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Subcellular distribution and chemical form of Pb in hyperaccumulator

Yanqun ZU,Yuan LI,Huan MIN,Fangdong ZHAN,Li QIN,Jixiu WANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 250-258 doi: 10.1007/s11783-014-0643-3

摘要： Solution culture was conducted in order to understand accumulation characteristics and chemical forms of Pb in ( ) and the response of root exudates to Pb addition. The results showed that: 1) Pb contents in the shoot and root of increased with increasing in Pb concentrations in solution. 2) The contents of Pb chemical forms under Pb addition followed as: HAc extractable fraction (F )>HCl extractable fraction (F )>NaCl extractable fraction (F )>ethanol-extractable fraction (F )>water extractable fraction (F ). 3) Increased Pb level in the medium caused increases in Pb contents in the four subcellular fractions of shoots and roots, with most accumulation in FIV (Fraction IV, soluble fraction) in shoots and FI (Fraction I, cell wall fraction) in roots. 4) Contents of soluble sugar and free amino acid of root exudates increased with increasing Pb concentration in solution. Significantly positive correlations between Pb and contents of soluble sugar and free amino acid were observed. 5) With Pb concentrations in solution, low molecular weight organic acids (LMWOAs) contents followed the tendency: tartaric acid>acetic acid>malic acid>citric acid. Significantly positive correlation was observed between Pb and citric acid contents. The results indicate that soluble sugars, free amino acid and citric acid in root exudates of facilitate the absorption and accumulation of Pb, which exist in NaCl-, HCl- and HAc- extractable Pb forms, FI and FIV fractions, resulting in tolerance of to Pb.

关键词： Pb     Arenaria orbiculata     chemical forms     subcellular distribution     root exudates     hydroponic culture    

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Comparisons in subcellular and biochemical behaviors of cadmium between low-Cd and high-Cd accumulation

Meng XUE, Yihui ZHOU, Zhongyi YANG, Biyun LIN, Jiangang YUAN, Shanshan WU

《环境科学与工程前沿（英文）》 2014年 第8卷 第2期   页码 226-238 doi: 10.1007/s11783-013-0582-4

摘要： Subcellular distributions and chemical forms of cadmium (Cd) in the leaves, stems and roots were investigated in low-Cd accumulation cultivars and high-Cd accumulation cultivars of pakchoi ( L.). Root cell wall played a key role in limiting soil Cd from entering the protoplast, especially in the low-Cd cultivars. The high-Cd cultivars had significantly higher leaf and stem Cd concentrations than the low-Cd cultivars in cell wall fraction, chloroplast/trophoplast fraction, organelle fraction and soluble fraction. In low-Cd cultivars, which were more sensitive and thus had greater physiological needs of Cd detoxification than high-Cd cultivars, leaf vacuole sequestrated higher proportions of Cd. Cd in the form of pectate/protein complexes (extracted by 1 mol·L NaCl) played a decisive role in Cd translocation from root to shoot, which might be one of the mechanisms that led to the differences in shoot Cd accumulation between the two types of cultivars. Furthermore, the formation of Cd-phosphate complexes (extracted by 2% HAc) was also involved in Cd detoxification within the roots of pakchoi under high Cd stress, suggesting that the mechanisms of Cd detoxification might be different between low- and high-Cd cultivars.

关键词： cadmium (Cd)     low-Cd cultivar     pakchoi (Brassica chinensis L.)     subcellular distribution     chemical forms    

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Copper and zinc interaction on water clearance and tissue metal distribution in the freshwater mussel

Tianxiang XIA, Xuehua LIU

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 236-242 doi: 10.1007/s11783-010-0218-8

