资源类型

期刊论文 303

会议视频 6

年份

2024 1

2023 39

2022 41

2021 29

2020 19

2019 20

2018 21

2017 6

2016 10

2015 12

2014 6

2013 10

2012 10

2011 13

2010 16

2009 13

2008 12

2007 16

2006 2

2005 2

展开 ︾

关键词

低成本 2

催化剂 2

反应模型 2

增材制造 2

热力学 2

能源 2

&alpha 1

4D打印 1

5G 1

Al-Cr203体系 1

COVID-19 1

DNA计算 1

F-B双相钢 1

GPS 1

K平均聚类 1

PCR核酸检测 1

Pd局域环境 1

RGB-D 1

TiC 1

展开 ︾

检索范围:

排序: 展示方式:

Dual-reaction-center catalytic process continues Fenton’s story

Chao Lu, Kanglan Deng, Chun Hu, Lai Lyu

《环境科学与工程前沿(英文)》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1261-x

摘要: Abstract • Dual-reaction-center (DRC) system breaks through bottleneck of Fenton reaction. • Utilization of intrinsic electrons of pollutants is realized in DRC system. • DRC catalytic process well continues Fenton’s story. Triggered by global water quality safety issues, the research on wastewater treatment and water purification technology has been greatly developed in recent years. The Fenton technology is particularly powerful due to the rapid attack on pollutants by the generated hydroxyl radicals (•OH). However, both heterogeneous and homogeneous Fenton/Fenton-like technologies follow the classical reaction mechanism, which depends on the oxidation and reduction of the transition metal ions at single sites. So even after a century of development, this reaction still suffers from its inherent bottlenecks in practical application. In recent years, our group has been focusing on studying a novel heterogeneous Fenton catalytic process, and we developed the dual-reaction-center (DRC) system for the first time. In the DRC system, H2O2 and O2 can be efficiently reduced to reactive oxygen species (ROS) in electron-rich centers, while pollutants are captured and oxidized by the electron-deficient centers. The obtained electrons from pollutants are diverted to the electron-rich centers through bonding bridges. This process breaks through the classic Fenton mechanism, and improves the performance and efficiency of pollutant removal in a wide pH range. Here, we provide a brief overview of Fenton’s story and focus on combing the discovery and development of the DRC technology and mechanism in recent years. The construction of the DRC and its performance in the pollutant degradation and interfacial reaction process are described in detail. We look forward to bringing a new perspective to continue Fenton’s story through research and development of DRC technology.

关键词: Dual reaction centers     Fenton     Pollutant utilization     Electron transfer    

Facile route to achieve MoSe-NiSe on nickel foam as efficient dual functional electrocatalysts for overall

《能源前沿(英文)》 2022年 第16卷 第3期   页码 483-491 doi: 10.1007/s11708-022-0813-0

摘要: Since the catalytic activity of present nickel-based synthetic selenide is still to be improved, MoSe2-Ni3Se2 was synthesized on nickel foam (NF) (MoSe2-Ni3Se2/NF) by introducing a molybdenum source. After the molybdenum source was introduced, the surface of the catalyst changed from a single-phase structure to a multi-phase structure. The catalyst surface with enriched active sites and the synergistic effect of MoSe2 and Ni3Se2 together enhance the hydrogen evolution reactions (HER), the oxygen evolution reactions (OER), and electrocatalytic total water splitting activity of the catalyst. The overpotential of the MoSe2-Ni3Se2/NF electrocatalyst is only 259 mV and 395 mV at a current density of 100 mA/cm2 for HER and OER, respectively. MoSe2-Ni3Se2/NF with a two-electrode system attains a current density of 10 mA/cm2 at 1.60 V. In addition, the overpotential of HER and OER of MoSe2-Ni3Se2/NF within 80000 s and the decomposition voltage of electrocatalytic total water decomposition hardly changed, showing an extremely strong stability. The improvement of MoSe2-Ni3Se2/NF catalytic activity is attributed to the establishment of the multi-phase structure and the optimized inoculation of the multi-component and multi-interface.

