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| 1 | DNA image cytometry test for primary screening of esophageal cancer: a population-based multi-center study in high-risk areas in China显示文摘Objective: To evaluate the feasibility of DNA image cytometry(DNA-ICM) as a primary screening method for esophageal squamous cell cancer(ESCC).Methods: A total of 5,382 local residents aged 40–69 years from three high-risk areas in China(Linzhou in Henan province, Feicheng in Shandong province and Cixian in Hebei province) from 2008 to 2011 were recruited in this population-based screening study. And 2,526 subjects declined to receive endoscopic biopsy examination with Lugol's iodine staining, while 9 and 815 subjects were excluded from liquid-based cytology and DNA-ICM test respectively due to slide quality. Finally, 2,856, 5,373 and 4,567 subjects were enrolled in the analysis for endoscopic biopsy examination, liquid-based cytology and DNA-ICM test, respectively. Sensitivity(SE), specificity(SP), negative predictive values(NPV) and positive predictive values(PPV) as well as their 95% confidence intervals(95% CI) for DNA-ICM, liquid-based cytology and the combination of the two methods were calculated. Receiver operating characteristic(ROC) curves were applied to determine the cutoff point of DNA-ICM for esophageal cancer.Results: DNA-ICM results were significantly correlative with esophageal cancer and precancer lesions(χ~2=18.016, P<0.001). The cutoff points were 5,802, 5,803 and 8,002 based on dissimilar pathological types of low grade intraepithelial neoplasia(LGIN), high grade intraepithelial neoplasia(HGIN), and ESCC, respectively, and 5,803 was chosen in this study considering the SE and SP. The SE, SP, PPV, NPV of DNA-ICM test(cutoff point 5,803) combined with liquid-based cytology [threshold atypical squamous cells of undetermined significance(ASCUS)] were separately 72.1%(95% CI: 70.3%-73.9%), 43.3%(95% CI: 41.3%-45.3%), 22.8%(95% CI: 21.1%-24.5%) and 87.0%(95% CI: 85.7%-88.3%) for LGIN, 85.7%(95% CI: 84.3%-87.1%), 41.3%(95% CI: 39.3%-43.3%), 4.6%(95% CI: 3.8%-5.4%) and 98.9%(95% CI: 98.5%-99.3%) for HGIN, and 96.0%(95% CI: 95.2%-96.8%), 40.8%(95% CI: 38.8%-42.8%), 1.7%(95% CI: 1.2%-2.2%) and 99.9%(95% CI: 99.8%-100.0%) for ESCC.Conclusions: It is possible to use DNA-ICM test as a primary screening method before endoscopic screening for esophageal cancer. | Meng Wang Changqing Hao Qing Ma Guohui Song Shanrui Ma Deli Zhao Lin Zhao Xinqing Li Wenqiang Wei | 2016 | Chinese Journal of Cancer Research2016，28，4： | 15 |
| 2 | Mechanical Properties and Transformation Behavior of NiTiNb Shape Memory Alloys显示文摘NiTiNb形状记忆合金经适当变形可获得宽相变滞后,已经在管路连接和密封领域获得广泛关注.关于Nb的加入与相变滞后的关系已获得较多研究.实际上,除了相变行为,由于合金化作用,Nb的加入对合金的力学性能的影响也具有重要影响.本研究制备了不同微观结构、相近的马氏体相变开始温度的Ni47Ti44Nb9和Ni49.8Ti45.2Nb5合金,对比研究Nb对NiTiNb形状记忆合金的力学行为和相变特征的影响。结果表明,Nb的存在形态对合金的力学性能有很大影响,特别是合金的屈服强度以及屈服行为。分析讨论预变形下合金的相变滞后及相对机理。 | Liu Wei Zhao Xinqing | 2009 | Chinese Journal of Aeronautics2009，22，5： | 13 |
| 3 | NEW TECHNOLOGY FOR FAULT DIAGNOSIS BASED ON WAVELET DENOISING AND MODIFIED EXPONENTIAL TIME-FREQUENCY DISTRIBUTION显示文摘Fast wavelet multi-resolution analysis (wavelet MRA) provides a effective tool for analyzing and canceling disturbing components in original signal. Because of its exponential frequency axis, this method isn’t suitable for extracting harmonic components. The modified exponential time-frequency distribution ( MED) overcomes the problems of Wigner distribution( WD) ,can suppress cross-terms and cancel noise further more. MED provides high resolution in both time and frequency domains, so it can make out weak period impulse components fmm signal with mighty harmonic components. According to the 'time' behavior, together with 'frequency' behavior in one figure,the essential structure of a signal is revealed clearly. According to the analysis of algorithm and fault diagnosis example, the joint of wavelet MRA and MED is a powerful tool for fault diagnosis. | Wang Xinqing,Wang Yaohua,Qian Shuhua,Chen Liuhai (Engineering College of PLA University of Science and Technology) Xu Yanshen,Zhao Xiangsong (Tianjin University) | 2001 | Chinese Journal of Mechanical Engineering2001，14，3： | 13 |
