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49篇 您的检索式:作者名="Dewen Li"
    题名 作者 年代 出处 被引量
1Late Cenozoic deformation subsequence in northeastern margin of Tibet --Detrital AFT records from Linxia Basin显示文摘Two events of Tibet uplifting are revealed by detrital apatite fission track (AFT) age data from Linxia Basin. They occurred at about 14 and 5.4-8.0 MaBP respectively. We interpret the first one to be related to the uplifting of the northern Tibet, which might have resulted from convectively removing the thickened lower lithosphere. The second one is a result of Laji Mountain uplifting. Numerous studies of the Tibetan Plateau suggest that the onset time of the deformation in the northeastern margin of Tibetan Plateau and the time of Tibet attaining to its present elevation is about 8 MaBP. They are approximately coincident with the uplift of Lajishan Mountain. It suggests that the northeastern margin of Tibet propagated northeastwardly to its present site in about 8 MaBP for accommodating the sustained convergence between India-Eurasia plate and for keeping its high elevation. The active block pattern dominating the strong earthquake distribution of Chinese continent probably formed at about 8.0-5.4 MaBP.ZHENG Dewen (郑德文) ZHANG Peizhen (张培震) WAN Jinglin (万景林) LI Chuanyou (李传友) CAO Jixiu (曹继秀) 2003Science China Earth Sciences2003,46,z2:25
2Distribution of green algae micro-propagules and their function in the formation of the green tides in the coast of Qinhuangdao,the Bohai Sea, China显示文摘Since 2015, a novel green tide has been recurring in the coastal areas of Qinhuangdao at the western coast of the Bohai Sea in China, threatening the environment and ecosystem of the Beidaihe seaside holiday resort along the coast. Micro-propagules of the green algae including gametes, spores, micro-germlings and micro-vegetative fragments play an important role in the formation of green tides. They serve as a 'seed source' of green macroalgae, and their distributions could reflect and influence the 'algae source' of green tides. In this study,monthly surveys in the inshore and offshore areas of the Qinhuangdao coast were conducted from April to September 2016 and in January 2017 to investigate the tempo-spatial distribution patterns and the biomass variations of the green algae micro-propagules. The obtained results show that micro-propagules were mainly distributed in the inshore areas with a significantly decreasing abundance towards offshore areas. Their biomass was highest in July and August, and lowest in winter. The areas that were affected by the green tides showed a remarkably higher abundance of micro-propagules compared to other areas. These micro-propagules could serve as the 'seed' source of green tides. Their distribution patterns indicate that the green tide in the coastal areas of Qinhuangdao originated locally.Hongbin Han Wei Song Zongling Wang Dewen Ding Chao Yuan Xuelei Zhang Yan Li 2019Acta Oceanologica Sinica2019,38,8:8
3Stable isotope labelled mass spectrometry for quantification of the relative abundances for expressed proteins induced by PeaT1显示文摘The protein elicitor from the mycelium of Alternaria tenuissima has been isolated.The elicitor triggered resistance to the tobacco mosaic virus in tobacco by inducing relative oxygen species,but without causing hypersensitive necrosis.The elicitor is reported to impart resistance against Verticillium dahliae and to increase yield in cotton,but its mechanism is not yet clear.In this study,the stable isotope labelled mass spectrometry method was used to quantify the relative abundances of protein expression induced by PeaT1 in Arabidopsis.A significant difference in the relative abundances for the expression of different proteins related to metabolism,modification,regulatory,defense,stress and antioxidation was found in Arabidopsis.LI GuangYue,YANG XiuFen,ZENG HongMei,MAO JianJun,LIU Hua,ZHANG YunHua & QIU DeWen* Key Laboratory for Biological Control of the Ministry of Agriculture,Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing 100081,China 2010Science China(Life Sciences)2010,53,12:7