摘要： Copper and zinc interaction on clearance from water and distribution in different tissues was investigated for the freshwater mussel, , under laboratory conditions. Clearance rate of Cu or Zn from water was highly dependent on exposure concentration. Interaction effect was most evident at 300 μg·L Cu exposure and depressed the Zn clearance rate significantly ( <0.05). However, the presence of 100 μg·L and 300 μg·L Zn hardly affected the Cu clearance rate. The 300 μg·L Cu presence enhanced Cu accumulation in each tissue most significantly ( <0.01), but caused Zn content to decrease in the gills by 62% ( <0.05), viscera by 49% ( <0.05) and foot by 31% ( <0.05), and increase in the mantle by 97% ( <0.05) and the muscles by 243% ( <0.05) for different Zn exposure treatments. The response of metal accumulation in various tissues of the test mussels indicated that Zn transferred from the gills, viscera and foot to the mantle and muscles might be one of the important characteristics of the Zn regulatory mechanism by leading to a narrow range of Zn concentration in the different tissues.

关键词： interaction     mussel     copper     zinc     clearance     distribution    

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Developmental expression of CAPON and Dexras1 in spinal cord of rats

LI Xin, CHENG Chun, CHEN Mengling, GAO Shangfeng, ZHAO Jian, NIU Shuqiong, SHEN Aiguo

《医学前沿（英文）》 2008年 第2卷 第1期   页码 75-81 doi: 10.1007/s11684-008-0014-1

摘要： To study the expression of the carboxy-terminal PSD-95/DLG/ZO-1 ligand of nNOS (CAPON) and Dexras1 mRNA during development in the spinal cord of rats, real-time polymerase chain reaction (Real-time PCR), as a quantitative method, was used to study the developmental expression of CAPON and Dexras1 mRNA level in the spinal cord. The spatial expression of CAPON and Dexras1 mRNA was examined by a combination of hybridization (ISH) and immunofluorescence. During the development of the spinal cord, CAPON mRNA was expressed in low levels from embryo day 14 to day 18. At postnatal day 1, it reached the peak and was expressed in the part which will become the dorsal horn when mature. It then decreased gradually until postnatal week 12, when it presented in the ventral horn. At embryo day 14, Dexras1 mRNA was expressed at low levels, increased during embryo day 16 to day 18 and peaked at postnatal day 1. Spatiotemporal expression of Dexras1 mRNA was similar to CAPON as confirmed by correlation analysis and colocalization. CAPON and neuronal nitric oxide synthase (nNOS) was expressed within the same cells of the dorsal horn at postnatal day 1 but had different subcellular localizations. Co-expression of CAPON and Dexras1 mRNA in myeloid tissue during development process of rat indicates that the adaptor protein, CAPON may play a probable role in differentiation of neurons, synaptic plasticity and synaptogenesis by regulating nNOS to activate Dexras1.

关键词： CAPON     ISH     differentiation     postnatal     different subcellular    

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Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 985-995 doi: 10.1007/s11705-021-2126-y

摘要： The high contents of nitrogen-containing organic compounds in biocrude obtained from hydrothermal liquefaction of microalgae are one of the most concerned issues on the applications and environment. In the project, Chlorella sp. and Spirulina sp. were selected as raw materials to investigate the influence of different reaction conditions (i.e., reaction temperature, residence time, solid loading rate) on the distribution of nitrogen in the oil phase and aqueous phase. Three main forms of nitrogen-containing organic compounds including nitrogen-heterocyclic compounds, amide, and amine were detected in biocrudes. The contents of nitrogen-heterocyclic compounds decreased with temperature while amide kept increasing. The effect of residence time on the components of nitrogen-containing organic compounds was similar with that of temperature. However, the influence of solid loading rate was insignificant. Moreover, it was also found that the differences of amino acids in the protein components in the two microalgae might affect the nitrogen distribution in products. For example, nitrogen in basic amino acids of Spirulina sp. preferred to go into the aqueous phase comparing with the nitrogen in neutral amino acids of Chlorella sp. In summary, a brief reaction map was proposed to describe the nitrogen pathway during microalgae hydrothermal liquefaction.