| 4 | Effects of biochar-based fertilizers on nutrient leaching in a tobacco-planting soil显示文摘Biochar is a soil amendment for increasing soil quality and decreasing nutrient leaching. However, there is little information on the impact of biochar-based fertilizer(BF) on soil nutrient leaching in agricultural soils. We conducted a soil column leaching experiment to study the effects of BF on the leaching of total nitrogen(TN), total phosphorus, and total potassium(TK) in tobacco soils. The distribution characteristics of NH_4^+-N, available P, and available K in soil profiles were analyzed after the application of BF. Biochar was prepared by pyrolysis of fluecured tobacco stems. It was applied at four levels, 0%, 3%,9%, and 15%(w/w), respectively, to the compound fertilizer. Compared with the control, the leaching loss of soil TN decreased by 8.36%, 6.72%, and 6.45%, and the loss of soil TK decreased by 9.18%, 9.31% and 11.82% in the 3%,9%, and 15% BF treatments, respectively. However, BF had no significant effect on the P leaching due to the low movement of P in the soil profile. In addition, the BF addition increased the immobilization of NH_4^+-N, available P, and available K in the soil profile. These results indicate that addition of BF to a tobacco-planting soil reduced nutrient leaching, and suggest that BF could be an effective method of applying biochar to agriculture fields. | Yunlong Li Jianzhong Cheng Xinqing Lee Yi Chen Weichang Gao Wenjie Pan Yuan Tang | 2019 | Acta Geochimica2019，38，1： | 13 |
| 5 | Effect of Cr on Microstructure and Fracture Toughness of Nb-20Ti-16Si-xCr Alloys显示文摘The present paper reported the phase stability and microstructures evolution of Nb-20Ti-16Si-xCr (x = 0~20at.%) in-situ composites as function of Cr addition. It was suggested that with the addition of Cr less than 7%, the silicide phase in as-cast Nb-20Ti-16Si alloy was Nb3Si. The silicides changed to be α-Nb5Si3 by the addition of Cr above 7%. It was found that annealing of 1300 ℃ for 100 h could result in the decomposition of Nb3Si to NbSS and α-Nb5Si3 in Cr containing Nb-20Ti-16Si based alloys by means of eutectoid reaction. Whereas in the case of alloy without Cr addition, the Nb3Si in Nb-20Ti-16Si alloy keep good stability during the high temperature annealing. The Cr additions larger than 5% in Nb-20Ti-16Si-xCr alloys could result in the formation of Cr-rich Laves phase. In addition, the influence of Cr addition on the room temperature fracture toughness of the alloys after annealing was reported. | Tang Liang Ma Chaoli Zhao Xinqing | 2009 | 稀有金属材料与工程2009，38，A03： | 11 |
| 6 | Effects of Nb Content on Yield Strength of NiTiNb Alloys in Martensite State显示文摘采用SEM,EDS,DSC和拉伸实验等方法测试两种单相NiTiNb合金(Ni50Ti48Nb2和Ni49.5Ti46.5Nb4),以分析Nb原子在NiTi相中的固溶量对合金由马氏体自协作而导致的屈服强度的影响。根据实验结果,推断Nb原子固溶量对NiTi相的屈服强度负相关。本次研究与前期实验结果相比较,提出了一个有关Nb含量对NiTiNb合金的马氏体态屈服强度有两个共同作用机制的假设.一个是Nb原子固溶弱化机制,另一个是Nb相复合强化机制。这个假设比较圆满的解释了(NiTi)50-0.5xNbx合金的马氏体态屈服强度随Nb含量的增加,先降低然后再大幅增加的实验结果。 | Xiao Fu Ma Guojun Zhao Xinqing Xu Huibin | 2009 | Chinese Journal of Aeronautics2009，22，6： | 11 |
| 7 | An infrared target intrusion detection method based on feature fusion and enhancement显示文摘Infrared target intrusion detection has significant applications in the fields of military defence and intelligent warning.In view of the characteristics of intrusion targets as well as inspection difficulties,an infrared target intrusion detection algorithm based on feature fusion and enhancement was proposed.This algorithm combines static target mode analysis and dynamic multi-frame correlation detection to extract infrared target features at different levels.Among them,LBP texture analysis can be used to effectively identify