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Short-term prediction of influent flow rate and ammonia concentration in municipal wastewater treatment

Shuai MA, Siyu ZENG, Xin DONG, Jining CHEN, Gustaf OLSSON

《环境科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 128-136 doi: 10.1007/s11783-013-0598-9

摘要： The prediction of the influent load is of great importance for the improvement of the control system to a large wastewater treatment plant. A systematic data analysis method is presented in this paper in order to estimate and predict the periodicity of the influent flow rate and ammonia (NH ) concentrations: 1) data filtering using wavelet decomposition and reconstruction; 2) typical cycle identification using power spectrum density analysis; 3) fitting and prediction model establishment based on an autoregressive model. To give meaningful information for feedforward control systems, predictions in different time scales are tested to compare the corresponding predicting accuracy. Considering the influence of the rainfalls, a linear fitting model is derived to estimate the relationship between flow rate trend and rain events. Measurements used to support coefficient fitting and model testing are acquired from two municipal wastewater treatment plants in China. The results show that 1) for both of the two plants, the periodicity affects the flow rate and NH concentrations in different cycles (especially cycles longer than 1 day); 2) when the flow rate and NH concentrations present an obvious periodicity, the decreasing of prediction accuracy is not distinct with increasing of the prediction time scales; 3) the periodicity influence is larger than rainfalls; 4) the rainfalls will make the periodicity of flow rate less obvious in intensive rainy periods.

关键词： influent load prediction     wavelet de-noising     power spectrum density     autoregressive model     time-frequency analysis     wastewater treatment    

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Development and application of a random walk model of atmospheric diffusion in the emergency response of nuclear accidents

CHI Bing, LI Hong, FANG Dong

《能源前沿（英文）》 2007年 第1卷 第2期   页码 195-201 doi: 10.1007/s11708-007-0025-7

摘要： Plume concentration prediction is one of the main contents of radioactive consequence assessment for early emergency response to nuclear accidents. Random characteristics of atmospheric diffusion itself was described, a random walk model of atmospheric diffusion (Random Walk) was introduced and compared with the Lagrangian puff model (RIMPUFF) in the nuclear emergency decision support system (RODOS) developed by the European Community for verification. The results show the concentrations calculated by the two models are quite close except that the plume area calculated by Random Walk is a little smaller than that by RIMPUFF. The random walk model for atmospheric diffusion can simulate the atmospheric diffusion in case of nuclear accidents, and provide more actual information for early emergency and consequence assessment as one of the atmospheric diffusion module of the nuclear emergency decision support system.

关键词： RODOS     concentration prediction     information     nuclear     RIMPUFF    

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Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1354-1371 doi: 10.1007/s11705-022-2286-4

摘要： With the increasing development of digital devices and electric vehicles, high energy-density rechargeable batteries are strongly required. As one of the most promising anode materials with an ultrahigh specific capacity and extremely low electrode potential, lithium metal is greatly considered an ideal candidate for next-generation battery systems. Nevertheless, limited Coulombic efficiency and potential safety risks severely hinder the practical applications of lithium metal batteries due to the inevitable growth of lithium dendrites and poor interface stability. Tremendous efforts have been explored to address these challenges, mainly focusing on the design of novel electrolytes. Here, we provide an overview of the recent developments of localized high-concentration electrolytes in lithium metal batteries. Firstly, the solvation structures and physicochemical properties of localized high-concentration electrolytes are analyzed. Then, the developments of localized high-concentration electrolytes to suppress the formation of dendritic lithium, broaden the voltage window of electrolytes, enhance safety, and render low-temperature operation for robust lithium metal batteries are discussed. Lastly, the remaining challenges and further possible research directions for localized high-concentration electrolytes are outlined, which can promisingly render the practical applications of lithium metal batteries.

关键词： high-concentration electrolyte     localized high-concentration electrolyte     lithium metal battery     solid electrolyte interphase     dendrite    

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PM concentration declining saves health expenditure in China

《环境科学与工程前沿（英文）》 2023年 第17卷 第7期 doi: 10.1007/s11783-023-1690-4

摘要：

● Monthly hospitalization expenses are sensitive to increases in PM2.5 exposure.

