资源类型

期刊论文 43

年份

2023 2

2022 5

2021 5

2019 4

2018 5

2017 1

2016 1

2015 4

2014 1

2013 3

2012 1

2010 2

2009 1

2008 2

2007 4

2003 1

1999 1

展开 ︾

关键词

动态拉伸本构模型 1

原子结构 1

提取冶金 1

支护方案 1

断裂失效判据 1

河谷浅埋 1

现场监测 1

贵金属 1

软弱围岩 1

钨合金 1

隧道工程 1

展开 ︾

检索范围：

排序： 展示方式：

Surface water treatment benefits from the presence of algae: Influence of algae on the coagulation behavior

Yanxia Zhao, Huiqing Lian, Chang Tian, Haibo Li, Weiying Xu, Sherub Phuntsho, Kaimin Shih

《环境科学与工程前沿（英文）》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1350-x

摘要： Abstract • Emerging titanium coagulation was high-efficient for algae-laden water treatment. • Polytitanium coagulation was capable for both algae and organic matter removal. • Surface water purification was improved by around 30% due to algae inclusion. • Algae functioned as flocculant aid to assist polytitanium coagulation. • Algae could enhance charge neutralization capability of polytitanium coagulant. Titanium-based coagulation has proved to be effective for algae-laden micro-polluted water purification processes. However, the influence of algae inclusion in surface water treatment by titanium coagulation is barely reported. This study reports the influence of both Microcystis aeruginosa and Microcystis wesenbergii in surface water during polytitanium coagulation. Jar tests were performed to evaluate coagulation performance using both algae-free (controlled) and algae-laden water samples, and floc properties were studied using a laser diffraction particle size analyzer for online monitoring. Results show that polytitanium coagulation can be highly effective in algae separation, removing up to 98% from surface water. Additionally, the presence of algae enhanced organic matter removal by up to 30% compared to controlled water containing only organic matter. Polytitanium coagulation achieved significant removal of fluorescent organic materials and organic matter with a wide range of molecular weight distribution (693–4945 Da) even in the presence of algae species in surface water. The presence of algae cells and/or algal organic matter is likely to function as an additional coagulant or flocculation aid, assisting polytitanium coagulation through adsorption and bridging effects. Although the dominant coagulation mechanisms with polytitanium coagulant were influenced by the coagulant dosage and initial solution pH, algae species in surface water could enhance the charge neutralization capability of the polytitanium coagulant. Algae-rich flocs were also more prone to breakage with strength factors approximately 10% lower than those of algae-free flocs. Loose structure of the flocs will require careful handling of the flocs during coagulation-sedimentation-filtration processes.

关键词： Coagulation     Polytitanium chloride     Coagulation behaviour     Algae     Floc property    

HTML PDF 收藏

ANN-based empirical modelling of pile behaviour under static compressive loading

Abdussamad ISMAIL

《结构与土木工程前沿（英文）》 2018年 第12卷 第4期   页码 594-608 doi: 10.1007/s11709-017-0446-2

摘要： Artificial neural networks have been widely used over the past two decades to successfully develop empirical models for a variety of geotechnical problems. In this paper, an empirical model based on the product-unit neural network (PUNN) is developed to predict the load-deformation behaviour of piles based SPT values of the supporting soil. Other parameters used as inputs include particle grading, pile geometry, method of installation as well as the elastic modulus of the pile material. The model is trained using full-scale pile loading tests data retrieved from FHWA deep foundations database. From the results obtained, it is observed that the proposed model gives a better simulation of pile load-deformation curves compared to the Fleming’s hyperbolic model and t-z approach.

关键词： piles in compression     load-deformation behaviour     product-unit neural network    

HTML PDF 收藏

Aortic aneurysm and chronic disseminated intravascular coagulation: a retrospective study of 235 patients

