|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Meteorological control on CO_2 flux above broad-leaved Korean pine mixed forest in Changbai Mountains显示文摘The impacts of temperature, photosynthetic active radiation (PAR) and vapor pressure deficit (VPD) on CO2 flux above broad-leaved Korean pine mixed forest in the Changbai Mountains were studied based on eddy covariance and meteorological factors measurements.The results showed that, daytime CO2 flux was mainly controlled by PAR and they fit Michaelis-Menten equation. Meanwhile VPD also had an influence on the daytime flux. Drier air reduced the CO2 assimilation of the ecosystem, the drier the air, the more the reduction of the assimilation. And the forest was more sensitive to VPD in June than that in July and August. The respiration of the ecosystem was mainly controlled by soil temperature and they fit exponential equation. It was found that this relationship was also correlated with seasons; respiration from April to July was higher than that from August to November under the same temperature. Daily net carbon exchange of the ecosystem and the daily mean air temperature fit exponential equation. It was also found that seasonal trend of net carbon exchange was the result of comprehensive impacts of temperature and PAR and so on. These resulted in the biggest CO2 uptake in June and those in July and August were next. Annual carbon uptake of the forest ecosystem in 2003 was -184 gC. m-2. | GUAN Dexin, WU Jiabing, YU Guirui, SUN Xiaomin, ZHAO Xiaosong, HAN Shijie & JIN Changjie Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China | 2005 | Science China Earth Sciences2005，48，z1： | 15 |
| 2 | Eddy flux corrections for CO_2 exchange in broad-leaved Korean pine mixed forest of Changbai Mountains显示文摘Based on analysis of mechanisms causing energy no-closure and nocturnal low fluxes issues for CO2 exchange studies by eddy covariance method, corrections were done with the raw data sets obtained from Changbai Mountains forest flux site, to evaluate the impacts of sonic anemometer tilt, frequency response limitations and advection on estimation of CO2 exchange, respectively. The results show that the planar fit coordinate transforming method is superior to the streamline coordinate transforming method in tilt correction. The latter could cause a systematical underestimation of eddy fluxes relating with the angle of sensor and terrain tilt. The underestimation of CO2 and energy fluxes for frequency response limitations average 3.0% and 2.0% during daytime, respectively, which increase by 9.0% and 5.5% during nighttime, respectively. The corrections of frequency response limitations are closely related to atmospheric stability. The advection loss of CO2 fluxes is dominated by nocturnal vertical advection, which is at least 18% when the horizontal advection is neglected. It is suggested that more work be done to understand the characteristics of horizontal advection and turbulent eddies under a complexcircumstance. | WU Jiabing, GUAN Dexin, SUN Xiaomin, YU Guirui, ZHAO Xiaosong, HAN Shijie & JIN Changjie Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Graduate school of the Chinese Academy of Sciences, Beijing 100093, China Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China | 2005 | Science China Earth Sciences2005，48，z1： | 8 |
| 3 | Electroreduction of CO_(2) in Ionic Liquid-Based Electrolytes显示文摘Electroreduction of carbon dioxide(CO_(2))to value-added chemicals and fuels is a promising approach for sustainable energy conversion and storage.Many electrocatalysts have been designed for this purpose and studied extensively.The role of the electrolyte is particularly interesting and is pivotal for designing electrochemical devices by taking advantage of the synergy between electrolyte and catalyst.Recently,ionic liquids as electrolytes have received much attention due to their high CO2 adsorption capacity,high selectivity,and low energy consumption. | Dexin Yang Qinggong Zhu Buxing Han | 2020 | The Innovation2020，1，1： | 6 |
| 4 | Anoxic degradation of nitrogenous heterocyclic compounds by activated sludge and their active sites显示文摘The potential for degradation of five nitrogenous heterocyclic compounds(NHCs), i.e.,imidazole, pyridine, indole, quinoline, and carbazole, was investigated under anoxic conditions with acclimated activated sludge. Results showed that NHCs with initial concentration of 50 mg/L could be completely degraded within 60 hr. The degradation of five NHCs was dependent upon the chemical structures with the following sequence:imidazole > pyridine > indole > quinoline > carbazole in terms of their degradation rates.Quantitative structure–biodegradability relationship studies of the five NHCs showed that the anoxic degradation rates were correlated well with highest occupied molecular orbital.Additionally, the active sites of NHCs identified by calculation were confirmed by analysis of intermediates using gas chromatography and mass spectrometry. | Peng Xu Hongjun Han Haifeng Zhuang Baolin Hou Shengyong Jia Dexin Wang Kun Li Qian Zhao | 2015 | Journal of Environmental Sciences2015，27，5： | 5 |
