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碳酸盐岩 3

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Experimental determination of Cd

Farhah Amalya ISMAIL, Ahmad Zaharin ARIS

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 356-364 doi: 10.1007/s11783-013-0488-1

摘要: Carbonate shells have an astonishing ability in the removal of Cd in a short time period with emphasis on being a low cost adsorbent. In the present study, the sorption capacity of carbonate shells was studied for Cd in batch experiments. The influence of different carbonate shell sizes and physico-chemical factors were evaluated and the results were analyzed for its correlation matrices by using Predictive Analytics Software (PASW). The mineralogy state of aqueous solution regarding the saturation index was simulated using PHREEQC to identify the Cd uptake mechanism. The Cd uptake rates were calculated as well as Ca , concentration, pH, ambient humidity and temperature were measured. Cd removal of 91.52% was achieved after 5 h adsorption. The adsorption efficiencies were significantly influenced by pH as they increased with the increase of pH from acidic solution (5.50±0.02) to slightly alkaline (7.60±0.05). In addition, the mineralogy state of aqueous solution calculated from PHREEQC confirmed that the increment of Ca and concentrations in solution was attributed to the dissolution of carbonate shells. Moreover, the ion exchange adsorption mechanism of Cd toward Ca was identified as the process involved in Cd uptake.

关键词: carbonate shell     cadmium     heavy metal     adsorption mechanism     saturation state    

Isogeometric cohesive zone model for thin shell delamination analysis based on Kirchhoff-Love shell model

Tran Quoc THAI, Timon RABCZUK, Xiaoying ZHUANG

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 267-279 doi: 10.1007/s11709-019-0567-x

摘要: We present a cohesive zone model for delamination in thin shells and composite structures. The isogeometric (IGA) thin shell model is based on Kirchhoff-Love theory. Non-Uniform Rational B-Splines (NURBS) are used to discretize the exact mid-surface of the shell geometry exploiting their C -continuity property which avoids rotational degrees of freedom. The fracture process zone is modeled by interface elements with a cohesive law. Two numerical examples are presented to test and validate the proposed formulation in predicting the delamination behavior of composite structures.

关键词: cohesive zone model     IGA     Kirchhoff-Love model     thin shell analysis     delamination    

Polyethylene glycol-supported ionic liquid as a highly efficient catalyst for the synthesis of propylene carbonate

Rui YAO, Hua WANG, Jinyu HAN

《化学科学与工程前沿(英文)》 2012年 第6卷 第3期   页码 239-245 doi: 10.1007/s11705-012-1297-y

摘要: The coupling reaction of propylene and CO to form propylene carbonate (PC) was promoted by an ionic liquid (IL) covalently bound to polyethylene glycol (PEG). The supported ionic liquid, which has both acidic and basic components, proved to be an active catalyst for PC synthesis under mild conditions. The effects of different cations and anions, reaction temperature, CO pressure, and reaction time were investigated. It was demonstrated that the acid group in the catalyst plays an important role in the reaction. With this system, a high PC yield (95%) was achieved under mild conditions (3.0 MPa, 120°C and 4 h) without a co-solvent. In addition, the catalyst was readily recovered and reused. Based on the experimental results, a plausible mechanism for the catalyst was proposed.

关键词: ionic liquid     PEG-supported ionic liquid     carbon dioxide     propylene carbonate    

Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket

Shucheng YANG, Yanling HE, Charles CHOU, Pengxiang ZHANG, Dongqi WANG, Yonghong LIU,

《环境科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 142-149 doi: 10.1007/s11783-010-0026-3

摘要: Calcium carbonate often precipitates in anaerobic reactors treating wastewater with high calcium content. The aim of this paper is to study the effect of wastewater composition on calcium carbonate precipitation in upflow anaerobic sludge blanket (UASB) reactors. Two laboratory-scale UASB reactors were operated with calcium-containing influents using acetate and carbohydrate as substrate, respectively. There was an obvious accumulation of inorganic precipitate observed in the biogranules. Observations via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) showed that the acclimated biogranules in the two reactors differed in microstructure. Calcium carbonate was found to have precipitated on the surface of acetate-degrading biogranules, but precipitated at the core of the carbohydrate-degrading biogranules. The results indicated that substrates had significant influence on the location of calcium carbonate precipitation in anaerobic granular sludge, which was expected due to the different methanogens distribution and pH gradient within the granular sludge degrading various substrates. Moreover, the location of calcium carbonate precipitation substantially affected the specific methanogenic activity (SMA) of the granular sludge. The SMA of the acetate-degrading biogranules dropped from 1.96 gCOD·gVSS·d to 0.61 gCOD·gVSS·d after 180-d of operation in the reactor. However, the SMA of the carbohydrate-degrading biogranules was not adversely affected by calcium carbonate precipitation.

