding icodextrin dwell are similar to classic PET with preceding glucose dwell. If Uni-PET is used, it may not be necessary to replace preceding nocturnal exchange of icodextrin with that of dextrose as is currently advised. 展开更多
关键词 ICODEXTRIN Peritoneal membrane Peritoneal Equilibration test Peritoneal Dialysis Fluid Peritoneal Dialysis
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Treatment of Chinese traditional medicine wastewater in a submerged membrane bioreactor
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作者 任南琪 陈兆波 +1 位作者 张颖 呼冬雪 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第1期89-92,共4页
A pilot scale test was conducted in a submerged membrane bioreactor SMBR with capacity of 10. 0 m^3/d for 120 days to treat high-strength Chinese traditional medicine wastewater. Performance of the SMBR was investigat... A pilot scale test was conducted in a submerged membrane bioreactor SMBR with capacity of 10. 0 m^3/d for 120 days to treat high-strength Chinese traditional medicine wastewater. Performance of the SMBR was investigated with a sludge retention time ( TSR ) of 50 days, a hydraulic retention time ( THR ) of 8.0 h, membrane flux of 8. 0 IV( m^2 · h) and dissolved oxygen (DO) concentration of 2. 0 - 3. 0 mg/L, respectively. It was observed that the SMBR had high capacity of COD and suspended solid (SS) removal. The influent COD concentration was fluctuated between I 000 and 5 000 mg/L, while the averaged effluent COl) concentration was only 44. 6 mg/L. The influent SS concentration was fluctuated between 1 000 and 1 600 mg/L, while little effluent SS was detected. It was found that the COD remove rate increased with mixed liquor suspended solids (MLSS) and organic loading rate (ROL). In order to obtain good-quality effluent, the operational conditions of the SMBR were suggested as follows: the temperature was controlled above 10 ℃, MLSS about 7000 mg/L, R,L under 24. 76 kg/( m^3 · d), low vacuum value and constant water flux. 展开更多
关键词 submerged membrane bioreactor (SMBR) Chinese traditional medicine wastewater mixed liquor suspended solids (MISS) organic loading rate (RoL) pilot plant test
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Dip-coating of SiO2 onto ZnO-SiC Composite Membrane
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作者 Hyeyoun Hwang Hyunji Choi Miewon Jung 《Journal of Energy and Power Engineering》 2015年第6期562-565,共4页
SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed ... SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed by heat-treatment. This membrane was characterized by XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy) and BET (Brunauer-Emmett-Teller) instruments. Hydrogen permeation test was conducted at 0.1 MPa pressure and also variation of temperatures. The obtained value of heat-treated membrane after dip-coating at 298 K was obtained as 1.61 × 10-6 mol/(m2·s·Pa). 展开更多
关键词 ZnO-SiC membrane dip-coated hydrogen permeation test.
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Sensitivity of Different Cytotoxic Responses of Vero Cells Exposed to Organic Chemical Pollutants and their Reliability in the Bio-toxicity Test of Trace Chemical Pollutants
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作者 TING-TING LIAO YAN-LING SHI JIAN-WEI JIA AND LEI WANG 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2010年第3期219-229,共11页
