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Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第3期   页码 397-404 doi: 10.1007/s11705-019-1884-2

摘要： Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media.

关键词： photocatalysis     covalent triazine framework     aqueous medium     SBA-15     solid state    

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大中功率节能调速传动的合理电压等级

马小亮

《中国工程科学》 2001年 第3卷 第11期   页码 80-84

摘要：

大中功率风机和泵采用变频调速可节约大量电能，大部分功率在0.2～2 MW范围中。我国现在200 kW以上的电机多是中压，现行中压电网多为10 kV，选用10 kV直接变频从技术和经济角度看都不太合理。由于变频器输入侧都有变压器，因此电机和变频器没有必要和电网一致。文章讨论不同功率段的合理电压等级以及在电机电压和电网电压不同情况下当变频器出现故障时如何实现旁路工作。

关键词： 大中功率     节能调速     合理电压等级     低压变频     中压变频     旁路    

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Uncoupled state space solution to layered poroelastic medium with anisotropic permeability and compressible

Zhiyong AI, Wenze ZENG, Yichong CHENG, Chao WU

《结构与土木工程前沿（英文）》 2011年 第5卷 第2期   页码 171-179 doi: 10.1007/s11709-011-0103-0

摘要： This paper presents an uncoupled state space solution to three-dimensional consolidation of layered poroelastic medium with anisotropic permeability and compressible pore fluid. Starting from the basic equations of poroelastic medium, and introducing intermediate variables, the state space equation usually comprising eight coupled state vectors is uncoupled into two sets of equations of six and two state vectors in the Laplace-Fourier transform domain. Combined with the continuity conditions between adjacent layers and boundary conditions, the uncoupled state space solution of a layered poroelastic medium is obtained by using the transfer matrix method. Numerical results show that the anisotropy of permeability and the compressibility of pore fluid have remarkable influence on the consolidation behavior of poroelastic medium.

关键词： uncoupled state space solution     layered poroelastic medium     three-dimensional consolidation     anisotropic permeability     compressible pore fluid    

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Preparation of solar selective absorbing CuO coating for medium temperature application

HUANG Qunwu, WANG Yiping, LI Jinhua

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 256-260 doi: 10.1007/s11705-007-0046-0

摘要： A new method of preparing CuO solar selective absorbing coating for medium temperature is presented. After pretreatment, brass was overlaid with CuO by chemical plating. The effects of reactant concentration, reaction temperature and reaction time on the absorptivity of CuO coating were investigated. The optimized condition of preparing CuO coating was obtained. The CuO coating was analyzed with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). In order to prolong the period of use, the CuO coating was protected by TiO. The experiment shows that the TiO/CuO coating is more heat-resistant, acid-resistant, and wear resistant than CuO coating, without losing absorptivity markedly. The TiO coating can reduce emissivity and protect the CuO coating.

关键词： photoelectron spectroscopy     temperature     pretreatment     absorptivity     microscopy    

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Frontier of continuous structural health monitoring system for short & medium span bridges and condition

Ayaho MIYAMOTO, Risto KIVILUOMA, Akito YABE

《结构与土木工程前沿（英文）》 2019年 第13卷 第3期   页码 569-604 doi: 10.1007/s11709-018-0498-y

摘要： It is becoming an important social problem to make maintenance and rehabilitation of existing short and medium span(10-20 m) bridges because there are a huge amount of short and medium span bridges in service in the world. The kernel of such bridge management is to develop a method of safety(condition) assessment on items which include remaining life and load carrying capacity. Bridge health monitoring using information technology and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. The aim of this paper is to introduce a state-of-the-art on not only a rational bridge health monitoring system incorporating with the information and communication technologies for lifetime management of existing short and medium span bridges but also a continuous data collecting system designed for bridge health monitoring of mainly short and medium span bridges. In this paper, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyse the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first is a special designed mobile loading device(vehicle) for short and medium span road bridges to assess the structural safety(performance) and derive optimal strategies for maintenance using reliability based method. The second is a long term health monitoring method by using the public buses as part of a public transit system (called bus monitoring system) to be applied mainly to short and medium span bridges, along with safety indices, namely, “characteristic deflection” which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.

