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Air pressure law of a reservoir constructed in karst sinkholes

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Journal of Mountain Science 2024年第3期21卷 1048-1057页

作者： YU Bo TAI shengping ZHENG Kexun CHEN Shiwan HAN Xiao wang Senlin ZUO Shuangying Power China Guiyang Engineering Corporation Limited Guiyang 550081China College of Resources and Environmental Engineering Key Laboratory of Karst Georesources and EnvironmentMinistry of EducationGuizhou UniversityGuiyang 550025China

Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.

关键词： Simulation test Karst sinkhole Pumped storage reservoir Air pressure Flow rate

High-temperature CO_(2) sorbents with citrate and stearate intercalated Ca-Al hydrotalcite-like as precursor

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Chinese Journal of Chemical Engineering 2022年第10期50卷 177-184页

作者： Tao Jiang Fei Xiao Yujun Zhao shengping wang Xinbin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin UniversityTianjin 300072China

CO_(2),one of the main components of greenhouse gases,increased rapidly because of the growing use of fossil fuels.And CaO sorbents possess the capability to be used in capture of CO_(2) at high temperature.In the work,Ca-Al complex oxides derived from citrate and stearate intercalated layered double hydroxides were fabricated and their CO_(2) adsorption capacity was compared with that from CO_(3)^(2-)intercalated layered double hydroxides.The results presented that the sorbents(Ca/Al=5)with Ca-Al-citrate layered double hydroxides as precursors performed best and displayed remarkable CO_(2) capture capacity of 52.0%(mass)at the carbonization temperature of 600℃without distinct recession during cycling adsorption/desorption tests.The excellent CO_(2) adsorption capacity of the sorbent was ascribed to its smaller crystallite size of calcinated particles,optimized pore size distribution as well as homogeneous distributed Ca and Al in the sorbent.

关键词： Layered doublehydroxides CO_(2)capture CaO-based Organic ions

Coupling effect of bifunctional ZnCe@SBA-15 catalyst in 1,3-butadiene production from bioethanol

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Chinese Journal of Chemical Engineering 2022年第5期35卷 162-170页

作者： Zheng wang Sijia Li shengping wang Jiaxu Liu Yujun Zhao Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Fine Chemicals Department of Catalytic Chemistry and EngineeringDalian University of TechnologyDalian 116024China

A series of bifunctional Zn Ce@SBA-15 catalysts with different Zn/Ce ratios were prepared by a solid-state grinding strategy and used in the conversion of ethanol to 1,3-butadiene(ETB).For the supported metal oxides,Zn O serves as the active sites for the dehydrogenation of ethanol,and CeO_(2) promotes the aldolcondensation reaction.Based on the results of Py-FTIR and NH_(3)-TPD,it suggests that the yield of 1,3-butadiene is positively correlated with the number of weak Lewis acid sites on the catalyst surface,given their benefit for aldol-condensation reactions.The catalyst with an optimal Zn/Ce ratio of about 1:5 has the highest concentration of weak Lewis acid.Coupling with the Zn O sites,it contributes to a 98.4%conversion of ethanol and a 45.2%selective of 1,3-butadiene under relatively mild reaction conditions(375°C,101.325 k Pa,and 0.54 h^(-1)).

关键词： Biomass Catalyst Coupling effect Lewis acid 1 3-butadiene Optimization

Enhanced hydrodeoxygenation of lignin-derived anisole to arenes catalyzed by Mn-doped Cu/Al_(2)O_(3)

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Green Energy & Environment 2023年第3期8卷 927-937页

作者： Xiaofei wang Shixiang Feng Yue wang Yujun Zhao Shouying Huang shengping wang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou350207China

Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures.For the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or its derivatives remains a challenge.Herein,we synthesized Mndoped Cu/Al_(2)O_(3) catalysts from layered double hydroxides(LDHs)for liquid-phase HDO of lignin-derived anisole.Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al_(2)O_(3).With Mn doping increasing,the surface of Cu particles was modified with MnO_(x) along with enhanced generation of oxygen vacancies(Ov).The evolution of active sites structure led to a controllable adsorption geometry of anisole,which was beneficial for increasing arenes selectivity.As a result,the arenes selectivity obtained on 4Cu/8Mn4AlO_(x) was increased to be more than 6 folds of that value on 4Cu/4Al_(2)O_(3) over the synergistic sites between metal Cu and Ov generated on MnO_(x).

