资源类型

期刊论文 493

会议视频 2

会议专题 1

年份

2024 2

2023 51

2022 38

2021 48

2020 32

2019 25

2018 34

2017 30

2016 23

2015 28

2014 31

2013 13

2012 31

2011 13

2010 19

2009 17

2008 18

2007 17

2006 2

2005 4

展开 ︾

关键词

N-糖基化 3

S-N曲线 3

免疫球蛋白 G 2

免疫球蛋白G 2

农业面源污染 2

大坝 2

糖基化 2

面源污染 2

N-糖组 1

N-聚糖模型 1

N-糖基化 1

N-糖链 1

CCS 1

CO2 加氢 1

CO2-ECBM 1

COVID-19 1

F-N图 1

FLTD型脉冲加速器 1

GIS 1

展开 ︾

检索范围：

排序： 展示方式：

Metabolic flux analysis on arachidonic acid fermentation

JIN Mingjie, HUANG He, ZHANG Kun, YAN Jie, GAO Zhen

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 421-426 doi: 10.1007/s11705-007-0077-6

摘要： The analysis of flux distributions in metabolic networks has become an important approach for understanding the fermentation characteristics of the process. A model of metabolic flux analysis of arachidonic acid (AA) synthesis in ME-1 was established and carbon flux distributions were estimated in different fermentation phases with different concentrations of N-source. During the exponential, decelerating and stationary phase, carbon fluxes to AA were 3.28%, 8.80% and 6.97%, respectively, with sufficient N-source broth based on the flux of glucose uptake, and those were increased to 3.95%, 19.21% and 39.29%, respectively, by regulating the shifts of carbon fluxes via fermentation with limited N-source broth and adding 0.05% NaNO at 96 h. Eventually AA yield was increased from 1.3 to 3.5 g · L. These results suggest a way to improve AA fermentation, that is, fermentation with limited N-source broth and adding low concentration N-source during the stationary phase.

关键词： AA     different fermentation     concentration N-source     exponential     metabolic    

HTML PDF 收藏

δN-stable isotope analysis of NH: An overview on analytical measurements, source sampling and its source

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1414-6

摘要：

• Challenges in sampling of NH3 sources for d15N analysis are highlighted.

关键词： Aerosol ammonium     Atmospheric gaseous ammonia     Isotope fingerprinting     Isotope-based source apportionment     Ammonia gas-to-particle conversion    

HTML PDF 收藏

Impacts of n-alkane concentration on soil bacterial community structure and alkane monooxygenase genes

Yueqiao Liu, Aizhong Ding, Yujiao Sun, Xuefeng Xia, Dayi Zhang

《环境科学与工程前沿（英文）》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1064-5

摘要：

Soil microbial community is not significantly shaped by alkane concentrations

Alkane concentrations alter dominant alkane degraders in soils

Different alkanes are preferentially degraded at different contamination level

Different types of alkane monooxygenase genes responsible for alkane degradation

关键词： Petroleum hydrocarbon contaminated site     n-alkane contamination level     n-alkane biodegradation     Soil bacterial community     Alkane degraders     Alkane-monooxygenase genes    

HTML PDF 收藏

Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

Yufen REN, Zhiwei XU, Xinyu ZHANG, Xiaoke WANG, Xiaomin SUN, D. J. BALLANTINE, Shengzhong WANG

《环境科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 106-116 doi: 10.1007/s11783-012-0474-z

摘要： Nitrogen contamination of surface water is a worldwide environmental problem with intensive agriculture and high population densities. We assessed the spatial and seasonal variation in concentrations of total nitrogen and different nitrogen species present in surface-water in Beijing, China. Also, chemical ( ) and isotopic ( ) indicators were used to identify nitrate sources. The results showed that, during 2009 and 2010, nitrate nitrogen concentrations ranged from 0.7 to 7.6 mg·L , ammonium nitrogen from 0.1 to 3.4 mg·L , and total nitrogen from 2.4 to 17.0 mg·L . Inorganic nitrogen accounted for between 60 and 100% of total nitrogen at the ten monitoring sites. Nitrate nitrogen, ammonium nitrogen, and total nitrogen concentrations at the 2 downstream monitoring sites in south-eastern Beijing were significantly higher than those at the other eight upstream monitoring sites ( <0.01). Examination of seasonal variation showed that there was a significant inverse relationship between nitrate nitrogen concentrations and precipitation, and that nitrate nitrogen concentrations peaked in the dry seasons. The information given by the values and nitrate nitrogen concentrations, combined with the ratio distribution, showed that domestic sewage was the major source of nitrate in Beijing. Methods to control and reduce sewage pollution are urgently needed to help manage surface water quality in Beijing.

