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开放的复杂巨系统 4

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Synthesis of ordered cerium-doped cubic mesoporous silica using long-chain ionic liquid as template

YUE Hongxia, ZHAO Hongmei, LIU Longjiang, WANG Siping, Ruan Qiong, WANG Tongwen

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 135-139 doi: 10.1007/s11705-008-0031-2

摘要: The long-chain ionic liquid 1-hexadecyl-3-methylimidazolium chloride (CmimCl) was used as a template to prepare cerium-doped MCM-48 materials in basic medium by a hydrothermal synthesis procedure. The effect of the amount of Ce salt and CmimCl/Si on the synthesis were discussed in detail. This mesoporous material exhibits a pore architecture which is cubic 3 gyroid and possesses a large surface area and a narrow pore distribution. Cerium in calcined porous framework exists in the form of well-dispersed tetrahedral coordination. The CmimCl shows a high tendency toward self-aggregation that allows the formation of the cerium-doped gyroid mesostructure by using the appropriate amount of Ce salt.

关键词: mesoporous     CmimCl/Si     tendency     mesostructure     synthesis procedure    

Systematic screening procedure and innovative energy-saving design for ionic liquid-based extractive

《化学科学与工程前沿(英文)》 2023年 第17卷 第1期   页码 34-45 doi: 10.1007/s11705-022-2234-3

摘要: In the traditional extractive distillation process, organic solvents are often used as entrainers. However, environmental influence and high energy-consumption are significant problems in industrial application. In this study, a systematic screening strategy and innovative energy-saving design for ionic liquid-based extractive distillation process was proposed. The innovative energy-saving design focused on the binary minimum azeotrope mixtures isopropanol and water. Miscibility, environmental impact and physical properties (e.g., melting point and viscosity) of 30 ionic liquids were investigated. 1-Ethyl-3-methyl-imidazolium dicyanamide and 1-butyl-3-methyl-imidazolium dicyanamide were selected as candidate entrainers. Feasibility analysis of these two ionic liquids was further performed via residue curve maps, isovolatility line and temperature profiles. An innovative ionic liquid-based extractive distillation process combining distillation column and stripping column was designed and optimized with the objective function of minimizing the total annualized cost. The results demonstrate that the total annualized cost was reduced by 19.9% with 1-ethyl-3-methyl-imidazolium dicyanamide as the entrainer and by 24.3% with 1-butyl-3-methyl-imidazolium dicyanamide, compared with that of dimethyl sulfoxide. The method proposed in this study is conducive to the green and sustainable development of extractive distillation process.

关键词: ionic liquid     entrainer screening     feasibility analysis     extractive distillation    

Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

《医学前沿(英文)》 2008年 第2卷 第3期   页码 244-247 doi: 10.1007/s11684-008-0046-6

摘要: Shunts and devascularizations have totally different effects on the hemodynamics of the portal venous system. The actual results of pericardial devascularization (PCDV) alone and conventional splenorenal shunt combined with pericardial devascularization (combined procedure, CP) should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics in the portal venous system after CP and PCDV only. In 20 patients who received CP and 18 who received PCDV, hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure (FPP) was continuously detected by a transducer during the operations. Compared to the preoperative data, a decreased flow in the portal vein (PVF) [(563.12 ± 206.42) mL/min (1080.63 ± 352.85) mL/min, < 0.05], a decreased portal vein diameter (PVD) [(1.20 ± 0.11) cm (1.30 ± 0.16) cm, < 0.01], a decreased FPP [(21.50 ± 2.67) mmHg (29.88 ± 2.30) mmHg, < 0.01] and an increased flow in the superior mesenteric vein (SMVF) [(1105.45 ± 309.03) mL/min (569.13 ± 178.46) mL/min, < 0.05] were found in the CP group after operation; a decreased PVD [(1.27 ± 0.16) cm (1.40 ± 0.23) cm, < 0.05], a decreased PVF [(684.60 ± 165.73) mL/min (1175.64 ± 415.09) mL/min, < 0.05], a decreased FPP [(24.40 ± 3.78) mmHg (28.80 ± 3.56) mmHg, < 0.05] and an increased SMVF [(697.91 ± 121.83) mL/min (521.30 ± 115.82) mL/min, < 0.05] were observed in the PCDV group. After operation, PVF in the CP group [(563.12 ± 206.42) mL/min (684.60 ± 165.73) mL/min, > 0.05] had no significant decrease, while FPP [(21.50 ± 2.67) mmHg (24.40 ± 3.78) mmHg, < 0.01] had a significant decrease as compared with that in the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP was much better in the combined procedure than in PCDV alone. Further, there was no significant difference in PVF between the two groups. It is suggested that the combined surgical procedure could integrate the advantages of shunting with those of devascularization, as well as maintaining the normal anatomic structure of hepatic portal system, thus it should be one of the best choices for patients with portal hypertension when surgical interventions are considered.