关键词: three-dimensional molybdenum nanomaterials     hydrogen evolution reaction     oxygen evolution reaction     overall water splitting    

Microfluidic dual loops reactor for conducting a multistep reaction

Si Hyung Jin, Jae-Hoon Jung, Seong-Geun Jeong, Jongmin Kim, Tae Jung Park, Chang-Soo Lee

《化学科学与工程前沿(英文)》 2018年 第12卷 第2期   页码 239-246 doi: 10.1007/s11705-017-1680-9

摘要: Precise control of each individual reaction that constitutes a multistep reaction must be performed to obtain the desired reaction product efficiently. In this work, we present a microfluidic dual loops reactor that enables multistep reaction by integrating two identical loop reactors. Specifically, reactants A and B are synthesized in the first loop reactor and transferred to the second loop reactor to synthesize with reactant C to form the final product. These individual reactions have nano-liter volumes and are carried out in a stepwise manner in each reactor without any cross-contamination issue. To precisely control the mixing efficiency in each loop reactor, we investigate the operating pressure and the operating frequency on the mixing valves for rotary mixing. This microfluidic dual loops reactor is integrated with several valves to realize the fully automated unit operation of a multistep reaction, such as metering the reactants, rotary mixing, transportation, and collecting the product. For proof of concept, CdSeZn nanoparticles are successfully synthesized in a microfluidic dual loops reactor through a fully automated multistep reaction. Taking all of these features together, this microfluidic dual loops reactor is a general microfluidic screening platform that can synthesize various materials through a multistep reaction.

关键词: microfluidics     multistep reaction     rotary mixing     nanoparticle    

Analysis of the treatment outcomes of esophageal variceal bleeding patients from multiple centers in

WANG Zhiqiang

《医学前沿(英文)》 2008年 第2卷 第2期   页码 171-173 doi: 10.1007/s11684-008-0031-0

摘要: This study aimed to investigate the treatment outcomes of esophageal variceal bleeding (EVB) in China. A total of 1087 cases were collected from 19 hospitals in 16 large and medium sized cities across China between January 1st, 2005 and January 1st, 2006. There were 313 cases (29.0%) of mild (<400 mL), 494 cases (45.8%) of moderate (400–1500 mL) and 272 cases (25.2%) of severe (>1500 mL) bleeding. Successful hemostasis was achieved in 89.8% of cases. Seven hundred and eighty-five cases were treated by medication with a hemostasis rate of 91.8%. Seventy-one cases were treated using a Sengstaken-Blakemore tube with a hemostasis rate of 54.9%. Thirty-seven cases were treated with emergency endoscopic variceal ligation with a hemostasis rate of 83.8%. Seventy-seven cases were treated with endoscopic sclerotherapy with a hemostasis rate of 94.8%. Forty-three cases were treated with emergency surgical operation with a hemostasis rate of 95.3%. Sixty-six cases were treated with combined therapy with a hemostasis rate of 97.0%. There was a significant difference ( < 0.01) in the successful hemostasis rate between different treatments. The overall mortality was 10.1%, among which 6.6% was directly caused by bleeding. The multivariate logistic regression analysis shows that the severity of bleeding, treatment methods, liver dysfunction and activation of hepatitis were predictive factors for successful hemostasis. Most cases of EVB were mild and moderate in severity. The first-line treatment for EVB is medication. Emergency endoscopic intervention has not been widely available yet. The overall management outcome of EVB has been improved.

关键词: significant difference     predictive     medication     first-line treatment     bleeding    

Multi-timescale optimization scheduling of interconnected data centers based on model predictive control

《能源前沿(英文)》 doi: 10.1007/s11708-023-0912-6

摘要: With the promotion of “dual carbon” strategy, data center (DC) access to high-penetration renewable energy sources (RESs) has become a trend in the industry. However, the uncertainty of RES poses challenges to the safe and stable operation of DCs and power grids. In this paper, a multi-timescale optimal scheduling model is established for interconnected data centers (IDCs) based on model predictive control (MPC), including day-ahead optimization, intraday rolling optimization, and intraday real-time correction. The day-ahead optimization stage aims at the lowest operating cost, the rolling optimization stage aims at the lowest intraday economic cost, and the real-time correction aims at the lowest power fluctuation, eliminating the impact of prediction errors through coordinated multi-timescale optimization. The simulation results show that the economic loss is reduced by 19.6%, and the power fluctuation is decreased by 15.23%.

关键词: model predictive control     interconnected data center     multi-timescale     optimized scheduling     distributed power supply     landscape uncertainty    

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 475-489 doi: 10.15302/J-FASE-2022459

摘要:

● Virtual joint centers on N agronomy were established between UK and China.