关键词： microalgae     hydrothermal liquefaction     biocrude     nitrogen distribution    

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Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady

Xiyan GUO, Yongping YANG

《能源前沿（英文）》 2011年 第5卷 第1期   页码 69-74 doi: 10.1007/s11708-010-0117-7

摘要： A coal-fired power unit frequently operates under unsteady conditions; thus, in order to acquire scientific energy analysis of the unit, thermodynamic analysis of a single-phase heated surface in a boiler under such conditions requires investigation. Processes are analyzed, and distributions of energy and exergy are qualitatively revealed. Models for energy analysis, entropy analysis, and exergy analysis of control volumes and irreversible heat transfer processes are established. Taking the low-temperature superheater of a 610 t/h-boiler as an example, the distribution of energy, entropy production, and exergy is depicted quantitatively, and the results are analyzed.

关键词： thermodynamic model     energy distribution     boiler     unsteady conditions    

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Estimation of distribution algorithm enhanced particle swarm optimization for water distribution network

Xuewei QI,Ke LI,Walter D. POTTER

《环境科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 341-351 doi: 10.1007/s11783-015-0776-z

摘要： The optimization of a water distribution network (WDN) is a highly nonlinear, multi-modal, and constrained combinatorial problem. Particle swarm optimization (PSO) has been shown to be a fast converging algorithm for WDN optimization. An improved estimation of distribution algorithm (EDA) using historic best positions to construct a sample space is hybridized with PSO both in sequential and in parallel to improve population diversity control and avoid premature convergence. Two water distribution network benchmark examples from the literature are adopted to evaluate the performance of the proposed hybrid algorithms. The experimental results indicate that the proposed algorithms achieved the literature record minimum (6.081 M$) for the small size Hanoi network. For the large size Balerma network, the parallel hybrid achieved a slightly lower minimum (1.921M?) than the current literature reported best minimum (1.923M?). The average number of evaluations needed to achieve the minimum is one order smaller than most existing algorithms. With a fixed, small number of evaluations, the sequential hybrid outperforms the parallel hybrid showing its capability for fast convergence. The fitness and diversity of the populations were tracked for the proposed algorithms. The track record suggests that constructing an EDA sample space with historic best positions can improve diversity control significantly. Parallel hybridization also helps to improve diversity control yet its effect is relatively less significant.

关键词： particle swarm optimization (PSO)     diversity control     estimation of distribution algorithm (EDA)     water distribution network (WDN)     premature convergence     hybrid strategy    

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Hazard and vulnerability evaluation of water distribution system in cases of contamination intrusion

Kunlun XIN, Tao TAO, Yong WANG, Suiqing LIU

《环境科学与工程前沿（英文）》 2012年 第6卷 第6期   页码 839-848 doi: 10.1007/s11783-012-0409-8

摘要： In this paper, it proposed an index system for hazard and vulnerability evaluations of water distribution networks, based on the simulation of contamination events caused by pollutant injections at different junctions. It attempted to answer the following two questions in the case of contamination events: 1) Which are the most hazardous junctions? 2) Which are the most vulnerable junctions? With EPANET toolkit, it simulated the propagation of the contaminant, and calculated the peak concentration of the contaminant and mass delivered at different nodes. According to types of consumers, different weights were assigned to the consumer nodes for assessing the influence of the contaminant on the consumers. Using the method proposed herein, both the hazard index and vulnerability index were calculated for each node in the pipe network. The presented method was therefore applied to the water network of the city of Zhenjiang, which contains two water plants, two booster pump stations with storage tanks. In conclusion, the response time, the relationships between the peak concentration of contaminant and the total absorption are the most important factors in hazard and vulnerability evaluation of the water distribution network.

关键词： water distribution network     hazard     vulnerability     contaminant accident    

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Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

《机械工程前沿（英文）》 2011年 第6卷 第2期   页码 241-248 doi: 10.1007/s11465-011-0219-x

摘要：

This paper presents a new calculation method that can calculate the load distribution on pipe threaded connections under tension load. On the basis of elastic mechanics, the new method was developed by analyzing each thread tooth, and a new deformation and covariant equation by making a mechanics analysis on each thread tooth was obtained. Compared with the traditional method proposed by the previous references, the new deformation and covariant equation could be used to describe the relation between the previous and the next thread tooth. By applying the new method on the sample of P-110S pipe threaded connection, the obtained results show that the load on thread tooth mainly concentrates on the four or five threads engaged and the middle teeth were not utilized well to bear the loads. The model offers a new way to calculate the loads carried on the thread teeth under tension load.

