维普中文期刊产品整合服务
14篇 您的检索式:作者名="Dashan Wang"
    题名 作者 年代 出处 被引量
1Leaching ion adsorption rare earth by aluminum sulfate for increasing efficiency and lowering the environmental impact显示文摘The leaching efficiency(LE) of ion adsorption rare earth(IARE) by the sulfate and chloride of ammonium,magnesium and aluminum were comparatively determined using column leaching method. It is found that at equal equivalent concentration of cation, the LE of IARE by aluminum sulfate is the highest, and the zeta potential of clay mineral particles in the tailing is near to zero, which means a lower risk of landslide and pollutant emission. Furthermore, the optimum concentration of aluminum sulfate is determined to be0.02 mol/L, which is much lower than that of ammonium sulfate and magnesium sulfate. To reduce the production cost and environmental impact, we proposed a multi-stage leaching process, which was firstly leaching with ammonium sulfate and then with aluminum sulfate, following by water washing and lime neutralizing. With the ratio of ammonium sulfate to aluminum sulfate varying from 1:0 to 0.5:0.5, the residual ammonium in tailing decreases from 11.2% to 0.6%, however, the LE of RE shows an optimum value at 0.8:0.2. By neutralizing the pH of tailing with lime water to over 6, the ion concentration in water rinsing solution can meet the requirement for water discharge. At the same time, the zeta potential of clay particles is found to be around-5 mV, means a relatively lower risk of landslide. These facts indicate that the LE of IARE can be increased and the danger caused by tailings landslides and pollutant emissions can be reduced by replacing ammonium sulfate with aluminum sulfate as leaching reagent.Lifen Yang Cuicui Li Dashan Wang Fengyang Li Yanzhu Liu Xuezhen Zhou Mingbiao Liu Xiufeng Wang Yongxiu Li 2019Journal of Rare Earths2019,37,4:19
2Evaluating the fractionation of ion-adsorption rare earths for in-situ leaching and metallogenic mechanism显示文摘The fractionation of ion adsorption rare earths(IAREs) along the depth in a shaft of a deposit at Dajishan,Jiangxi, China was comparatively evaluated using the partition values(PVs) and relative fractionation values(RFVs) of the leached rare earths(REs). It is found that both PVs and RFVs can objectively reflect the migration and fractionation of REs, but RE content and abrasion pH could not. However, the RFVs can provide more information to quantitatively evaluating the migration and fractionation characteristics of REs along the selected direction and region than PVs could, which is of significance for designing the optimal procedures of in-situ leaching based on the determined flow direction of injecting solution. It is demonstrated that the migration of Ce, Pr, and Nd along the depth direction is inert, and that of REs post Sm and Y is active. Meanwhile, the migration of La shows region characteristics which is active in the upper and inert in lower region. More interesting, the dependence of RFVs on atomic number of REs displays a tetrad group variation trend. However, the fractionation of REs among clay minerals with different particle sizes is not evident, especially for the clay in the bottom region. These results indicate that the migration and fractionation of REs not only are dominated by the adsorption of their hydrated ions, but also rely on their hydrolysis tendency, which provide information for understanding the metallogenic mechanism of IAREs.Qiuhua Xu Lifeng Yang Dashan Wang Xiao Hou Yuanyuan Sun Xuezhen Zhou Xinmu Zhou Yongxiu Li 2018Journal of Rare Earths2018,36,12:4
3Phylotranscriptomics of Swertiinae(Gentianaceae)reveals that key floral traits are not phylogenetically correlated显示文摘Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth.Floral traits in plants are widely used to explore phylogenetic relationships and to delineate taxonomic groups.The subtribe Swertiinae(Gentianaceae)comprises more than 350 species with high floral diversity ranging from rotate to tubular corollas and possessing diverse nectaries.Here we performed phylogenetic analysis of 60 species from all 15 genera of the subtribe Swertiinae sensu Ho and Liu,representing the range of floral diversity,using data from the nuclear and plastid genomes.Extensive topological conflicts were present between the nuclear and plastome trees.Three of the 15 genera represented by multiple species are polyphyletic in both trees.Key floral traits including corolla type,absence or presence of lobe scales,nectary type,nectary position,and