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Size-controllable synthesis of monodispersed nitrogen-doped carbon nanospheres from polydopamine for high-rate

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1788-1800 doi: 10.1007/s11705-023-2326-8

摘要: Monodispersed nitrogen-doped carbon nanospheres with tunable particle size (100–230 nm) were synthesized via self-polymerization of biochemical dopamine in the presence of hexamethylenetetramine as a buffer and F127 as a size controlling agent. Hexamethylenetetramine can mildly release NH3, which in turn initiates the polymerization reaction of dopamine. The carbon nanospheres obtained exhibited a significant energy storage capability of 265 F·g–1 at 0.5 A·g–1 and high-rate performance of 82% in 6 mol·L–1 KOH (20 A·g–1), which could be attributed to the presence of abundant micro-mesoporous structure, doped nitrogen functional groups and the small particle size. Moreover, the fabricated symmetric supercapacitor device displayed a high stability of 94% after 5000 cycles, revealing the considerable potential of carbon nanospheres as electrode materials for energy storage.

关键词: carbon nanospheres     size-controlled     nitrogen-doped     high-rate     supercapacitors    

Concept and application of anaerobic suspended granular sludge bed (SGSB) reactor for wastewater treatment

Mingxia ZHENG,Zhong YAN,Jiane ZUO,Kaijun WANG

《环境科学与工程前沿(英文)》 2014年 第8卷 第5期   页码 797-804 doi: 10.1007/s11783-013-0597-x

摘要: Bed expansion serves an important function in the design and operation of an upflow anaerobic reactor. An analysis of the flow pattern of expanded granular sludge bed (EGSB) reactors shows that most EGSB reactors do not behave as expanded bed reactors, as is widely perceived. Rather, these reactors behave as fluidized bed reactors based on the classic chemical reactor theory. In this paper, four bed expansion modes, divided as static bed, expanded bed, suspended bed, and fluidized bed, for bioreactors are proposed. A high-rate anaerobic suspended granular sludge bed (SGSB) reactor was then developed. The SGSB reactor is an upflow anaerobic reactor, and its expansion degree can be easily controlled within a range to maintain the suspended status of the sludge bed by controlling upflow velocity. The results of the full-scale reactor confirmed that the use of SGSB reactors is advantageous. The full-scale SGSB reactor runs stably and achieves high COD removal efficiency (about 90%) at high loading rates (average 40 kg-COD·m ·d , maximum to 52 kg-COD·m ·d ) based on the SGSB theory, and its expansion degree is between 22% and 37%.

关键词: expansion characteristic     high-rate bioreactor     anaerobic suspended granular sludge bed     expanded granular sludge bed reactor    

Petroleum pitch derived hard carbon via NaCl-template as anode materials with high rate performance for

《化学科学与工程前沿(英文)》 doi: 10.1007/s11705-024-2430-4

摘要: Sodium-ion batteries (SIBs) have garnered significant interest in energy storage due to their similar working mechanism to lithium ion batteries and abundant reserves of sodium resource. Exploring facile synthesis of a carbon-based anode materials with capable electrochemical performance is key to promoting the practical application of SIBs. In this work, a combination of petroleum pitch and recyclable sodium chloride is selected as the carbon source and template to obtain hard carbon (HC) anode for SIBs. Carbonization times and temperatures are optimized by assessing the sodium ion storage behavior of different HC materials. The optimized HC exhibits a remarkable capacity of over 430 mAh·g–1 after undergoing full activation through 500 cycles at a density of current of 0.1 A·g–1. Furthermore, it demonstrates an initial discharge capacity of 276 mAh·g–1 at a density of current of 0.5 A·g–1. Meanwhile, the optimized HC shows a good capacity retention (170 mAh·g–1 after 750 cycles) and a remarkable rate ability (166 mAh·g–1 at 2 A·g–1). The enhanced capacity is attributed to the suitable degree of graphitization and surface area, which improve the sodium ion transport and storage.