关键词: CINAg     N-CIRCLE     nitrogen use efficiency     reactive nitrogen     sustainable production    

A novel task-oriented framework for dual-arm robotic assembly task

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 528-545 doi: 10.1007/s11465-021-0638-2

摘要: In industrial manufacturing, the deployment of dual-arm robots in assembly tasks has become a trend. However, making the dual-arm robots more intelligent in such applications is still an open, challenging issue. This paper proposes a novel framework that combines task-oriented motion planning with visual perception to facilitate robot deployment from perception to execution and finish assembly problems by using dual-arm robots. In this framework, visual perception is first employed to track the effects of the robot behaviors and observe states of the workpieces, where the performance of tasks can be abstracted as a high-level state for intelligent reasoning. The assembly task and manipulation sequences can be obtained by analyzing and reasoning the state transition trajectory of the environment as well as the workpieces. Next, the corresponding assembly manipulation can be generated and parameterized according to the differences between adjacent states by combining with the prebuilt knowledge of the scenarios. Experiments are set up with a dual-arm robotic system (ABB YuMi and an RGB-D camera) to validate the proposed framework. Experimental results demonstrate the effectiveness of the proposed framework and the promising value of its practical application.

关键词: dual-arm assembly     AI reasoning     intelligent system     task-oriented motion planning     visual perception    

Improved nitrogen removal in dual-contaminated surface water by photocatalysis

Yongming ZHANG, Rong YAN, Zhen ZOU, Jiewei WANG, Bruce E. RITTMANN

《环境科学与工程前沿(英文)》 2012年 第6卷 第3期   页码 428-436 doi: 10.1007/s11783-012-0401-3

摘要: River waters in China have dual contamination by nutrients and recalcitrant organic compounds. In principle, the organic compounds could be used to drive denitrification of nitrate, thus arresting eutrophication potential, if the recalcitrant organics could be made bioavailable. This study investigated the potential to make the recalcitrant organics bioavailable through photocatalysis. Batch denitrification tests in a biofilm reactor demonstrated that dual-contaminated river water was short of available electron donor, which resulted in low total nitrogen (TN) removal by denitrification. However, the denitrification rate was increased significantly by adding glucose or by making the organic matters of the river water more bioavailable through photocatalysis. Photocatalysis for 15 min increased the Chemical Oxygen Demand (COD) of the river water from 53 to 84 mg·L and led to a 4-fold increase in TN removal. The increase in TN removal gave the same effect as adding 92 mg·L of glucose. During the photocatalysis experiments, the COD increased because photocatalysis transformed organic molecules from those that are resistant to dichromate oxidation in the COD test to those that can be oxidized by dichromate. This phenomenon was verified by testing photocatalysis of pyridine added to the river water. These findings point to the potential for N removal via denitrification after photocatalysis, and they also suggest that the rivers in China may be far more polluted than indicated by COD assays.

关键词: dual contamination     eutrophication     photocatalysis     remediation     surface water    

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1700-1712 doi: 10.1007/s11705-022-2207-6

摘要: The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha. Herein, for a better catalyst design and operation parameters optimization, the reaction pathways and equilibrium yields for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins were analyzed thermodynamically. The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways, respectively. However, the formation of light paraffin severely limits the maximum selectivity toward light olefins. The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins. The results are thus useful as a direction for future catalyst improvements, facilitating superior reaction pathways to enhance light olefins. In addition, the equilibrium yield of light olefins increased with increasing the chain length, and the introduction of cyclo-paraffin inhibits the formation of light olefins. High temperatures and low pressures favor the formation of ethylene, and moderate temperatures and low pressures favor the formation of propylene. n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90% and 55.77%, respectively. This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词: naphtha     catalytic pyrolysis     reaction pathway     equilibrium yield    

Development of a dual temperature control system for isoprene biosynthesis in

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1079-1089 doi: 10.1007/s11705-021-2088-0

摘要: Conflict between cell growth and product accumulation is frequently encountered in the biosynthesis of secondary metabolites. To address the growth-production conflict in yeast strains harboring the isoprene synthetic pathway in the mitochondria, the dynamic control of isoprene biosynthesis was explored. A dual temperature regulation system was developed through engineering and expression regulation of the transcriptional activator Gal4p. A cold-sensitive mutant, Gal4ep19, was created by directed evolution of Gal4p based on an internally developed growth-based high-throughput screening method and expressed under the heat-shock promoter PSSA4 to control the expression of PGAL-driven pathway genes in the mitochondria. Compared to the control strain with constitutively expressed wild-type Gal4p, the dual temperature regulation strategy led to 34.5% and 72% improvements in cell growth and isoprene production, respectively. This study reports the creation of the first cold-sensitive variants of Gal4p by directed evolution and provides a dual temperature control system for yeast engineering that may also be conducive to the biosynthesis of other high-value natural products.