the posterior feature patterns which have been contained in the target library,while motion frame difference method can detect the moving regions of the image,improve the integrity of target regions such as camouflage,sheltering and deformation.In order to integrate the advantages of the two methods,the enhanced convolutional neural network was designed and the feature images obtained by the two methods were fused and enhanced.The enhancement module of the network strengthened and screened the targets,and realized the background suppression of infrared images.Based on the experiments,the effect of the proposed method and the comparison method on the background suppression and detection performance was evaluated,and the results showed that the SCRG and BSF values of the method in this paper had a better performance in multiple data sets,and it’s detection performance was far better than the comparison algorithm.The experiment results indicated that,compared with traditional infrared target detection methods,the proposed method could detect the infrared invasion target more accurately,and suppress the background noise more effectively. | Xiaodong Hu Xinqing Wang Xin Yang Dong Wang Peng Zhang Yi Xiao | 2020 | Defence Technology(防务技术)2020，16，3： | 8 |
| 8 | Martensitic transformation involved mechanical behaviors and wide hysteresis of NiTiNb shape memory alloys | Minjuan Wang Mingyang Jiang Guangyue Liao Shun Guo Xinqing Zhao | 2012 | Progress in Natural Science:Materials International2012，22，2： | 7 |
| 9 | Characteristics and distribution of low molecular weight organic acids in the sediment porewaters in Bosten Lake, China显示文摘The composition and vertical profiles of low molecular-weight organic acids (LMWOAs) and the contribution of them to dissolved organic matter (DOM) in sediment porewaters in Bosten Lake, Xinjiang, China were investigated. The results showed that total concentration of LMWOAs was up to 94.5 μmol/L and their proportion in DOM was 5.6%, suggesting that LMWOAs were important chemical components in DOM in lake sediment porewaters. Among the seven LMWOAs, pyruvic and acetic acid had the highest concentrations with 26.30 and 8.31 μmol/L, accounting for 51.4% and 14.92% of LMWOAs, respectively. Trifluoroacetic and sorbic acid had the lowest concentrations, indicating that the compositions of LMWOAs in relative reducing environments were largely different from those reported in glacier, atmosphere and soils. The concentrations of lactic, acetic, formic, sorbic and oxalic acid decreased with increasing depth, probably relating to stronger microbial activities in the initial stage of early diagenesis. Trifluoroacetic acid was mainly anthropogenic with its concentration, showing a diusive trend from the surface to bottom sediments. The concentrations of lactic acid and nitrate generally showed a consistent profile. The increasing concentration of pyruvic acid in the vertical profile was just opposite to that of sulfate, revealing a significant negative relationship between them. Oxalic acid remained constant except for an obvious peak at 6 cm depth. The results indicated the diversities in sources and behaviors for various LMWOAs during early diagenesis in sediments. | Min Xiao Fengchang Wu Haiqing Liao Wen Li Xinqing Lee Rongsheng Huang | 2010 | Journal of Environmental Sciences2010，22，3： | 7 |
| 10 | A review of control loop monitoring and diagnosis:Prospects of controller maintenance in big data era显示文摘Owing to wide applications of automatic control systems in the process industries, the impacts of controller performance on industrial processes are becoming increasingly significant. Consequently, controller maintenance is critical to guarantee routine operations of industrial processes. The workflow of controller maintenance generally involves the following steps: monitor operating controller performance and detect performance degradation, diagnose probable root causes of control system malfunctions, and take specific actions to resolve associated problems. In this article, a comprehensive overview of the mainstream of control loop monitoring and diagnosis is provided, and some existing problems are also analyzed and discussed. From the viewpoint of synthesizing abundant information in the context of big data, some prospective ideas and promising methods are outlined to potentially solve problems in industrial applications. | Xinqing Gao Fan Yang Chao Shang Dexian Huang | 2016 | Chinese Journal of Chemical Engineering2016，24，8： | 6 |