null

《医学前沿（英文）》 2017年 第11卷 第1期   页码 62-67 doi: 10.1007/s11684-017-0498-7

摘要：

Chronic disseminated intravascular coagulation (DIC) is a rare but devastating complication of aortic aneurysm (AA). This study investigated the clinical manifestations, laboratory findings, and treatment of patients with AA-associated chronic DIC (AA-DIC) and explored the mechanisms, duration, and therapeutic response of AA-DIC. We retrospectively reviewed the medical records of 235 AA patients admitted at the Peking Union Medical College Hospital between September 2009 and January 2015. The patients were classified as those with DIC (AA-DIC) and those without DIC (non-DIC). The AA-DIC group showed a significantly higher proportion of female patients and a significantly longer AA disease course than the non-DIC group did. The AA-DIC patients presented mural thrombi, dissecting aneurysms, a family history of AA, and diabetes significantly more frequently than the non-DIC patients did. Furthermore, multiple regression analyses revealed that sex, mural thrombus, aneurysm type, diabetes, and stent surgery are possible independent risk factors for AA-DIC patients. Fifty-two (22.1%) patients presented AA-DIC. Among these patients, 43 had non-typical DIC and 9 had typical DIC; the mortality rate of the latter was 22.2%. The mean age of the patients with typical DIC was significantly higher than of that of patients with non-typical DIC. The non-typical DIC patients also presented abnormal coagulation disorders of varying degrees. Furthermore, heparin or low-molecular-weight heparin improved the clinical symptoms and laboratory parameters in patients with AA and typical DIC. Thus, chronic DIC should be considered in patients with AA.

关键词： aortic aneurysm     disseminated intravascular coagulation     anticoagulation therapy    

HTML PDF 收藏

Investigation of the hydro-mechanical behaviour of compacted expansive clay

Yujun CUI, An Ninh TA, Anh Minh TANG, Yingfa LU,

《结构与土木工程前沿（英文）》 2010年 第4卷 第2期   页码 154-164 doi: 10.1007/s11709-010-0019-0

摘要： The hydro-mechanical behaviour of compacted expansive Romainville clay was investigated. The soil was air-dried, crushed, and passed through a 2 mm sieve before being statically compacted to a dry density of 1.35 Mg/m. The mechanical behaviour was investigated by tests in oedometer with controlled suction using the vapor equilibrium technique (suction = 0, 9, 39, and 110 MPa). The vertical stress was applied in the range of 0–800 kPa. The experimental results are shown as follows: 1) wetting-induced swelling was higher at lower vertical stresses; 2) the vertical stress under which no swelling occurred during water flooding was estimated at 60 kPa, which can be considered as the swelling pressure of the soil tested; 3) the soil compressibility (changes of volume upon stress increases) was strongly influenced by the soil suction: the lower the suction, the higher the compressibility. The hydraulic behaviour was investigated using a large-scale infiltration chamber (800 mm × 1000 mm in section and 1000 mm high). The large size of the soil column allowed burying the volumetric water content sensors (ThetaProbe) without significantly affecting the water transfer and the soil swelling during infiltration. The soil suction was monitored along the soil height (every 100 mm) using various relative humidity sensors and psychrometers. In the infiltration test, water was kept on the soil surface and changes in suction and volumetric water content were monitored for 338 d. The wetting front has reached the bottom of the soil column at the end of the test. The data from the simultaneous monitoring of suction and water content were used to determine the water retention curve and the unsaturated hydraulic conductivity using the instantaneous profile method. It has been observed that the soil water retention curve depends on the soil depth; that is to be related to the soil depth-dependent swelling. The unsaturated hydraulic conductivity was found to be quite low, comprised between 3 × 10 m/s (at saturated state) and 10 m/s (at about 100 MPa suction).

关键词： Romainville clay     suction control     oedometer test     large infiltration task     hydro-mechanical behaviour    

HTML PDF 收藏

Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membrane

《环境科学与工程前沿（英文）》 2022年 第16卷 第8期 doi: 10.1007/s11783-022-1531-x

摘要：

• Ceramic membrane filtration showed high performance for surface water treatment.

关键词： Ceramic membrane     Coagulation     Polytitanium chloride     Membrane fouling    

HTML PDF 收藏

Nonlinear dynamic behaviour of a cam mechanism with oscillating roller follower in presence of profile

Walha LASSAAD, Tounsi MOHAMED, Driss YASSINE, Chaari FAKHER, Fakhfakh TAHER, Haddar MOHAMED

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 127-136 doi: 10.1007/s11465-013-0254-x

摘要：

In this paper we investigate the nonlinear dynamic behaviour of a cam mechanism with oscillating roller follower in presence of defects. The nonlinear developed lumped-mass model includes eight degrees of freedom with two nonlinear hertzian contacts. The first one is located between cam and first roller while the second is between second roller and the sliding rod. The nonlinear dynamic behaviour is described by second order differential equations which are resolved by using the implicit Newmark algorithm combined with the Newton-Raphson iterative scheme. The influence of the cam profile error on the dynamic behaviour is also investigated.