关键词: petroleum pitch     hard carbon     sodium-ion batteries     high rate     recyclable template    

Achievement of high rate nitritation with aerobic granular sludge reactors enhanced by sludge recirculation

Zulkifly JEMAAT,Josep Anton TORA,Albert BARTROLI,Julián CARRERA,Julio PEREZ

《环境科学与工程前沿(英文)》 2015年 第9卷 第3期   页码 528-533 doi: 10.1007/s11783-014-0641-5

摘要: A ratio control strategy has been used to demonstrate the feasibility of this automatic control procedure for the achievement of stable full and partial nitritation. The control strategy assured constant ratio between the dissolved oxygen (DO) and the total ammonia nitrogen (TAN) concentrations in the bulk liquid of aerobic granular sludge reactors operating in continuous mode. Three different set-ups with different reactor capacities were used (3, 110, and 150 L). High strength synthetic wastewaters and reject water were tested with similar performance. Achieved nitrogen loading rates ranged between 0.4 and 6.1 kgN·m ·d , at temperatures between 20°C and 30°C. Granular sludge and nitritation were stable in the long term continuous operation of the reactors. Suitable stable effluent for Anammox has been obtained using the desired TAN setpoint (i.e. 50% of influent ammonium oxidation). An existing biofilm model developed incorporating the implemented control loops and validated in a previous publication was used to investigate the effects of the ammonium concentration of the influent and the biofilm density on the achievement of full nitritation. The model demonstrated how sludge recirculation events led to a stable and significant increase of the biomass concentration in the reactor, which in turn resulted in the achievement of high nitrogen loading rates, due to the action of the control strategy. The model predicted an enhancement of stable full nitritation at higher ammonium concentrations in the influent. Poor influence of the biofilm density in the achievement of full nitritation was predicted with the model.

关键词: partial nitrification     reject water     high strength ammonium wastewater     closed-loop control    

The removal of trimethoprim and sulfamethoxazole by a high infiltration rate artificial composite soil

Qinqin Liu,Miao Li,Fawang Zhang,Hechun Yu,Quan Zhang,Xiang Liu

《环境科学与工程前沿(英文)》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0920-z

摘要: Artificial composite soil treatment system with the high infiltration rate (1.394 m·d ) had a good removal efficiency of TMP (80%–90%) and SMX (60%–70%). The removal mechanism of TMP and SMX was mainly sorption and was related with hydrogeochemical process. Sulfamethoxzole (SMX) and trimethoprim (TMP), two combined-using sulfonamide antibiotics, have gained increasing attention in the surface water, groundwater and the drinking water because of the ecological risk. The removal of TMP and SMX by artificial composite soil treatment system (ACST) with different infiltration rates was systematically investigated using K , Na , Ca , Mg hydrogeochemical indexes. Batch experiments showed that the sorption onto the low-cost and commercially available clay ceramsites was effective for the removal of SMX and TMP from water. The column with more silty clay at high infiltration rate (1.394 m·d ) had removal rates of 80% to 90% for TMP and 60% to 70% for SMX. High SMX and TMP removal rates had a higher effluent concentration of K , Ca and Mg and had a lower effluent Na concentration. Removal was strongly related to sorption. The results showed that the removal of SMX and TMP was related to hydrogeochemical processes. In this study, ACST is determined to be applicable to the drinking water plants.

关键词: Trimethoprim     Sulfamethoxazole     Artificial composite soil treatment     Hydrogeochemical processes     Ion exchange    

二极管泵浦的高重频脉冲固体激光器研究

周寿桓,姜东升

《中国工程科学》 2000年 第2卷 第1期   页码 53-56

摘要:

文章报道二极管泵浦的1 000Hz高重频、脉冲固体激光器的实验研究结果:双向端面泵浦,每个脉冲输出43mJ,近TEM00模,光-光转换效率η=43%。采用端面泵浦结构,在输出激光的效率、模式上都具有明显的优势,对工作物质冷却的结构也比较简单,且不会因为冷却而牺牲泵浦效率。