Objective To find a sensitive cytotoxic response to reflect the bio-toxicity of trace organic pollutants, the sensitivity and reliability of morphological change and proliferation inhibition of Vero cells exposed to 2... Objective To find a sensitive cytotoxic response to reflect the bio-toxicity of trace organic pollutants, the sensitivity and reliability of morphological change and proliferation inhibition of Vero cells exposed to 2, 4, 6-trichlorophenol (TCP) and the leachate from products related to drinking water (PRDW) were compared, and the mechanism of the morphological change in Vero cells exposed to chemical pollutants was studied. Methods Vero cells were treated by different concentration of TCP and the leachate from PRDW. Methylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT) assay was carried out for proliferation inhibition. Bioluminescence method was carried out as another method to test the toxicity of TCP. Flow Cytometry assay was used to test cell Apoptosis and damage of cell-membrane. Results 0.25 mg/L TCP had an effect on cell morphology, and the proportion of morphologically changed cells increased with increasing TCP concentration. At low TCP concentrations, inhibition of cell proliferation did not seem to correlate to TCP concentration, and was negative when TCP concentration was 〈1.0 mg/L. After exposure to leachate from PRDW extracted at different temperatures, the percentage of morphologically changed cells increased with extracting temperature, but the inhibition of cell proliferation failed to reflect the correlation between extracting temperature and proliferation inhibition of Vero cells. Although the Sensitivity of bioluminescence method seems to be similar to morphological change in Veto cells, the bacterial in this method is not homologous enough with human body cells to reflect the toxicity to human body. These imply cell morphological change is a more sensitive and reliable method to reflect bio-toxicity of organic pollutants than proliferation inhibition. Flow cytometry analysis and cell rejuvenation experiments indicated cell membrane damage, which results in cell morphological change, was an early and sensitive cytotoxic response comparing with necrosis. Conelusion These results indicated that the cell membrane toxicity represented by morphological changes is a more sensitive and reliable method to indicate the composite bio-toxicity of trace chemicals than proliferation inhibition, inhibition on bioluminescence and necrosis. Nevertheless, the quantification of morphological change should be studied further. 展开更多
关键词 Vero cell Morphological change membrane damage Bio-toxicity test Drinking water
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基于深度学习模型的中试纳滤系统膜污染预测研究 被引量:1
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作者 陈艳 牛亚林 +3 位作者 彭兴 郑文静 徐小虎 徐鹏成 《兰州交通大学学报》 CAS 2024年第5期103-112,共10页
膜污染的预测或模拟对于阐明膜污染机理和制定有效的污染控制措施具有重要意义。建立了一种门控循环单元(GRU)模型,用于预测中试纳滤系统的过滤性能,并探究膜的污染机理。采用跨膜压差(TMP)作为输出变量,考察以TMP自身为输入变量的单输... 膜污染的预测或模拟对于阐明膜污染机理和制定有效的污染控制措施具有重要意义。建立了一种门控循环单元(GRU)模型,用于预测中试纳滤系统的过滤性能,并探究膜的污染机理。采用跨膜压差(TMP)作为输出变量,考察以TMP自身为输入变量的单输入时间序列模型的预测效果,并探讨了9种水质参数:pH、水温、电导率、总溶解性固体(TDS)、总硬度(TH)、浊度、高锰酸盐指数(CODMn)、溶解性有机碳(DOC)以及UV254的独立和耦合效应对膜污染及预测结果的影响,筛选出最优模型与膜污染预测中常用的机器学习算法——随机森林(RF)和时间序列预测中广泛使用的长短时记忆网络(LSTM)进行比较。结果表明:以TMP自身数据作为输入的LSTM以及GRU单输入时间序列预测模型的R^(2)分别达到了0.9613和0.9861;水质参数对TMP的相关性顺序依次为:温度>电导率>TDS>总硬度>高锰酸盐指数>DOC>浊度>UV254>pH;以温度和电导率为输入的多变量GRU模型预测效果最佳(R^(2)=0.8344),预测精度优于相同时间步长的单输入GRU模型(R^(2)=0.4555)以及相同输入参数的多变量LSTM(R^(2)=0.6428)和RF模型(R^(2)=-4.1894),在此基础上增加或减少水质参数作为模型输入,模型的预测精度均有所下降。时间序列模型在膜污染预测方面展现出了较高的可靠性,GRU模型预测精度更高,在膜污染预测中具备更高的应用潜力。输入变量的特征选择对高效预测膜污染具有重要意义,对输入水质数据进行特征选择,可以显著提升模型的预测性能。此外,预测结果反向验证了水温和无机离子耦合是造成冬季纳滤膜污染的主要原因,冬季纳滤运行过程中要注意温度和无机离子污染对纳滤膜运行稳定性的影响。 展开更多