关键词： cam     nonlinear behaviour     oscillating roller follower     profile error    

HTML PDF 收藏

Performance evaluation on the pollution control against wet weather overflow based on on-site coagulation

Zongqun Chen, Wei Jin, Hailong Yin, Mengqi Han, Zuxin Xu

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1400-z

摘要： Abstract • A way for overflow control based on on-site coagulation/flocculation was proposed. • Coagulant and flocculant dose were optimized based on pollutant removal performance. • Settling time of 5 min is enough in a proper transmission distance. • Fast removal of particulate pollutants could be achieved under varied flow. The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers. The conventional overflow treatment based on coagulation/flocculation in terminal drainage systems requires relatively large space and long retention time demand that makes it not applicable in crowded urban drainage systems or under heavy rains. On-site coagulation/flocculation in terminal drainage pipes was proposed in this study which was aimed to transfer the coagulation/flocculation process to the inside of pipes at the terminal drainage system to save space and reduce the retention time of the coagulation/flocculation process. The optimized dose of chemicals was studied first which was 80 mg/L of coagulant and 0.8 mg/L of flocculant. Settling for only 5 min can remove most of the pollutants at 406.5 m of transmission distance. In addition, the relation of wet weather overflow rate and concentration of pollution load on the on-site coagulation/flocculation process was investigated, which indicated that high removal of pollutant was gained at a large range of flow velocity and pollutant concentration. Finally, the study confirmed electric neutralization, bridging, and net capture as the major mechanisms in this process, and further optimization was proposed. The proposed process can reduce much turbidity, chemical oxygen demand, and total phosphorous, but hardly remove soluble ammonia and organics. This work provides scientific guidance to address wet weather overflow in terminal drainage pipes.

关键词： Wet weather overflow     On-site coagulation/flocculation     Fast removal of particulate pollutants    

HTML PDF 收藏

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)    

HTML PDF 收藏

Clinical study on the related markers of blood coagulation in the patients with ANFH after SARS

WU Lianhua, GAO Chunjin, WANG Guozhong, YANG Lin, HOU Xiaomin, GE Huan, XIA Chengqing, QI Man

《医学前沿（英文）》 2007年 第1卷 第4期   页码 410-412 doi: 10.1007/s11684-007-0080-9

摘要： The aim of this research was to investigate the blood coagulation function in the patients with avascular necrosis of the femoral head (ANFH) after severe acute respiratory syndrome (SARS). The expression of CD31, CD61, CD62p, CD63 and PAC-1 on platelet membrane was measured respectively by flowcytometry, and the plasma prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (Fbg) were measured by blood clotting instrument in 26 patients with ANFH after SARS and in 17 healthy adults. The expression of CD31, CD61, CD 62p, CD63 and PAC-1 on platelet membrane in 26 patients was all lower than that in 17 healthy subjects (<0.01). The levels of PT, APTT, TT and Fbg in 26 patients were all normal. There is no significant difference (>0.05) in those markers between patients and 17 healthy adults. The blood may not be in hypercoagulable state in patients with ANFH after SARS.

关键词： significant difference     partial thromboplastin     coagulation function     femoral     healthy    

HTML PDF 收藏

Effects of water quality on the coagulation performances of humic acids irradiated with UV light

Wendong WANG,Qinghai FAN,Zixia QIAO,Qin YANG,Yabo WANG,Xiaochang WANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第1期   页码 147-154 doi: 10.1007/s11783-014-0749-7

摘要： The presence of humic acid in drinking water treatment has received significant attention in recent years because of its adverse effects on the removal of many pollutants in coagulation. In this paper, the effects of water quality including pH, turbidity, alkalinity, and hardness on the removal of humic acid were investigated in a UV light hybridized coagulation process. Our results suggested that UV light radiation could effectively improve the removal rate of humic acid in coagulation under both neutral and basic conditions, and the variations of the selected water quality parameters had little adverse effect on the function of UV light. After UV light radiation, the removal rate of the nitro-humic acid (NHA) increased from 20% to 60% in coagulation, and increased further to 75% and 85% for the raw waters with 10.0 NTU kaolin and 100 mg·L hardness, respectively. In addition to NHA, the removal rates of the humic acid extracted from peat coal (PHA) and the humic acid provided by Japan metals and chemicals company (JHA) in coagulation were also improved, both in the range of 80%–90% after undergoing UV light radiation. By changing the radiation location from prior to coagulation to the flocculation process, similar experimental results were obtained. The formation of positive charged sites after UV light radiation was considered to be the primary factor that led to an enhanced removal of the humic acid in coagulation.