| 11 | Performance of ecological restoration in an impaired coral reef in the Wuzhizhou Island, Sanya, China显示文摘Coral restoration is becoming popular to help restoring degraded coral reefs.However,few studies have tried to monitor the long-term recovery of coral reefs,which makes it diffi cult to assess the performance of the restoration.We monitored the growth of three transplanted Acropora corals and naturally-attached Pocillopora damicornis on artifi cial reefs(ARs)from October 2014 to September 2018 during which there were several attacks of typhoons.Results show that two staghorn Acropora species had the highest growth rates(11.0–12.1 cm/a),followed by table coral A.divaricate(5.6 cm/a)and P.damicornis(4.8 cm/a).A linear growth pattern was found for the three Acropora species;the pattern gradually slowed in P.damicornis.There was a strong interspecifi c competition for space among the corals on ARs,and it led to the sharply declined occurrence of slow-growing P.darmicornis colonies in 2017.Coral recovery was successful at the Wuzhizhou Island and quickly increased AR complexity.However,the ARs made of metal frames fail to resist the direct attack from a catastrophic typhoon.Therefore,concrete and environmentalfriendly materials should be used in future restoration.This study is the fi rst report on long-term monitoring and assessment of coral reef restoration in China.The results off er future guide of reef restoration for impaired coral reefs in regions easily aff ected by typhoons. | Xinqing ZHENG Yuanchao LI Jilin LIANG Rongcheng LIN Daoru WANG | 2021 | Journal of Oceanology and Limnology2021，39，1： | 6 |
| 12 | Evidence of China's sea boundary in the South China Sea显示文摘According to a series of important historical maps,i.e.,the Location Map of the South China Sea Islands,the Nansha Islands,Zhongsha Islands,Xisha Islands,Yongxing Island and Shidao Island,and Taiping Island(archived by the Territorial Administration Division of the Ministry of Interior of Republic of China in 1946),and the Administration District Map of the Republic of China published in 1948,the dashed line surrounding the South China Sea Islands represents China's sea boundary in the South China Sea at that time.It was both connected with,and an extension of,the land boundary of China.At that time the dashed line was used to represent the waters boundaries while the solid line was used to represent the land boundary—a universal method used in maps that was then recognized internationally.The above observation provides historical and scientific evidence of China's sea boundary in the South China Sea that is useful for the international maritime delimitation over the South China Sea area. | WANG Ying GE Chendong ZOU Xinqing | 2017 | Acta Oceanologica Sinica2017，36，4： | 6 |
| 13 | Twin structure of the lath martensite in low carbon steel显示文摘It has been well accepted that the martensites in quenched carbon steels exhibit two typical morphologies which are closely dependent on the carbon content, i.e. lath martensite in low carbon steels and lenticular martensite in high carbon steels. Based on conventional belief, the lath martensites in low carbon steels are with high density dislocations as the substructure, in contrast to twin substructure in lenticular high carbon martensite. In the present work, an intensive transmission electron microscopy investigation