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Seasonal variation of nitrogen and phosphorus in Xiaojiang River—A tributary of the Three Gorges Reservoir

Zhe LI , Jinsong GUO , Man LONG , Fang FANG , Jinping SHENG , Hong ZHOU ,

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 334-340 doi: 10.1007/s11783-009-0039-y

摘要： A yearlong monitoring program in the backwater area of Xiaojiang River (XBA) was launched in order to investigate the eutrophication of backwater areas in tributaries of the Yangtze River in the Three Gorges Reservoir (TGR) in China, starting after the impoundment water level of the TGR reached 156 m. From March 2007 to March 2008, the average concentration of total nitrogen (TN) and total phosphorus (TP) were (1553 ± 484) μg·L and (62 ± 31) μg·L, respectively. The mean value of chlorophyll was (9.07 ± 0.91) μg·L. The trophic level of XBA was meso-eutrophic, while the general nutrient limitation was phosphorus. The results indicated that XBA has a strong ability to purify itself and has non-point source pollution from terrestrial runoff. The variation of TN/TP ratio was caused by a variation in TN rather than in TP when TN/TP<22. N-fixation from cyanobacteria occurred and became an important process in overcoming the nitrogen deficit under a low TN/TP ratio. When TN/TP ≥ 22, the variation of TP affected the TN/TP ratio more significantly than TN. The increase of TP in XBA was caused mainly by particulate phosphorus, which could originate from a non-point source as adsorptive inorganic forms after heavy rainfall and surface runoff. An increase in the river’s flow could also contribute to an unstable environment for the growth of phytoplankton.

关键词： Three Gorges Reservoir     eutrophication     nitrogen     phosphorus     seasonal variation     chlorophyll    

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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    

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Optimization for operating modes based on simulation of seasonal underground thermal energy storage

ZHAO Jun, CHEN Yan, LI Xinguo

《能源前沿（英文）》 2008年 第2卷 第3期   页码 298-301 doi: 10.1007/s11708-008-0053-y

摘要： A simulation was performed, which concerned the feasibility of seasonal underground thermal energy storage (UTES) in Tianjin, China. The investigated system consisted of 8 boreholes. In summer, residual solar thermal energy was emitted into the soil surrounding the borehole heat exchangers through which the stored energy was extracted in winter with a ground coupled heat pump (GCHP) to provide a proper heating temperature. A simulation study was performed to study the influence of system operation modes on thermal recovery based on the experimental data of a GCHP system, local meteorological conditions and soil properties in Tianjin. The results indicate a thermal recovery ratio of less than 67% and different temperature distributions under three modes. Finally, an operation mode was suggested based on both lower loss and better thermal recovery in the UTES.
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Numerical simulation of underground seasonal cold energy storage for a 10 MW solar thermal power plant

Zulkarnain ABBAS, Yong LI, Ruzhu WANG

《能源前沿（英文）》 2021年 第15卷 第2期   页码 328-344 doi: 10.1007/s11708-020-0676-1

摘要： This paper aims to explore an efficient, cost-effective, and water-saving seasonal cold energy storage technique based on borehole heat exchangers to cool the condenser water in a 10 MW solar thermal power plant. The proposed seasonal cooling mechanism is designed for the areas under typical weather conditions to utilize the low ambient temperature during the winter season and to store cold energy. The main objective of this paper is to utilize the storage unit in the peak summer months to cool the condenser water and to replace the dry cooling system. Using the simulation platform transient system simulation program (TRNSYS), the borehole thermal energy storage (BTES) system model has been developed and the dynamic capacity of the system in the charging and discharging mode of cold energy for one-year operation is studied. The typical meteorological year (TMY) data of Dunhuang, Gansu province, in north-western China, is utilized to determine the lowest ambient temperature and operation time of the system to store cold energy. The proposed seasonal cooling system is capable of enhancing the efficiency of a solar thermal power plant up to 1.54% and 2.74% in comparison with the water-cooled condenser system and air-cooled condenser system respectively. The techno-economic assessment of the proposed technique also supports its integration with the condenser unit in the solar thermal power plant. This technique has also a great potential to save the water in desert areas.

