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Experimental and kinetic study on laminar flame speeds of ammonia/syngas/air at a high temperature and

《能源前沿(英文)》 2022年 第16卷 第2期   页码 263-276 doi: 10.1007/s11708-021-0791-7

摘要: The laminar flame speeds of ammonia mixed with syngas at a high pressure, temperature, and different syngas ratios were measured. The data obtained were fitted at different pressures, temperatures, syngas ratios, and equivalence ratios. Four kinetic models (the Glarborg model, Shrestha model, Mei model, and Han model) were compared and validated with experimental data. Pathway, sensitivity and radical pool analysis are conducted to find out the deep kinetic insight on ammonia oxidation and NO formation. The pathway analysis shows that H abstraction reactions and NHi combination reactions play important roles in ammonia oxidation. NO formation is closely related to H, OH, the O radical produced, and formation reactions. NO is mainly formed from reaction, HNO+ H= NO+ H2. Furthermore, both ammonia oxidation and NO formation are sensitive to small radical reactions and ammonia related reactions.

关键词: ammonia mixed with syngas     laminar flame speed     kinetic model     sensitivity analysis     pathway analysis    

Impact of preozonation on the bioactivity and biodiversity of subsequent biofilters under low temperature conditions—A pilot study

Jiaxuan YANG, Jun MA, Dan SONG, Xuedong ZHAI, Xiujuan KONG

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0844-z

摘要: The bioactivity was enhanced by preozonation under low temperature conditions. Higher level of BDOC/AOC and DO may enhance the nitrifying performance. High level of biodiversity and bioactivity may help maintain the stability of filters. Water quality and DO could selectively enhance different microbial communities. The combination of preozonation and subsequent biological granular activated carbon (O /BAC) filtration is well known as a promising method for the removal of many pollutants. Temperature and nutrients are the dominant factors in external conditions to influence the biological communities. To explore the influence of preozonation under low temperature, the factors such as dissolved oxygen (DO), dissolved organic carbon (DOC) and NH -N were analyzed from the sampling ports every week; triphenyl tetrazolium chloride-dehydrogenase activity (TTC-DHA) and the nitrifying activity were detected along the bed height of biofilter at four levels (10, 40, 70 and 110 cm) on the 90th, 110th, and 130th day; microbial community, based on 16S rRNA gene-denaturing gradient gel electrophoresis (DGGE), was monitored on the 130th day of the operation. The observed microbial property showed that preozonation had a positive influence on bioactivity, biomass and nitrifying activity. Community analysis showed no significant difference on the biodiversity of nitrifying bacteria between the parallel filters in the inlet end based on the method employed. This result showed that biofilters’ performance is not correlated well with microbial biodiversity. The elevated functionality in O /BAC filters can be a result of increased microbial activity, which was promoted by preozonation.

关键词: Preozonation     BAC filtration     High ammonia level     Bacterial activity     Microbial community structure     Pilot scale study    

Nitrification and denitrification in biological activated carbon filter for treating high ammonia source

LIU Jianguang, ZHANG Xiaojian, WANG Zhansheng

《环境科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 94-98 doi: 10.1007/s11783-008-0020-1

摘要: Since the ammonia in the effluent of the traditional water purification process could not meet the supply demand, the advanced treatment of a high concentration of 4-N micro-polluted source water by biological activated carbon filter (BACF) was tested. The filter was operated in the downflow manner and the results showed that the removing rate of NH4-N was related to the influent concentration of NH4-N. Its removing rate could be higher than 95% when influent concentration was under 1.0 mg/L. It could also decrease with the increasing influent concentration when the 4-N concentration was in the range from 1.5 to 4.9 mg/L and the dissolved oxygen (DO) in the influent was under 10 mg/L, and the minimum removing rate could be 30%. The key factor of restricting nitrification in BACF was the influent DO. When the influent NH4-N concentration was high, the DO in water was almost depleted entirely by the nitrifying and hetetrophic bacteria in the depth of 0.4 m filter and the filter layer was divided into aerobic and anoxic zones. The nitrification and degradation of organic matters existed in the aerobic zone, while the denitrification occurred in the anoxic zone. Due to the limited carbon source, the denitrification could not be carried out properly, which led to the accumulation of the denitrification intermediates such as NO2. In addition to the denitrification bacteria, the nitrification and the heterotrophic bacteria existed in the anoxic zone.