关键词: transcriptional activator     directed evolution     dynamic control     heat-shock     isoprene    

基于双CPU结构的数据监控系统设计

贾贵玺,齐乐

《中国工程科学》 2006年 第8卷 第4期   页码 68-71

摘要:

针对通信系统中,对所有客户线路的电压、电流、温度等数据进行实时多路采集监控,提出了一种基于双CPU结构的数据监控系统的设计方法以及硬件组成。讨论了系统主要芯片之间的连线方法以及软件流程。该系统已经成功应用在邮电系统48V通信线路监控。实践证明,双CPU设计方案不仅满足了系统高运算量、高实时性、抗干扰性要求,而且优化了软硬件设计。

关键词: 数据监控     双CPU     双口RAM    

Experimental study of stratified lean burn characteristics on a dual injection gasoline engine

Chun XIA, Tingyu ZHAO, Junhua FANG, Lei ZHU, Zhen HUANG

《能源前沿(英文)》 2022年 第16卷 第6期   页码 900-915 doi: 10.1007/s11708-021-0812-6

摘要: Due to increasingly stringent fuel consumption and emission regulation, improving thermal efficiency and reducing particulate matter emissions are two main issues for next generation gasoline engine. Lean burn mode could greatly reduce pumping loss and decrease the fuel consumption of gasoline engines, although the burning rate is decreased by higher diluted intake air. In this study, dual injection stratified combustion mode is used to accelerate the burning rate of lean burn by increasing the fuel concentration near the spark plug. The effects of engine control parameters such as the excess air coefficient (Lambda), direct injection (DI) ratio, spark interval with DI, and DI timing on combustion, fuel consumption, gaseous emissions, and particulate emissions of a dual injection gasoline engine are studied. It is shown that the lean burn limit can be extended to Lambda= 1.8 with a low compression ratio of 10, while the fuel consumption can be obviously improved at Lambda= 1.4. There exists a spark window for dual injection stratified lean burn mode, in which the spark timing has a weak effect on combustion. With optimization of the control parameters, the brake specific fuel consumption (BSFC) decreases 9.05% more than that of original stoichiometric combustion with DI as 2 bar brake mean effective pressure (BMEP) at a 2000 r/min engine speed. The NOx emissions before three-way catalyst (TWC) are 71.31% lower than that of the original engine while the particle number (PN) is 81.45% lower than the original engine. The dual injection stratified lean burn has a wide range of applications which can effectively reduce fuel consumption and particulate emissions. The BSFC reduction rate is higher than 5% and the PN reduction rate is more than 50% with the speed lower than 2400 r/min and the load lower than 5 bar.

关键词: dual injection     stratified lean burn     gasoline engine     particulate matter emission     combustion analysis    

Optimization of the power, efficiency and ecological function for an air-standard irreversible Dual-Miller

Zhixiang WU, Lingen CHEN, Yanlin GE, Fengrui SUN

《能源前沿(英文)》 2019年 第13卷 第3期   页码 579-589 doi: 10.1007/s11708-018-0557-z

摘要: This paper establishes an irreversible Dual-Miller cycle (DMC) model with the heat transfer (HT) loss, friction loss (FL) and other internal irreversible losses. To analyze the effects of the cut-off ratio ( ) and Miller cycle ratio ( ) on the power output ( ), thermal efficiency ( ) and ecological function ( ), obtain the optimal and optimal , and compare the performance characteristics of DMC with its simplified cycles and with different optimization objective functions, the , and of irreversible DMC are analyzed and optimized by applying the finite time thermodynamic (FTT) theory. Expressions of , and are derived. The relationships among , , and compression ratio ( ) are obtained by numerical examples. The effects of and on , , , maximum power output ( ), maximum efficiency ( ) and maximum ecological function ( ) are analyzed. Performance differences among the DMC, the Otto cycle (OC), the Dual cycle (DDC), and the Otto-Miller cycle (OMC) are compared for fixed design parameters. Performance characteristics of irreversible DMC with the choice of , and as optimization objective functions are analyzed and compared. The results show that the irreversible DMC engine can reach a twice-maximum power, a twice-maximum efficiency, and a twice-maximum ecological function, respectively. Moreover, when choosing as the optimization objective, there is a 5.2% of improvement in while there is a drop of only 2.7% in compared to choosing as the optimization objective. However, there is a 5.6% of improvement in while there is a drop of only 1.3% in compared to choosing as the optimization objective.