关键词: 脉冲固体激光器     端面泵浦     高重复频率    

铋基亲钠框架互穿钠金属负极实现无枝晶/高倍率钠离子电池

赵婉玉, 郭敏, 左志军, 赵晓莉, 窦湟琳, 张宜杰, 李时莹, 吴子辰, 石雅雲, 马紫峰, 杨晓伟

《工程(英文)》 2022年 第11卷 第4期   页码 89-96 doi: 10.1016/j.eng.2021.08.028

摘要:

具有高体积能量密度的钠(Na)金属电池非常需要能够在高倍率下运行的性能。然而在大倍率下,钠离子块体金属负极中不均匀且大量的迁移会导致金属的局部沉积/溶解,带来严重的枝晶生长和松散堆叠的问题。在本工作中,我们设计了具有亲钠性质的铋化钠/钠互穿金属负极(Na/Na3Bi)。与块体钠相比,这种互穿负极提供了强烈的Na+吸附能力和低的离子扩散势垒,确保了Na+的均匀成核和快速迁移,从而实现在高电流密度下的均匀沉积和溶解。此外,亲钠性的铋基材料能够保证金属钠沉积在框架的内部,实现金属的致密沉积,有利于提高体积容量。Na/Na3Bi 金属负极能够同时承受高电流密度(5 mA∙cm−2)和高循环容量(5 mA∙h∙cm−2),并且可以在2 mA∙cm−2的电流密度下长期(长达2800 h)稳定循环。

关键词: 钠金属负极     无枝晶负极     致密电沉积     亲钠性铋基材料     离子传输壁垒    

Progress on major genes for high fecundity in ewes

Qiuyue LIU,Zhangyuan PAN,Xiangyu WANG,Wenping HU,Ran DI,Yaxing YAO,Mingxing CHU

《农业科学与工程前沿(英文)》 2014年 第1卷 第4期   页码 282-290 doi: 10.15302/J-FASE-2014042

摘要: The existence of major genes affecting fecundity in sheep flocks throughout the world has been demonstrated. Three major genes whose mutations can increase ovulation rate have been discovered, and all related to the transforming growth factor β (TGF-β) superfamily. The mutant of bone morphogenetic protein receptor 1B (BMPR1B) has an additive effect on ovulation rate. Six mutations ( , , , , , ) of bone morphogenetic protein 15 (BMP15) related with fertility have been identified that share the same mechanism. All the mutants can increase ovulation rate in heterozygotes and cause complete sterility in homozygotes. Homozygous ewes with two new mutations ( ) of BMP15 had increased ovulation rate without causing sterility. There are five mutations in growth differentiation factor 9 (GDF9) associated with sheep prolificacy where and have additive an effect on ovulation rate and litter size. The newly identified β-1,4-N-acetylgalactosaminyltransferase 2 ( ) gene of is proposed as a new mechanism of ovulation rate regulation in sheep. is an X-linked maternally imprinted gene which increases ovulation rate. In addition, several putative major genes need to be verified. This review is focused on the identification of the mutations and mechanisms whereby the major genes affecting ovulation rate.

关键词: major gene     ovulation rate     sheep     reproduction    

Behavior of steel fiber–reinforced high-strength concrete at medium strain rate

Chujie JIAO, Wei SUN, Shi HUAN, Guoping JIANG

《结构与土木工程前沿(英文)》 2009年 第3卷 第2期   页码 131-136 doi: 10.1007/s11709-009-0027-0

摘要: Impact compression experiments for the steel fiber–reinforced high-strength concrete (SFRHSC) at medium strain rate were conducted using the split Hopkinson press bar (SHPB) testing method. The volume fractions of steel fibers of SFRHSC were between 0 and 3%. The experimental results showed that, when the strain rate increased from threshold value to 90 s , the maximum stress of SFRHSC increased about 30%, the elastic modulus of SFRHSC increased about 50%, and the increase in the peak strain of SFRHSC was 2-3 times of that in the matrix specimen. The strength and toughness of the matrix were improved remarkably because of the superposition effect of the aggregate high-strength matrix and steel fiber high-strength matrix. As a result, under impact loading, cracks developed in the SFRHSC specimen, but the overall shape of the specimen remained virtually unchanged. However, under similar impact loading, the matrix specimens were almost broken into small pieces.

