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| 1 | Selective extraction and conversion of lignin in actual biomass to monophenols: A review显示文摘Our over dependency on the fossil resource for industrial chemicals and fuels faces great challenges.Recently, the production of monophenols from lignin in lignocellulosic biomass is regarded as a promising process for sustainable biofuels. This article discusses the conversion of lignin in actual biomass directly to monophenols. The two step way including extraction of lignin from biomass and further degradation of the lignin oligomers to monophenols is especially discussed. The obtained monophenols can also be converted to chemicals with low-oxygen content via hydrodeoxygenation process. For extraction of lignin,co-solvent system is the most adopted for hydrolysis or solvolysis of lignin assisted by acid or alkaline catalysts. The structure of the obtained oligomers derived from lignin is discussed in detail. For lignin depolymerization, hydrogenolysis is an efficient method with the use of gaseous hydrogen or alcohols as hydrogen source. At the meantime, depolymerization mechanism and the route for repolymerization of the reaction intermediates are presented here. In hydrodeoxygenation process, metal catalysts, especially noble metal catalysts are required. The precise effects of the reaction solvents and catalysts on extraction and degradation of lignin need to be further investigated, and this will benefit to design more efficient strategies for lignin utilization. | Zhicheng Jiang Changwei Hu | 2016 | Journal of Energy Chemistry2016，25，6： | 7 |
| 2 | Modeling permafrost properties in the Qinghai-Xizang(Tibet) Plateau显示文摘Water and heat dynamics in the active layer at a monitoring site in the Tanggula Mountains, located in the permafrost region of the Qinghai-Xizang(Tibet) Plateau(QXP), were studied using the physical-process-based COUPMODEL model, including the interaction between soil temperature and moisture under freeze-thaw cycles. Meteorological, ground temperature and moisture data from different depths within the active layer were used to calibrate and validate the model. The results indicate that the calibrated model satisfactorily simulates the soil temperatures from the top to the bottom of the soil layers as well as the moisture content of the active layer in permafrost regions. The simulated soil heat flux at depths of 0 to 20 cm was consistent with the monitoring data, and the simulations of the radiation balance components were reasonable. Energy consumed for phase change was estimated from the simulated ice content during the freeze/thaw processes from 2007 to 2008. Using this model, the active layer thickness and the energy consumed for phase change were predicted for future climate warming scenarios. The model predicts an increase of the active layer thickness from the current 330 cm to approximately 350–390 cm as a result of a 1–2°C warming. However, the effect active layer thickness of more precipitation is limited when the precipitation is increased by 20%–50%. The COUPMODEL provides a useful tool for predicting and understanding the fate of permafrost in the QXP under a warming climate. | HU GuoJie ZHAO Lin WU XiaoDong LI Ren WU TongHua XIE ChangWei PANG QiangQiang XIAO Yao LI WangPing QIAO YongPing SHI JianZong | 2015 | Science China Earth Sciences2015，58，12： | 7 |
| 3 | Efficient production of biodiesel from both esterification and transesterification over supported SO^(2-)_4–MoO_3–ZrO_2–Nd_2O_3/SiO_2 catalysts显示文摘SO2-4–Mo O3–Zr O2–Nd2O3/Si O2(SMZN/Si O2) catalysts for the production of biodiesel via both esterification and transesterification were prepared and characterized by N2adsorption-desorption isotherms,X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetry analysis(TGA),ammonia adsorption Fourier transform infrared spectra(NH3-FTIR),and ammonia adsorption temperature programmed desorption(NH3-TPD) to reveal the dependence of the stable catalytic activity on calcination time. The reason for catalyst deactivation was also studied. The calcination time remarkably affected the types of active centers on SMZN/Si O2-2,and 4 h was found to be the optimal calcination time. SO4 species bonded with small size Zr O2 were found to be the stable active centers,where the leaching of SO2-4and the deposition of coke were inhibited. The deposition of coke was easier on large size Zr O2 than on small size ones. Calcination in air flow could eliminate the deposited coke to recover the deactivated catalysts. | Xiuqin Li Dongmei Tong Changwei Hu | 2015 | Journal of Energy Chemistry2015，24，4： | 6 |