4Effect of Direct Quenching on Microstructure and Mechanical Properties of a Wear-resistant Steel显示文摘A wear-resistant steel was hot rolled at the same finish temperature,and subsequently treated with conventional reheat quenching and tempering process(RQ&T) and direct quenching and tempering process(DQ&T),respectively.The effect of direct quenching on the microstructure and mechanical properties was investigated in detail by using optical microscope,transmission electron microscope and scanning electron microscope equipped with electron backscattered diffraction.The results showed that the microstructures of both the RQ and DQ specimens were complex constituents of lath martensite and lower bainite.Compared with the RQ specimen,the lower bainite content in DQ specimen was much higher.Furthermore,the bainite in the DQ specimen extended into and segmented the prior austenite grains,which can decrease martensite packet size.The proportion of high-angle boundary in the DQ specimen was higher than that in the RQ specimen,which may improve the impact toughness.The carbides in DQ&T specimen were much finer and distributed even dispersively because direct quenching can retain substantive defects which may provide more nucleation sites for carbide precipitation in the tempering process.Besides,the mechanical properties of DQ and DQ&T specimens were superior than those subjected to RQ and RQ&T processes,respectively.Hongyu SONG Shunhu ZHANG Liangyun LAN Canming LI Haitao LIU Dewen ZHAO Guodong WANG 2013Acta Metallurgica Sinica(English Letters)2013,26,4:7
5Scene recognition combining structural and textural features显示文摘Automatic recognition of the contents of a scene is an important issue in the field of computer vision. Although considerable progress has been made, the complexity of scenes remains an important challenge to computer vision research. Most previous approaches for scene recognition are based on the so-called 'bag of visual words' model, which uses clustering methods to quantize numerous local region descriptors into a codebook. The size of the codebook and the selection of initial clustering centers greatly affect the performance. Furthermore, the large size of the codebook leads to high computational costs and large memory consumption. To overcome these weaknesses, we present an unsupervised natural scene recognition approach that is not based on the 'bag of visual words' model. This approach constructs multiple images of different resolutions and extracts structural and textural features from these images. The structural features are represented by weighted histograms of the gradient orientation descriptor, which is presented in this paper, and the textural features are represented by filter responses of Gabor filters and a Schmid set. We regard the structural and textural features as two independent feature channels, and combine them to realize automatic categorization of scenes using a support vector machine. We then evaluated our approach using three commonly used datasets with various scene categories. Our experiments demonstrate that the weighted histograms of the gradient orientation descriptor outperform the classical scale invariant feature transform descriptor in natural-scene recognition, and our approach achieves good performance with respect to current state-of-the-art methods.ZHOU Li HU DeWen ZHOU ZongTan 2013Science China(Information Sciences)2013,56,7:7
6Fault-Growth Pattern of the South Margin Normal Fault of the Yuguang Basin in Northwest Beijing and its Influencing Factors显示文摘Based on high-resolution remote sensing image interpretation, digital elevation model 3-D analysis, field geologic field investigation, trenching engineering, and ground-penetrating radar, synthetic research on the evolution of the Yuguang Basin South Margin Fault (YBSMF) in northwest Beijing was carried out. We found that the propagation and growth of faults most often occurred often at two locations: the fault overlapping zone and the uneven or rough fault segment. Through detailed observation and analysis of all cropouts of faults along the YBSMF from zone a to zone i, we identified three major factors that dominate or affect fault propagation and growth. First, the irregularity of fault geometry determine the propagation and growth of the fault, and therefore, the faults always propagate and grow at such irregular fault segments. The fault finally cuts off and eliminates its irregularity, making the fault geometry and fault plane smoother than before, which contributes to the slipping movement of the half-graben block in the basin. Second, the scale of the irregularity of the fault geometry affects the result of fault propagation and growth, that is, the degree of the cutting off of fault irregularity. The degree of cutting off decreases as irregularity scale increases. Third, the maximum possible slip displacement of the fault segment influences the duration of fault propagation and growth. The duration at the central segments with a large slip displacement is longer than that at the end segments with a smaller slippage value.WANG Lin TIAN Qinjian LI Dewen ZHANG Xiaoliang 2013Acta Geologica Sinica(English Edition)2013,87,3:6