| 5 | Random seismic noise attenuation by learning-type overcomplete dictionary based on K-singular value decomposition algorithm显示文摘The transformation of basic functions is one of the most commonly used techniques for seismic denoising,which employs sparse representation of seismic data in the transform domain. The choice of transform base functions has an influence on denoising results. We propose a learning-type overcomplete dictionary based on the K-singular value decomposition( K-SVD) algorithm. To construct the dictionary and use it for random seismic noise attenuation,we replace fixed transform base functions with an overcomplete redundancy function library. Owing to the adaptability to data characteristics,the learning-type dictionary describes essential data characteristics much better than conventional denoising methods. The sparsest representation of signals is obtained by the learning and training of seismic data. By comparing the same seismic data obtained using the learning-type overcomplete dictionary based on K-SVD and the data obtained using other denoising methods,we find that the learning-type overcomplete dictionary based on the K-SVD algorithm represents the seismic data more sparsely,effectively suppressing the random noise and improving the signal-to-noise ratio. | XU Dexin HAN Liguo LIU Dongyu WEI Yajie | 2016 | Global Geology2016，19，1： | 2 |
| 6 | Selective electroreduction of carbon dioxide to formic acid on electrodeposited SnO_2@N-doped porous carbon catalysts显示文摘Electrocatalytic reduction of CO_2 is a promising route for energy storage and utilization. Herein we synthesized SnO_2 nanosheets and supported them on N-doped porous carbon (N-PC) by electrodeposition for the first time. The SnO_2 and N-PC in the SnO_2@N-PC composites had exellent synergistic effect for electrocatalytic reduction of CO_2 to HCOOH. The Faradaic efficiency of HCOOH could be as high as 94.1% with a current density of 28.4 mA cm-2 in ionic liquid-MeCN system. The reaction mechanism was proposed on the basis of some control experiments. This work opens a new way to prepare composite electrode for electrochemical reduction of CO_2. | Lu Lu Xiaofu Sun Jun Ma Qinggong Zhu Congyi Wu Dexin Yang Buxing Han | 2018 | Science China Chemistry2018，61，2： | 2 |
| 7 | Comparison of finite difference and pseudo-spectral methods in forward modelling based on metal ore model of random media显示文摘With more applications of seismic exploration in metal ore exploration,forward modelling of seismic wave has become more important in metal ore. Finite difference method and pseudo-spectral method are two important methods of wave-field simulation. Results of previous studies show that both methods have distinct advantages and disadvantages: Finite difference method has high precision but its dispersion is serious; pseudospectral method considers both computational efficiency and precision but has less precision than finite-difference. The authors consider the complex structural characteristics of the metal ore,furthermore add random media in order to simulate the complex effects produced by metal ore for wave field. First,the study introduced the theories of random media and two forward modelling methods. Second,it compared the simulation results of two methods on fault model. Then the authors established a complex metal ore model,added random media and compared computational efficiency and precision. As a result,it is found that finite difference method is better than pseudo-spectral method in precision and boundary treatment,but the computational efficiency of pseudospectral method is slightly higher than the finite difference method. | LIU Dongyu HAN Liguo ZHANG Pan XU Dexin | 2016 | Global Geology2016，19，2： | 1 |
| 8 | Petrography and geochemistry of the Middle Devonian coal from Luquan,Yunnan province China显示文摘 | Dai Shifeng Han Dexin Chou Chenlin | 2006 | Fuel2006，85，4： | 1 |
| 9 | Geochemical evidence for mudstone as the possible major oil source rock in the Jurassic Turpan Basin, Northwest China显示文摘 | Chen Jianping Qin Yong Huffe B G Wang Darui Han Dexin Huang Difan | 2001 | Org Geochem2001，32，9： | 1 |
| 10 | Antithrombin gene Arg197Stop mutation-associated venous sinus thrombosis in a Chinese family显示文摘This study sought to elucidate the genetic correlation of cerebral venous sinus thrombosis caused by a hereditary antithrombin deficiency in a Chinese family,at the genetic and protein levels.A nonsense mutation from C to T on locus 6431 in exon 3B of the antithrombin gene was observed,leading to an arginine (CGA) to stop codon (TGA) change in the protein.This is the first report of this mutation in China.Ineffective heparin therapy in the propositus patient is associated with a lack of heparin binding sites after antithrombin gene mutation.Characteristic low intracranial pressure in the acute phase might be specific to this patient with cerebral venous sinus thrombosis. | Ang Li Tianhui Liu Zhandong Liu Jimei Li Chunling Zhang Jun Chen Jinmei Sun Yanfei Han Lili Wang Dexin Wang Qiming Xue Baoen Wang | 2011 | Neural Regeneration Research2011，6，20： | 1 |