关键词： Air pollution     Health expenditure     PM2.5 concentration     Economic impact     Heterogeneous effect    

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Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要： The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词： notch stress concentration factor     rib–deck weld     parametric analysis     regression analysis     parametric equation    

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Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1065-1071 doi: 10.1007/s11705-019-1909-x

摘要： Micro-arc oxidation (MAO) is an efficient approach to improve the hardness, wear resistance, and other properties of aluminum alloys. In order to investigate the effect of the electrolyte concentration on the properties of MAO coatings for LY12 alloy, the voltage variation during the MAO process was recorded. The surface morphologies and phase compositions of the coatings produced with different electrolytes were investigated using scanning electron microscopy and X-ray diffraction, respectively. The roughness and thickness of the coatings were measured using a pocket roughness meter and an eddy-current thickness meter, respectively. The tribological performances of the coatings were investigated against GCr15 bearing steel on a ball-on-disc wear tester in open air. The results showed that with an increase in the Na SiO content, the working voltage of the MAO process decreased, the roughness and thickness of the coatings increased significantly, and the relative content of the -Al O phase decreased. With an increase in the KOH content, the working voltage decreased slightly, the roughness and thickness of the coatings increased slightly, and the α- and -Al O phase contents remained unchanged. The friction coefficient and wear rate of the coatings increased with an increase in the Na SiO and KOH concentrations. A decrease in the porosity and roughness and an increase in the α-Al O content of the coatings reduced their wear mass loss.

关键词： aluminum alloy     micro-arc oxidation     coating     electrolyte concentration     tribological performance    

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Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

《医学前沿（英文）》 2008年 第2卷 第1期   页码 11-14 doi: 10.1007/s11684-008-0003-4

摘要： Using the plasma aldosterone concentration to plasma renin activity ratio (PAC/PRA ratio) as the screening test of choice for primary aldosteronism in hypertensive patients, we studied the clinical characteristics and the diagnostic value of PAC/PRA ratio in primary aldosteronism. The plasma aldosterone concentration (PAC) and plasma renin activity (PRA) levels were measured by radioimmunoassay in 902 hypertensive patients from out-patient clinics or hospitals. One hundred and twenty-six suspected primary aldosteronism patients whose PAC/PRA ratio was > 25 ng/dL/ng/mL/hr had a lamellar computed tomography (CT) scan in the adrenal gland and follow-up visits. The proportion of primary aldosteronism in hypertensive patients was 14% (126/902). There were 54 patients with unilateral or bilateral hyperplasia and 25 patients with adenoma according to the CT scan. 39% (49/126) of the patients with primary aldosteronism had hypokalemia. Twenty-five patients received surgical treatment. The efficacy and cure rates were 100% (25/25) and 48% (12/25), respectively. The effective rate of aldactone and the single-drug cure rate were 89% (48/54) and 24% (13/54), respectively. Primary aldosteronism affects over 10% of hypertensive patients in China. The PAC/PRA ratio can be considered as a routine screening test in hypertensives, especially resistant hypertensive patients and a high PAC/PRA ratio is an invaluable index in primary aldosteronism diagnosis.
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Effects of gradient concentration on the microstructure and electrochemical performance of LiNi

Wenming Li, Weijian Tang, Maoqin Qiu, Qiuge Zhang, Muhammad Irfan, Zeheng Yang, Weixin Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 988-996 doi: 10.1007/s11705-020-1918-9