was made to characterize the microstructures of the lath martensite in a low carbon steel of 0.2 wt%C. It was found that lots of lath martensites consist of twin as their substructure, rather than high density dislocations. In addition, nanoscale precipitates cohering with ferrite matrix were found at the twin interfaces. The orientation relationships between the precipitates and the ferrite matrix are in good agreement with that of primitive hexagonal ω phase in titanium alloys and other bcc metals or alloys. | Pan Zhang Yulin Chen Wenlong Xiao Dehai Ping Xinqing Zhao | 2016 | Progress in Natural Science:Materials International2016，26，2： | 6 |
| 14 | Nitrous oxide emissions from different land use patterns in a typical karst region, Southwest China显示文摘Fluxes of nitrous oxide (N2O) from different land use patterns (matured forest, secondary forest, grassland and cropland) in a subtropical karst region of Guizhou Province, Southwest China, were measured for one year with a closed static chamber technique and by gas chromatography. The results showed that soil under different land uses was a source of atmospheric N2O. The cropland was a source with relatively high N2O as compared to forest and grassland, but no significant differences were observed. N2O emissions from soils varied with land use change and fertilizer application. There were two peaks of N2O flux occurred following the combination of two obvious precipitation and fertilizer events in the cultivated land. Converting from the matured forest to secondary forest tended to increase annual emissions of N2O (from 1.40 to 1.65 kg N ha -1 a -1 ), while changing land use from secondary forest to scattered grassland tended to decrease annual emissions of N2O slightly (from 1.65 to 1.45 kg N ha -1 a -1 ). Our range of cumulative annual N2O emission across different land uses (1.40-1.91 kg N ha -1 a -1 ) in a karst region is in general agreement with previously published data in a non-karst region. However, in the maize field, N2O emission factor (EF) was 0.34% for fertilizer application, which is about 71.2% lower than the IPCC default value. It is suggested that current IPCC (Intergovernmental Panel on Climate Change) EF methodology could overestimate N2O emission from the karstic cropland. Anyway, the N2O emission from cropland in the karst region would contribute significantly to the global N2O budget, so reducing fertilization frequency during the crop growing season could lead to a decrease in N2O emission in the whole year. | CHENG Jianzhong LEE Xinqing ZHOU Zhihong WANG Bing XING Ying CHENG Hongguang | 2013 | Chinese Journal Of Geochemistry2013，32，2： | 5 |
| 15 | Seasonal variations of carboxylic acids and their contributions to the rainwater acidity: A case study of Guiyang and Shangzhong,China显示文摘Low molecule weight carboxylic acids are ubiquitous and important chemical constituents in the troposphere.Seven carboxylic acids in the rainwater of Guiyang and Shangzhong were simultaneously determined by ion chromatography from April 2006 to April 2007.Formic, acetic and oxalic acids were found to be the predominant carboxylic acids.Their volume weighted average concentration (VWA) in the rainwater of Guiyang were 14.24 μmol/L, 9.35 μmol/L and 2.79 μmol/L, respectively;as compared to 4.95 μmol/L, 1.35 μmol/L and 2.31 μmol/L in the rainwater of Shangzhong.In Shangzhong it is witnessed that the concentra-tions of these acids were higher in the summer than in the winter and direct emissions from vegetations or soils may account for the main provenance of the acids.This is, however, not the case in Guiyang, where the concentrations of the carboxylic acids were higher during the non-growing season than during the growing season.The relatively weak scavenging affected by scarce and little rainwater as well as the particles accompanied with the rainfall may have some effect on the carboxylic acids during the wintertime in Guiyang.Carboxylic acids