stigma type are randomly distributed in the nuclear and plastome trees without phylogenetic correlation.We also revealed the likely ancient hybrid origin of one large clade comprising 10 genera with diverse floral traits.These results highlight the complex evolutionary history of this subtribe.The phylogenies constructed here provide a basic framework for further exploring the ecological and genetic mechanisms underlying both species diversification and floral diversity.Chunlin Chen Brad R.Ruhfel Jialiang Li Zefu Wang Lushui Zhang Lei Zhang Xingxing Mao Ji Wang Dashan He Yue Luo Quanjun Hu Yuanwen Duan Xiaoting Xu Zhenxiang Xi Jianquan Liu 2023Journal of Integrative Plant Biology2023,65,6:1
4Technical innovations in ear reconstruction using a skin expander with autogenous cartilage grafts显示文摘Yu Dashan Jiang Haiyue Yang Qinghua Pan Bo Lin Lin Wang Tailing Wang Yanmei Qin Xiao Zhuang Hongxing 2008Journal of Plastic, Reconstructive & Aesthetic Surgery2008,,:1
5A note on certain square functions on product spaces显示文摘We study certain square functions on product spaces Rn × Rm, whose integral kernels are obtained from kernels which are homogeneous in each factor Rn and Rm and locally in L(log+ L) away from Rn × {0} and {0} × Rm by means of polynomial distortions in the radial variable. As a model case, we obtain that the Marcinkiewicz integral operator is bounded on Lp(Rn × Rm)(p>1) for Ω ∈ Llog+ L(Sn-1 × Sm-1) satisfying the cancellation condition.WANG Meng, CHEN Jiecheng2 & FAN Dashan Department of Mathematics, Zhejiang University (at Yuquan campus), Hangzhou 310027, China Department of Mathematics, Zhejiang University (at Xixi campus), Hangzhou 310028, China Department of Mathematics, University of Wisconsin-Milwaukee, Milwaukee, WI53201, USA 2006Science China Mathematics2006,49,1:1
6Analysis on the Wear Performances of Cemented Carbide Tools Containing Ti in the Coatings When Machining Ti⁃6Al⁃4V Alloys显示文摘Because of the high affinity of the same element Ti,cemented carbide tools containing Ti seem to be non⁃optimal in machining titanium alloys.However,in practice,cemented carbide tools containing Ti are still widely used in machining titanium alloys.Cutting experiments were conducted in order to systematically explain the contradictions between the practice and theory.The diffusion process between titanium alloys and the cemented carbide tools was analyzed by auger electron spectroscopy detecting the cutting regions.It was also analyzed by Ti/Co diffusion behavior simulated by molecular thermodynamics.The experimental results and the simulation results showed that the mutual diffusion of Ti/Co atoms was the major reason for the diffusion wear.The dissolution⁃diffusion wear was one of the main wear mechanisms for the cemented carbide tools containing Ti in the coatings.Moreover,four types of cemented carbide tools and two other types of cermet tools were used to machine the Ti⁃6Al⁃4V alloys at different cutting speeds to further verify the high affinity of cutting tools containing Ti in the substrate/coating.The verification experiments results showed that the cemented carbide tools containing Ti generally cannot be used for machining titanium alloys,but could show less affinity in the cutting regions with reasonable cutting conditions.Jianfei Sun Daxi Du Zixuan Ding Kai Wang Dashan Bai Wuyi Chen 2021Journal of Harbin Institute of Technology(New Series)2021,28,6:0
7Detour-phased perovskite ultrathin planar lens using direct femtosecond laser writing显示文摘Perovskite-enabled optical devices have drawn intensive interest and have been considered promising candidates for integrated optoelectronic systems.As one of the important photonic functions,optical phase modulation previously was demonstrated with perovskite substrate and complex refractive index engineering with laser scribing.Here we report on the new scheme of achieving efficient phase modulation by combining detour phase design with 40 nm ultrathin perovskite films composed of nanosized crystalline particles.Phase modulation was realized by binary amplitude patterning,which significantly simplifies the fabrication process.Perovskite nanocrystal films exhibit significantly weak ion migration effects under femtosecond laser writing,resulting in smooth edges along the laser ablated area and high diffractive optical quality.Fabrication of a detour-phased perovskite ultrathin planar lens with a diameter of 150μm using femtosecond laser scribing was experimentally demonstrated.A high-performance 3D focus was observed,and the fabrication showed a high tolerance with different laser writing powers.Furthermore,the high-quality imaging capability of perovskite ultrathin planar lenses with a suppressed background was also demonstrated.WENKAI YANG LIGE LIU DASHAN DONG XIN ZHANG HAN LIN YUNKUN WANG HONG YANG YUNAN GAO HAIZHENG ZHONG BAOHUA JIA KEBIN SHI 2022Photonics Research2022,10,12:0