摘要： Nickel(Ni)-rich layered materials have attracted considerable interests as promising cathode materials for lithium ion batteries (LIBs) owing to their higher capacities and lower cost. Nevertheless, Mn-rich cathode materials usually suffer from poor cyclability caused by the unavoidable side-reactions between Ni ions on the surface and electrolytes. The design of gradient concentration (GC) particles with Ni-rich inside and Mn-rich outside is proved to be an efficient way to address the issue. Herein, a series of LiNi Co Mn O (LNCM622) materials with different GCs (the atomic ratio of Ni/Mn decreasing from the core to the outer layer) have been successfully synthesized via rationally designed co-precipitation process. Experimental results demonstrate that the GC of LNCM622 materials plays an important role in their microstructure and electrochemical properties. The as-prepared GC3.5 cathode material with optimal GC can provide a shorter pathway for lithium-ion diffusion and stabilize the near-surface region, and finally achieve excellent electrochemical performances, delivering a discharge capacity over 176 mAh·g at 0.2 C rate and exhibiting capacity retention up to 94% after 100 cycles at 1 C. The rationally-designed co-precipitation process for fabricating the Ni-rich layered cathode materials with gradient composition lays a solid foundation for the preparation of high-performance cathode materials for LIBs.

关键词： gradient concentration     Ni-rich     LiNi0.6Co0.2-Mn0.2O2     electrochemical performance     lithium-ion battery    

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Study of simultaneous saccharification and fermentation for steam exploded wheat straw to ethanol

LUO Peng, YANG Chuanmin, LIU Zhong, WANG Gaosheng

《化学科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 447-451 doi: 10.1007/s11705-008-0069-1

摘要： Although simultaneous saccharification and fermentation (SSF) has been investigated extensively, the optimum condition for SSF of wheat straw has not yet been determined. Dilute sulfuric acid impregnated and steam explosion pretreated wheat straw was used as a substrate for the production of ethanol by SSF through orthogonal experiment design in this study. Cellulase mixture (Celluclast 1.5 l and -glucosidase Novozym 188) were adopted in combination with the yeast AS2.1. The effects of reaction temperature, substrate concentration, initial fermentation liquid pH value and enzyme loading were evaluated and the SSF conditions were optimized. The ranking, from high to low, of influential extent of the SSF affecting factors to ethanol concentration and yield was substrate concentration, enzyme loading, initial fermentation liquid pH value and reaction temperature, respectively. The optimal SSF conditions were: reaction temperature, 35°C; substrate concentration, 100 g·L; initial fermentation liquid pH, 5.0; enzyme loading, 30 FPU·g. Under these conditions, the ethanol concentration increased with reaction time, and after 72 h, ethanol was obtained in 65.8% yield with a concentration of 22.7 g·L.

关键词： optimal SSF     substrate concentration     optimum condition     enzyme loading     ethanol concentration    

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Numerical and experimental research of the characteristics of concentration solar cells

Zilong WANG, Hua ZHANG, Binlin DOU, Weidong WU, Guanhua ZHANG

《能源前沿（英文）》 2021年 第15卷 第2期   页码 279-291 doi: 10.1007/s11708-019-0637-8

摘要： The development of automatic tracking solar concentrator photovoltaic systems is currently attracting growing interest. High concentration photovoltaic systems (HCPVs) combining triple-junction InGaP/lnGaAs/Ge solar cells with a concentrator provide high conversion efficiencies. The mathematical model for triple-junction solar cells, having a higher efficiency and superior temperature characteristics, was established based on the one-diode equivalent circuit cell model. A paraboloidal concentrator with a secondary optic system and a concentration ratio in the range of 100X–150X along with a sun tracking system was developed in this study. The GaInP/GalnAs/Ge triple-junction solar cell, produced by AZUR SPACE Solar Power, was also used in this study. The solar cells produced by Shanghai Solar Youth Energy (SY) and Shenzhen Yinshengsheng Technology Co. Ltd. (YXS) were used as comparison samples in a further comparative study at different concentration ratios (200X–1000X). A detailed analysis on the factors that influence the electrical output characteristics of the InGaP/lnGaAs/Ge solar cell was conducted with a dish-style concentrating photovoltaic system. The results show that the short-circuit current ( ) and the open-circuit voltage ( ) of multi-junction solar cells increases with the increasing concentration ratio, while the cell efficiency ( ) of the solar cells increases first and then decreases with increasing concentration ratio. With increasing solar cell temperature, increases, while and decrease. A comparison of the experimental and simulation results indicate that the maximum root mean square error is less than 10%, which provides a certain theoretical basis for the study of the characteristics of triple-junction solar cell that can be applied in the analysis and discussion regarding the influence of the relevant parameters on the performance of high concentration photovoltaic systems.