| 11 | A Pilot-scale Study on Coal Gasification Wastewater Reclamation Using Pretreatment Alternatives Combined with Ultrafiltration and Reverse Osmosis显示文摘Aims to investigate the performance of the pilot-scale reclamation plant for coal gasification wastewater( CGW) using ultrafiltration and reverse osmosis with appropriate pretreatment alternatives,different pre-treatment alternatives- coagulation,adsorption,and ozonation methods were employed to treat the secondary effluent of coal gasification wastewater( SECGW) in a pilot-scale pressurized membrane system. The performance was compared to choose the most suitable pre-treatment alternative for the SECGW reclamation.Ozone reaction achieved highest COD removal efficiency( 79.6%- 91.0%),resulting in the stable normalized parameters of the subsequent ultrafiltration and reverse osmoses. In contrast,the coagulation and adsorption processes achieved only 32. 8%- 45. 7% and 53. 1%- 64. 6% decreases in COD,respectively. The residual organic pollutants in the reverse osmosis feed water led to an increase in normalized pressure drop and a decrease in normalized permeability( or membrane transference coefficient). The hydrophobic fraction was the main constituent( approx. 70% of DOC) in pretreated SECGW, and the hydrophobic-neutral fraction contributed mostly to the UV absorbance( 53%). Fluorescence excitation emission matrices revealed that ozonation removed most of the hydrophobic and aromatic proteins such as tyrosine and tryptophan which dominated in raw wastewater. The recalcitrant compounds such as phenolic compounds, heterocyclic compounds,especially long-chain hydrocarbons,which were easily attached to the membrane surface and contributed to organic fouling,could be oxidized and mineralized by ozone. Among the three pretreatments,ozonation showed highest removal efficiencies of hydrophobic and aromatic proteins,therefore resulting in highest normalized permeability. | Qian Zhao Hongjun Han Fang Fang Peng Xu Kun Li Dexin Wang | 2015 | Journal of Harbin Institute of Technology(New Series)2015，22，6： | 1 |
| 12 | Enhancing the selective hydrogenation of benzene to cyclohexene over Ru/TiO_2 catalyst in the presence of a very small amount of ZnO显示文摘Highly efficient and greener hydrogenation of benzene to cyclohexene is of great importance but is challenging.In this work,Ru/Ti O2 catalyst was prepared by a simple chemical-reduction method.The catalyst was characterized by transmission electron spectroscopy(TEM),X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and nitrogen adsorption-desorption techniques.It was shown that the Ru nanoparticles with average size of about 2.2 nm were dispersed uniformly on the surface of the Ti O2 support.The effect of a very small amount of Zn O in Na OH solution on the selectivity to cyclohexene was investigated under different conditions by using Ru/Ti O2 catalyst.It was found that the addition of a small amount of Zn O to the Na OH solution could effectively enhance the selectivity to cyclohexene and that the yield of cyclohexene could reach 41.5%.Control experiments revealed that the main reason for the enhancement of the selectivity to cyclohexene was the presence of Zn O in the form of Na2Zn(OH)4 in the alkaline solution,which effectively retarded the further hydrogenation of cyclohexene.A recycling experiment showed that the yield of cyclohexene was not obviously decreased after four reuses. | Tianbin Wu Peng Zhang Tao Jiang Dexin Yang Buxing Han | 2015 | Science China Chemistry2015，58，1： | 0 |
| 13 | The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering emulsions and enhance oil recovery显示文摘Nanoparticles with high surface energy and chemical activity have drawn substantial attention in petroleum industry. Recently, Janus nanoparticles exhibited tremendous potential in enhanced oil recovery (EOR) due to their asymmetric structures and properties. In this study, a series of amphiphilic pseudo-Janus@OTAB (PJ@C18) nanoparticles with different concentrations of stearyltrimethylammoium bromide (OTAB) were successfully fabricated. The structures and properties of PJ@C18 were characterized by Fourier transform infrared spectroscopy and ζ-potential measurements. Based on the emulsification experimental results, the interaction models and the self-assembly behavior between hydrophilic nanoparticles (SiO_(2)@NH_(2)) and OTAB molecules at the oil/water interface were proposed, which was further confirmed via the measurements of the contact angle and dynamic interfacial tension. Interestingly, it was found that the change of pH value from 7.5 to 4.0 caused the type reversal of the PJ@C18-1000 stabilized Pickering emulsions. Furthermore, the PJ@C18-1000 stabilized Pickering emulsion system with excellent salt and temperature tolerances (10000 mg∙L^(–1), 90℃) significantly improved the oil recovery in the single-tube (more than 17%) and double-tube (more than 25%) sand pack model flooding tests. The findings of this study could help to better understand the construction mechanism of pseudo-Janus silica/surfactant assembly and the potential application of PJ@C18-1000 stabilized Pickering emulsions for EOR. | Han Jia Jiajun Dai Tingyi Wang Yingbiao Xu Lingyu Zhang Jianan Wang Lin Song Kaihe Lv Dexin Liu Pan Huang | 2022 | Frontiers of Chemical Science and Engineering2022，16，7： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员