The carbon dioxide removal potential of Liquid Air Energy Storage: A high-level technical and economic

Andrew LOCKLEY, Ted von HIPPEL

《工程管理前沿(英文)》 2021年 第8卷 第3期   页码 456-464 doi: 10.1007/s42524-020-0102-8

摘要: Liquid Air Energy Storage (LAES) is at pilot scale. Air cooling and liquefaction stores energy; reheating revaporises the air at pressure, powering a turbine or engine (Ameel et al., 2013). Liquefaction requires water & CO removal, preventing ice fouling. This paper proposes subsequent geological storage of this CO – offering a novel Carbon Dioxide Removal (CDR) by-product, for the energy storage industry. It additionally assesses the scale constraint and economic opportunity offered by implementing this CDR approach. Similarly, established Compressed Air Energy Storage (CAES) uses air compression and subsequent expansion. CAES could also add CO scrubbing and subsequent storage, at extra cost. CAES stores fewer joules per kilogram of air than LAES – potentially scrubbing more CO per joule stored. Operational LAES/CAES technologies cannot offer full-scale CDR this century (Stocker et al., 2014), yet they could offer around 4% of projected CO disposals for LAES and<25% for current-technology CAES. LAES CDR could reach trillion-dollar scale this century (20 billion USD/year, to first order). A larger, less certain commercial CDR opportunity exists for modified conventional CAES, due to additional equipment requirements. CDR may be commercially critical for LAES/CAES usage growth, and the necessary infrastructure may influence plant scaling and placement. A suggested design for low-pressure CAES theoretically offers global-scale CDR potential within a century (ignoring siting constraints) – but this must be costed against competing CDR and energy storage technologies.

关键词: carbon dioxide removal     Liquid Air Energy Storage     Compressed Air Energy Storage     geoengineering    

高放废物地质处置:进展与挑战

王驹

《中国工程科学》 2008年 第10卷 第3期   页码 58-65

摘要:

随着我国核能事业的飞速发展,高水平放射性废物的处理和处置,即将成为一个重大的安全和环保问题。在介绍国内外进展的基础上,重点讨论了高放废物地质处置面临的挑战:处置库场址地质演化的精确预测、深部地质环境特征、多场耦合条件下(中(高)温、应力作用、水力作用、化学作用、生物作用和辐射作用等)深部岩体、地下水和工程材料的行为、低浓度超铀放射性核素的地球化学行为与随地下水迁移行为及处置系统的安全评价。

关键词: 高放废物     地质处置     地下实验室     科学挑战    

Abundance and distribution of ammonia-oxidizing archaea in Tibetan and Yunnan plateau agricultural soils

Kun DING,Xianghua WEN,Liang CHEN,Daishi HUANG,Fan FEI,Yuyang LI

《环境科学与工程前沿(英文)》 2014年 第8卷 第5期   页码 693-702 doi: 10.1007/s11783-014-0635-3

摘要: As low oxygen and high ultraviolet (UV) exposure might significantly affect the microbial existence in plateau, it could lead to a specialized microbial community. To determine the abundance and distribution of ammonia-oxidizing archaea (AOA) in agricultural soil of plateau, seven soil samples were collected respectively from farmlands in Tibet and Yunnan cultivating the wheat, highland-barley, and colza, which are located at altitudes of 3200–3800 m above sea level. Quantitative PCR (q-PCR) and clone library targeting on gene were used to quantify the abundances of AOA and ammonia-oxidizing bacteria (AOB), and characterize the community structures of AOA in the samples. The number of AOA cells (9.34 × 10 –2.32 × 10 g soil) was 3.86–21.84 times greater than that of AOB cells (6.91 × 10 –1.24 × 10 g soil) in most of the samples, except a soil sample cultivating highland-barley with an AOA/AOB ratio of 0.90. Based Kendall’s correlation coefficient, no remarkable correlation between AOA abundance and the environmental factor was observed. Additionally, the diversities of AOA community were affected by total nitrogen and organic matter concentration in soils, suggesting that AOA was probably sensitive to several environmental factors, and could adjust its community structure to adapt to the environmental variation while maintaining its abundance.