关键词： concentration     three-junction solar cell     mathematical model     electrical properties     solar energy    

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Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration

ZHOU Xuefei, REN Nanqi

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 53-56 doi: 10.1007/s11783-007-0010-8

摘要： In this study, the two-stage upflow anaerobic sludge blanket (UASB) system and batch experiments were employed to evaluate the performance of anaerobic digestion for the treatment of high concentration methanol wastewater. The acid resistance of granular sludge and methanogenic bacteria and their metabolizing activity were investigated. The results show that the pH of the first UASB changed from 4.9 to 5.8 and 5.5 to 6.2 for the second reactor. Apparently, these were not the advisable pH levels that common methanogenic bacteria could accept. The methanogenic bacteria of the system, viz. Methanosarcina barkeri, had some acid resistance and could still degrade methanol at pH 5.0. If the methanogenic bacteria were trained further, their acid resistance would be improved somewhat. Granular sludge of the system could protect the methanogenic bacteria within its body against the impact of the acidic environment and make them degrade methanol at pH 4.5. The performance of granular sludge was attributed to its structure, bacteria species, and the distribution of bacterium inside the granule.

关键词： pH     Granular     upflow anaerobic     advisable pH     methanogenic    

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Spatial prediction of soil contamination based on machine learning: a review

《环境科学与工程前沿（英文）》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1693-1

摘要：

● A review of machine learning (ML) for spatial prediction of soil contamination.

关键词： Soil contamination     Machine learning     Prediction     Spatial distribution    

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Purification and concentration of gluconic acid from an integrated fermentation and membrane process

Parimal Pal, Ramesh Kumar, Subhamay Banerjee

《化学科学与工程前沿（英文）》 2019年 第13卷 第1期   页码 152-163 doi: 10.1007/s11705-018-1721-z

摘要： A response surface method was used to optimize the purification and concentration of gluconic acid from fermentation broth using an integrated membrane system. was used for the bioconversion of the glucose in sugarcane juice to gluconic acid (concentration 45 g?L ) with a yield of 0.9 g?g . The optimum operating conditions, such as trans-membrane pressure (TMP), pH, cross-flow rate (CFR) and initial gluconic acid concentration, were determined using response surface methodology. Five different types of polyamide nanofiltration membranes were screened and the best performing one was then used for downstream purification of gluconic acid in a flat sheet cross-flow membrane module. Under the optimum conditions (TMP= 12 bar and CFR= 400 L?h ), this membrane retained more than 85% of the unconverted glucose from the fermentation broth and had a gluconic acid permeation rate of 88% with a flux of 161 L?m ?h . Using response surface methods to optimize this green nanofiltration process is an effective way of controlling the production of gluconic acid so that an efficient separation with high flux is obtained.

关键词： gluconic acid     optimized nanofiltration     green processing     process intensification    

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Soil selenium concentration and Kashin-Beck disease prevalence in Tibet, China

Shunjiang LI, Wei LI, Xia HU, Linsheng YANG, Ruodeng XIRAO

《环境科学与工程前沿（英文）》 2009年 第3卷 第1期   页码 62-68 doi: 10.1007/s11783-009-0009-4

摘要： In order to investigate the correlation between the prevalence of Kashin-Back disease (KBD) and Se concentrations, natural soil samples and cultivated soil samples were collected from southeastern Tibet, China; and the soil Se concentrations were measured by atomic fluorescent spectrophotometer. It was found that the mean Se concentrations of natural soil samples in KBD areas, from the first layer to the third layer, were 0.17 mg/kg, 0.11 mg/kg, and 0.10 mg/kg, respectively, and in non-disease areas were 0.21 mg/kg, 0.24 mg/kg, and 0.13 mg/kg, respectively. The mean Se concentrations of cultivated soil samples were 0.10 mg/kg in KBD areas and 0.23 mg/kg in non-disease areas, respectively. Soil Se concentrations in KBD areas were lower than that in non-disease areas, and the mean concentrations of soil Se in Tibet were lower than the average of China (0.29 mg/kg). Therefore , there is a close relationship between soil Se concentrations and KBD in Tibet. More studies should be concentrated on the impacts of Se deficiency in soils and its relationship with Se concentrations in food-grain and the human body in Tibet areas.