关键词： load distribution     calculation method     pipe threaded connections     tension load    

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Numerical simulation of the heat flux distribution in a solar cavity receiver

Yueshe WANG, Xunwei DONG, Jinjia WEI, Hui JIN

《能源前沿（英文）》 2011年 第5卷 第1期   页码 98-103 doi: 10.1007/s11708-010-0019-8

摘要： In the solar tower power plant, the receiver is one of the main components of efficient concentrating solar collector systems. In the design of the receiver, the heat flux distribution in the cavity should be considered first. In this study, a numerical simulation using the Monte Carlo Method has been conducted on the heat flux distribution in the cavity receiver, which consists of six lateral faces and floor and roof planes, with an aperture of 2.0 m×2.0 m on the front face. The mathematics and physical models of a single solar ray’s launching, reflection, and absorption were proposed. By tracing every solar ray, the distribution of heat flux density in the cavity receiver was obtained. The numerical results show that the solar flux distribution on the absorbing panels is similar to that of CESA-I’s. When the reradiation from walls was considered, the detailed heat flux distributions were issued, in which 49.10% of the total incident energy was absorbed by the central panels, 47.02% by the side panels, and 3.88% was overflowed from the aperture. Regarding the peak heat flux, the value of up to 1196.406 kW/m was obtained in the center of absorbing panels. These results provide necessary data for the structure design of cavity receiver and the local thermal stress analysis for boiling and superheated panels.

关键词： solar cavity receiver     Monte Carlo method     heat flux distribution    

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The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

《环境科学与工程前沿（英文）》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1356-4

摘要：

•Bacterial concentrations from eight stages were 104–105copies/m3.

关键词： Size distribution     Airborne bacteria     Biological diversity     Human pathogenic bacteria     Composting plants    

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Reactive power deployment and cost benefit analysis in DNO operated distribution electricity markets

Atma Ram GUPTA,Ashwani KUMAR

《能源前沿（英文）》 2019年 第13卷 第1期   页码 86-98 doi: 10.1007/s11708-017-0456-8

摘要： The aim of this paper is to analyze unbalanced radial distribution systems (UBRDS) with the distribution static compensator (D-STATCOM). The main objectives of this paper are D-STATCOM allocation in UBRDS with an objective of providing reactive power support to enhance voltage profile and reduce line losses of the distribution network, determination of optimal D-STATCOM rating subjected to minimization of total cost, and impact of D-STATCOM placement on improving power factor and savings in cost of energy loss. The analysis is conducted on a large industrial load model with light, medium and high loading scenarios. Further, the impact of load growth is also considered for better planning of the power distribution system. The results are obtained on standard 25-bus UBRDS to check the feasibility of the proposed methodology.

关键词： unbalanced distribution system     D-STATCOM     voltage sensitivity index     load models     load growth     distribution network operator (DNO)    

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Distributed energy management for networked microgrids in a three-phase unbalanced distribution network

《能源前沿（英文）》 2023年 第17卷 第3期   页码 446-446 doi: 10.1007/s11708-022-0851-7

摘要： Owing to increased penetration of three-phase and single-phase microgrids, distributed energy resources (DERs), and responsive loads, the maintenance of a three-phase balance by distribution networks is a significant challenge. Existing literature on distributed energy management for networked microgrids generally neglects the distribution network or employs a simplified phase balanced distribution network; thus, these evaluations are not applicable. Further, the underlying mutual coupling between the different phases of distribution feeders results in a more challenging situation. To solve this issue, this study sought to propose distributed energy management based on a three-phase unbalanced distribution network. Various three-phase or single-phase microgrids, utility-owned DERs, and responsive loads were coordinated through iteratively adjusted price signals. Based on the price signals received, the microgrid controllers (MCs) and distribution management system (DMS) updated the schedules of the DERs and responsive loads under their jurisdiction separately. The price signals were then updated according to the generation-load mismatch at each node and distributed to the corresponding MCs and DMS for the next iteration. The iteration continued until a sufficiently small generation-load mismatch was achieved at all nodes, that is, a balanced generation and load at all nodes under the agreed price signals. Considering a three-phase unbalanced distribution network, the price signals were determined per phase per node. Overall, the proposed distributed energy management coordinates microgrids, utility-owned DERs, responsive loads with guaranteed network constraints, and preserves the privacy of microgrid customers. This distributed energy management method was further demonstrated through various case studies on a three-phase networked microgrid test system.