A dynamic procedure based on the scale-similarity hypotheses for large-eddy simulation

ZHOU Bing, CUI Guixiang, CHEN Naixiang

《能源前沿(英文)》 2007年 第1卷 第4期   页码 468-472 doi: 10.1007/s11708-007-0069-z

摘要: Current dynamic procedures in large-eddy simulation treat the two subgrid-scale stresses in the Germano identity with the same subgrid base model. Thus to get the base model coefficient, the coefficient must be assumed to be consta

关键词: large-eddy simulation     Germano identity     coefficient     subgrid-scale    

新建有岩爆倾向硬岩矿床采矿技术研究工作程序

郭然,于润沧

《中国工程科学》 2002年 第4卷 第7期   页码 51-55

摘要:

目前矿山的岩爆研究工作大都是围绕着如何预报和防治岩爆展开的,针对如何开展新建或尚未发生过岩爆矿山的岩爆研究工作不多。文章重点探讨了新建有岩爆倾向硬岩矿床开采技术研究工作程序,为建立有岩爆倾向深赋硬岩矿床采矿理论体系奠定了基础。

关键词: 岩爆     采矿技术     工作程序    

过程神经元网络的若干理论问题

何新贵,梁久祯

《中国工程科学》 2000年 第2卷 第12期   页码 40-44

摘要:

文章提出一种过程神经元模型,其输人为与时间有关的函数或过程,它是传统人工神经元模型在时间域上的扩展。基于这种过程神经元模型,给出了一种仅含一个隐层的前馈型过程神经网络模型,即基展开过程神经元网络模型。证明了相应的连续性定理,逼近定理,计算能力定理等。

关键词: 过程神经元网络     函数逼近能力     计算能力     连续性    

三峡升船机船厢室施工程序研究

曾明

《中国工程科学》 2013年 第15卷 第9期   页码 40-44

摘要:

针对三峡升船机船厢室平衡重和船厢荷载的施加顺序对塔柱埋件结构部位变形的影响,对船厢室的施工顺序和设备安装顺序方案进行了研究,解决了船厢和平衡重荷载的施加顺序对螺母柱、齿条和纵向导向变位影响的施工技术难题。根据对塔柱结构进行的仿真计算结果,分析了船厢与平衡重荷载施加顺序分别对螺母柱、齿条、纵向导向部位横河向、顺河向和竖向变形的影响,通过对施工程序优化提出了合理的升船机船厢室的施工程序以及施工总进度计划安排。该施工程序能够使螺母柱、齿条、纵向导向、船厢结构与塔柱在各工况下的位移满足安全要求,并且基于该施工程序的施工进度满足升船机试运行要求。工程实践证明了本文所建立的三峡升船机船厢室施工程序的合理性与科学性,确保了三峡升船机船厢室的顺利施工,保障了升船机的安全运行,可为类似升船机船厢室的施工提供参考。

关键词: 施工程序     船厢室     升船机     三峡工程    

New concept and procedure for reliability assessment of an IEC 61850 based substation and distribution

Hosein HAYATI,Amir AHADI,Seyed Mohsen MIRYOUSEFI AVAL

《能源前沿(英文)》 2015年 第9卷 第4期   页码 387-398 doi: 10.1007/s11708-015-0382-6

摘要: Smart grid is a power grid consists of extensive monitoring systems which deal with the monitoring of attributes such as current, voltage, power, and energy at distribution transformers, substations transformers, distribution switching devices and smart meters. Smart grid with advanced communication technologies can be used for several purposes such as efficiency and reliability improvement. IEC 61850 is the core standard in the smart grid domain for distribution and substation automation. This paper introduces a vision of modern substation and distribution systems using the IEC 61850. Network operators mainly assume that the modern substation and distribution systems based on the IEC 61850 are reliable for a long-time of operation. However, similar to any other systems, the implemented IEC 61850 might fail because of the operational failures or aging failures. This paper proposes a novel method for reliability evaluation of modern substation and distribution systems. A typical IEC 61850 based distribution and substation system is developed and analyzed using the proposed method. The fault tree analysis (FTA) is used to quantify the reliability of the system. The technique is implemented and demonstrated on the Roy Billinton test system (RBTS). The analysis is further extended on a 400/63 kV substation with a breaker- and-a-half configuration. In addition, the technique proves to be robust under different operations. The results verify the feasibility and applicability of the proposed method.