关键词： nitrogen concentration     spatial and seasonal variation     stable nitrogen isotope     urban ecosystem     source    

HTML PDF 收藏

Effects of nitrate concentration on biological hydrogen production by mixed cultures

Bo WANG, Wei WAN, Jianlong WANG,

《环境科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 380-386 doi: 10.1007/s11783-009-0142-0

摘要： The effects of nitrate on fermentative hydrogen production and soluble metabolites from mixed cultures were investigated by varying nitrate concentrations from 0 to 10g N/L at 35°C with an initial pH of 7.0. The results showed that the substrate degradation rate, hydrogen production potential, hydrogen yield, and average hydrogen production rate initially increased with increasing nitrate concentrations from 0 to 0.1g N/L, while they decreased with increasing nitrate concentrations from 0.1 to 10g N/L. The maximum hydrogen production potential of 305.0mL, maximum hydrogen yield of 313.1mL/g glucose, and maximum average hydrogen production rate of 13.3mL/h were obtained at a nitrate concentration of 0.1g N/L. The soluble metabolites produced by the mixed cultures contained only ethanol and acetic acid (HAc) without propionic acid (HPr) and butyric acid (HBu). This study used the Modified Logistic model to describe the progress of cumulative hydrogen production in batch tests. A concise model was proposed to describe the effects of nitrate concentration on average hydrogen production rate.

关键词： nitrogen source     biohydrogen     fermentative hydrogen production     quantitative kinetic model    

HTML PDF 收藏

Synthesis and thermosensitive behavior of dextran graft copolymers containing poly (N-vinylcaprolactam

SHI Huangying, CHEN Wenjuan, ZHANG Liming

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 72-75 doi: 10.1007/s11705-007-0015-7

摘要： New graft copolymers were synthesized by grafting N-vinylcaprolactam onto dextran. Their composition and structure were investigated by elemental analyses, infrared spectra and thermogravimetric analyses. By optical transmittance measurements, it was found that the aqueous solutions of these graft copolymers showed a temperature-dependent transmittance change due to the introduction of thermosensitive poly (-vinylcaprolactam) graft chains. Moreover, the lower critical solution temperature (LCST) of the graft copolymer in aqueous solution was dependent on its grafting extent and concentration. The LCST value was found to increase with the increase of the grafting extent and decrease with the increase of the copolymer concentration. With these stimuli-response properties, such polysaccharide derivative may hold potential applications in biomedicine and biotechnology.

关键词： transmittance     copolymer concentration     LCST     temperature     elemental    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

Development of source profiles and their application in source apportionment of PM

Ningning Zhang, Mazhan Zhuang, Jie Tian, Pengshan Tian, Jieru Zhang, Qiyuan Wang, Yaqing Zhou, Rujin Huang, Chongshu Zhu, Xuemin Zhang, Junji Cao

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0879-1

摘要： Seasonal and spatial distribution of PM and its component were shown. Local source profiles of major PM sources were developed. Source apportionment was conducted using CMB model. Inorganic secondary components is the biggest contribution at Xiamen. Ambient PM samples were collected at four sites in Xiamen, including Gulangyu (GLY), Hongwen (HW), Huli (HL) and Jimei (JM) during January, April, July and October 2013. Local source samples were obtained from coal burning power plants, industries, motor vehicles, biomass burning, fugitive dust, and sea salt for the source apportionment studies. The highest value of PM mass concentration and species related to human activities (SO , NO , Pb, Ni, V, Cu, Cd, organic carbon (OC) and elemental carbon (EC)) were found in the ambient samples from HL, and the highest and lowest loadings of PM and its components occurred in winter and summer, respectively. The reconstructed mass balance indicated that ambient PM consisted of 24% OM (organic matter), 23% sulfate, 14% nitrate, 9% ammonium, 9% geological material, 6% sea salt, 5% EC and 10% others. For the source profiles, the dominant components were OC for coal burning, motor vehicle, biomass burning and sea salt; SO for industry; and crustal elements for fugitive dust. Source contributions were calculated using a chemical mass balance (CMB) model based on ambient PM concentrations and the source profiles. GLY was characterized by high contributions from secondary sulfate and cooking, while HL and JM were most strongly affected by motor vehicle emissions, and biomass burning and fugitive dust, respectively. The CMB results indicated that PM from Xiamen is composed of 27.4% secondary inorganic components, 20.8% motor vehicle emissions, 11.7% fugitive dust, 9.9% sea salt, 9.3% coal burning, 5.0% biomass burning, 3.1% industry and 6.8% others.