关键词: steel fiber–reinforced high-strength concrete (SFRHSC)     high strain rates     split Hopkinson press bar (SHPB)     strain rate hardening effects    

Microbial community dynamics at high organic loading rates revealed by pyrosequencing during sugar refinery

Liguo Zhang, Qiaoying Ban, Jianzheng Li

《环境科学与工程前沿(英文)》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1045-8

摘要:

High strength sugar refinery wastewater was treated in a mesophilic UASB.

Pyrosequencing reveals microbial community succession with OLR increase.

Diversity of microbial communities in OLR12 is much higher than those in OLR36 and OLR54.0 kgCOD/(kg VSS·d).

Fermentative bacteria could deal with increasing OLR through the increase of microbial diversity and quantity.

Hydrogen-producing acotogens and methanogens mainly coped with high OLR shocks by increasing the quantity of community

关键词: Upflow anaerobic sludge blanket     Sugar refinery wastewater     Organic loading rate     Pyrosequencing     Microbial community structure    

Reconsideration on the effect of nitrogen on mixed culture polyhydroxyalkanoate production toward high

Zhiqiang Chen, Lizhi Zhao, Ye Ji, Qinxue Wen, Long Huang

《环境科学与工程前沿(英文)》 2019年 第13卷 第4期 doi: 10.1007/s11783-019-1135-2

摘要:

Effect of nitrogen on mixed culture PHA production was reconsidered.

Enrichment history of PHA accumulating culture was discussed.

Higher PHA content and biomass growth were achieved in presence of nitrogen.

Enrichment strategy toward higher PHA accumulation was investigated.

Microbial community succession in PHA accumulation phase was investigated.

关键词: Polyhydroxyalkanoate (PHA)     Organic loading rate     Nitrogen content     Biomass growth     Enrichment history    

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1411-9

摘要:

• Actual SAORs was determined using MLVSS and temperature.

关键词: Specific ammonia oxidation rate     Sequencing batch reactor     Biomass     Temperature coefficient     Model simulation    

Use of float consumption rate in resource leveling of construction projects

Atilla DAMCI, Gul POLAT, Firat Dogu AKIN, Harun TURKOGLU

《工程管理前沿(英文)》 2022年 第9卷 第1期   页码 135-147 doi: 10.1007/s42524-020-0118-0

摘要: The management of resources has been claimed to be as important as scheduling methods. Inefficiency in managing resources may bring about severe delays and cost overruns caused by resource shortages in some cases and/or idle resources in others. Therefore, resources should be utilized efficiently to prevent project failures. Resource leveling is one of the approaches that are used for the management of resources. It aims to minimize fluctuations, peaks, and valleys in resource utilization without changing the completion time of a project and the number of resources required. Although the main principle behind traditional resource leveling is achieving an even flow of resources while the original project duration remains unchanged, the literature supports the need to develop an efficient model that discriminates among the activities that are selected for participation in resource leveling. For this purpose, this study has developed a model that considers the float consumption rates of activities in resource leveling. The float consumption rate is the percentage that is set to determine the maximum amount of float which will be consumed to shift the start time of the activity. The proposed model allows a scheduler to assign float consumption rates to each activity that can be used during the resource leveling procedure. When the required information is inputted, the proposed model automatically changes the required daily resources as it shifts the noncritical activities along their available total float times. The proposed model is expected to minimize the likelihood of severe delays and cost overruns. The model is demonstrated by constructing a network and its resource utilization histograms.