7Magnetic labeling of natural lipid encapsulations wit ron-based nanoparticles显示文摘Dewen Ye Yan Li Ning Gu 2018Nano Research2018,11,6:6
8The discovery and environmental significance of Chifeng wind route and huge pots of Inner Mongolia and Hebei Province显示文摘The pots discovered in Inner Mongolia and Hebei Province are huge with a maximum diameter of 9 m and a depth of 3.5 m, singular in shape,caused by weathering and wind erosion and have certain direction. They are a kind of typical climatic geomorphology. ThisZhijiu Cui Hongjiang Li Ling Nan Dewen Li 1999Chinese Science Bulletin1999,44,16:5
9Freeform OST-HMD system with large exit pupil diameter and vision correction capability显示文摘Compactness and light weight,large exit pupil diameter and distance,small distortion for virtual image,and see-through light paths are pivotal factors to achieve a better,wearable experience of optical see-through headmounted displays(OST-HMDs).In addition,light efficiency of the virtual image light path is an important factor for heat dissipation in HMD devices.This paper presents a new type of OST-HMD optical system that includes three wedge-shaped freeform prisms and two symmetric lenses.Based on a 0.71 in.microdisplay,an OST-HMD prototype with a diagonal field of view(FOV)of 45.3°,an F-number(F/#)of 1.8,an exit pupil size of 12 mm×8 mm,and an eye relief of 18 mm is demonstrated.The maximum value of distortion of the final system is 0.6%and 0.4%for virtual image and see-through light path,respectively.The overall dimension of the optical system per eye is no larger than 30 mm(width)×40 mm(height)×14 mm(thickness),and the weight of the optical module including lenses,holder,and microdisplay is 12.8 g.The light efficiency of the virtual image light path is up to 50%higher than those of other OST-HMD optical solutions.DEWEN CHENG JIAXI DUAN HAILONG CHEN HE WANG DANYANG LI QIWEI WANG QICHAO HOU TONG YANG WEIHONG HOU DONGHUA WANG XIAOYU CHI BIN JIANG YONGTIAN WANG 2022Photonics Research2022,10,1:5
10Effect of variety and drying method on the nutritive value of corn for growing pigs显示文摘Background:This experiment was conducted to determine the nutritive value of corn from the north of China for growing pigs.The experiment examined corn variety(LS1,LS2,LS3 and LS4)grown in one location,drying method(sun dried and artificially dried)and different drying temperatures.Corn harvested at 20-25%moisture was dried to about 12%moisture by sun drying and artificially drying at 80,100,or 120℃ in a fluidized bed dryer.Ninety-six barrows(average BW of 33.4 ± 2.7 kg)were housed in individual metabolism crates to facilitate separate collection of feces and urine.A five-day collection period followed a seven-day diet acclimation period.Results:The results indicated that variety significantly influenced(P<0.01)the 1,000 kernel weight of corn but not the bulk weight.Variety also influenced the available energy content(digestible energy of dry matter,P<0.01;metabolisable energy of dry matter,P<0.01)and digestibility of organic matter(P<0.01),as well as dry matter(P<0.01)and gross energy(GE)content(P<0.02).The drying method of corn significantly influenced the 1,000 kernel weight(P<0.01),bulk weight(P<0.01)and digestibility of ether extract(EE)(P<0.01).No effect of drying temperature on the digestibility of organic matter,dry matter(DM),crude protein(CP),neutral detergent fiber(NDF),acid detergent fiber(ADF)and gross energy was observed,but gelatinization(P<0.05)and test weight(P<0.01)decreased with an increase in temperature.Conclusions:Variety has a significant impact on the nutritive value of corn for growing pigs,and greater attention needs to be paid to these influences in the assignment of the nutritive value of corn given to growing pigs.Quanfeng Li Meng Shi Chuanxin Shi Dewen Liu Xiangshu Piao Defa Li Changhua Lai 2014Journal of Animal Science and Biotechnology2014,5,4:5
11Classification and 3-D distribution of upper layer water masses in the northern South China Sea显示文摘Using the fuzzy cluster analysis and the temperature-salinity(T-S) similarity number analysis of cruise conductivity-temperature-depth(CTD) data in the upper layer(0–300 m) of the northern South China Sea(NSCS), we classify the upper layer water of the NSCS into six water masses: diluted water(D), surface water(SS),the SCS subsurface water mass(U_S), the Pacific Ocean subsurface water mass(U_P), surface-subsurface mixed water(SU) and subsurface-intermediate mixed water(UI). A new stacked stereogram is used to illustrate the water mass distribution, and to examine the source and the distribution of U_P, combining with the sea surface height data and geostrophic current field. The results show that water mass U_P exists in all four seasons with the maximum range in spring and the minimum range in summer. In spring and winter, the U_P intrudes into the Luzon Strait and the southwest of Taiwan Island via the northern Luzon Strait in the form of nonlinear Rossby eddies, and forms a high temperature and high salinity zone east of the Dongsha Islands. In summer, the U_P is sporadically distributed in the study area. In autumn, the U_P is located in the upper 200 m layer east of Hainan Island.Jia Zhu Quanan Zheng Jianyu Hu Hongyang Lin Dewen Chen Zhaozhang Chen Zhenyu Sun Liyan Li Hao Kong 2019Acta Oceanologica Sinica2019,38,4:5