关键词： seasonal cold energy storage     borehole heat exchangers     typical meteorological data     TRNSYS     condenser cooling     techno-economic assessment    

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Seasonal and treatment-process variations in invertebrates in drinking water treatment plants

Zhiling Wu, Xianchun Tang, Hongbin Chen

《环境科学与工程前沿（英文）》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1354-6

摘要： Abstract • Seasonal and treatment-process variations in invertebrates in a DWTP were analyzed. • The propagation and leakage of invertebrates in BAC filter were the most serious. • Invertebrates can survive and reproduce in chlorine disinfected clear water tanks. • Proportions of endogenous invertebrates increased along the treatment process. Problems associated with excessive propagation and leakage of invertebrates in drinking water have received increasing attention in recent years. We performed a monthly survey of invertebrate abundance and taxa in the effluent of each treatment stage in a drinking water treatment plant between May 2015 and April 2016 and analyzed seasonal and treatment-process variations in invertebrates. The results showed that invertebrate abundances in raw water, effluent of the biological activated carbon (BAC) filter, and finished water significantly correlated with water temperature, whereas no correlation was observed between water temperature and invertebrate abundance in the effluents of the sedimentation tank and sand filter. The dominant taxa in the effluent of each treatment stage were rotifers, nematodes, and crustaceans. The sedimentation tank could efficiently remove invertebrates with an annual average removal rate of 92%. The propagation and leakage of invertebrates occurred in the sand and BAC filters but more seriously in the latter. The average reproduction rate in the BAC filter was 268.8% with rotifers as the taxon that leaked the most. Invertebrate survival and reproduction were also observed in the chlorine-disinfected clean water reservoir with an average reproduction rate of 41.9%. Owing to differences in chlorine resistance, the reproduction ability of the dominant taxa was in the order nematodes>crustaceans>rotifers. The proportion of endogenous invertebrates gradually increased along the treatment process. The average proportion of endogenous invertebrates in the finished water was higher than 79.0%. Our findings suggested that waterworks should pay more attention to endogenous invertebrate growth.

关键词： Invertebrates     Drinking water     Seasonal variations     Treatment process    

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Temperature variation of concrete box girder bridge

Jian WANG, Zhi FANG,

《结构与土木工程前沿（英文）》 2009年 第3卷 第4期   页码 407-413 doi: 10.1007/s11709-009-0053-y

摘要： On the basis of theoretical analysis and measurement on site, the temperature gradients and its variation on concrete box girder bridges resulting from ambient temperature, solar radiation, and structural temperature fields were discussed. With the help of the heat transfer theory and finite element method (FEM), the heat flux of the surface of concrete box girder was carried out, and all the heat fluxes were described as the convection. The results were compared with that from field measurements, and a good correlation was found. It was revealed that the methods, the parameters, the boundary condition used in this paper were reasonable. Last, some conclusions were obtained, which could provide the basis for box girder design under solar radiation.

关键词： temperature     transfer     correlation     radiation     variation    

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Assessment of liver volume variation to evaluate liver function

null

《医学前沿（英文）》 2012年 第6卷 第4期   页码 421-427 doi: 10.1007/s11684-012-0223-5

摘要：

In order to assess the value of liver volumetry in cirrhosis and acute liver failure (ALF) patients, we explored the correlation between hepatic volume and severity of the hepatic diseases. The clinical data of 48 cirrhosis patients with 60 normal controls and 39 ALF patients were collected. Computed tomography-derived liver volume (CTLV) and body surface area (BSA) of normal controls were calculated to get a regression formula for standard liver volume (SLV) and BSA. Then CTLV and SLV of all patients were calculated and grouped by Child-Turcotte-Pugh classification for cirrhosis patients and assigned according to prognosis of ALF patients for further comparison. It turned out that the mean liver volume of the control group was 1 058±337 cm3. SLV was correlated with BSA according to the regression formula. The hepatic volume of cirrhosis patients in Child A, B level was not reduced, but in Child C level it was significantly reduced with the lowest liver volume index (CTLV/SLV). Likewise, in the death group of ALF patients, the volume index was significantly lower than that of the survival group. Based on volumetric study, we proposed an ROC (receiver operating characteristic) analysis to predict the prognosis of ALF patients that CTLV/SLV<83.9% indicates a poor prognosis. In conclusion, the CTLV/SLV ratio, which reflects liver volume variations, correlates well with the liver function and progression of cirrhosis and ALF. It is also a very useful marker for predicting the prognosis of ALF.