in the rainwater of Guiyang were estimated to account for 18.7% to the free acidity, where formic, acetic and oxalic acids accounted for 7.9%, 4.7%, 6.1%, respectively.In Shangzhong, the 3 primary carboxylic acids represented 58.1% to the free acidity where formic, acetic and oxalic acids represented 25.1%, 7.5%, 25.5%, respectively.Carboxylic anions accounted for 6.6% (1.7%–19.2%) to the total anions in the rainwater of Guiyang.Carboxylic anions repre-sented 13.2% (0.5%–92.2%) to the total anions in the rainwater of Shangzhong.These results indicated that carboxylic acids were the important contributors to the rainwater acidity, especially in remote regions. | XU Gang LEE XinQing LU YingChun CHEN YingJun HUANG DaiKuan | 2010 | Chinese Science Bulletin2010，55，16： | 5 |
| 16 | Precise recognition of warhead and decoy based on components of micro-Doppler frequency curves显示文摘From the view of electromagnetic scattering,it is indicated that the micro-Doppler (m-D) character-istics of an extended target undergoing micro-motions are actually induced by the change of incident directions of radar pulses.Different micro-motions may lead to similar change of incident directions,consequently inducing similar m-D characteristics.To tackle this problem,rather than distinguish warhead and decoy directly from m-D characteristics,the frequency components of m-D frequency curves are used as a new characteristic for recognition in this paper.To get high precision of frequency components estimation,model-based parameter estimation (MBPE) is utilized to extract the m-D frequency curves from TFR.To obtain high accurate simu-lation results,the backscattered signal simulation is conducted by full-wave numerical method.The simulation results validate the theoretical analysis and the high performance of the proposed method. | GUO KunYi SHENG XinQing | 2012 | Science China(Information Sciences)2012，55，4： | 5 |
| 17 | Factors regulating population dynamics of the amphipod Ampithoe valida in a eutrophic subtropical coastal lagoon显示文摘Year-round investigations were carried out to address the population dynamics of amphipod Ampithoe valida and its potential regulating factors in the Yundang Lagoon (a eutrophic subtropical coastal lagoon in Xiamen City, China) from October 2007 to October 2008. The results show that A. valida population was largely composed of juveniles and reached a peak abundance (12.02 × 10 3 ind./m2 ) in March, but sharply shrunk in July. The monthly variation pattern of A. valida seemed to follow that of Ulva lactuca which is the main food resource for A. valida, indicating a strong influence of food availability on A. valida population dynamics. Life cycle studies in laboratory indicate that A. valida adopted an r-selected life strategy, e.g., rapid growth rate (0.216-0.302 mm/d), consecutive breeding (4-10 times), short reproductive rhythm (9-17 d) and huge fecundity (24-192 eggs or 6-94 juveniles per brood), which contributed to the fast population growth of A. valida from January to March. Although temperature may also be a significant cause, A. valida could grow quickly and show normal reproductive traits (i.e., the timing of sexual differentiation or maturity, the reproductive rhythm, the number of broods all through its lifespan and offspring production) in temperature between 15-30 C. Therefore, the temperature variation in the lagoon water should not account for the sharp variation of A. valida population by affecting the survival, growth and reproduction of the amphipod. However, negative correlation between water temperature and U. lactuca biomass in the lagoon suggested that temperature could have indirectly affected the population dynamics of A. valida by affecting its food availability. The authors conclude that, in the Yundang Lagoon, the population dynamics of A. valida was mainly controlled by the food availability rather than water temperature. | ZHENG Xinqing HUANG Lingfeng HUANG Bangqin LIN Yongqing | 2013 | Acta Oceanologica Sinica2013，32，6： | 5 |
