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| 1 | Pattern and timing of late Cenozoic rapid exhumation and uplift of the Helan Mountain,China显示文摘The Helan Mountain, an intraplate deformation belt in the North China Craton, is located in the northern portion of the China North-South seismic belt, and at the northwestern margin of the Ordos Block. The Cenozoic deformation history of the Helan Mountain is characterized by extension along the eastern Helan Mountain fault (EHSF), resulting in the exhumation and uplift of the Helan Mountain, relative to the rifting of the adjacent Yinchuan Basin. Here we present new apatite fission track (AFT) data from several transects adjacent to the EHSF in the central and northern Helan Mountain. AFT ages from the northern Helan Mountain (Dawukou and Zhengyiguan transects) range from 10 Ma to 89 Ma, whereas AFT ages from the southern Helan Mountain (Suyukou transect) are greater than 71 Ma. The AFT data analysis reveals initiation of rapid uplift and exhumation of the Helan Mountain at 10–12 Ma. Additionally, a plot of the AFT ages versus their mean track length shows a distinctive 'boomerang' pattern indicating that the Helan Mountain experienced a discrete phase of accelerated exhumation beginning at 10-12 Ma. Spatially, AFT samples systematically increase in age away from the EHSF and are consistent with late Cenozoic exhumation that was slow in the southwestern Helan Mountain and rapid in the northeastern Helan Mountain, as well more rapid adjacent to the EHSF and slower away from the EHSF. Obviously, the spatial distribution of late Cenozoic exhumation indicates that normal faulting of the EHSF is related to southwestward tilting and rapid exhumation of the Helan Mountain beginning at 10–12 Ma. The uplift and exhumation of the Helan Mountain was a response to the intensive extension of the northwestern margin of the Ordos Block in the late Cenozoic; this occurred under a regional extensional stress field oriented NW-SE along the Yinchuan-Jilantai-Hetao and the Weihe-Shanxi graben systems adjacent to the Ordos Block. | LIU JianHui ZHANG PeiZhen ZHENG DeWen WAN JinLin WANG WeiTao DU Peng LEI QiYun | 2010 | Science China Earth Sciences2010，53，3： | 23 |
| 2 | China’s Urban and Rural Old Age Security System: Challenges and Options显示文摘This paper reviews the development of the urban and rural old age security system in China, and discusses the challenges in the process of constructing a sustained old age security system. Although funding gaps and empty individual accounts have imposed a heavy burden on the sustainability of China’s urban pension system, there is a relatively high coverage rate of 35.3 percent for urban workers. However, China’s pension system provides low coverage rate for rural farmers. The more rapidly aging population and lower incomes in rural areas pose challenges to the vulnerable rural household support system. The separation of the old age security system between rural and urban areas also puts great pressure as a result of urbanization on farmers who lose their farmland. Therefore, it is urgent for China to speed up the reform of its old age security system to provide an institutional support for its economic and social transition. | Dewen Wang | 2006 | China & World Economy2006，14，1： | 23 |
| 3 | Employment Effectiveness of China's Economic Stimulus Package显示文摘用一个输入产量方法,这份报纸在中国的经济和雇用上模仿全球金融危机的影响和出口的衰落。与缩小外部需求,增加国内需求为维持经济生长并且支持雇用变得关键。我们的模仿的结果显示没有显著地减少生长,有雇用的一种投资情形能作为优先级完成雇用最大化的目的。公共投资应该集中于雇用,教育,健康,住房和社会安全到重新平衡中国是经济以便它能认识到支撑并且稳定的经济生长。 | Fang Cai Dewen Wang Huaehu Zhang | 2010 | China & World Economy2010，18，1： | 13 |
| 4 | Derivation of Plastic Work Rate Done per Unit Volume for Mean Yield Criterion and Its Application显示文摘In Haigh Westergaard stress space linear combination of twin shear stress and Tresca yield functions is called the mean yield (MY) criterion. The mathematical relationship of the criterion and its plastic work rate done per unit volume were derived. A generalized worked example of slab forging was analyzed by the criterion and its corresponding plastic work rate done per unit volume. Then, the precision of the solution was compared with those by Mises and Twin shear stress yield criterions, respectively. It turned out that the calculated results by MY criterion were in good agreement with those by Mises criterion. | Dewen ZHAO Yingjie XIE Xiaowen WANG Xianghua LIU | 2005 | Journal of Materials Science & Technology2005，21，4： | 8 |
| 5 | Distribution 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 | 2019 | Acta Oceanologica Sinica2019，38，8： | 8 |
| 6 | Effect 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 | 2013 | Acta Metallurgica Sinica(English Letters)2013，26，4： | 7 |