8Reflective ultrathin light-sheet microscopy with isotropic 3D resolutions显示文摘Light-sheet fluorescence microscopy(LSFM)has played an important role in bio-imaging due to its advantages of high photon efficiency,fast speed,and long-term imaging capabilities.The perpendicular layout between LSFM excitation and detection often limits the 3D resolutions as well as their isotropy.Here,we report on a reflective type light-sheet microscope with a mini-prism used as an optical path reflector.The conventional high NA objectives can be used both in excitation and detection with this design.Isotropic resolutions in 3D down to300 nm could be achieved without deconvolution.The proposed method also enables easy transform of a conventional fluorescence microscope to high performance light-sheet microscopy.YUE WANG DASHAN DONG WENKAI YANG RENXI HE MING LEI KEBIN SHI 2024Photonics Research2024,12,2:0
9Oscillatory hyper Hilbert transforms along variable curves显示文摘For n = 2 or 3 and x ∈ Rn, we study the oscillatory hyper Hilbert transform Tα,β f(x)=∫Rf(x-Г(t,x))e^-i|t|-β|t|^-1-α dt along an appropriate variable curveГ(t, x) in R^n (namely,Г(t, x) is a curve in R^n for each fixed x), where α〉β〉0. We obtain some LP boundedness theorems of Tα,β, under some suitable conditions on α and β. These results are extensions of some earlier theorems. However, Tα,β f(x) is not a convolution in general. Thus, we only can partially employ the Plancherel theorem, and we mainly use the orthogonality principle to prove our main theorems.Jiecheng CHEN Dashan FAN Meng WANG 2019Frontiers of Mathematics in China2019,14,4:0
10Evaluation of extreme precipitation based on satellite retrievals over China显示文摘The objective of this study is to evaluate satellite precipitation extremes of the Tropical Rainfall Measuring Mission (TRMM)3B42Version 7 product over China during the period of 2009-2013.Eight extreme indices are used to characterize precipitation extremes: monthly maximum 1-day precipitation (RX 1day),monthly maximum consecutive 2-day precipitation (RX2day), monthly maximum 5-day consecutive precipitation (RX5day),simple daily intensity index (SDII),annual total precipitation amount for the wet days (PRCPTOT), annual wet days (R1),consecutive dry days (CDD),and consecutive wet days (CWD).The precipitation amount for indices RXlday,RX2day,RX5day,and PRCPTOT is well captured by TRMM 3B42-V7,as verified by lower mean relative bias and normalized root mean square error and the high spatial correlation coefficient.In contrast,the performance of TRMM 3B42-V7in depicting the indices on intensity and duration (i.e.,SDII,R1,CDD,and CWD) is not as good as its performance in depicting the precipitation amount indices.TRMM 3B42-V7can reproduce extreme indices better in eastern China than in westem China,and better in summer than in winter. Probability density function is also calculated better for RXlday,RX2day,RX5day,and PRCPTOT than for SDII, R1,CDD,and CWD.Investigation on the monthly time series of RX1day,RX2day,and RX5day at different spatial scales indicates that TRMM 3B42-V7 performs better at the large spatial scale than at the grid cell scale.Caution should be observed when the satellite-based extreme indices are used.Xuerongzi HUANG Dashan WANG Yu LIU Zhizhou FENG Dagang WANG 2018Frontiers of Earth Science2018,12,4:0
11Structural plasticity-based hydrogel optical Willshaw model for one-shot on-the-fly edge learning显示文摘Autonomous one-shot on-the-fly learning copes with the high privacy,small dataset,and in-stream data at the edge.Implementing such learning on digital hardware suffers from the well-known von-Neumann and scaling bottlenecks.The optical neural networks featuring large parallelism,low latency,and high efficiency offer a promising solution.However,ex-situ training of conventional optical networks,where optical path configuration and deep learning model optimization are separated,incurs hardware,energy and time overheads,and defeats the advantages in edge learning.Here,we introduced a bio-inspired material-algorithm co-design to construct a hydrogel-based optical Willshaw model(HOWM),manifesting