12A model to assess fundamental and realized carrying capacities of island ecosystem:A case study in the southern Miaodao Archipelago of China显示文摘Research on carrying capacity, aiming at maintaining the limited ability of the Earth's life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess the localized sustainability of coupled social and ecological systems. A definition termed the ecosystem-based carrying capacity of island(EBCCI) was developed in this paper of which the indices of fundamental and realized carrying capacities of island(FCCI and RCCI) were highlighted to emphasize the inter-dependencies between social systems and ecological systems. In order to avoid the difficulties and uncertainties of direct assessment, the related assessment model was established on the basis of synthetic evaluation of inherent and external factors affecting the EBCCI. The southern Miaodao Archipelago(SMA) located in the intersection of the Bohai Sea and the Yellow Sea, China, was taken as a typical example to acquire integrated recognition of the island ecosystem and its carrying capacity so as to discuss its sustainable development. The index scores of FCCI and RCCI in the SMA were 0.818 5 and 0.712 9 out of 1.0, respectively, with acceptable uncertainties. The results showed a relatively well capacity to sustain progress and relatively well realization of the carrying capacity of island ecosystem, owing to a well capacity of ecologically regulating, general performance of both ecologically supporting and resource provisioning, and a relatively high level of social supporting system. The study implied that it was critical to optimize the inter-dependencies and to sustain the relative balance between social systems and ecological systems so as to improve the RCCI and further facilitate the sustainability of SMA. The approach proposed in this paper provides a powerful tool which is well applicative to the regional level of an oceanic island or archipelago to study the sustainable development and can be further popularized to the coastal zone.SHI Honghua SHEN Chengcheng ZHENG Wei LI Fen WANG Xiaoli CHI Yuan GUO Zhen QIAO Mingyang GAO Liyuan DING Dewen 2016Acta Oceanologica Sinica2016,35,2:4
13Comments on the planation surface once more显示文摘The authors reviewed the research of planation surface in recent years and commented on the development of method and theory about the planation surface. Some aspects of research, such as the restrictive planation surface, the karst planation surface, the fossil planation surface, the dating of weathering crust, the research of weathering crust and environmental evolution, extremely enriched the method and theory of the planation surface. Besides, the authors pointed out that we must take further steps to study the following issues: the deformation of planation surface, the original height of planation surface, the recognition and contrast of the planation surface. The weathering crust and planation surface should be regarded as a whole, and it will still be a principal aspect in the future.CUI Zhijiu LI Dewen FENG Jinliang LIU Gengnian 2002Chinese Science Bulletin2002,47,10:4
14Anti-rutting performance evaluation of modified asphalt binders: A review显示文摘Asphalt pavement inevitably suffers rutting distress induced by repeated loads under high temperatures, which can be effectively alleviated by the modification of asphalt binders.This paper summarized the asphalt modifiers for enhancing the performance of asphalt pavement at high temperatures in terms of the modifier type, additive amount and improving effect. Then, the anti-rutting performance evaluation methods of asphalt binder were introduced with details, including the ring and ball(R&B) test, the dynamic viscosity test, the zero/low shear viscosity(ZSV/LSV) test, the dynamic shear rheometer(DSR) test,the repeated creep and recovery(RCR) test, and the multiple stress creep and recovery(MSCR) test. Furthermore, the sensitivity of the evaluation method to asphalt modifier