关键词： condition assessment     short & medium span bridge     structural health monitoring(SHM)     long-term data collection     system     maintenance     bridge performance     information technology     loading vehicle(public bus)     in-situ loading    

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大中型水利工程建设管理的实践和体会

张基尧

《中国工程科学》 2011年 第13卷 第8期   页码 22-25

摘要： 水利工程建设是基础设施建设的重要组成部分。加强水利工程建设管理是提高水利投资效益和社会、经济、生态效益的重要途经，是工程管理科学研究的重要内容。文章主要阐述了不同阶段大中型水利工程建设管理的责任主体、管理重点、有效做法和成功案例。

关键词： 大中型水利工程；项目管理；实践体会    

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Alumina modified sodium vanadate cathode for aqueous zinc-ion batteries

《能源前沿（英文）》   页码 775-781 doi: 10.1007/s11708-023-0902-8

摘要： Aqueous zinc-ion batteries (ZIBs) have great prospects for widespread application in massive scale energy storage. By virtue of the multivalent state, open frame structure and high theoretical specific capacity, vanadium (V)-based compounds are a kind of the most developmental potential cathode materials for ZIBs. However, the slow kinetics caused by low conductivity and the capacity degradation caused by material dissolution still need to be addressed for large-scale applications. Therefore, sodium vanadate Na2V6O16·3H2O (NVO) was chosen as a model material, and was modified with alumina coating through simple mixing and stirring methods. After Al2O3 coating modification, the rate capability and long-cycle stability of Zn//NVO@Al2O3 battery have been significantly improved. The discharge specific capacity of NVO@Al2O3 reach up to 228 mAh/g (at 4 A/g), with a capacity reservation rate of approximately 68% after 1000 cycles, and the Coulombic efficiency (CE) is close to 100%. As a comparison, the capacity reservation rate of Zn//NVO battery is only 27.7%. Its superior electrochemical performance is mainly attributed to the Al2O3 coating layer, which can increase zinc-ion conductivity of the material surface, and to some extent inhibit the dissolution of NVO, making the structure stable and improving the cyclic stability of the material. This paper offers new prospects for the development of cathode coating materials for ZIBs.

关键词： cathodes     aqueous zinc-ion batteries     sodium vanadate     alumina     coating    

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Isolation of highly purity cellulose from wheat straw using a modified aqueous biphasic system

Lifeng YAN, Yi ZHAO, Qing GU, Wan LI

《化学科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 282-291 doi: 10.1007/s11705-012-0901-5

摘要： Cellulose samples with molecular weights ranging from 8.39 × 10 to 11.00 × 10 g/mol were obtained from wheat straw. The dewaxed wheat straw was pretreated with aqueous hydrochloric acid followed by delignification using an environmentally benign poly(ethyleneglycol)/salt aqueous biphasic system. The yield of cellulose was in the range of 48.9%–55.5% and the cellulose contained 1.2%–3.2% hemicelluloses, and 0.97%–3.47% lignin. All the isolated cellulose samples could be directly dissolved in a 6 wt-% NaOH/4 wt-% urea aqueous solution through a precooling-thawing process to form a homogenous solution. The separation process was investigated and the obtained cellulose and its solution were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray apparatus, and X-ray diffraction. The results revealed that aqueous soluble cellulose can be directly prepared from wheat straw by this method and this study opens a novel pathway to prepare cellulosic materials from agricultural waste.

关键词： cellulose     straw     separation     aqueous solution    

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USING AN AQUEOUS ENZYMATIC METHOD

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 623-634 doi: 10.15302/J-FASE -2021400

摘要：

Schizochytrium sp., a marine microalga, is a potential source of edible oil due to its short growth cycle and rapid lipid accumulation, especially of docosahexaenoic acid. An approach to isolate edible microalgal oil from Schizochytrium sp. using aqueous enzymatic extraction (AEE) was developed. Parameters were optimized by single-factor experiments followed by Box-Behnken design. Proteases were effective in extracting oil. The maximum free oil recovery (49.7%±0.58%) and total oil recovery (68.1%±0.94%) were obtained under optimum conditions of liquid-to-solid ratio of 4.8:1, a 2.5% enzyme concentration of papain and an extraction time of 2.2 h. There was a significant difference (P<0.05) in polyunsaturated fatty acid composition between microalgal oil obtained by AEE and by Soxhlet extraction, with the former having superior physiochemical properties and higher concentrations of bioactive components including total phenolic compounds and total tocopherols. These findings indicate a potential application of AEE for extraction of oil from Schizochytrium sp.

 

关键词： antioxidant activity / aqueous enzymatic extraction / edible microalgal oil / fatty acid composition / physicochemical properties    

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Conversion of phenol to cyclohexane in the aqueous phase over Ni/zeolite bi-functional catalysts

Jimei Zhang, Fuping Tian, Junwen Chen, Yanchun Shi, Hongbin Cao, Pengge Ning, Shanshan Sun, Yongbing Xie

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 288-298 doi: 10.1007/s11705-020-1932-y

摘要： A series of Ni/HZSM-5 and Ni/HIM-5 bi-functional catalysts were synthesized and applied to the aqueous-phase hydrodeoxygenation (HDO) of phenol. The Ni dispersibility and particle sizes were shown to be directly related to the porosity and crystal sizes of the parent zeolites, which further influenced the catalytic performances. The large pores and small crystal sizes of the parent zeolites were beneficial for dispersing Ni and forming small Ni particles, and the corresponding Ni/zeolite catalyst exhibited a higher phenol conversion and selectivity towards hydrocarbons. Importantly, the Ni/HIM-5 bi-functional catalyst exhibited a high activity (98.3%) and high selectivity for hydrocarbons (98.8%) when heated at 220°C for 1 h and is thus a new potential catalyst for the HDO of phenolics to form hydrocarbons in the aqueous phase.