关键词: calcium carbonate     precipitation     anaerobic granular sludge     wastewater composition     microstructure     upflow anaerobic sludge blanket (UASB)    

Property-performance relationship of core-shell structured black TiO photocatalyst for environmental

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1711-3

摘要:

● Properties and performance relationship of CSBT photocatalyst were investigated.

关键词: Black TiO2     Core-shell structure     Property-performance relationship     Agro-industrial effluent     Environmental remediation    

Novel eco-efficient reactive distillation process for dimethyl carbonate production by indirect alcoholysis

Iulian Patraşcu, Costin S. Bîldea, Anton A. Kiss

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 316-331 doi: 10.1007/s11705-021-2047-9

摘要: Dimethyl carbonate is an eco-friendly essential chemical that can be sustainably produced from CO , which is available from carbon capture activities or can even be captured from the air. The rapid increase in dimethyl carbonate demand is driven by the fast growth of polycarbonates, solvent, pharmaceutical, and lithium-ion battery industries. Dimethyl carbonate can be produced from CO through various chemical pathways, but the most convenient route reported is the indirect alcoholysis of urea. Previous research used techniques such as heat integration and reactive distillation to reduce the energy use and costs, but the use of an excess of methanol in the trans-esterification step led to an energy intensive extractive distillation required to break the dimethyl carbonate-methanol azeotrope. This work shows that the production of dimethyl carbonate by indirect alcoholysis of urea can be improved by using an excess of propylene carbonate (instead of an excess of methanol), a neat feat that we showed it requires only 2.64 kW·h·kg dimethyl carbonate in a reaction-separation-recycle process, and a reactive distillation column that effectively replaces two conventional distillation columns and the reactor for dimethyl carbonate synthesis. Therefore, less equipment is required, the methanol-dimethyl carbonate azeotrope does not need to be recycled, and the overall savings are higher. Moreover, we propose the use of a reactive distillation column in a heat integrated process to obtain high purity dimethyl carbonate (>99.8 wt-%). The energy requirement is reduced by heat integration to just 1.25 kW·h·kg dimethyl carbonate, which is about 52% lower than the reaction-separation-recycle process. To benefit from the energy savings, the dynamics and control of the process are provided for ±10% changes in the nominal rate of 32 ktpy dimethyl carbonate, and for uncertainties in reaction kinetics.

关键词: dimethyl carbonate     reactive distillation     process design     plantwide control    

Development of dimensionless P-I diagram for curved SCS sandwich shell subjected to uniformly distributed

Yonghui WANG, Ximei ZHAI

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1432-1445 doi: 10.1007/s11709-019-0566-y

摘要: The curved steel-concrete-steel (SCS) sandwich shell was recently proposed to resist blast loading and it showed better blast resistant performance as compared to flat SCS sandwich shell via developing compressive force along the shell. In this paper, a dimensionless Pressure-Impulse (P-I) diagram was constructed as a convenient tool to predict the damage level of curved SCS sandwich shell subjected to uniformly distributed blast loading. The curved SCS sandwich shell was equivalent to a single-degree-of-freedom (SDOF) system and the equation of motion was established by employing the Lagrange’s equation. To construct the dimensionless P-I diagram, the energy balance method was utilized to yield the pressure and impulse asymptotes and the responses in the dynamic response regime were obtained via employing the SDOF method. Then, the finite element method was employed to validate the developed dimensionless P-I diagram. Finally, the procedures of using the constructed dimensionless P-I diagram to quickly conduct the blast resistant design of curved SCS sandwich shell were presented.