| 4 | Detecting Droughts in Southwest China from GPS Vertical Position Displacements显示文摘The solid Earth responds elastically to terrestrial water storage(TWS)changes.Here global positioning system(GPS)vertical position data at 31 stations from the crustal movement observation network of China(CMONOC)from August 2010 to December 2016 are used to detect droughts in Southwest China.Monthly GPS vertical position displacements respond negatively to precipitation changes and TWS changes observed by gravity recovery and climate experiments(GRACE)as well as river water level variations.GPS vertical position anomalies(the non-seasonal term)are well correlated negatively(correlations of about-0.70)with the commonly used meteorological composite index(CI)in China and the GRACE drought severity index(GRACE-DSI),but less correlated with the standardized precipitation evapotranspiration index(SPEI).Compared to CI,GPS vertical position anomalies have the advantage of detecting droughts caused by abrupt precipitation deficits in a short time.GRACE-DSI is less accurate in drought monitoring for some periods due to the missing data,while the severity of abrupt precipitation absent in some cases can be overestimated from SPEI with big variability.This study shows the reliability and advantages of GPS data in drought monitoring. | Chaolong YAO Zhicai LUO Yueming HU Changwei WANG Rui ZHANG Jinming LI | 2020 | Journal of Geodesy and Geoinformation Science2020，3，3： | 5 |
| 5 | Catalytic pyrolysis of Pubescens to phenols over Ni/C catalyst显示文摘The pyrolysis of Pubescens over Ni/C catalyst was studied at 350°C in H2 flow.The presence of Ni/C catalyst efficiently improved the degradation of raw materials,and produced bio-oil with high content of phenols but low contents of acetic acid,furfural and water.In the reaction,Ni/C catalyst plays the role of catalytic decomposition and catalytic hydrogenation.The existence of the carbon carrier favors the formation of active Ni in small sizes with more defects,which results in high catalytic activity of Ni in biomass decomposition and selective production of phenols. | LUO Jia LI Jie SHEN DanFeng HE Ling TONG DongMei HU ChangWei | 2010 | Science China Chemistry2010，53，7： | 4 |
| 6 | An analytical model for estimating soil temperature profiles on the Qinghai-Tibet Plateau of China显示文摘Soil temperature is a key variable in the control of underground hydro-thermal processes. To estimate soil temperature more accurately, this study proposed a solution method of the heat conduction equation of soil temperature(improved heat conduction model) by applying boundary conditions that incorporate the annual and diurnal variations of soil surface temperature and the temporal variation of daily temperature amplitude, as well as the temperature difference between two soil layers in the Tanggula observation site of the Qinghai-Tibet Plateau of China. We employed both the improved heat conduction model and the classical heat conduction model to fit soil temperature by using the 5 cm soil layer as the upper boundary for soil depth. The results indicated that the daily soil temperature amplitude can be better described by the sinusoidal function in the improved model, which then yielded more accurate soil temperature simulating effect at the depth of 5 cm. The simulated soil temperature values generated by the improved model and classical heat conduction model were then compared to the observed soil temperature values at different soil depths. Statistical analyses of the root mean square error(RMSE), the normalized standard error(NSEE) and the bias demonstrated that the improved model showed higher accuracy, and the average values of RMSE, bias and NSEE at the soil depth of 10–105 cm were 1.41°C, 1.15°C and 22.40%, respectively. These results indicated that the improved heat conduction model can better estimate soil temperature profiles compared to the traditional model. | HU Guojie ZHAO Lin WU Xiaodong LI Ren WU Tonghua XIE Changwei QIAO Yongping SHI Jianzong CHENG Guodong | 2016 | Journal of Arid Land2016，8，2： | 4 |