关键词： coagulation     drinking water     humic acid     UV light radiation     water quality    

HTML PDF 收藏

Influence of coagulation bath on morphology of cellulose membranes prepared by NMMO method

LU Yangcheng, WU Yingxin

《化学科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 204-208 doi: 10.1007/s11705-008-0027-y

摘要： To control the morphology of cellulose membranes used for separation, they were prepared by the NMMO method using water, methanol, ethanol and their binary solution as coagulation baths. Morphologies of the surface and cross section of dry membranes were observed. The pore structure parameters of wet membranes were determined. By comparison, the process and mechanism of pore formation in dry membranes were suggested, and the relativity of cellulose crystal size to average pore diameter in wet membranes and their influences were discussed. The results show that the morphology of dry membranes is clearly varied with coagulation baths, while the porosity of wet membranes is almost constant. Porous structures can appear in the compact region of dry membranes due to swelling from water. These pores have a virtual effect on the average pore diameter of wet membranes. By changing the composition of coagulation baths, the microstructure of cellulose membranes in a dry or wet environment can be adjusted separately.

关键词： comparison     NMMO     constant     diameter     process    

HTML PDF 收藏

Bending and rotational behaviour of semi-continuous composite beams

WANG Jingfeng, LI Guoqiang

《结构与土木工程前沿（英文）》 2008年 第2卷 第2期   页码 116-122 doi: 10.1007/s11709-008-0015-9

摘要： Stresses and deflections were measured in various semi-continuous composite beams. The bending and rotational capacities of the composite connections were measured in terms of beam curvatures and deflections by using two full-scale semi-rigid composite frames with monotonic loadings. The effect of semi-rigid connections on the performance of composite beams with various loadings was compared with predictions and codes. The tests show that the semi-continuous composite beams are more economic and effective than the simple or continuous composite beams. The semi-rigid connections affect the bending capacities and beam deflections, so the connection behavior should be considered in the design of composite beams. Yielding analysis of the steel beam bottom flange has some influence on the deflection calculation of composite beams.

关键词： rotational     effective     deflection calculation     semi-continuous composite     full-scale semi-rigid    

HTML PDF 收藏

Effect of embedment length of untreated natural fibres on the bond behaviour in cement mortar

Gudimella RAMAKRISHNA, Sriraman PRIYADHARSHINI

《结构与土木工程前沿（英文）》 2018年 第12卷 第4期   页码 454-460 doi: 10.1007/s11709-017-0454-2

摘要： The present investigation is focused on studying the effects of various matrices with 1:3, 1:4 and 1:5 mortars and fibre types of sisal and coir on the bond behavior at various ages of curing, i.e., 24 h, 3 d, 7 d and 28 d. The other parameters included in the investigation are water/cement (w/c) ratio, sand gradation and embedment length of fibres. In addition, the type of failure of sisal and coir fibres for different mixes of mortars at various curing ages is also reported. From the results, it is seen that the bond strength is improving with respect to age of curing in case of sisal fibres, but decreases in case of coir fibres. The failure of fibres due to fibre fracture is observed in sisal fibres and fibre pullout is observed in coir fibres. The other varying parameters such as mortar mixes, sand gradation, w/c ratio and embedded length also showed significant effect on bond behaviour of sisal and coir fibre with the cement mortar mixes.

关键词： bond strength     cement mortar     natural fibre     pullout test     type of failure    

HTML PDF 收藏

Development of combined coagulation-hydrolysis acidification-dynamic membrane bioreactor system for treatment

Xue Shen, Lei Lu, Baoyu Gao, Xing Xu, Qinyan Yue

《环境科学与工程前沿（英文）》 2019年 第13卷 第1期 doi: 10.1007/s11783-019-1093-8

摘要：

• We created a combined system for treating oilfield polymer-flooding wastewater.

• The system was composed of coagulation, hydrolysis acidification and DMBR.

• Coagulant integrated with demulsifier dominated the removal of crude oil.

• The DMBR proceed efficiently without serious membrane fouling.