关键词： Anisole Hydrodeoxygenation Oxygen vacancy Arenes Metal oxide

Vertical structure of tidal currents in the Xuliujing Section of Changjiang River Estuary

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Acta Oceanologica Sinica 2023年第2期42卷 44-55页

作者： Zhigao Chen Ya Ban Xiaoye Chen Dajun Li shengping wang Faculty of Geomatics East China University of TechnologyNanchang330013China Chongqing Academy of Metrology and Quality Inspection Chongqing401120China Nanjing White Shark Surveying and Mapping Technology Co. LtdNanjing210038China Key Laboratory of Marine Environmental Survey Technology and Application Ministry of Natural ResourcesGuangzhou510300China

Three long-term fixed acoustic Doppler current profilers were first used for investigating the vertical structure of tidal currents in Xuliujing Section of Changjiang River Estuary.Moreover,three different periods(spring,summer and fall)were also considered for investigating seasonal variations.The semi-diurnal tides were the most energetic,with along-channel speed of up to 80 cm/s for M_(2)constituent,which dominates at all stations with percent energy up to 65%–75%during seasons.The shape of tidal ellipses of the most energetic semi-diurnal constituent M_(2)showed obvious polarization of the flow paralleling to the riverbank,with the minor semi-axis being generally less than 20%of the major one.The maximum velocity of mean current is appeared in top layers at all the three stations,and the velocity decreased with the depth.The seasonal variations of direction are also observed,which is probably caused by complex local topography since the erosion and deposition in riverbed.Observed vertical variation of four parameters of M_(2)ellipses,agreed well with the optimally fit frictional solutions in top and middle layers.However,there was an obvious difference between frictional model and observed data in the lower water column.Discrepancies are probably on account of stratification,which strengthens in summer and fall due to the freshening influence of the Changjiang River Estuary outflow.

关键词： vertical structure seasonal variations tidal current mean current acoustic Doppler current profiler Changjiang River Estuary

The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 397-407页

作者： Deng Pan Jiahua Zhou Bo Peng shengping wang Yujun Zhao Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin300072China SINOPEC Research Institute of Petroleum Processing(RIPP) Beijing100083China

The catalytic hydrogenation of carboxylic acid to alcohols is one of the important strategies for the conversion of biomass.Herein,a series of Ni-doped PtSn catalysts were prepared,characterized and studied in the hydrogenation of acetic acid.The Ni dopant has a strong interaction with Pt,which promotes the hydrogen adsorption,providing an activated hydrogen-rich environment for the hydrogenation.Meanwhile,the presence of Ni also improves the Pt dispersion,giving more accessible active sites for hydrogen activation.The cooperation of Pt and Ni significantly promotes the catalytic activity of the hydrogenation of acetic acid to ethanol.As a result,the catalyst with 0.1%Ni exhibits the best reaction activity,and its space time yield is twice as that of the PtSn/SiO2 catalyst.It provides a meaningful instruction on the catalyst design for the carboxylic acid hydrogenation.