关键词 膜污染预测 深度学习 GRU 纳滤 中试
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血栓弹力图与常规凝血试验应用于ECMO治疗中止凝血管理的对比研究
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作者 李豪 李思娜 +6 位作者 黄惠妮 阳子骥 谢慧琼 罗瑞献 向淑麟 黎海澜 莫柱宁 《中国输血杂志》 CAS 2024年第6期613-619,共7页
目的探讨血栓弹力图(thromboelastography,TEG)与常规凝血试验各参数的相关性和一致性,评价2种方法在体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)支持治疗患者肝素抗凝监测及凝血功能监测中的应用价值。方法选取2021年10月... 目的探讨血栓弹力图(thromboelastography,TEG)与常规凝血试验各参数的相关性和一致性,评价2种方法在体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)支持治疗患者肝素抗凝监测及凝血功能监测中的应用价值。方法选取2021年10月—2022年12月就诊于广西壮族自治区人民医院重症医学科的138例ECMO支持治疗的患者,对同步检测的共317对普通TEG、肝素酶纠正的血栓弹力图(heparinase-modified thromboelastography,hmTEG)参数与活化部分凝血活酶时间(APTT)、纤维蛋白原(Fib)、血小板计数(Plt)等指标进行相关性及一致性分析,并对ECMO建立时和ECMO运行24 h后的指标进行比较。结果hmTEG的凝血反应时间(R)与APTT的相关系数(r=0.441,P<0.05)低于普通TEG R值与APTT的相关系数(r=0.547,P<0.05);普通TEG的凝固角(α-Angle)、凝血形成时间(K)与Fib无相关关系(P>0.05),而hmTEG的α-Angle、K与Fib的相关系数分别为0.359(P<0.05)、-0.343(P<0.05);hmTEG的最大振幅(MA)与Plt的相关性为0.456(P<0.05),远低于其与Fib的相关性(r=0.715,P<0.05)。APTT和hmTEG对ECMO支持治疗患者普通肝素抗凝效果的判断具有中度的一致性(P<0.05)。ECMO上机24 h后Plt明显低于ECMO建立时(P<0.05),而Fib、APTT及hmTEG各参数等指标在两者间比较差异均无统计学意义(P>0.05)。结论hmTEG可以更好地反映ECMO支持治疗患者真实的凝血因子功能水平,使用hmTEG和APTT评估ECMO支持治疗患者肝素是否超量的结果可以相互参考,且hmTEG具有独特的优势。常规凝血试验和TEG检测不能相互替代,联合应用利于实现更好地抗凝和凝血管理。 展开更多
关键词 体外膜肺氧合 血栓弹力图 常规凝血试验 抗凝
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矩形平面投影气膜结构风振响应特性及风振系数研究
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作者 陈昭庆 魏超 +3 位作者 王爽 赵军宾 武岳 苏宁 《振动工程学报》 EI CSCD 北大核心 2024年第7期1115-1125,共11页
近年来,矩形平面投影气膜结构被广泛应用于大跨度气膜煤仓等设施中,但是规范中尚无该类结构的风振系数。本文通过风洞测压试验,测量了典型矢跨比矩形平面投影气膜结构的风荷载;运用非线性动力时程分析法分析了结构的风振响应。研究了风... 近年来,矩形平面投影气膜结构被广泛应用于大跨度气膜煤仓等设施中,但是规范中尚无该类结构的风振系数。本文通过风洞测压试验,测量了典型矢跨比矩形平面投影气膜结构的风荷载;运用非线性动力时程分析法分析了结构的风振响应。研究了风速、风向、跨度、矢跨比和内压等参数对结构变形和响应极值的影响。结果表明:结构呈现迎风面及背风面凹陷、顶部和两侧向外凸的平均变形特征;极值响应的分布受结构参数和风向角的影响;响应的大小与跨度和矢跨比呈正相关;增大内压在一定程度上可以提高结构的抗风性,内压调控区间建议为400~500Pa;给出了可供抗风设计参考的位移风振系数及应力风振系数。 展开更多
关键词 充气膜结构 风洞试验 风振响应 风振系数
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胶囊形气膜结构风致气弹响应及风振系数研究
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作者 陈昭庆 宋鹏飞 +3 位作者 闫科晔 武岳 苏宁 曾聪 《振动工程学报》 EI CSCD 北大核心 2024年第1期31-39,共9页
针对1/3矢跨比胶囊形气膜结构进行了气弹模型风洞试验,研究了结构的风致气弹响应变化规律,并给出了可供设计参考的风振系数。研究发现:结构平均变形呈迎风面凹陷,顶部隆起,横风向向外凸出的趋势,且这种变形趋势随着内压减小和风速增大... 针对1/3矢跨比胶囊形气膜结构进行了气弹模型风洞试验,研究了结构的风致气弹响应变化规律,并给出了可供设计参考的风振系数。研究发现:结构平均变形呈迎风面凹陷,顶部隆起,横风向向外凸出的趋势,且这种变形趋势随着内压减小和风速增大越来越明显。0°风向角时的平均变形和振幅大于45°风向角时的平均变形和振幅大于90°风向角时的平均变形和振幅,结构合位移均值的极值出现在迎风面与顶面中心点;0°和45°风向角下,顶点竖向振幅>顺风向振幅>横风向振幅,结构以1阶模态振动为主;90°风向角下,顶点横风向振幅大于其他两个方向,结构以1阶和2阶模态叠加振动为主。各工况下结构的内压均有不同程度的减小。最后给出了考虑流固耦合效应的响应风振系数。 展开更多
关键词 风致气弹响应 胶囊形气膜 气弹模型 风洞试验 响应风振系数
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组合荷载下索拉骨架膜结构参数优化设计
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作者 李延民 李政权 《重庆理工大学学报(自然科学)》 CAS 北大核心 2024年第9期82-90,共9页
为使索拉骨架膜结构满足力学性能、所用耗材最少,建立一种新型索拉式骨架膜结构模型。运用ANSYS分析不同荷载组合工况下膜结构杆件轴力和变形,对比得到对膜结构最不利的荷载工况。运用正交试验法对最不利荷载工况下有限元结果进行分析,... 为使索拉骨架膜结构满足力学性能、所用耗材最少,建立一种新型索拉式骨架膜结构模型。运用ANSYS分析不同荷载组合工况下膜结构杆件轴力和变形,对比得到对膜结构最不利的荷载工况。运用正交试验法对最不利荷载工况下有限元结果进行分析,得到杆件截面尺寸及杆件空间几何布置对压杆稳定性和杆件变形的影响程度。以弦杆挠度、支撑杆和斜腹杆长细比、压杆稳定临界压力为约束条件,以膜结构质量最小为优化目标,采用响应面法,对骨架膜结构进行优化设计,得到最优设计方案:弦杆与腹杆夹角(A)为42°、跨高比(B)为12、斜腹杆外径(C)为28 mm、斜腹杆径厚比(D)为10、支撑杆外径(E)为51 mm、支撑杆径厚比(F)为15、弦杆宽度(G)为32 mm、弦杆高度(H)为95 mm,优化方案比初始设计方案质量减小6.82%,弦杆挠度减少21.22%。该方法为相似结构设计提供了有效的工程手段,其优化的弦杆与腹杆夹角、跨高比等关键结构参数与众不同,较全面地解决了此种膜结构设计的关键技术问题。 展开更多
关键词 索拉骨架膜结构 力学分析 正交试验 响应面法 结构优化
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