was analyzed using the normalization method. It was found that the indicators from the MSCR test could clearly reveal the influence of asphalt modifiers on high temperature performance of asphalt binder. But it still had some limitations affecting the accuracy of evaluation results, such as the number of creep-recovery cycles, the stress level and the recovery time. In addition, according to the rutting resistance improvement ratio(RRIR),the styrene-butadiene-styrene(SBS) modifier performed better in improving the rutting resistance of asphalt binder, compared with other modifiers when added within the usual dosage range.Yan Li Peiwen Hao Chaozhi Zhao Jwnqiang Ling Tao Wu Dewen Li Jingwen Liu Bowei Sun 2021Journal of Traffic and Transportation Engineering(English Edition)2021,8,3:4
15Comment on planation surface显示文摘Planation surfaces includes peneplain, pediment and etchplain, which differ from each other in formation and distribution. The double leveling surfaces theory offered by Budel can be used to explain the landforms in limestone areas. According to Budel, that the residue is the upper layer of a planation surface is very important in studying the formationZhiju Cui Dewen Li Yongqiu Wu Gengnian Liu 1999Chinese Science Bulletin1999,44,22:3
16Microbial Remediation and Optimization of Oil Polluted Wetlands at Dalian Bay in China显示文摘Objective The wetland at Dalian Bay in the Northeast of China has been polluted by oil severely. The effect of various microbes and operation parameters on the bioremediation of oil-polluted wetlands at Dalian Bay was investigated and reported previously. In the study, other operation conditions related to the status of medium were investigated via statistical experimental design and analysis and a necessary information is involved to use micro-technology in the application. Methods The method used involved the direct inoculation of selected bacteria, which were capable of degrading oil. The operation conditions were further optimized and evaluated by gravimetrical assay. Results The optimal pH and temperature for the studied bacteria to degrade the existing oil pollutants were established as pH 8.0 and 27℃. The mixed of various bacteria showed better results in terms of oil degradation than any single one. Among the selected four factors, disturbance, oxidant, nutrients, and biosurfactant, the former two contributed more impacts on the oil degradation in the early stage of process, while the latter two became the limiting factors in the late stage. Three sets of optimal conditions were obtained for each individual stage, but no one was suitable for the overall process. Conclusion The study demonstrated the technical feasibility of using direct inoculation into the contaminated soil samples to remove oil pollutants. It suggested that the operation conditions should be monitored and adjusted during the different stages of bio-reactions in the process to achieve the best result of oil degradation.LEI-CHANG HUANG SHU-HONG YE YU ZHANG YAO OLIVE LI XIANG-RONG WANG DEWEN DING 2007Biomedical and Environmental Sciences2007,20,5:3
17The contribution of attached Ulva prolifera on Pyropia aquaculture rafts to green tides in the Yellow Sea显示文摘Green tides caused by the unusual accumulation of high floating Ulva prolifera have occurred regularly in the Yellow Sea since 2007.The primary source of the Yellow Sea green tides is the attached algae on the Pyropia aquaculture rafts in the Subei Shoal.Ulva prolifera and Blidingia(Italic)sp.are the main species observed on Pyropia aquaculture rafts in the Subei Shoal.We found that U.prolifera has strong buoyancy and a rapid growth rate,which may explain why it is the dominant species of green tides that occur in the China's sea area of the Yellow Sea.The growth rate of floating U.prolifera was about 20%–31%d–1,which was much higher than Blidingia(Italic)sp.There were about 1.7×104 t of attached algae on the Pyropia aquaculture rafts in May 2012.We found that 39%of attached algae could float when the tide rose in the Subei Shoal,and U.prolifera accounted for 63%of the floating algae.Our analysis estimated that about 4000 t of attached U.prolifera floated into the surrounding waters of the Subei Shoal during the recycling period of aquaculture rafts.These results suggest that the initial floating biomass of large-scale green tides in the Yellow Sea is determined by the U.prolifera biomass attached to Pyropia aquaculture rafts,further impacting the scale of the green tide。Hongbin Han Shiliang Fan Wei Song Yan Li Jie Xiao Zongling Wang Xuelei Zhang Dewen Ding 2020Acta Oceanologica Sinica2020,39,2:3