关键词: ammonia-oxidizing archaea     ammonia-oxidizing bacteria     quantitative PCR     clone library     plateau    

Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

《能源前沿(英文)》 2011年 第5卷 第4期   页码 358-366 doi: 10.1007/s11708-011-0161-y

摘要: To investigate the performance of heat and mass transfer of ammonia-water during the process of falling film evaporation in vertical tube evaporator, a mathematical model of evaporation process was presented, the solution of which that needed a coordinate transformation was based on stream function. The computational results from the mathematical model were validated with experimental data. Subsequently, a series of parameters, such as velocity, film thickness and concentration, etc., were obtained from the mathematical model. Calculated results show that the average velocity and the film thickness change dramatically at the entrance region when <100 mm, while they vary slightly with the tube length in the fully developed region when >100 mm. The average concentration of the solution reduces along the tube length because of evaporation, but the reducing tendency becomes slow. It can be concluded that there is an optimalβrelationship between the tube length and the electricity generated. The reason for the bigger concentration gradient in the direction is that the smooth tube is chosen in the calculation. It is suggested that the roll-worked enhanced tube or other enhanced tube can reduce the concentration gradient in the film thickness direction and enhance the heat and mass transfer rate.

关键词: falling film evaporation     ammonia-water     heat and mass transfer    

Simulation on thermodynamic state of ammonia carbonation at low temperature and low pressure

Jingcai ZHAO, Xingfu SONG, Ze SUN, Jianguo YU

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 447-455 doi: 10.1007/s11705-013-1370-1

摘要: This study on thermodynamic property of NH -CO -H O system provided the basic data for ammonia carbonation. Simulations on vapor-liquid equilibrium (VLE) of ammonia carbonation with different physical properties were discussed in NH -H O and NH -CO -H O systems, respectively. The results indicated that at low temperature (303.15 K–363.15 K) and pressure (0.1–0.4 MPa), the PR (Peng-Robinson) equation was suitable for the description of the thermodynamic state in NH -H O system. NRTL (Non-Random-Two-Liquid) series models were selected for NH -CO -H O mixed electrolyte solution system. VLE data regression results showed that NRTL series models were suitable for describing thermodynamic properties of NH -CO -H O system, because average relative error fitting with each model was about 1%. As an asymmetric electrolytes model in NRTL model, E–NRTLRK (Electrolyte NRTL Redlich Kwong) could most accurately fit VLE data of NH -CO -H O system, with fitting error less than 1%. In the extent temperature range of 273.15 K–363.15 K, the prediction of product component using E-NRTLRK model for ammonia carbonation agreed well with the data reported in literature.

关键词: vapor-liquid equilibrium     activity coefficient     carbon dioxide     ammonia     NRTL    

Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power

Peng ZHENG, Xuan YAO, Wei ZHENG

《能源前沿(英文)》 2013年 第7卷 第1期   页码 127-132 doi: 10.1007/s11708-012-0225-7

摘要: Ammonia is highly volatile and will present substantial environmental and operation hazards when leaking into the air. However, ammonia is the most common reactant in the DENOX project to eliminate NO in the flue gas. The storage and transportation of liquid ammonia has always been a dilemma of the power plant. Urea is a perfect substitute source for ammonia in the plant. Urea hydrolysis technology can easily convert urea into ammonia with low expense. Presently, there is still no self-depended mature urea hydrolysis technology for the DENOX project in China; therefore, this paper proposes several guidelines to design the urea hydrolyser by theoretical analysis. Based on theoretical analysis, a simulation model is built to simulate the chemical reaction in the urea hydrolyser and is validated by the operational data of the commercial hydrolyser revealed in the literature. This paper endeavors to propose suggestions and guidelines to develop domestically urea hydrolysers in China.

关键词: urea     hydrolyser     ammonia     selective catalytic reduction (SCR)    

Enhancement on the ammonia oxidation capacity of ammonia-oxidizing archaeon originated from wastewater

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1375-1

摘要:

• AOA’s ammonia oxidizing capacity was enhanced under moderate magnetic field.