关键词： liver volume variation     cirrhosis     acute liver failure (ALF)    

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滇池北部重点水域蓝绿藻季节性变动下水体N∶P比值变化研究

何锋,段昌群,杜劲松,韩亚平,郭艳英,潘珉,宋任彬

《中国工程科学》 2010年 第12卷 第6期   页码 94-98

摘要：

受多种因素影响，滇池外海北部水域为蓝藻富集区。调查研究了蓝藻生物量季节性变动规律，对区域原水（不过滤）和净水（过滤了藻类）中N和P含量的变化也进行了监测。目的是研究蓝藻季节性消长对水体N和P含量的影响。结合生态化学计量学理论和方法，分析两者之间的关系。研究表明， 4—11月，为蓝藻水华爆发的时段，其中以5—9月最为严重。通过分析，水体N和P随蓝藻生物量呈现相应变动规律，水体叶绿素和TN，TP之间都呈现正相关关系，相关系数分别为0.955 和0.952 。利用生态化学计量学分析，蓝藻和水体中N∶P比值没有固定性，表明蓝藻没有表现出强烈的化学计量特征，而蓝藻的季节性变动也没有导致本区域水体具化学计量特性。通过分析滇池水体N∶P比值与蓝藻生物量变化之间相关关系,相关系数为-0.308，表明富营养化水体中N∶P比率对蓝藻生物量直接影响不大。因此,只有通过降低水体中N和P的浓度，才能控制蓝藻的爆发。

关键词： 滇池     蓝绿藻     N∶P比值     变化     生态化学计量学    

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arsenic trioxide on proliferation and apoptosis of U266 cells and its relationship with the expression variation

ZHAN Rong, YU Qinghong, HUANG Haobo

《医学前沿（英文）》 2008年 第2卷 第4期   页码 356-360 doi: 10.1007/s11684-008-0068-0

摘要： The aim of this article is to explore the effect of arsenic trioxide (AsO) on the proliferation and apoptosis of myeloma cell line U266 and its relationship with the expression variation of vascular endothelial growth factor (VEGF). The viability and apoptosis of U266 cells were observed by methylthiazolyl- tetrazolium (MTT) assay and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The effect of AsO on the VEGF expression of U266 cells were tested by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) analysis. We found that AsO could significantly inhibit the growth of U266 cells, and the concentration for 50% growth inhibition (IC) was 2 ?mol/L. After treatment with 2, 5, 10 ?mol/L AsO for 36 hours, dose-dependent apoptosis of U266 cells was observed. After treatment with 2, 5, 10 ?mol/L AsO for 72 hours, a dose-dependent reduction of VEGF in the supernatant of U266 cells culture was found. As far as single cells are concerned, nevertheless, the expression of VEGF mRNA did not vary. So we draw the conclusion that AsO could induce the apoptosis of U266 cells and inhibit their proliferation, decrease the tumor load, and lead to the reduction of VEGF in the culture supernatant, but not change the expression of VEGF in single U266 cells.

关键词： VEGF expression     expression variation     culture supernatant     labeling     concentration    

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Temporal variation of heavy metal pollution in urban stormwater runoff

Wen LI, Zhenyao SHEN, Tian TIAN, Ruimin LIU, Jiali QIU

《环境科学与工程前沿（英文）》 2012年 第6卷 第5期   页码 692-700 doi: 10.1007/s11783-012-0444-5

摘要： Stormwater runoff from three types of urban surfaces, a parking lot, a street, and a building roof, was monitored during four rainfall events that occurred in the one-year period from June 2009 to June 2010. The event mean concentrations (EMC) of dissolved copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and iron (Fe) exceeded China’s National Water Quality Standards for Surface Water. The degree of heavy metal contamination was related to the type of underlying surfaces. Additionally, the concentration of dissolved heavy metals peaked shortly after the runoff began and then declined sharply as a result of adequate flushing. First flush effects of varying degrees were also observed during all of the monitored rainfall events based on the first flush ratio ( ). Redundancy analysis revealed that four environmental variables (rainfall depth, intensity, antecedent dry weather period and type of underlying surface) had significant effects on the strengths of the first flush effects, accounting for 72.9% of the variation in the . Dissolved metals presented varying first flush effects on different underlying surfaces that occurred in the following relative order: parking lot>roof>road for low intensity and high runoff volume rainfall events; parking lot>road>roof for high intensity and low runoff volume events. The relative strength of the first flush for dissolved heavy metals was Fe, Mn>Cu, Zn>Pb.