Hebbian-rule-based structural plasticity for simultaneous optical path configuration and deep learning model optimization thanks to the underlying opto-chemical reactions.We first employed the HOWM as an all optical in-sensor AI processor for one-shot pattern classification,association and denoising.We then leveraged HOWM to function as a ternary content addressable memory(TCAM)of an optical memory augmented neural network(MANN)for one-shot learning the Omniglot dataset.The HOWM empowered one-shot on-the-fly edge learning leads to 1000boost of energy efficiency and 10boost of speed,which paves the way for the next-generation autonomous,efficient,and affordable smart edge systems.Dingchen Wang Dingyao Liu Yinan Lin Anran Yuan Woyu Zhang Yaping Zhao Shaocong Wang Xi Chen Hegan Chen Yi Zhang Yang Jiang Shuhui Shi Kam Chi Loong Jia Chen Songrui Wei Qing Wang Hongyu Yu Renjing Xu Dashan Shang Han Zhang Shiming Zhang Zhongrui Wang 2023InfoMat2023,5,4:0
12α-C(sp^(3))-H Arylation of Cyclic Carbonyl Compounds显示文摘α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.Mei Wang Wei Wang Dashan Li Wen-Jing Wang Rui Zhan Li-Dong Shao 2021Natural Products and Bioprospecting2021,11,4:0
13Associations of Ambient NO2 with Daily Hospitalization,Hospitalization Expenditure and Length of Hospital Stay of Cause-Specific Respiratory Diseases-Shanxi,China,2017-2019显示文摘Summary What is already known about this topic?Numerous epidemiological studies have documented the association between ambient nitrogen dioxide(NO2)and mortality and morbidity of respiratory diseases,however,research on the effect of NO2 on the length of hospital stay(LOS)and hospitalization expenditure is limited.What is added by this report?This study collected the respiratory hospitalization,hospital expenditure,and LOS for respiratory diseases from 2017-2019 in Shanxi,China,and comprehensively evaluated the association between ambient NO2 exposure and respiratory hospitalization,expenditure,and LOS.What are the implications for public health practice?This study provides evidence on the association between ambient NO2 and respiratory burden,suggesting that continuously reducing the NO2 concentrations could prevent respiratory diseaseassociated hospital admissions and decrease the relative burden in Shanxi Province and other similar regions.Dashan Zheng Dawei Cao Shiyu Zhang Huiqing Shen Yi Liu Qiyong Liu Jimin Sun Guangyuan Jiao Jianzhen Wang Xiaoran Yang Xinri Zhang Hualiang Lin 2022China CDC weekly2022,4,35:0
14Forest Restoration Potential in China:Implications for Carbon Capture显示文摘Reforestation is an eco-friendly strategy for countering rising carbon dioxide concentrations in the atmosphere and the negative effects of forest loss and degradation.China,with one of the world’s most considerable afforestation rates,has increased its forest cover from 16.6%20 years ago to 23.0%by 2020.However,the maximum potential forest coverage achieved via tree planting and restoration is uncertain.To map potential tree coverage across China,we developed a random forest regression model relating environmental factors and appropriate forest types.We estimate 67.2 million hectares of land currently available for tree restoration after excluding existing forested areas,urban areas,and agriculture land covers/uses,which is 50%higher than the current understanding.Converting these lands to the forest would generate 3.99 gigatons of new above-and belowground carbon stocks,representing an important contribution to achieving carbon neutrality.This potential is spatially imbalanced,with the largest restorable carbon potential being located in the southwest(29.5%),followed by the northeast(17.2%)and northwest(16.8%).Our study highlights the need to align tree restoration areas with the uneven distribution of carbon sequestration potential.In addition to being a biological mitigation strategy to partially offset carbon dioxide emissions from fossil fuel burning,reforestation should provide other environmental services such as the restoration of degraded soils,conservation of biological diversity,revitalization of hydrological integrity,localized cooling,and improvement in air quality.Because of the collective benefits of forest restoration,we encourage that such activities be ecosystem focused as opposed to solely focusing on tree planting.Xin Jiang Alan D Ziegler Shijing Liang Dashan Wang Zhenzhong Zeng 2022Journal of Remote Sensing2022,,1:0
返回顶部 每页显示:
共1页 首页 上一页 第1页 下一页 末页 /1 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费