关键词： PM2.5     Source profile     Source apportionment     CMB     Xiamen    

HTML PDF 收藏

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    

HTML PDF 收藏

The source and transport of bioaerosols in the air: A review

《环境科学与工程前沿（英文）》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1336-8

摘要：

• Emission of microbe from local environments is a main source of bioaerosols.

关键词： Bioaerosols     Diffusion     Source identification     Biogeography    

HTML PDF 收藏

Fault tolerant control strategy for modular PWM current source inverter

《能源前沿（英文）》 2023年 第17卷 第2期   页码 228-238 doi: 10.1007/s11708-022-0852-6

摘要： In this paper, a fault-tolerant control method for an input-series output-parallel modular grid-tied pulse-width modulation (PWM) current source inverter is proposed to address the most commonly seen single symmetrical gate-commutated thyristor (SGCT) open-circuit fault problems. This method actively offsets the neutral point of the current space vector to ensure a sinusoidal output of the grid current, and it can achieve the upper limit power of the inverter under the condition of a single SGCT open-circuit fault. In addition, an active damping control method based on grid harmonic current feedback is proposed after analyzing the influence of the transformer ferromagnetic resonance caused by the neutral point offset on the power quality of the grid current. It has been demonstrated that the proposed method effectively suppresses the resonance caused by the transformer and the modified modulation, improving the grid current’s power quality.

关键词： current source converter (CSC)     fault-tolerant control     space vector modulation     active damping     resonance suppression     power quality    

HTML PDF 收藏

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    

HTML PDF 收藏

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.
HTML PDF 收藏

Effect of different carbon sources on performance of an A

Dongliang Du, Chuanyi Zhang, Kuixia Zhao, Guangrong Sun, Siqi Zou, Limei Yuan, Shilong He

《环境科学与工程前沿（英文）》 2018年 第12卷 第2期 doi: 10.1007/s11783-017-0981-z

摘要： Effect of different carbon sources on purification performance and change of microbial community structure in a novel A N-MBR process were investigated. The results showed that when fed with acetate, propionate or acetate and propionate mixed (1:1) as carbon sources, the effluent COD, NH -N, TN and TP were lower than 30, 5, 15 and 0.5 mg·L , respectively. However, taken glucose as carbon source, the TP concentration of effluent reached 2.6 mg·L . Process analysis found that the amount of anaerobic phosphorus release would be the key factor to determine the above effectiveness. The acetate was beneficial to the growth of associated with biological phosphorus removal, which was the main cause of high efficiency phosphorus removal in this system. In addition, it could eliminate the associated with glycogen-accumulating organisms and guarantee high efficiency phosphorus uptake of phosphorus accumulating organisms in the system with acetate as carbon source.

关键词： Denitrifying phosphorus removal     Alternate anaerobic/anoxic-aerobic MBR (A2N-MBR)     Carbon source     Operation characteristic     Community structure    

HTML PDF 收藏

标题 作者 时间 类型 操作

Metabolic flux analysis on arachidonic acid fermentation

JIN Mingjie, HUANG He, ZHANG Kun, YAN Jie, GAO Zhen

期刊论文

δN-stable isotope analysis of NH: An overview on analytical measurements, source sampling and its source

期刊论文

Impacts of n-alkane concentration on soil bacterial community structure and alkane monooxygenase genes

Yueqiao Liu, Aizhong Ding, Yujiao Sun, Xuefeng Xia, Dayi Zhang

期刊论文

Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

Yufen REN, Zhiwei XU, Xinyu ZHANG, Xiaoke WANG, Xiaomin SUN, D. J. BALLANTINE, Shengzhong WANG

期刊论文

Effects of nitrate concentration on biological hydrogen production by mixed cultures

Bo WANG, Wei WAN, Jianlong WANG,

期刊论文

Synthesis and thermosensitive behavior of dextran graft copolymers containing poly (N-vinylcaprolactam

SHI Huangying, CHEN Wenjuan, ZHANG Liming

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

Development of source profiles and their application in source apportionment of PM

Ningning Zhang, Mazhan Zhuang, Jie Tian, Pengshan Tian, Jieru Zhang, Qiyuan Wang, Yaqing Zhou, Rujin Huang, Chongshu Zhu, Xuemin Zhang, Junji Cao

期刊论文

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

期刊论文

The source and transport of bioaerosols in the air: A review

期刊论文

Fault tolerant control strategy for modular PWM current source inverter

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

Effect of different carbon sources on performance of an A

Dongliang Du, Chuanyi Zhang, Kuixia Zhao, Guangrong Sun, Siqi Zou, Limei Yuan, Shilong He

期刊论文