关键词： urban stormwater     heavy metal pollution     temporal variation     event mean concentration     first flush effect     redundancy analysis    

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RESPONSE OF WHEAT COMPOSITE CROSS POPULATIONS TO DISEASE AND CLIMATE VARIATION OVER 13 GENERATIONS

《农业科学与工程前沿（英文）》 2021年 第8卷 第3期   页码 400-415 doi: 10.15302/J-FASE-2021394

摘要：

Since the F5 (2005), three winter wheat composite cross populations (CCPs) based on germplasm specifically suitable for low-input conditions were subjected to natural selection under organic and conventional management. In the F6, each CCP was divided into two parallel populations (12 CCPs in total) and maintained continuously until 2018. Commonly used modern cultivars with different disease susceptibilities were grown alongside to assess the agronomic performance of the CCPs. The organically managed CCPs were comparable in yield and foliar disease resistance to two continuously used reference cultivars, Achat and Capo. In contrast, under conventional management the cv. Capo outyielded the CCPs (Achat was not tested), highlighting the importance of parental cultivar choice for specific management systems. The CCPs were found to be moderately resistant to brown rust and even to the newly emerged stripe rust races prevalent in Europe since 2011. Differences between the CCPs were mainly due to parental genetic background and were significant in the first five generations, but were no longer so in the last five generations. In addition, these differences tended to vary depending on the experimental year and the environmental stresses present. In conclusion, the CCPs despite being derived from older cultivars are able to compete with more recently released reference cultivars under organic farming practices and represent a dynamic germplasm resource.

 

关键词： evolutionary breeding     heterogeneous crop population     management system    

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Spatial and seasonal variations in bacterial communities of the Yellow Sea by T-RFLP analysis

Hongyuan WANG, Xiaolu JIANG, Ya HE, Huashi GUAN

《环境科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 194-199 doi: 10.1007/s11783-009-0018-3

摘要： Four typical coastal sites (rocky shore, sandy shore, mud flat shore, and artificial harbor) at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities. This was accomplished by using terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR amplified 16S rDNA fragments. Two kinds of tetrameric restriction enzymes, I and I, were used in the experiment to depict the bacterial community diversity in different marine environments. It was found that the community compositions digested by the two enzymes separately were different. However, the results of bacterial community diversity derived from them were similar. The MDA analysis results of T-RFLP profiles coming from I and I both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations. With I as the sample, the pair wise -tests also revealed that variations were minor between each pair of marine environments, with ranging from 0.198 to 0.349. However, the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites ( ranging from 0.282 to 0.349).

关键词： terminal restriction fragment length polymorphism (T-RFLP)     bacterial community structure     marine microbial diversity     HhaI     MspI    

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Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

《环境科学与工程前沿（英文）》 2022年 第16卷 第6期 doi: 10.1007/s11783-022-1560-5

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Short-term effect of temperature variation on the competition between PAOs and GAOs during acclimation

Nanqi REN, Han KANG, Xiuheng WANG, Nan LI

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 277-282 doi: 10.1007/s11783-010-0226-x

摘要： Sequencing batch reactor (SBR) for enhanced biological phosphorus removal (EBPR) processes was used to investigate the impact of the temperature shock on the competition between phosphorus-accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) in start-up stage. During the 34 days operation, SBR was set with temperature variation(0–5 d, 22±1°C; 6–13 d, 29±1°C; 14–34 d, 14±1°C). PAOs and GAOs were analyzed by fluorescent in situ hybridization (FISH), and intracellular polyphosphate granules were stained by Neisser-stain. The results showed that the influence of temperature shock on PAOs’ abundance was more serious than that on GAOs in the enriching process. Under sudden and substantially temperature variation, from 22±1°C to 29±1°C and then to 14±1°C, the domination of PAOs was deteriorated. After temperature shock, PAOs’ competitive advantages at low temperature that concluded in other study did not appear in our study. As mesophilic, GAOs (indicated by and ) were more temperature adaptive and better grew and took the domination at 14±1°C in the end. In the competition process, organisms of tetrad forming organisms (TFOs)-like shape which were considered as typical GAOs, were observed. With the evidence of poly-P granules containing by Neisser-straining and result of FISH, these organisms of TFOs-like shape were better to be assumed as adaption state or a special self-protecting shape of PAOs.