关键词： Kashin-Beck disease (KBD)     selenium (Se)     soil     Tibet    

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Characterization of chlorine dioxide as disinfectant for the removal of low concentration microcystins

Mingsong WU, Junli HUANG, Yuling ZHANG, Shijie YOU, Shaofeng LI, Zhilin RAN, Yu TIAN

《环境科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 75-81 doi: 10.1007/s11783-011-0331-5

摘要： Microcystins, which represents one kind of cancerogenic organic compounds, is abundant in eutrophication water. The effects of reaction factors on chlorine dioxide (ClO ) for removal of low-concentration Microcystin-LR, Microcystin-RR, and Microcystin-YR in water as well as the reaction mechanisms was investigated by using enzyme-linked immunosorbent assay (ELISA) kit and gas chromatography–mass spectrometry (GC-MS). The results showed that MC-LR, MC-RR, and MC-YR could be efficiently decomposed by ClO . The degradation efficiency was shown positively correlated to the concentration of ClO and reaction time; while the effect of reaction temperature and pH is slight. The kinetic constants and activation energies of the reaction of MC-LR, MC-RR, and MC-YR with ClO are determined as 459.89, 583.15, 488.43 L·(mol·min) and 64.78, 53.01, 59.15 kJ·mol , respectively. As indicated by high performance liquid chromatography mass spectrometer (HPLC-MS) analysis, degradation should be accomplished via destruction of Adda group by oxidation, with the formation of dihydroxy substituendums as end products. This study has provided a fundamental demonstration of ClO serving as oxidizing disinfectant to eliminate microcystins from raw water source.

关键词： disinfection     chlorine dioxide     microcystins     reaction mechanism    

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标题 作者 时间 类型 操作

Short-term prediction of influent flow rate and ammonia concentration in municipal wastewater treatment

Shuai MA, Siyu ZENG, Xin DONG, Jining CHEN, Gustaf OLSSON

期刊论文

Development and application of a random walk model of atmospheric diffusion in the emergency response of nuclear accidents

CHI Bing, LI Hong, FANG Dong

期刊论文

Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

期刊论文

PM concentration declining saves health expenditure in China

期刊论文

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

期刊论文

Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

期刊论文

Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

期刊论文

Effects of gradient concentration on the microstructure and electrochemical performance of LiNi

Wenming Li, Weijian Tang, Maoqin Qiu, Qiuge Zhang, Muhammad Irfan, Zeheng Yang, Weixin Zhang

期刊论文

Study of simultaneous saccharification and fermentation for steam exploded wheat straw to ethanol

LUO Peng, YANG Chuanmin, LIU Zhong, WANG Gaosheng

期刊论文

Numerical and experimental research of the characteristics of concentration solar cells

Zilong WANG, Hua ZHANG, Binlin DOU, Weidong WU, Guanhua ZHANG

期刊论文

Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration

ZHOU Xuefei, REN Nanqi

期刊论文

Spatial prediction of soil contamination based on machine learning: a review

期刊论文

Purification and concentration of gluconic acid from an integrated fermentation and membrane process

Parimal Pal, Ramesh Kumar, Subhamay Banerjee

期刊论文

Soil selenium concentration and Kashin-Beck disease prevalence in Tibet, China

Shunjiang LI, Wei LI, Xia HU, Linsheng YANG, Ruodeng XIRAO

期刊论文

Characterization of chlorine dioxide as disinfectant for the removal of low concentration microcystins

Mingsong WU, Junli HUANG, Yuling ZHANG, Shijie YOU, Shaofeng LI, Zhilin RAN, Yu TIAN

期刊论文