关键词: finite-time thermodynamics     Dual-Miller cycle     power output     thermal efficiency     ecological function    

Effects of fuel combination and IVO timing on combustion and emissions of a dual-fuel HCCI combustion

Xin LIANG, Jianyong ZHANG, Zhongzhao LI, Jiabo ZHANG, Zhen HUANG, Dong HAN

《能源前沿(英文)》 2020年 第14卷 第4期   页码 778-789 doi: 10.1007/s11708-020-0698-8

摘要: This paper experimentally and numerically studied the effects of fuel combination and intake valve opening (IVO) timing on combustion and emissions of an n-heptane and gasoline dual-fuel homogeneous charge compression ignition (HCCI) engine. By changing the gasoline fraction (GF) from 0.1 to 0.5 and the IVO timing from –15°CA ATDC to 35°CA ATDC, the in-cylinder pressure traces, heat release behaviors, and HC and CO emissions were investigated. The results showed that both the increased GF and the retarded IVO timing delay the combustion phasing, lengthen the combustion duration, and decrease the peak heat release rate and the maximum average combustion temperature, whereas the IVO timing has a more obvious influence on combustion than GF. HC and CO emissions are decreased with reduced GF, advanced IVO timing and increased operational load.

关键词: homogeneous charge compression ignition     dual-fuel     n-heptane     gasoline     intake valve opening timing    

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

《能源前沿(英文)》 2016年 第10卷 第4期   页码 473-478 doi: 10.1007/s11708-016-0420-z

摘要: A dual input LED lighting scheme with constant illumination is proposed in this paper. The scheme employs a photovoltaic array as the first input and a battery as the second one. A microcontroller is programmed to operate a changeover switch as well as a DC-DC converter for uninterrupted and constant illumination in work place. The scheme is suitable for conference halls, laboratories, clean rooms, marriage halls, theaters, etc. The complete modeling, design and experimentation of the proposed scheme are explained and the economic viability of the scheme is justified.

关键词: photovoltaic     LED light     dual input     P&O algorithm    

标题 作者 时间 类型 操作

Dual-reaction-center catalytic process continues Fenton’s story

Chao Lu, Kanglan Deng, Chun Hu, Lai Lyu

期刊论文

Facile route to achieve MoSe-NiSe on nickel foam as efficient dual functional electrocatalysts for overall

期刊论文

Microfluidic dual loops reactor for conducting a multistep reaction

Si Hyung Jin, Jae-Hoon Jung, Seong-Geun Jeong, Jongmin Kim, Tae Jung Park, Chang-Soo Lee

期刊论文

Analysis of the treatment outcomes of esophageal variceal bleeding patients from multiple centers in

WANG Zhiqiang

期刊论文

Multi-timescale optimization scheduling of interconnected data centers based on model predictive control

期刊论文

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN

期刊论文

A novel task-oriented framework for dual-arm robotic assembly task

期刊论文

Improved nitrogen removal in dual-contaminated surface water by photocatalysis

Yongming ZHANG, Rong YAN, Zhen ZOU, Jiewei WANG, Bruce E. RITTMANN

期刊论文

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

期刊论文

Development of a dual temperature control system for isoprene biosynthesis in

期刊论文

基于双CPU结构的数据监控系统设计

贾贵玺,齐乐

期刊论文

Experimental study of stratified lean burn characteristics on a dual injection gasoline engine

Chun XIA, Tingyu ZHAO, Junhua FANG, Lei ZHU, Zhen HUANG

期刊论文

Optimization of the power, efficiency and ecological function for an air-standard irreversible Dual-Miller

Zhixiang WU, Lingen CHEN, Yanlin GE, Fengrui SUN

期刊论文

Effects of fuel combination and IVO timing on combustion and emissions of a dual-fuel HCCI combustion

Xin LIANG, Jianyong ZHANG, Zhongzhao LI, Jiabo ZHANG, Zhen HUANG, Dong HAN

期刊论文

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

期刊论文