关键词： fluorescent in situ hybridization (FISH)     tetrad forming organisms (TFOs)     temperature variation     enhanced biological phosphorus removal (EBPR)    

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Multi-stage dual replica bit-line delay technique for process-variation-robust timing of lowvoltageSRAMsense

Shou-biao TAN,Wen-juan LU,Chun-yu PENG,Zheng-ping LI,You-wu TAO,Jun-ning CHEN

《信息与电子工程前沿（英文）》 2015年 第16卷 第8期   页码 700-706 doi: 10.1631/FITEE.1400439

摘要： A multi-stage dual replica bit-line delay (MDRBD) technique is proposed for reducing access time by suppressing the sense-amplifier enable (SAE) timing variation of low voltage static random-access memory (SRAM) applications. Compared with the traditional technique, this strategy, using statistical theory, reduces the timing variation by using multi-stage ideas, meanwhile doubling the replica bit-line (RBL) capacitance and discharge path simultaneously in each stage. At a supply voltage of 0.6 V, the simulation results show that the standard deviations of the SAE timing and cycle time with the proposed technique are 69.2% and 47.2%, respectively, smaller than that with a conventional RBL delay technique in TSMC 65 nm CMOS technology (Taiwan Semiconductor Manufacturing Company, Taiwan).

关键词： Process-variation-robust     Sense amplifier (SA)     Replica bit-line (RBL) delay     Timing variation    

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标题 作者 时间 类型 操作

Seasonal variation of nitrogen and phosphorus in Xiaojiang River—A tributary of the Three Gorges Reservoir

Zhe LI , Jinsong GUO , Man LONG , Fang FANG , Jinping SHENG , Hong ZHOU ,

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

Optimization for operating modes based on simulation of seasonal underground thermal energy storage

ZHAO Jun, CHEN Yan, LI Xinguo

期刊论文

Numerical simulation of underground seasonal cold energy storage for a 10 MW solar thermal power plant

Zulkarnain ABBAS, Yong LI, Ruzhu WANG

期刊论文

Seasonal and treatment-process variations in invertebrates in drinking water treatment plants

Zhiling Wu, Xianchun Tang, Hongbin Chen

期刊论文

Temperature variation of concrete box girder bridge

Jian WANG, Zhi FANG,

期刊论文

Assessment of liver volume variation to evaluate liver function

null

期刊论文

滇池北部重点水域蓝绿藻季节性变动下水体N∶P比值变化研究

何锋,段昌群,杜劲松,韩亚平,郭艳英,潘珉,宋任彬

期刊论文

arsenic trioxide on proliferation and apoptosis of U266 cells and its relationship with the expression variation

ZHAN Rong, YU Qinghong, HUANG Haobo

期刊论文

Temporal variation of heavy metal pollution in urban stormwater runoff

Wen LI, Zhenyao SHEN, Tian TIAN, Ruimin LIU, Jiali QIU

期刊论文

RESPONSE OF WHEAT COMPOSITE CROSS POPULATIONS TO DISEASE AND CLIMATE VARIATION OVER 13 GENERATIONS

期刊论文

Spatial and seasonal variations in bacterial communities of the Yellow Sea by T-RFLP analysis

Hongyuan WANG, Xiaolu JIANG, Ya HE, Huashi GUAN

期刊论文

Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

期刊论文

Short-term effect of temperature variation on the competition between PAOs and GAOs during acclimation

Nanqi REN, Han KANG, Xiuheng WANG, Nan LI

期刊论文

Multi-stage dual replica bit-line delay technique for process-variation-robust timing of lowvoltageSRAMsense

Shou-biao TAN,Wen-juan LU,Chun-yu PENG,Zheng-ping LI,You-wu TAO,Jun-ning CHEN

期刊论文