关键词： aqueous-phase hydrodeoxygenation     phenol     hydrocarbons     Ni/HIM-5     bi-functional catalyst    

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Liquid metal as energy transportation medium or coolant under harsh environment with temperature below

Yunxia GAO, Lei WANG, Haiyan LI, Jing LIU

《能源前沿（英文）》 2014年 第8卷 第1期   页码 49-61 doi: 10.1007/s11708-013-0285-3

摘要： The current highly integrated electronics and energy systems are raising a growing demand for more sophisticated thermal management in harsh environments such as in space or some other cryogenic environment. Recently, it was found that room temperature liquid metals (RTLM) such as gallium or its alloys could significantly reduce the electronics temperature compared with the conventional coolant, like water, oil or more organic fluid. However, most of the works were focused on RTLM which may subject to freeze under low temperature. So far, a systematic interpretation on the preparation and thermal properties of liquid metals under low temperature (here defined as lower than 0°C) has not yet been available and related applications in cryogenic field have been scarce. In this paper, to promote the research along this important direction and to overcome the deficiency of RTLM, a comprehensive evaluation was proposed on the concept of liquid metal with a low melting point below zero centigrade, such as mercury, alkali metal and more additional alloy candidates. With many unique virtues, such liquid metal coolants are expected to open a new technical frontier for heat transfer enhancement, especially in low temperature engineering. Some innovative ways for making low melting temperature liquid metal were outlined to provide a clear theoretical guideline and perform further experiments to discover new materials. Further, a few promising applied situations where low melting temperature liquid metals could play irreplaceable roles were detailed. Finally, some main factors for optimization of low temperature coolant were summarized. Overall, with their evident merits to meet various critical requirements in modern advanced energy and power industries, liquid metals with a low melting temperature below zero centigrade are expected to be the next-generation high-performance heat transfer medium in thermal managements, especially in harsh environment in space.

关键词： liquid metal     cryogenics     low melting point     thermal management     aircraft     liquid cooling     space exploration    

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g-CN-coated MnO hollow nanorod cathode for stable aqueous Zn-ion batteries

《化学科学与工程前沿（英文）》 2023年 第17卷 第2期   页码 217-225 doi: 10.1007/s11705-022-2214-7

摘要： Aqueous zinc-ion batteries are attracting considerable attention because of their high safety compared with conventional lithium-ion batteries. Manganese-based materials have been widely developed for zinc-ion batteries cathode owning to their low cost, high security and simple preparation. However, the severe volume expansion and poor stability during charging and discharging limit the further development of manganese-based cathodes. Herein, superior α-MnO2@g-C3N4 was successfully prepared for stable zinc-ion batteries (ZIBs) cathode by introducing g-C3N4 nanosheets. Compared with pure α-MnO2, α-MnO2@g-C3N4 has a specific capacity of 298 mAh·g–1 at 0.1 A·g–1. Even at 1 A·g–1, the α-MnO2@g-C3N4 still retains 100 mAh·g–1 (83.4% retention after 5000 cycles), implying its excellent cycling stability. The α-MnO2@g-C3N4-based cathode has the highest energy density (563 Wh·kg–1) and power energy density (2170 W·kg–1). This work provides new avenues for the development of a wider range of cathode materials for ZIBs.

关键词： α-MnO2 hollow nanorods     g-C3N4     heterojunction     aqueous Zn-ion batteries    

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Oxidative treatment of aqueous monochlorobenzene with thermally-activated persulfate

Qishi LUO

《环境科学与工程前沿（英文）》 2014年 第8卷 第2期   页码 188-194 doi: 10.1007/s11783-013-0544-x

摘要： The oxidation of aqueous monochlorobenzene (MCB) solutions using thermally- activated persulfate has been investigated. The influence of reaction temperature on the kinetics of MCB oxidation was examined, and the Arrenhius Equation rate constants at 20°C, 30°C, 40°C, 50°C, and 60°C for MCB oxidation performance were calculated as 0, 0.001, 0.002, 0.015, 0.057 min , which indicates that elevated temperature accelerated the rate. The most efficient molar ratio of persulfate/MCB for MCB oxidation was determined to be 200 to 1 and an increase in the rate constants suggests that the oxidation process proceeded more rapidly with increasing persulfate/MCB molar ratios. In addition, the reactivity of persulfate in contaminated water is partly influenced by the presence of background ions such as Cl , , , and . Importantly, a scavenging effect in rate constant was observed for both Cl and but not for other ions. The effective thermally activated persulfate oxidation of MCB in groundwater from a real contaminated site was achieved using both elevated reaction temperature and increased persulfate/MCB molar ratio.