关键词： Coagulation     Hydrolysis acidification     Dynamic membrane bioreactor     Polymer flooding    

HTML PDF 收藏

Optimization and modeling of coagulation-flocculation to remove algae and organic matter from surface

Ziming Zhao, Wenjun Sun, Madhumita B. Ray, Ajay K Ray, Tianyin Huang, Jiabin Chen

《环境科学与工程前沿（英文）》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1159-7

摘要： Charge neutralization and sweep flocculation were the major mechanisms. Effect of process parameters was investigated. Optimal coagulation conditions were studied by response surface methodology. ANN models presented more robust and accurate prediction than RSM. Seasonal algal blooms of Lake Yangcheng highlight the necessity to develop an effective and optimal water treatment process to enhance the removal of algae and dissolved organic matter (DOM). In the present study, the coagulation performance for the removal of algae, turbidity, dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm (UV254) was investigated systematically by central composite design (CCD) using response surface methodology (RSM). The regression models were developed to illustrate the relationships between coagulation performance and experimental variables. Analysis of variance (ANOVA) was performed to test the significance of the response surface models. It can be concluded that the major mechanisms of coagulation to remove algae and DOM were charge neutralization and sweep flocculation at a pH range of 4.66–6.34. The optimal coagulation conditions with coagulant dosage of 7.57 mg Al/L, pH of 5.42 and initial algal cell density of 3.83 × 106 cell/mL led to removal of 96.76%, 97.64%, 40.23% and 30.12% in term of cell density, turbidity, DOC and UV254 absorbance, respectively, which were in good agreement with the validation experimental results. A comparison between the modeling results derived through both ANOVA and artificial neural networks (ANN) based on experimental data showed a high correlation coefficient, which indicated that the models were significant and fitted well with experimental results. The results proposed a valuable reference for the treatment of algae-laden surface water in practical application by the optimal coagulation-flocculation process.

关键词： Algae     Coagulation-flocculation     Response surface methodology     Artificial neural networks    

HTML PDF 收藏

标题 作者 时间 类型 操作

Surface water treatment benefits from the presence of algae: Influence of algae on the coagulation behavior

Yanxia Zhao, Huiqing Lian, Chang Tian, Haibo Li, Weiying Xu, Sherub Phuntsho, Kaimin Shih

期刊论文

ANN-based empirical modelling of pile behaviour under static compressive loading

Abdussamad ISMAIL

期刊论文

Aortic aneurysm and chronic disseminated intravascular coagulation: a retrospective study of 235 patients

null

期刊论文

Investigation of the hydro-mechanical behaviour of compacted expansive clay

Yujun CUI, An Ninh TA, Anh Minh TANG, Yingfa LU,

期刊论文

Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membrane

期刊论文

Nonlinear dynamic behaviour of a cam mechanism with oscillating roller follower in presence of profile

Walha LASSAAD, Tounsi MOHAMED, Driss YASSINE, Chaari FAKHER, Fakhfakh TAHER, Haddar MOHAMED

期刊论文

Performance evaluation on the pollution control against wet weather overflow based on on-site coagulation

Zongqun Chen, Wei Jin, Hailong Yin, Mengqi Han, Zuxin Xu

期刊论文

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

Haiqing CHANG,Baicang LIU,Wanshen LUO,Guibai LI

期刊论文

Clinical study on the related markers of blood coagulation in the patients with ANFH after SARS

WU Lianhua, GAO Chunjin, WANG Guozhong, YANG Lin, HOU Xiaomin, GE Huan, XIA Chengqing, QI Man

期刊论文

Effects of water quality on the coagulation performances of humic acids irradiated with UV light

Wendong WANG,Qinghai FAN,Zixia QIAO,Qin YANG,Yabo WANG,Xiaochang WANG

期刊论文

Influence of coagulation bath on morphology of cellulose membranes prepared by NMMO method

LU Yangcheng, WU Yingxin

期刊论文

Bending and rotational behaviour of semi-continuous composite beams

WANG Jingfeng, LI Guoqiang

期刊论文

Effect of embedment length of untreated natural fibres on the bond behaviour in cement mortar

Gudimella RAMAKRISHNA, Sriraman PRIYADHARSHINI

期刊论文

Development of combined coagulation-hydrolysis acidification-dynamic membrane bioreactor system for treatment

Xue Shen, Lei Lu, Baoyu Gao, Xing Xu, Qinyan Yue

期刊论文

Optimization and modeling of coagulation-flocculation to remove algae and organic matter from surface

Ziming Zhao, Wenjun Sun, Madhumita B. Ray, Ajay K Ray, Tianyin Huang, Jiabin Chen

期刊论文