| 7 | Iterative freeform lens design for optical field control显示文摘It is still very challenging to determine a freeform lens for converting a given input beam into a prescribed output beam where not only the irradiance distribution but also the phase distribution hardly can be expressed analytically.Difficulties arise because the ray mapping from the input beam to the output beam is not only intertwined with the required double freeform surfaces but also intertwined with the output phase distribution,whose gradient represents the directions of the output rays.Direct determination of such a problem is very difficult.Here,we develop a special iterative wavefront tailoring(IWT)method to tackle this problem.In a certain iteration,the current calculation data of the double freeform surfaces and the output phase gradient are used to update the coefficients of a Monge–Ampère equation describing an intermediate wavefront next to the entrance freeform surface.The solution to the wavefront equation could lead to an improved ray mapping to be used to update the corresponding phase gradient data and reconstruct the double freeform surfaces.In a demonstrative example that deviates much from the paraxial or small-angle approximation,the new IWT method can generate a freeform lens that performs much better than that designed by a conventional ray mapping method for producing two irradiance distributions in the forms of numerals'1'and'2'on two successive targets,respectively. | ZEXIN FENG DEWEN CHENG YONGTIAN WANG | 2021 | Photonics Research2021，9，9： | 7 |
| 8 | The role of new energy in carbon neutral显示文摘Carbon dioxide is an important medium of the global carbon cycle,and has the dual properties of realizing the conversion of organic matter in the ecosystem and causing the greenhouse effect.The fixed or available carbon dioxide in the atmosphere is defined as'gray carbon',while the carbon dioxide that cannot be fixed or used and remains in the atmosphere is called'black carbon'.Carbon neutral is the consensus of human development,but its implementation still faces many challenges in politics,resources,technology,market,and energy structure,etc.It is proposed that carbon replacement,carbon emission reduction,carbon sequestration,and carbon cycle are the four main approaches to achieve carbon neutral,among which carbon replacement is the backbone.New energy has become the leading role of the third energy conversion and will dominate carbon neutral in the future.Nowadays,solar energy,wind energy,hydropower,nuclear energy and hydrogen energy are the main forces of new energy,helping the power sector to achieve low carbon emissions.'Green hydrogen'is the reserve force of new energy,helping further reduce carbon emissions in industrial and transportation fields.Artificial carbon conversion technology is a bridge connecting new energy and fossil energy,effectively reducing the carbon emissions of fossil energy.It is predicted that the peak value of China’s carbon dioxide emissions will reach 110×10^(8) t in 2030.The study predicts that China’s carbon emissions will drop to 22×10^(8) t,33×10^(8) t and 44×10^(8) t,respectively,in 2060 according to three scenarios of high,medium,and low levels.To realize carbon neutral in China,seven implementation suggestions have been put forward to build a new'three small and one large'energy structure in China and promote the realization of China’s energy independence strategy. | ZOU Caineng XIONG Bo XUE Huaqing ZHENG Dewen GE Zhixin WANG Ying JIANG Luyang PAN Songqi WU Songtao | 2021 | Petroleum Exploration and Development2021，48，2： | 6 |
| 9 | Design and manufacture AR head-mounted displays:A review and outlook显示文摘Augmented reality head-mounted displays(AR-HMDs)enable users to see real images of the outside world and visualize virtual information generated by a computer at any time and from any location,making them useful for various applications.The manufacture of AR-HMDs combines the fields of optical engineering,optical materials,optical coating,precision manufacturing,electronic science,computer science,physiology,ergonomics,etc.This paper primarily focuses on the optical engineering of AR-HMDs.Optical combiners and display devices are used to combine real-world and virtual-world objects that are visible to the human eye.In this review,existing AR-HMD optical solutions employed for optical combiners are divided into three categories:optical solutions based on macro-,micro-,and nanooptics.The physical principles,optical structure,performance parameters,and manufacturing process of different types of AR-HMD optical solutions are subsequently analyzed.Moreover,their advantages and disadvantages are investigated and evaluated.In addition,the bottlenecks and future development trends in the case of AR-HMD optical solutions are discussed. | Dewen Cheng Qiwei Wang Yue Liu Hailong Chen Dongwei Ni Ximeng Wang Cheng Yao Qichao Hou Weihong Hou Gang Luo Yongtian Wang | 2021 | Light(Advanced Manufacturing)2021，2，3： | 6 |
| 10 | Fault-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 | 2013 | Acta Geologica Sinica(English Edition)2013，87，3： | 6 |
| 11 | Freeform 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 | 2022 | Photonics Research2022，10，1： | 5 |