关键词: resource management     resource leveling     float consumption rate     scheduling    

Performance of soft-hard-soft (SHS) cement based composite subjected to blast loading with consideration of interface properties

Jun WU,Xuemei LIU

《结构与土木工程前沿(英文)》 2015年 第9卷 第3期   页码 323-340 doi: 10.1007/s11709-015-0301-2

摘要: This paper presents a combined experimental and numerical study on the damage and performance of a soft-hard-soft (SHS) multi-layer cement based composite subjected to blast loading which can be used for protective structures and infrastructures to resist extreme loadings, and the composite consists of three layers of construction materials including asphalt concrete (AC) on the top, high strength concrete (HSC) in the middle, and engineered cementitious composites (ECC) at the bottom. To better characterize the material properties under dynamic loading, interface properties of the composite were investigated through direct shear test and also used to validate the interface model. Strain rate effects of the asphalt concrete were also studied and both compressive and tensile dynamic increase factor (DIF) curves were improved based on split Hopkinson pressure bar (SHPB) test. A full-scale field blast test investigated the blast behavior of the composite materials. The numerical model was established by taking into account the strain rate effect of all concrete materials. Furthermore, the interface properties were also considered into the model. The numerical simulation using nonlinear finite element software LS-DYNA agrees closely with the experimental data. Both the numerical and field blast test indicated that the SHS composite exhibited high resistance against blast loading.

关键词: high strength concrete (SHS)     engineered cementitious composite     interface     blast test     strain rate effect    

Effect of loading rate on shear strength parameters of mechanically and biologically treated waste

《环境科学与工程前沿(英文)》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1595-7

摘要:

● Mechanical behavior of MBT waste affected by loading rate was investigated.

关键词: Mechanically and biologically treated waste     Landfill     Triaxial test     Loading rate     Axial strain     Shear strength parameter    

标题 作者 时间 类型 操作

Size-controllable synthesis of monodispersed nitrogen-doped carbon nanospheres from polydopamine for high-rate

期刊论文

Concept and application of anaerobic suspended granular sludge bed (SGSB) reactor for wastewater treatment

Mingxia ZHENG,Zhong YAN,Jiane ZUO,Kaijun WANG

期刊论文

Petroleum pitch derived hard carbon via NaCl-template as anode materials with high rate performance for

期刊论文

Achievement of high rate nitritation with aerobic granular sludge reactors enhanced by sludge recirculation

Zulkifly JEMAAT,Josep Anton TORA,Albert BARTROLI,Julián CARRERA,Julio PEREZ

期刊论文

The removal of trimethoprim and sulfamethoxazole by a high infiltration rate artificial composite soil

Qinqin Liu,Miao Li,Fawang Zhang,Hechun Yu,Quan Zhang,Xiang Liu

期刊论文

二极管泵浦的高重频脉冲固体激光器研究

周寿桓,姜东升

期刊论文

铋基亲钠框架互穿钠金属负极实现无枝晶/高倍率钠离子电池

赵婉玉, 郭敏, 左志军, 赵晓莉, 窦湟琳, 张宜杰, 李时莹, 吴子辰, 石雅雲, 马紫峰, 杨晓伟

期刊论文

Progress on major genes for high fecundity in ewes

Qiuyue LIU,Zhangyuan PAN,Xiangyu WANG,Wenping HU,Ran DI,Yaxing YAO,Mingxing CHU

期刊论文

Behavior of steel fiber–reinforced high-strength concrete at medium strain rate

Chujie JIAO, Wei SUN, Shi HUAN, Guoping JIANG

期刊论文

Microbial community dynamics at high organic loading rates revealed by pyrosequencing during sugar refinery

Liguo Zhang, Qiaoying Ban, Jianzheng Li

期刊论文

Reconsideration on the effect of nitrogen on mixed culture polyhydroxyalkanoate production toward high

Zhiqiang Chen, Lizhi Zhao, Ye Ji, Qinxue Wen, Long Huang

期刊论文

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic

期刊论文

Use of float consumption rate in resource leveling of construction projects

Atilla DAMCI, Gul POLAT, Firat Dogu AKIN, Harun TURKOGLU

期刊论文

Performance of soft-hard-soft (SHS) cement based composite subjected to blast loading with consideration of interface properties

Jun WU,Xuemei LIU

期刊论文

Effect of loading rate on shear strength parameters of mechanically and biologically treated waste

期刊论文