关键词: blast loading     curved steel-concrete-steel sandwich shell     Pressure-Impulse diagram     single-degree-of-freedom method     finite element analysis    

地下水碳酸平衡检查系统

刘建刚,郑克勋,傅伟宁,吴顺华

《中国工程科学》 2003年 第5卷 第9期   页码 61-64

摘要:

文章主要研究地下水在不同温度和CO2分压条件下碳酸三种存在形式与pH值的关系,以便更有效地对地下水水质资料进行可靠性检查。分析认为HCO3-出现峰值的分界pH0值,纯水在CO2分压1~105Pa,温度0~30℃时的变化范围为7.92~8.60,碳酸盐岩地下水的变化范围为8.28~8.57。pH0值随温度的升高而降低。石灰岩和白云岩的pH0十分接近,碳酸盐岩地区的平衡特性将取决于方解石成分。

关键词: 碳酸盐岩     地下水     碳酸平衡     pH值    

Multi-objective optimization of molten carbonate fuel cell system for reducing CO

Ramin ROSHANDEL,Majid ASTANEH,Farzin GOLZAR

《能源前沿(英文)》 2015年 第9卷 第1期   页码 106-114 doi: 10.1007/s11708-014-0341-7

摘要: The aim of this paper is to investigate the implementation of a molten carbonate fuel cell (MCFC) as a CO separator. By applying multi-objective optimization (MOO) using the genetic algorithm, the optimal values of operating load and the corresponding values of objective functions are obtained. Objective functions are minimization of the cost of electricity (COE) and minimization of CO emission rate. CO tax that is accounted as the pollution-related cost, transforming the environmental objective to the cost function. The results show that the MCFC stack which is fed by the syngas and gas turbine exhaust, not only reduces CO emission rate, but also produces electricity and reduces environmental cost of the system.

关键词: molten carbonate fuel cell (MCFC)     multi-objective optimization (MOO)     Pareto curve     genetic algorithm     CO2 separation    

Pyrolysis transformation of ZIF-8 wrapped with polytriazine to nitrogen enriched core-shell polyhedrons

Nuoya Wang, Xinhua Huang, Lei Zhang, Jinsong Hu, Yimin Chao, Ruikun Zhao

《化学科学与工程前沿(英文)》 2021年 第15卷 第4期   页码 944-953 doi: 10.1007/s11705-020-2005-y

摘要: This work presents a simple effective strategy to synthesize -doped and shell-controlled carbon nanocages through a package baking approach. A green approach to synthesize core-shell ZIF-8@PTZ nanoparticles involves zinc contained ZIF-8 core wrapped by a N-enriched polytriazine (PTZ). Synthesized core-shell ZIF-8@PTZ nanoparticles are calcinated to further sublime zinc through PTZ shell and washed by HCl, leaving a porous carbon structure. At the meantime, hollow cavities were introduced into N-doped carbon polyhedrons via the sacrifice of ZIF-8 template (noted as ZIF-8@C/N-x). The electrochemical performance of the ZIF-8@C/N-x as supercapacitor electrode has demonstrated high energy density and specific capacitance, as well as a long-term cycleability showing 92% capacitance retention after 10000 cycles. There is a systematic correlation between micro-/meso-porosity of ZIF-8@C/N-x and their electrochemical performances.

关键词: core-shell     EDLC electrode     microporos nano polygons     nitrogen doped carbon    

Effect of potassium carbonate on catalytic synthesis of calcium carbide at moderate temperature

Dejun SHI, Ke QIAO, Zifeng YAN

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 372-375 doi: 10.1007/s11705-010-0570-1

摘要: Calcium carbide was successfully synthesized by carbothermal reduction of lime with coke at 1973 K for 1.5 h. The effect of potassium carbonate as additive on the composition and morphology of the product was investigated using X-ray diffraction and scanning electron microscope. Addition of potassium carbonate increased the yield of calcium carbide. The sample in the presence of potassium carbonate generated acetylene gas of 168.3 L/kg, which was 10% higher than that in the absence of potassium carbonate. This result confirmed the catalytic effect of potassium carbonate on the synthesis of calcium carbide. A possible mechanism of the above effects was that the additive, which was melted at the reduction temperature, dissolved CaO and so promoted the contact between CaO and carbon, which was essential for the solid-solid reaction to form calcium carbide.