| 7 | Fractional pyrolysis of Cyanobacteria from water blooms over HZSM-5 for high quality bio-oil production显示文摘Fractional pyrolysis and one-step pyrolysis of natural algae Cyanobacteria from Taihu Lake were comparatively studied from 200 to 500°C.One-step pyrolysis produced bio-oil with complex composition and low high heating value(HHV 30.9 MJ/kg). Fractional pyrolysis separated the degradation of different components in Cyanobacteria and improved the selectivity to products in bio-oil. That is, acids at 200°C, amides and acids at 300°C, phenols and nitriles at 400°C, and phenols at 500°C, were got as main products, respectively. HZSM-5 could promote the dehydration, cracking and aromatization of pyrolytic intermediates in fractional pyrolysis. At optimal HZSM-5 catalyst dosage of 1.0 g, the selectivity to products and the quality of bio-oil were improved obviously. The main products in bio-oil changed to nitriles(47.2%) at 300°C,indoles(51.3%) and phenols(36.3%) at 400°C. The oxygen content was reduced to 7.2 wt% and 9.4 wt%, and the HHV was raised to 38.1and 37.3 MJ/kg at 300 and 400°C, respectively. Fractional catalytic pyrolysis was proposed to be an efficient method not only to provide a potential solution for alleviating environmental pressure from water blooms, but also to improve the selectivity to products and obtain high quality bio-oil. | Huijuan Li Linling Li Rui Zhang Dongmei Tong Changwei Hu | 2014 | Journal of Energy Chemistry2014，23，6： | 3 |
| 8 | Efficient catalytic conversion of jatropha oil to high grade biofuel on Ni-Mo_(2)C/MCM-41 catalysts with tuned surface properties显示文摘The activity of Mo_(2) C-based catalyst on vegetable oil conversion into biofuel could be greatedly promoted by tuning the carbon content,while its modification mechanism on the surface properties remained elusive.Herein,the exposed active sites,the particle size and Lewis acid amount of Ni-Mo_(2) C/MCM-41 catalysts were regulated by varying CH_(4) content in carbonization gas.The activity of Ni-Mo_(2) C/MCM-41 catalysts in jatropha oil(JO)conversion showed a volcano-like trend over the catalysts with increasing CH_(4) content from 15%to 50%in the preparation process.The one prepared by 25%CH_(4) content(NiMo_(2) C(25)/MCM-41)exhibited the outstanding catalytic performance with 83.9 wt%biofuel yield and95.2%C_(15)-C_(18) selectivity.Such a variation of activity was ascribed to the most exposed active sites,the smallest particle size,and the lowest Lewis acid amount from Ni^(0) on the Ni-Mo_(2) C(25)/MCM-41 catalyst surface.Moreover,the Ni-Mo_(2) C(25)/MCM-41 catalyst could also effectively catalyze the conversion of crude waste cooking oil(WCO)into green diesel.This study offers an effective strategy to improve catalytic performance of molybdenum carbide catalyst on vegetable oil conversion. | Xiangze Du Keyao Zhou Linyuan Zhou Xiaomei Lei Huiru Yang Dan Li Changwei Hu | 2021 | Journal of Energy Chemistry2021，30，10： | 2 |
| 9 | Recent advances for the production of hydrocarbon biofuel via deoxygenation progress显示文摘The current world energy crisis and increasing environmental concerns over global climate change from combusting fossil fuel are driving researchers into a new route to produce fuels via sustainable resource to meet the demands of human. In recent years, deoxygenation as an alternative method has been applied in the production of hydrocarbon fuels, particularly via the deoxygenation of fatty acids and triglycerides from seed oils and fats, producing hydrocarbon fuels entirely fungible with fossil fuels. The deoxygenation of biobased feedstock to fuel-like hydrocarbons is critically reviewed in this article. The review mainly discusses the use of feedstock, innovation of catalysts, and the reaction mechanism involved in the production of hydrocarbon fuels via deoxygenation progress. | Dan Li Hui Xin Xiangzhe Du Xiaolei Hao Qingxue Liu Changwei Hu | 2015 | Science Bulletin2015，60，24： | 2 |
| 10 | Effect of CO_2 on the structural variation of Na_2WO_4/Mn/SiO_2 catalyst for oxidative coupling of methane to ethylene显示文摘In this work,the influence of CO2 on the structural variation and catalytic performance of Na2WO4/Mn/Si O2 for oxidative coupling of methane to ethylene was investigated. The catalyst was prepared by impregnation method and characterized by XRD,Raman and XPS techniques. Appropriate amount of CO2 in the reactant gases enhanced the formation of surface tetrahedral Na2WO4 species and promoted the migration of O in MOx,Na,W from the catalyst bulk to surface,which were favorable for oxidative coupling of methane. When the molar ratio of CH4/O2/CO2 was 3/1/2,enriched surface tetrahedral Na2WO4 species and high surface concentration of O in MOx,Na,W were detected,and then high CH4 conversion of 33.1% and high C2H4 selectivity of 56.2% were obtained. With further increase of CO2 in the reagent gases,the content of active surface tetrahedral Na2WO4 species and surface concentration of O in MOx,Na,W decreased,while that of inactive species(Mn WO4 and Mn2O3) increased dramatically,leading to low CH4 conversion and low C2H4 selectivity. It could be speculated that Na2WO4 crystal was transformed into Mn WO4 crystal with excessive CO2 added under the reaction conditions. Pretreatment of Na2WO4/Mn/Si O2 catalyst by moderate amount of CO2 before OCM also promoted the formation of Na2WO4 species. | Jia Shi Lu Yao Changwei Hu | 2015 | Journal of Energy Chemistry2015，24，4： | 2 |