关键词： acetic acid ethanol hydrogenation Pt Ni cooperation effect

Regulating electronic environment on alkali metal-doped Cu@NS-SiO_(2) for selective anisole hydrodeoxygenation

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绿色化学工程(英文) 2023年第3期4卷 294-302页

作者： Xiaofei wang Xiaoxue Han Li Kang Shixiang Feng Meiyan wang Yue wang Shouying Huang Yujun Zhao shengping wang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou350207China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China

Lignin utilization is a potential approach for replacing fossil energy and releasing the environment pressure.Herein,we synthesized a series of novel Cu-based catalysts,Cu@NS-SiO_(2)(NS=nano sphere)and alkali metals(Na,K,Rb,and Cs)doped Cu@NS-SiO_(2),and applied them in hydrodeoxygenation reaction of anisole.High Cu dispersion was presented on all catalysts.The modification of alkali metals on Cu@NS-SiO_(2) significantly enhanced the electron density of Cu sites in the following order:Cs>Rb>K>Na,among which Cs decreased the Cu_(2)p_(3)/2 binding energy most(by 0.7 eV).Moreover,the modification did not substantially affect the geometric structure of Cu species.This regulable electronic environment of Cu sites was crucial for selective deoxygenation and inhibiting the hydrogenation of aromatic rings in anisole,and thus promoted the selectivity of benzene.Compared with Cu@NS-SiO_(2)(~59%),the highest benzene selectivity was obtained on Cs/10Cu@NS-SiO_(2) at~83%.

关键词： Anisole Hydrodeoxygenation Arenes Alkali metal Electronic effect

Bidirectional catalysis of CoNiP for LiSdeposition/decomposition reactions in Li–S batteries

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Science China Chemistry 2023年

作者： Luluan Feng shengping wang Faculty of Materials Science and Chemistry China University of Geosciences

To improve the electrochemical activity of S electrodes in Li–S batteries, the synergistic electrocatalysis mechanism of Co0.4Ni1.6P with Ni and Co bimetal interactions is clarified. The alternating crystal structure of Co and Ni regulates the adsorption and decomposition energy of Co0.4Ni1.6P to polysulfides and has the bidirectional catalysis for the Li2S1–2deposition/decomposition process. Co0.4Ni1.6P can promote the breaking of the S–S bond of Li2S4and decrease the decomposition energy barrier of Li2S. This regulation accelerates the discharge/charge reaction between S, polysulfides, and Li2S and improves the kinetics of the S electrodes. The 1st, 100th, and 200thdischarge capacity densities at 0.1 mA cm-2of the S electrodes with a high sulfur loading were 1,405, 987.2, and 828.4 mAh g-1S, respectively. The bidirectional catalytic mechanism is a novel idea for improving the electrochemical performance of Li–S batteries.

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Electrocarboxylation of CO_(2) with Organic Substrates:Toward Cathodic Reaction

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Transactions of Tianjin University 2023年第4期29卷 254-274页

作者： He Yao Mei-Yan wang Chengguang Yue Bangman Feng Wenhao Ji Chunbo Qian shengping wang Sheng Zhang Xinbin Ma School of Chemical Engineering and Technology Key Laboratory for Green Chemical Technology of Ministry of EducationCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin 300072China Ningbo Key Laboratory of Green Petrochemical Carbon Emission Reduction Technology and Equipment Zhejiang Institute of Tianjin UniversityNingbo 315200China

Electrocarboxylation of carbon dioxide(CO_(2))using organic substrates has emerged as a promising method for the sustainable synthesis of value-added carboxylic acids due to its renewable energy source and mild reaction conditions.The reactivity and product selectivity of electrocarboxylation are highly dependent on the cathodic behavior,involving a sequence of electron transfers and chemical reactions.Hence,it is necessary to understand the cathodic reaction mechanisms for optimizing reaction performance and product distribution.In this work,a review of recent advancements in the electrocarboxylation of CO_(2)with organic substrates based on different cathodic reaction pathways is presented to provide a reference for the development of novel methodologies of CO_(2)electrocarboxylation.Herein,cathodic reactions are particularly classified into two categories based on the initial electron carriers(i.e.,CO_(2)radical anion and substrate radical anion).Furthermore,three cathodic pathways(ENE(N),ENED,and EDEN)of substrate radical anion-induced electrocarboxylation are discussed,which differ in their electron transfer sequence,substrate dissociation,and nucleophilic reaction,to highlight their implications on reactivity and product selectivity.

关键词： Carbon dioxide Electrocatalysis Carboxylation Cathodic reaction Carboxylic acids