18Cloud-based parallel power flow calculation using resilient distributed datasets and directed acyclic graph显示文摘With the integration of distributed generation and the construction of cross-regional long-distance power grids, power systems become larger and more complex.They require faster computing speed and better scalability for power flow calculations to support unit dispatch.Based on the analysis of a variety of parallelization methods, this paper deploys the large-scale power flow calculation task on a cloud computing platform using resilient distributed datasets(RDDs).It optimizes a directed acyclic graph that is stored in the RDDs to solve the low performance problem of the MapReduce model.This paper constructs and simulates a power flow calculation on a large-scale power system based on standard IEEE test data.Experiments are conducted on Spark cluster which is deployed as a cloud computing platform.They show that the advantages of this method are not obvious at small scale, but the performance is superior to the stand-alone model and the MapReduce model for large-scale calculations.In addition, running time will be reduced when adding cluster nodes.Although not tested under practical conditions, this paper provides a new way of thinking about parallel power flow calculations in large-scale power systems.Dewen WANG Fangfang ZHOU Jiangman LI 2019Journal of Modern Power Systems and Clean Energy2019,7,1:3
19Multi-aiming Strategy Design for Quadruple Prism Shaped Central Receiver in Solar Power Tower System显示文摘For solar power tower technology, the improvement of interception efficiency of heliostat field and the extension of central receiver's life time are two technical difficulties. To the receiver, higher interception efficiency means more thermal shocks and stronger stresses of high temperatures mainly contribute to the reduction of receiver's life time. To address these problems,a semi-random distribution strategy is proposed to select the best aiming point of the heliostat, and the distribution of onedimensional array arranged on the centerline of the receiver is carried out for further optimization. It is shown by simulation that through our optimization the temperature distribution on the receiver surface becomes much more uniform while maintaining acceptable interception efficiency.Wenjun Huang Yingmei Qi Fuxing Yi Dewen Li Hao Wang 2017IEEE/CAA Journal of Automatica Sinica2017,4,2:2
20Predicting corn digestible and metabolizable energy content from its chemical composition in growing pigs显示文摘Background:The nutrient composition of corn is variable.To prevent unforeseen reductions in growth performance,grading and analytical methods are used to minimize nutrient variability between calculated and analyzed values.This experiment was carried out to define the sources of variation in the energy content of com and to develop a practical method to accurately estimate the digestible energy(DE) and metabolisable energy(ME)content of individual com samples for growing pigs.Twenty samples were taken from each of five provinces in China(Jilin,Hebei,Shandong,Liaoning,and Henan) to obtain a range of quality.Results:The DE and ME contents of the 100 corn samples were measured in 35.3 ± 1.92 kg growing pigs(six pigs per corn sample).Sixty corn samples were used to build the prediction model;the remaining forty samples were used to test the suitability of these models.The chemical composition of each corn sample was determined,and the results were used to establish prediction equations for DE or ME content from chemical characteristics.The mean DE and ME content of the 100 samples were 4,053 and 3,923 kcal/kg(dry matter basis),respectively.The physical characteristics were determined,as well,and the results indicated that the bulk weight and 1,000-kernel weight were not associated with energy content.The DE and ME values could be accurately predicted from chemical characteristics.The best fit equations were as follows:DE,kcal/kg of DM = 1062.68 +(49.72 x EE) +(0.54 x GE) +(9.11 x starch),with R^2 = 0.62,residual standard deviation(RSD) = 48 kcal/kg,and P< 0.01;ME,kcal/kg of dry matter basis(DM) = 671.54 +(0.89 x DE)-(5.57 x NDF)-(191.39 x ash),with R2 = 0.87,RSD = 18 kcal/kg,and P<0,01.Conclusion:This experiment confirms the large variation in the energy content of corn,describes the factors that influence this variation,and presents equations based on chemical measurements that may be used to predict the DE and ME content of individual corn samples.Quanfeng Li Jianjun Zang Dewen Liu Xiangshu Piao Chanqhua Lai Defa Li 2014Journal of Animal Science and Biotechnology2014,5,3:2
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