| 11 | The direct pyrolysis and catalytic pyrolysis of Nannochloropsis sp. residue for renewable bio-oils显示文摘 | Pan Pan Changwei Hu Wenyan Yang Yuesong Li Linlin Dong Liangfang Zhu Dongmei Tong Renwei Qing Yong Fan | 2010 | Bioresource Technology2010，，： | 1 |
| 12 | Electrochemical oxidation of Rhodamine B on RuO2-PdO-TiO2/Ti electrode 显示文摘 | Lin Dua Jin Wub Changwei Hu | 2012 | Electrochimica Acta2012，68，： | 1 |
| 13 | Chemisorption of methane over Ni/Al2O3 catalysis显示文摘 | Yaoqiang Chen Changwei Hu | 2000 | J Mol Catal A: Chem2000，152，： | 1 |
| 14 | Erratum to: Recent advances for the production of hydrocarbon biofuel via deoxygenation progress显示文摘1 Erratum to:Sci.Bull.(2015)60(24):2096–2106DOI 10.1007/s11434-015-0971-0In the original publication of this paper,the pathways proposed for the deoxygenation of a fatty acid ester into hydrocarbons in Scheme 2 was incorrect.The corrected pathways appear in this erratum(Scheme 2). | Dan Li Hui Xin Xiangzhe Du Xiaolei Hao Qingxue Liu Changwei Hu | 2016 | Science Bulletin2016，61，3： | 1 |
| 15 | The direct pyrolysis and catalytic pyrolysis of nannochloropsis residue for renewable bio-oils显示文摘 | Pan Pan Hu Changwei Li Yuesong | 2010 | Bioresource Technology2010，101，12： | 1 |
| 16 | Phytoremediation of the polluted Waigang River and general survey on variation of phytoplankton population显示文摘 | Changwei Hu Yuxiong Ou Dayi Zhang Hui Zhang Cheng Yan Yongjun Zhao Zheng Zheng | 2012 | Environmental Science and Pollution Research2012，，9： | 1 |
| 17 | Catalytic pyrolysis of several kinds of bamboos over zeolite NaY显示文摘 | Weiyan Qi Changwei Hu Guiying Li | 2006 | Green Chemistry2006，8，： | 1 |
| 18 | Advance in the synthesis of aromatic amine via direct animation显示文摘Arylamines are very common and important organic molecules. Acting as important intermediates in medical and chemical industry, they are widely used in the synthesis of Pharmaceuticals, dyes, pesticides, rubber additives, isocyanates and heterocyclic compounds. The traditional methods for the synthesis of arylamines include several steps. The production of aniline, for example, includes the following steps: the production of nitro-benzene by the nitration of benzene, and the reduction of the | Tong Chen Changwei Hu Zhenjing Fu Anmin Tian | 2002 | Chinese Science Bulletin2002，47，23： | 1 |
| 19 | Effects of vanadium(V)-substitution on the oxidative properties of α-Keggin-type heteropolyanion clusters——progress in DFT theoretical studies显示文摘The redox properties of α-Keggin-type heteropolyanion clusters [XM12O40]n-(X = Si,P; M = Mo,W) mainly depend on their constituent outer metal-oxygen cages {M12O36}. They act as 'reservoirs',through which the transfer and transition of electrons and protons may occur. At the atomic and molecular level,the redox properties of these clusters can be controlled and also tuned by modifying the metal M in the cages and the central heteroatom X of the clusters. Combined with relevant experimental results,this review summarizes our recent theoretical investigations of the effect of vanadium substitution on the redox properties of Keggin anion clusters. Theoretical modeling and calculation results showed that the oxidative ability of the modified species was increased by partial substitution of the cage M atoms of the Keggin clusters by vanadium atoms which have lower electronegativity. A linear correlation between the catalytic efficiency per vanadium atom and the microstructures of the vanadium(V)-substituted heteropolyanions [PVnMo12-nO40](3+n)-(n = 1-3) was established for the first time. This relationship may be suitable to interpret the catalytic behavior of the title compounds in the hydroxylation of benzene to phenol,and may also be used in understanding other reactions such as the oxidative dehydrogenation of isobutyric acid and the nitration of adamantine. The establishment of this nearly linear structure-property relationship may lay the foundations of understanding the behavior of the title compounds in homogeneous catalytic oxidation reactions,and may direct the design of future catalysts and the choice of other catalytic reactions. | WANG JinYue FU XiaoHong WANG Jian HU ChangWei | 2009 | Science China Chemistry2009，52，12： | 1 |
| 20 | Influence of preparation conditions on the dispersion and distribution of nickel species and on the bahavior of low nickel loading Ni/Al2O3 catalyst显示文摘 | Hu Changwei | 1994 | J Nat Gas Chem1994，3，2： | 1 |
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