关键词: Ammonia-oxidizing archaeon     Ammonia oxidation     Magnetic field     Magnetotaxis     Heredity    

Upgrade of three municipal wastewater treatment lagoons using a high surface area media

John WANG, Peng JIN, Paul L. BISHOP, Fuzhi LI

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 288-293 doi: 10.1007/s11783-011-0280-z

摘要: Lagoon-based municipal wastewater treatment plants (WWTPs) are facing difficulties meeting the needs of rapid population growth as well as the more stringent requirements of discharge permits. Three municipal WWTPs were modified using a high surface area media with upgraded fine-bubble aeration systems. Performance data collected showed very promising results in terms of five-day biochemical oxygen demand (BOD ), ammonia (NH ) and total suspended solids (TSS) removal. Two-year average ammonia effluents were 4.1 mg·L for Columbia WWTP, 4 mg·L for Larchmont WWTP and 2.1 mg·L for Laurelville WWTP, respectively. Two- year average BOD effluents were 6.8, 4.9 and 2.7 mg·L , and TSS effluents were 15.0, 9.6 and 7.5 mg·L . The systems also showed low fecal coliform (FC) levels in their effluents.

关键词: wastewater lagoons     wastewater biological treatment     ammonia removal     high surface area media     fine bubble aeration    

NO hydrogenation to NH over FeCu/TiO catalyst with improved activity

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1973-1985 doi: 10.1007/s11705-023-2364-2

摘要: Ammonia is crucial in industry and agriculture, but its production is hindered by environmental concerns and energy-intensive processes. Hence, developing an efficient and environmentally friendly catalyst is imperative. In this study, we employed a straightforward and efficient impregnation technique to create various Cu-doped catalysts. Notably, the optimized 10Fe-8Cu/TiO2 catalyst exhibited exceptional catalytic performance in converting NO to NH3, achieving an NO conversion rate exceeding 80% and an NH3 selectivity exceeding 98% at atmospheric pressure and 350 °C. We employed in situ diffuse reflectance Fourier transform infrared spectroscopy and conducted density functional theory calculations to investigate the intermediates and subsequent adsorption. Our findings unequivocally demonstrate that Cu doping enhances the rate-limiting hydrogenation step and lowers the energy barrier for NH3 desorption, thereby resulting in improved NO conversion and enhanced selectivity toward ammonia. This study presents a pioneering approach toward energy-efficient ammonia synthesis and recycling of nitrogen sources.

关键词: NO hydrogenation     synthetic ammonia     10Fe-xCu/TiO2     high selectivity    

Influencing mechanism of high solid concentration on anaerobic mono-digestion of sewage sludge without

Yuyao ZHANG,Huan LI,Can LIU,Yingchao CHENG

《环境科学与工程前沿(英文)》 2015年 第9卷 第6期   页码 1108-1116 doi: 10.1007/s11783-015-0806-x

摘要: High-solids anaerobic digestion of sewage sludge was a promising process, but high solid concentration negatively influenced methane production. The influencing mechanism was systematically analyzed in this study through a series of static anaerobic digestion experiments at total solids (TS) contents of 3%–15%. The results showed that TS 6% was the boundary between low-solids and high-solids anaerobic digestion, and the accumulative methane yield decreased exponentially when TS increased from 6% to 15%. The performance of anaerobic digestion was directly determined by the efficiency of mass transfer, and the relation between methane yield and sludge diffusive coefficients was well described by a power function. Thus, the increasing TS resulted in an exponential increase in sludge viscosity but an exponential decrease in diffusive coefficient. The blocked mass transfer led to the accumulation of volatile fatty acids (VFAs) and free ammonia. Acetic metabolism was the main process, whereas butyric and propionic metabolisms occurred at the initial stage of high-solids anaerobic digestion. The concentration of VFAs reached the maximum at the initial stage, which were still lower than the threshold influencing methanogens. The concentration of free ammonia increased gradually, and the methanogenesis was inhibited when free ammonia nitrogen exceeded 50 mg·L . Consequently, the deterioration of high-solids anaerobic digestion was related to the blocked mass transfer and the resulting ammonia accumulation.