| 12 | Assessment and regulation of ocean health based on ecosystem services: Case study in the Laizhou Bay, China显示文摘The ecosystem-based management of nearshore waters requires integrated assessment of ocean health and scientific guidance on artificial regulations to promote sustainable development. Quantitative approaches were developed in this paper to assess present and near-term ocean health based on ecosystem services. Results of the case study in the Laizhou Bay of China showed that the index score of ocean health was 0.785 6 out of 1.0 at present and was expected to range from 0.555 1 to 0.804 1 in the near-term future depending on different intensities of artificial regulation of negative pressures. Specifically, the results of ocean health at present mainly indicated that cultural services and provisioning services performed essentially perfectly while supporting services and regulating services functioned less well. It can be concluded that this nearshore ecosystem would partially lose supporting and regulating services in the near-term future if the increasing pressures were not wellregulated but that all of these categories of ecosystem services could be slightly improved if the negative pressures were fully controlled. Additionally, it is recommended that publicity and education on ecosystem services especially on cultural services and regulating services should be further strengthened. The analytical process and resulting quantification provide flexible tools to guide future development of regulations so as to facilitate ecosystem-based management in the coastal zone. | SHEN Chengcheng ZHENG Wei SHI Honghua DING Dewen WANG Zongling | 2015 | Acta Oceanologica Sinica2015，34，12： | 4 |
| 13 | A 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 | 2016 | Acta Oceanologica Sinica2016，35，2： | 4 |
| 14 | Retinal projection head-mounted display显示文摘 | Junguo LIN Dewen CHENG Cheng YAO Yongtian WANG | 2017 | Frontiers of Optoelectronics2017，10，1： | 4 |
| 15 | Microbial 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 | 2007 | Biomedical and Environmental Sciences2007，20，5： | 3 |
| 16 | The 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 | 2020 | Acta Oceanologica Sinica2020，39，2： | 3 |
| 17 | Contact stress non-uniformity of wafer surface for multi-zone chemical mechanical polishing process显示文摘A finite element analysis(FEA)model is developed for the chemical-mechanical polishing(CMP)process on the basis of a 12-in five-zone polishing head.The proposed FEA model shows that the contact stress non-uniformity is less dependent on the material property of the membrane and the geometry of the retaining ring.The larger the elastic modulus of the pad,the larger contact stress non-uniformity of the wafer.The applied loads on retaining ring and zone of the polishing head significantly affect the contact stress distribution.The stress adjustment ability of a zone depends on its position.In particular,the inner-side zone has a high stress adjustment ability,whereas the outer-side zone has a low stress adjustment ability.The predicted results by the model are shown to be consistent with the experimental data.Analysis results have revealed some insights regarding the performance of the multi-zone CMP. | WANG TongQing LU XinChun ZHAO DeWen HE YongYong | 2013 | Science China(Technological Sciences)2013，56，8： | 3 |
| 18 | Cloud-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 | 2019 | Journal of Modern Power Systems and Clean Energy2019，7，1： | 3 |
| 19 | Sensitivity and Uncertainty Analysis of Regional Marine Ecosystem Services Value显示文摘Marine ecosystem services are the benefits which people obtain from the marine ecosystem,including provisioning services,regulating services,cultural services and supporting services. The human species,while buffered against environmental changes by culture and technology,is fundamentally dependent on the flow of ecosystem services. Marine ecosystem services become increasingly valuable as the terrestrial resources become scarce. The value of marine ecosystem services is the monetary flow of ecosystem services on specific temporal and spatial scales,which often changes due to the variation of the goods prices,yields and the status of marine exploitation. Sensitivity analysis is to study the relationship between the value of marine ecosystem services and the main factors which affect it. Uncertainty analysis based on varying prices,yields and status of marine exploitation was carried out. Through uncertainty analysis,a more credible value range instead of a fixed value of marine ecosystem services was obtained in this study. Moreover,sensitivity analysis of the marine ecosystem services value revealed the relative importance of different factors. | SHI Honghua ZHENG Wei WANG Zongling DING Dewen | 2009 | Journal of Ocean University of China2009，8，2： | 3 |
| 20 | Iterative freeform lens design for prescribed irradiance on curved target显示文摘Current freeform illumination optical designs are mostly focused on producing prescribed irradiance distributions on planar targets.Here,we aim to design freeform optics that could generate a desired illumination on a curved target from a point source,which is still a challenge.We reduce the difficulties that arise from the curved target by involving its varying z-coordinates in the iterative wavefront tailoring(IWT)procedure.The new IWT-based method is developed under the stereographic coordinate system with a special mesh transformation of the source domain,which is suitable for light sources with light emissions in semi space such as LED sources.The first example demonstrates that a rectangular flat-top illumination can be generated on an undulating surface by a spherical-freeform lens for a Lambertian source.The second example shows that our method is also applicable for producing a non-uniform irradiance distribution in a circular region of the undulating surface. | Zexin Feng Dewen Cheng Yongtian Wang | 2020 | Opto-Electronic Advances2020，3，7： | 2 |
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