关键词: calcium carbide     synthesis     catalysis    

Influence of crystalline phase of Li-Al-O oxides on the activity of Wacker-type catalysts in dimethyl carbonate

Yadong GE, Yuanyuan DONG, Shengping WANG, Yujun ZHAO, Jing LV, Xinbin MA

《化学科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 415-422 doi: 10.1007/s11705-012-1214-4

摘要: The catalysts supported on LiAl O (spinel) for vapor phase synthesis of dimethyl carbonate (DMC) from methyl nitrite (MN) have been studied. Their catalytic activities on supports prepared by different methods were evaluated in a continuous reactor. The samples were characterized by powder X-ray diffraction, N adsorption-desorption isotherms, fourier transform infrared spectroscopy and temperature-programmed reduction of H . Li/Al molar ratio and calcination temperature greatly influence the structure of crystalline phase of Li-Al-O oxides. Desirable LiAl O (spinel) was formed at 800°C, while LiAl O (primitive cube) formed at 900°C is undesirable for the reaction. A high Li/Al molar ratio, which was related with LiAlO , also slowed the reaction rate. The electron transfer ability and the interaction with active component are the important properties of the spinel-based supports. The CuCl -PdCl /LiAl O (spinel) with better electron transfer ability and low Pd reduction temperature exhibited a better catalytic ability.

关键词: Wacker-type catalyst     dimethyl carbonate     methyl nitrite     spinel    

Direct synthesis of diphenyl carbonate over heterogeneous catalyst: effects of structure of substituted

WU Guangwen, JIN Fang, WU Yuxin, ZHANG Guangxu, LI Dinghuo, WANG Cunwen, MA Peisheng

《化学科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 59-64 doi: 10.1007/s11705-007-0012-x

摘要: The perovskite-type compound LaMnO was substituted for the part of La in position A and for the part of Mn in position B by citrate method. The phases were detected by X-ray diffraction. Powder morphologies were scanned by scanning electron microscopy. The valence of atoms was determined by X-ray photoelectron spectroscopy. It was found that the perovskite can form crystal defect and increase the proportion of high valence B element by doping. Active component Pd was loaded on various perovskite supports for synthesis of diphenyl carbonate. The results showed that the activities of catalysts in which supports have crystal defect by substitution were higher. It can be concluded that perovskite with defect structure by doping could lead to the formation of oxygen vacancy where the lattice oxygen became exchangeable with the oxygen gas. Also, this improved the redox process of the carrier by transferring electrons and activities of catalysts.

关键词: photoelectron spectroscopy     diphenyl carbonate     proportion     diffraction     perovskite    

CC@BCN@PANI core-shell nanoarrays as ultra-high cycle stability cathode for Zn-ion hybrid supercapacitors

《能源前沿(英文)》 2023年 第17卷 第4期   页码 555-566 doi: 10.1007/s11708-023-0882-8

摘要: Exploring cathode materials that combine excellent cycling stability and high energy density poses a challenge to aqueous Zn-ion hybrid supercapacitors (ZHSCs). Herein, polyaniline (PANI) coated boron-carbon-nitrogen (BCN) nanoarray on carbon cloth surface is prepared as advanced cathode materials via simple high-temperature calcination and electrochemical deposition methods. Because of the excellent specific capacity and conductivity of PANI, the CC@BCN@PANI core-shell nanoarrays cathode shows an excellent ion storage capability. Moreover, the 3D nanoarray structure can provide enough space for the volume expansion and contraction of PANI in the charging/discharging cycles, which effectively avoids the collapse of the microstructure and greatly improves the electrochemical stability of PANI. Therefore, the CC@BCN@PANI-based ZHSCs exhibit superior electrochemical performances showing a specific capacity of 145.8 mAh/g, a high energy density of 116.78 Wh/kg, an excellent power density of 12 kW/kg, and a capacity retention rate of 86.2% after 8000 charge/discharge cycles at a current density of 2 A/g. In addition, the flexible ZHSCs (FZHSCs) also show a capacity retention rate of 87.7% at the current density of 2 A/g after 450 cycles.