关键词: anaerobic digestion     methane     sewage sludge     volatile fatty acids     free ammonia    

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 286-292 doi: 10.1007/s11709-007-0037-8

摘要: The suspendome used as the roof of the VIP hall in Tianjin Museum was analyzed by ANASYS under the assumptions of hinged joints and rigid joints in up chord, respectively, and the results show that the member force and nodal displacement under the two assumptions have little difference. Thus, it is attained that the suspendome can be analyzed with the assumption of hinged joints. A full-scale test on the suspendome with half-cable and half-pipe was carried out. The loading system, arrangement of measuring points, and the test procedures are introduced. Also, a test on steel wire ropes for elastic module was carried out. The experimental and theoretical values of member forces and nodal displacements were compared and it showed that they accord well with each other under low-level load. While under high-level load, the experimental value was bigger than the theoretical value due to the influence of the test environment. With the increase of the load, tension of outside cables and looseness of inside cables occurred, which indicated that the prestressing value in inside cables should be properly assigned. Both the experimental and theoretical results verify that the suspendome has a wide application prospect with the advantages of perfect mechanical characteristics, low steel consumption, convenient construction and low cost.

关键词: Tianjin     influence     displacement     high-level     low-level    

用于微光摄像的高灵敏度电子轰击电荷耦器件

周立伟,刘广荣,高稚允,王仲春

《中国工程科学》 1999年 第1卷 第3期   页码 56-62

摘要:

文章综述微光成像的电子轰击电荷耦合器件(EBCCD)的进展。EBCCD是将像管的荧光屏以对电子灵敏的背照明、减薄CCD代替,将电子图像直接转变为视频信号,其在所有光照等级下,特别是在极低微光下的调制传递函数(MTF)、分辨力、信噪比、余辉等均优于像增强器耦合CCD(ICCD)。文中较为详细地叙述了倒像式EBCCD设计与减薄工艺,给出各种类型倒像式EBCCD像管的技术参数,分析和比较了近贴式与倒像式EBCCD与ICCD的性能,指出了EBCCD在军用夜视技术与民用技术未来发展中的地位与重要性。

关键词: 微光成像     电荷耦合器件     电子轰击CCD    

标题 作者 时间 类型 操作

Experimental and kinetic study on laminar flame speeds of ammonia/syngas/air at a high temperature and

期刊论文

Impact of preozonation on the bioactivity and biodiversity of subsequent biofilters under low temperature conditions—A pilot study

Jiaxuan YANG, Jun MA, Dan SONG, Xuedong ZHAI, Xiujuan KONG

期刊论文

Nitrification and denitrification in biological activated carbon filter for treating high ammonia source

LIU Jianguang, ZHANG Xiaojian, WANG Zhansheng

期刊论文

The carbon dioxide removal potential of Liquid Air Energy Storage: A high-level technical and economic

Andrew LOCKLEY, Ted von HIPPEL

期刊论文

高放废物地质处置:进展与挑战

王驹

期刊论文

Abundance and distribution of ammonia-oxidizing archaea in Tibetan and Yunnan plateau agricultural soils

Kun DING,Xianghua WEN,Liang CHEN,Daishi HUANG,Fan FEI,Yuyang LI

期刊论文

Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

期刊论文

Simulation on thermodynamic state of ammonia carbonation at low temperature and low pressure

Jingcai ZHAO, Xingfu SONG, Ze SUN, Jianguo YU

期刊论文

Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power

Peng ZHENG, Xuan YAO, Wei ZHENG

期刊论文

Enhancement on the ammonia oxidation capacity of ammonia-oxidizing archaeon originated from wastewater

期刊论文

Upgrade of three municipal wastewater treatment lagoons using a high surface area media

John WANG, Peng JIN, Paul L. BISHOP, Fuzhi LI

期刊论文

NO hydrogenation to NH over FeCu/TiO catalyst with improved activity

期刊论文

Influencing mechanism of high solid concentration on anaerobic mono-digestion of sewage sludge without

Yuyao ZHANG,Huan LI,Can LIU,Yingchao CHENG

期刊论文

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

期刊论文

用于微光摄像的高灵敏度电子轰击电荷耦器件

周立伟,刘广荣,高稚允,王仲春

期刊论文