| 18 | Nitrogen and phosphorus balance analysis of cultivated land in Jiangsu plain,China显示文摘Jiangsu plain is located along the downstream of the Yangtze River, the north part of which is also the coast area of the Yellow Sea. The specific location makes the local environmental issues regionally important. This paper studied arable land area, plantation structure, livestock sector data, which shows that livestock sector contributes a big amount of nitrogen and phosphorus, in terms of the demand from the agriculture use in Jiangsu plain. But actually, there is still much mineral fertiliser used in agriculture, which causes the N and P produced from livestock sector being an important source of pollution to the environment. The paper suggests to tighten up manure management, in order to lead to a big reduction in the pollution to both soil and surface water. | ZOU Xinqing Pierre Gerber LI Haiyu LIU Qingsong WANG Qian SHEN Jingfen SHI Binwen | 2001 | Chinese Science Bulletin2001，46，S1： | 5 |
| 19 | Liquid-Solid Phase Equilibria of Nb-Si-Ti Ternary Alloys显示文摘To determine the liquid-solid phase equilibria of the Nb-Si-Ti ternary system,Nb-Si-Ti alloys of different compositions are pre-pared. By means of scanning electron microscopy (SEM),X-ray diffraction (XRD) and electron probe microanalysis (EPMA),the phases in the alloys,such as Si-based solutions,Ti(Nb)Si,Ti(Nb)Si2,Nb(Ti)Si2,Ti(Nb)5Si4,Nb(Ti)5Si3,Ti(Nb)5Si3,Nb(Ti)3Si and Nb-based solutions are identified,and the phase evolution is analyzed. As a result,the microstructural and microchemical evidence pro-vides a clear definition of the Nb-Si-Ti liquidus surface projection and indicates that the ternary phase diagram has seven transition reac-tions. | Bao Jing Huang Qiang Tang Liang Geng Tai Zhao Xinqing Ma Chaoli | 2008 | Chinese Journal of Aeronautics2008，21，3： | 5 |
| 20 | Investigation of low-molecular weight organic acids and their spatiotemporal variation characteristics in Hongfeng Lake,China显示文摘The identities and concentrations of low-molecular-weight organic acids (LMWOAs) were determined by ion chromatography throughout a 20-m water column in Hongfeng Lake, China. The spatiotemporal variations of LMWOAs and their contributions to dissolved organic matter (DOM) in a research period of 24 hr were also investigated. The results demonstrated that five LMWOAs (lactic, acetic, pyruvic, sorbic, oxalic acid) were detected, and their total concentration and proportion in DOC were 6.55 μmol/L and 7.47%. Their average levels were 2.50, 0.65, 2.35, 0.96 and 0.09 μmol/L, respectively. LMWOAs were higher during daytime (10:00-18:00 on Jun 13, 2008) than nighttime (21:00-6:00 the next morning), in particular 4.99 μmol/L high in the epilimnion ( 1 m water depth), reflecting the fact that direct import from terrigenous sources and photochemical production from humic materials were dominant during LMWOAs' origin and accumulation. The same factors caused LMWOAs to be 0.63 μmol/L in the epilimnion higher than in the hypolimnion. The rapid decrease of total organic acid (TOA) up until 18:00 mainly resulted from bio-uptake and mineralization in the hypolimnion (>1 m water depth). Pyruvic acid increased with time in the epilimnion and decreased in the hypolimnion, largely related to the two contrary processes of continuous degradation and synthesis of macromolecular organic matter during life materials' cycle mediated by organisms. Simultaneously, plankton behavior and thermal stratification played a pivotal role in LMWOAs' behavior in the water column, causing decreasing and increasing profiles. The distribution of LMWOAs represents an interesting resource for biogeochemical research of DOM in aquatic ecosystems. | Min Xiao Fengchang Wu Liying Wang Xinqing Li Rongsheng Huang | 2013 | Journal of Environmental Sciences2013，25，2： | 5 |
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