关键词： persulfate     monochlorobenzene     advanced oxidation process    

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Modeling the aqueous reaction kinetics of estriol with ferrate

Cong LI, Naiyun GAO

《化学科学与工程前沿（英文）》 2009年 第3卷 第1期   页码 39-45 doi: 10.1007/s11705-009-0098-4

摘要： In this study the aqueous oxidation kinetics of estriol (E3) by potassium ferrate (K FeO ), a chemical for its strong oxidizing power and for producing a coagulant from its reduced state (i.e. Fe(III)), was evaluated in the range of pH 8-12 with different molar ratios of the reactants. As the degree of Fe(VI) protonation varies with the solution pH, it was found that a first order model was not suitable to describe the oxidation reaction. This paper describes a theoretical representation that closely models the reaction kinetics of E3 and ferrate. From this modeling, the reaction rates of HFe and Fe with E3 have been determined. The results show that the reactivity of HFe with dissociated and undissociated E3 is greater than that of Fe , and that E3 is more reactive in its dissociated state.

关键词： ferrate     estriol     endocrine disruptor     kinetics     oxidation    

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Pathway of the ozonation of 2,4,6-trichlorophenol in aqueous solution

PI Yunzheng, WANG Jianlong

《环境科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 179-183 doi: 10.1007/s11783-007-0031-3

摘要： The reaction mechanism and pathway of the ozonation of 2,4,6-trichlorophenol (2,4,6-TCP) in aqueous solution were investigated. The removal efficiency and the variation of HO, Cl, formic acid, and oxalic acid were studied during the semi-batch ozonation experiments (continuous for ozone gas supply, fixed volume of water sample). The results showed that when there was no scavenger, the removal efficiency of 0.1 mmol/L 2,4,6-TCP could reach 99% within 6 min by adding 24 mg/L ozone. The reaction of molecular ozone with 2,4,6-TCP resulted in the formation of HO. The maximal concentration of HO detected during the ozonation could reach 22.5% of the original concentration of 2,4,6-TCP. The reaction of ozone with HO resulted in the generation of a lot of OH° radicals. Therefore, 2,4,6-TCP was degraded to formic acid and oxalic acid by ozone and OH° radicals together. With the inhibition of OH°radicals, ozone molecule firstly degraded 2,4,6-TCP to form chlorinated quinone, which was subsequently oxidized to formic acid and oxalic acid. Two reaction pathways of the degradation of 2,4,6-TCP by ozone and O/OH° were proposed in this study.
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标题 作者 时间 类型 操作

Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

期刊论文

大中功率节能调速传动的合理电压等级

马小亮

期刊论文

Uncoupled state space solution to layered poroelastic medium with anisotropic permeability and compressible

Zhiyong AI, Wenze ZENG, Yichong CHENG, Chao WU

期刊论文

Preparation of solar selective absorbing CuO coating for medium temperature application

HUANG Qunwu, WANG Yiping, LI Jinhua

期刊论文

Frontier of continuous structural health monitoring system for short & medium span bridges and condition

Ayaho MIYAMOTO, Risto KIVILUOMA, Akito YABE

期刊论文

大中型水利工程建设管理的实践和体会

张基尧

期刊论文

Alumina modified sodium vanadate cathode for aqueous zinc-ion batteries

期刊论文

Isolation of highly purity cellulose from wheat straw using a modified aqueous biphasic system

Lifeng YAN, Yi ZHAO, Qing GU, Wan LI

期刊论文

USING AN AQUEOUS ENZYMATIC METHOD

期刊论文

Conversion of phenol to cyclohexane in the aqueous phase over Ni/zeolite bi-functional catalysts

Jimei Zhang, Fuping Tian, Junwen Chen, Yanchun Shi, Hongbin Cao, Pengge Ning, Shanshan Sun, Yongbing Xie

期刊论文

Liquid metal as energy transportation medium or coolant under harsh environment with temperature below

Yunxia GAO, Lei WANG, Haiyan LI, Jing LIU

期刊论文

g-CN-coated MnO hollow nanorod cathode for stable aqueous Zn-ion batteries

期刊论文

Oxidative treatment of aqueous monochlorobenzene with thermally-activated persulfate

Qishi LUO

期刊论文

Modeling the aqueous reaction kinetics of estriol with ferrate

Cong LI, Naiyun GAO

期刊论文

Pathway of the ozonation of 2,4,6-trichlorophenol in aqueous solution

PI Yunzheng, WANG Jianlong

期刊论文