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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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An investigation of reaction furnace temperatures and sulfur recovery

S. ASADI, M. PAKIZEH, M. POURAFSHARI CHENAR

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 362-371 doi: 10.1007/s11705-011-1106-z

摘要： In a modern day sulfur recovery unit (SRU), hydrogen sulfide (H S) is converted to elemental sulfur using a modified Claus unit. A process simulator called TSWEET has been used to consider the Claus process. The effect of the H S concentration, the H S/CO ratio, the input air flow rate, the acid gas flow of the acid gas (AG) splitter and the temperature of the acid gas feed at three different oxygen concentrations (in the air input) on the main burner temperature have been studied. Also the effects of the tail gas ratio and the catalytic bed type on the sulfur recovery were studied. The bed temperatures were optimized in order to enhance the sulfur recovery for a given acid gas feed and air input. Initially when the fraction of AG splitter flow to the main burner was increased, the temperature of the main burner increased to a maximum but then decreased sharply when the flow fraction was further increased; this was true for all three concentrations of oxygen. However, if three other parameters (the concentration of H S, the ratio H S/CO and the flow rate of air) were increased, the temperature of the main burner increased monotonically. This increase had different slopes depending on the oxygen concentration in the input air. But, by increasing the temperature of the acid gas feed, the temperature of the main burner decreased. In general, the concentration of oxygen in the input air into the Claus unit had little effect on the temperature of the main burner (This is true for all parameters). The optimal catalytic bed temperature, tail gas ratio and type of catalytic bed were also determined and these conditions are a minimum temperature of 300°C, a ratio of 2.0 and a hydrolysing Claus bed.

关键词： Claus unit     concentration of H2S     tail gas ratio     sulfur recovery     catalytic bed    

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Optical performance analysis of an innovative linear focus secondary trough solar concentrating system

Xiliang ZHANG, Zhiying CUI, Jianhan ZHANG, Fengwu BAI, Zhifeng WANG

《能源前沿（英文）》 2019年 第13卷 第3期   页码 590-596 doi: 10.1007/s11708-018-0602-y

摘要： The parabolic trough solar concentrating system has been well developed and widely used in commercial solar thermal power plants. However, the conventional system has its drawbacks when connecting receiver tube parts and enhancing the concentration ratio. To overcome those inherent disadvantages, in this paper, an innovative concept of linear focus secondary trough concentrating system was proposed, which consists of a fixed parabolic trough concentrator, one or more heliostats, and a fixed tube receiver. The proposed system not only avoids the end loss and connection problem on the receiver during the tracking process but also opens up the possibility to increase the concentration ratio by enlarging aperture. The design scheme of the proposed system was elaborated in detail in this paper. Besides, the optical performance of the semi and the whole secondary solar trough concentrator was evaluated by using the ray tracing method. This innovative solar concentrating system shows a high application value as a solar energy experimental device.

关键词： secondary parabolic trough solar concentrator     ray tracing method     linear focus     concentration ratio     optical performance    

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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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A Novel Electrochemical Reactor for Nitrogen and Phosphorus Recovery from Domestic Wastewater

Shiting Ren, Mengchen Li, Jianyu Sun, Yanhong Bian, Kuichang Zuo, Xiaoyuan Zhang, Peng Liang, Xia Huang

《环境科学与工程前沿（英文）》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0983-x

摘要： To separate and concentrate NH4+ and PO43 from the synthetic wastewater to the concentrated solution through a novel electrochemical reactor with circulated anode and cathode using the difference of the concentration between electrode chamber and middle chamber. In recent years, the research on electrochemical processes have been focused on phosphate and ammonium removal and recovery. Among the wide range of possibilities with regards to electrochemical processes, capacitive deionization (CDI) saves the most energy while at the same time does not have continuity and selectivity. In this study, a new electrochemical reactor with electrolyte cyclic flowing in the electrode chambers was constructed to separate and concentrate phosphate and ammonium continuously and selectively from wastewater, based on the principle of CDI. At the concentration ratio of NaCl solution between the electrode chambers and the middle chamber (r) of 25 to 1, phosphate and ammonium in concentration level of domestic wastewater can be removed and recovered continuously and selectively as struvite. Long-term operation also indicated the ability to continuously repeat the reaction and verified sustained stability. Further, the selective recovery at the certain r could also be available to similar technologies for recovering other kinds of substances.

关键词： Nutrients recovery     Electrochemical reactor     Electrolyte cyclic flowing     Concentration ratio     Struvite    

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油压极值比与极值比效率

齐茂林

《中国工程科学》 2001年 第3卷 第4期   页码 73-75

摘要：

文章应用基础公式，推导液压系统油压极值比与极值比效率之间的关系式。该式说明，油压极值比越大，极值比效率就越低。提出了油压极值比是可以设计和选择的。

关键词： 油压极值比     极值比效率     液压系统    

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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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Controlling interstory drift ratio profiles via topology optimization strategies

《结构与土木工程前沿（英文）》 2023年 第17卷 第2期   页码 165-178 doi: 10.1007/s11709-022-0892-3

摘要： An approach to control the profiles of interstory drift ratios along the height of building structures via topology optimization is proposed herein. The theoretical foundation of the proposed approach involves solving a min–max optimization problem to suppress the maximum interstory drift ratio among all stories. Two formulations are suggested: one inherits the bound formulation and the other utilizes a p-norm function to aggregate all individual interstory drift ratios. The proposed methodology can shape the interstory drift ratio profiles into inverted triangular or quadratic patterns because it realizes profile control using a group of shape weight coefficients. The proposed formulations are validated via a series of numerical examples. The disparity between the two formulations is clear. The optimization results show the optimal structural features for controlling the interstory drift ratios under different requirements.

关键词： interstory drift ratio     aggregation function     bound formulation     min–max problem     topology optimization    

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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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A methodology of implementing target mixing ratio for asphalt mixture

Yucheng HUANG, Lun JI, Rui WEN, Ming ZHANG

《结构与土木工程前沿（英文）》 2017年 第11卷 第3期   页码 308-314 doi: 10.1007/s11709-017-0405-y

摘要： In order to implement the objective mix design of hot mix asphalt adequately during the construction process, the significance of objective mixing ratio was elaborated, and the variability of materials and its control method were analyzed. An engineering example is used to illustrate the debugging process of asphalt mixture batching & mixing plant and the dynamic quality management methods. The results show that the set of methods can not only implement the objective mixing ratio of hot mix asphalt adequately, but also control production during the construction process effectively.

关键词： asphalt mixture     target mixing ratio     mix design implementation     batching & mixing plant debugging    

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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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标题 作者 时间 类型 操作

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

ZHANG Huilan, WANG Daowen

期刊论文

An investigation of reaction furnace temperatures and sulfur recovery

S. ASADI, M. PAKIZEH, M. POURAFSHARI CHENAR

期刊论文

Optical performance analysis of an innovative linear focus secondary trough solar concentrating system

Xiliang ZHANG, Zhiying CUI, Jianhan ZHANG, Fengwu BAI, Zhifeng WANG

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

A Novel Electrochemical Reactor for Nitrogen and Phosphorus Recovery from Domestic Wastewater

Shiting Ren, Mengchen Li, Jianyu Sun, Yanhong Bian, Kuichang Zuo, Xiaoyuan Zhang, Peng Liang, Xia Huang

期刊论文

油压极值比与极值比效率

齐茂林

期刊论文

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

期刊论文

Controlling interstory drift ratio profiles via topology optimization strategies

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

A methodology of implementing target mixing ratio for asphalt mixture

Yucheng HUANG, Lun JI, Rui WEN, Ming ZHANG

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