关键词: CC@BCN@PANI cathode     Zn-ion hybrid supercapacitor     core-shell nanoarrays     high energy density     ultra-high cycle stability    

Recent advances in gold-metal oxide core-shell nanoparticles: Synthesis, characterization, and their

Michelle Lukosi,Huiyuan Zhu,Sheng Dai

《化学科学与工程前沿(英文)》 2016年 第10卷 第1期   页码 39-56 doi: 10.1007/s11705-015-1551-1

摘要: Heterogeneous catalysis with core-shell structures has been a large area of focus for many years. This paper reviews the most recent work and research in core-shell catalysts utilizing noble metals, specifically gold, as the core within a metal oxide shell. The advantage of the core-shell structure lies in its capacity to retain catalytic activity under thermal and mechanical stress, which is a pivotal consideration when synthesizing any catalyst. This framework is particularly useful for gold nanoparticles in protecting them from sintering so that they retain their size, structure, and most importantly their catalytic efficiency. The different methods of synthesizing such a structure have been compiled into three categories: seed-mediated growth, post selective oxidation treatment, and one-pot chemical synthesis. The selective oxidation of carbon monoxide and reduction of nitrogen containing compounds, such as nitrophenol and nitrostyrene, have been studied over the past few years to evaluate the functionality and stability of the core-shell catalysts. Different factors that could influence the catalyst’s performance are the size, structure, choice of metal oxide shell and noble metal core and thereby the interfacial synergy and lattice mismatch between the core and shell. In addition, the morphology of the shell also plays a critical role, including its porosity, density, and thickness. This review covers the synthesis and characterization of gold-metal oxide core-shell structures, as well as how they are utilized as catalysts for carbon monoxide (CO) oxidation and selective reduction of nitrogen-containing compounds.

关键词: core-shell     characterization     core-shell structure     Different     stability    

标题 作者 时间 类型 操作

Experimental determination of Cd

Farhah Amalya ISMAIL, Ahmad Zaharin ARIS

期刊论文

Isogeometric cohesive zone model for thin shell delamination analysis based on Kirchhoff-Love shell model

Tran Quoc THAI, Timon RABCZUK, Xiaoying ZHUANG

期刊论文

Polyethylene glycol-supported ionic liquid as a highly efficient catalyst for the synthesis of propylene carbonate

Rui YAO, Hua WANG, Jinyu HAN

期刊论文

Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket

Shucheng YANG, Yanling HE, Charles CHOU, Pengxiang ZHANG, Dongqi WANG, Yonghong LIU,

期刊论文

Property-performance relationship of core-shell structured black TiO photocatalyst for environmental

期刊论文

Novel eco-efficient reactive distillation process for dimethyl carbonate production by indirect alcoholysis

Iulian Patraşcu, Costin S. Bîldea, Anton A. Kiss

期刊论文

Development of dimensionless P-I diagram for curved SCS sandwich shell subjected to uniformly distributed

Yonghui WANG, Ximei ZHAI

期刊论文

地下水碳酸平衡检查系统

刘建刚,郑克勋,傅伟宁,吴顺华

期刊论文

Multi-objective optimization of molten carbonate fuel cell system for reducing CO

Ramin ROSHANDEL,Majid ASTANEH,Farzin GOLZAR

期刊论文

Pyrolysis transformation of ZIF-8 wrapped with polytriazine to nitrogen enriched core-shell polyhedrons

Nuoya Wang, Xinhua Huang, Lei Zhang, Jinsong Hu, Yimin Chao, Ruikun Zhao

期刊论文

Effect of potassium carbonate on catalytic synthesis of calcium carbide at moderate temperature

Dejun SHI, Ke QIAO, Zifeng YAN

期刊论文

Influence of crystalline phase of Li-Al-O oxides on the activity of Wacker-type catalysts in dimethyl carbonate

Yadong GE, Yuanyuan DONG, Shengping WANG, Yujun ZHAO, Jing LV, Xinbin MA

期刊论文

Direct synthesis of diphenyl carbonate over heterogeneous catalyst: effects of structure of substituted

WU Guangwen, JIN Fang, WU Yuxin, ZHANG Guangxu, LI Dinghuo, WANG Cunwen, MA Peisheng

期刊论文

CC@BCN@PANI core-shell nanoarrays as ultra-high cycle stability cathode for Zn-ion hybrid supercapacitors

期刊论文

Recent advances in gold-metal oxide core-shell nanoparticles: Synthesis, characterization, and their

Michelle Lukosi,Huiyuan Zhu,Sheng Dai

期刊论文