关键词： distributed optimization     energy management     networked microgrids     three-phase distribution network     distributed energy resources    

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Power system reconfiguration and loss minimization for a distribution systems using “Catfish PSO” algorithm

K Sathish KUMAR,S NAVEEN

《能源前沿（英文）》 2014年 第8卷 第4期   页码 434-442 doi: 10.1007/s11708-014-0313-y

摘要： One of the very important ways to save electrical energy in the distribution system is network reconfiguration for loss reduction. Distribution networks are built as interconnected mesh networks; however, they are arranged to be radial in operation. The distribution feeder reconfiguration is to find a radial operating structure that optimizes network performance while satisfying operating constraints. The change in network configuration is performed by opening sectionalizing (normally closed) and closing tie (normally opened) switches of the network. These switches are changed in such a way that the radial structure of networks is maintained, all of the loads are energized, power loss is reduced, power quality is enhanced, and system security is increased. Distribution feeder reconfiguration is a complex nonlinear combinatorial problem since the status of the switches is non-differentiable. This paper proposes a new evolutionary algorithm (EA) for solving the distribution feeder reconfiguration (DFR) problem for a 33-bus and a 16-bus sample network, which effectively ensures the loss minimization.

关键词： distribution system reconfiguration (DFR)     power loss reduction     catfish particle swarm optimization (catfish PSO)     radial structure    

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标题 作者 时间 类型 操作

Subcellular distribution and chemical form of Pb in hyperaccumulator

Yanqun ZU,Yuan LI,Huan MIN,Fangdong ZHAN,Li QIN,Jixiu WANG

期刊论文

Comparisons in subcellular and biochemical behaviors of cadmium between low-Cd and high-Cd accumulation

Meng XUE, Yihui ZHOU, Zhongyi YANG, Biyun LIN, Jiangang YUAN, Shanshan WU

期刊论文

Copper and zinc interaction on water clearance and tissue metal distribution in the freshwater mussel

Tianxiang XIA, Xuehua LIU

期刊论文

Developmental expression of CAPON and Dexras1 in spinal cord of rats

LI Xin, CHENG Chun, CHEN Mengling, GAO Shangfeng, ZHAO Jian, NIU Shuqiong, SHEN Aiguo

期刊论文

Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

期刊论文

Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady

Xiyan GUO, Yongping YANG

期刊论文

Estimation of distribution algorithm enhanced particle swarm optimization for water distribution network

Xuewei QI,Ke LI,Walter D. POTTER

期刊论文

Hazard and vulnerability evaluation of water distribution system in cases of contamination intrusion

Kunlun XIN, Tao TAO, Yong WANG, Suiqing LIU

期刊论文

Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

期刊论文

Nikos Hatziargyrio：The Role of Data in Intelligent Distribution Grids（2022年6月6日）

2022年07月07日

会议视频

Numerical simulation of the heat flux distribution in a solar cavity receiver

Yueshe WANG, Xunwei DONG, Jinjia WEI, Hui JIN

期刊论文

The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

期刊论文

Reactive power deployment and cost benefit analysis in DNO operated distribution electricity markets

Atma Ram GUPTA,Ashwani KUMAR

期刊论文

Distributed energy management for networked microgrids in a three-phase unbalanced distribution network

期刊论文

Power system reconfiguration and loss minimization for a distribution systems using “Catfish PSO” algorithm

K Sathish KUMAR,S NAVEEN

期刊论文