关键词: IEC 61850     reliability assessment     fault tree analysis    

过程神经网络的训练及其应用

何新贵,梁久祯,许少华

《中国工程科学》 2001年 第3卷 第4期   页码 31-35

摘要:

研究过程神经网络的学习算法及其在过程模式识别中的应用。针对权值基展开的过程神经网络讨论了权值基的选取规则和对采样曲线的标准化处理问题,给出了含一个隐层的过程神经网络的误差反传播学习算法。以聚合化学反应和渗流实验两个具体实例验证了算法的有效性,也说明了过程神经网络的广泛应用前景。

关键词: 过程神经网络     学习算法     模式识别     化学反应     渗流    

A super-element approach for structural identification in time domain

LI Jie, ZHAO Xin

《机械工程前沿(英文)》 2006年 第1卷 第2期   页码 215-221 doi: 10.1007/s11465-006-0004-4

摘要: For most time-domain identification methods, a complete measurement for unique identification results is required for structural responses. However, the number of transducers is commonly far less than the number of structural degrees of freedom (DOFs) in practical applications, and thus make the time-domain identification methods rarely feasible for practical systems. A super-element approach is proposed in this study to identify the structural parameters of a large-scale structure in the time domain. The most interesting feature of the proposed super-element approach is its divide-and-conquer ability, which can be applied to identify large-scale structures using a relatively small number of transducers. The super-element model used for time domain identification is first discussed in this study. Then a parameterization procedure based on the sensitivities of response forces is introduced to establish the identification equations of super-elements. Some principles are suggested on effective decomposing of the whole structure into super-elements for identification purposes. Numerical simulations are conducted at the end of this study. The numerical results show that all structural parameters can be identified using a relatively small number of transducers, and the computational time can also be greatly shortened.

关键词: numerical     effective decomposing     parameterization procedure     divide-and-conquer ability     time-domain identification    

长距离输油输气管道建设——焊接工艺制订及焊接设备选型

郭海云,李桓,李国华,胡连海

《中国工程科学》 2001年 第3卷 第12期   页码 76-79

摘要:

举世瞩目的西气东输工程开工在即,大投资、长距离、大管径、短工期、高质量、地质条件多样、 施工单位众多等是其主要特点。其中焊接工艺的制订及焊接设备的选型涉及许多技术问题,将对施工进度、施 工质量、施工单位的经济效益产生重大影响,应引起足够重视。

关键词: 输油输气管道建设     焊接设备     选型    

A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid

Tingting MA, Ying TENG, Peter CHRISTIE, Yongming LUO, Yongshan CHEN, Mao YE, Yujuan HUANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 31-42 doi: 10.1007/s11783-012-0463-2

摘要: An optimized procedure based on gas chromatography-mass spectrometry (GC-MS) combined with accelerated solvent extraction (ASE) is developed for the analysis of six phthalic acid esters (PAEs), which are priority soil pollutants nominated by United States Environmental Protection Agency (USEPA). Quantification of PAEs in soil employs ultrasonic extraction (UE) (USEPA 3550) and ASE (USEPA 3545), followed by clean up procedures involving three different chromatography columns and two combined elution methods. GC-MS conditions under selected ion monitoring (SIM) mode are described and quality assurance and quality control (QA/QC) criteria with high accuracy and sensitivity for target analytes were achieved. Method reliability is assured with the use of an isotopically labeled PAE, di- -butyl phthalate-d4 (DnBP-D4), as a surrogate, and benzyl benzoate (BB) as an internal standard, and with the analysis of certified reference materials (CRM). QA/QC for the developed procedure was tested in four PAE-spiked soils and one PAE-contaminated soil. The four spiked soils were originated from typical Chinese agricultural fields and the contaminated soil was obtained from an electronic waste dismantling area. Instrument detection limits (IDLs) for the six PAEs ranged 0.10–0.31 μg·L and method detection limits (MDLs) of the four spiked soils varied from a range of 20–70 μg·kg to a range of 90– 290 μg·kg . Linearity of response between 20 μg·L and 2 mg·L was also established and the correlation coefficients ( ) were all>0.998. Spiked soil matrix showed relative recovery rates between 75 and 120% for the six target compounds and about 93% for the surrogate substance. The developed procedure is anticipated to be highly applicable for field surveys of soil PAE pollution in China.

关键词: phthalic acid esters     quality assurance and quality control     soil type     accelerated solvent extraction     certified reference materials    

Automated synthesis of steady-state continuous processes using reinforcement learning

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 288-302 doi: 10.1007/s11705-021-2055-9

摘要: Automated flowsheet synthesis is an important field in computer-aided process engineering. The present work demonstrates how reinforcement learning can be used for automated flowsheet synthesis without any heuristics or prior knowledge of conceptual design. The environment consists of a steady-state flowsheet simulator that contains all physical knowledge. An agent is trained to take discrete actions and sequentially build up flowsheets that solve a given process problem. A novel method named SynGameZero is developed to ensure good exploration schemes in the complex problem. Therein, flowsheet synthesis is modelled as a game of two competing players. The agent plays this game against itself during training and consists of an artificial neural network and a tree search for forward planning. The method is applied successfully to a reaction-distillation process in a quaternary system.

关键词: automated process synthesis     flowsheet synthesis     artificial intelligence     machine learning     reinforcement learning    

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    

Emission characteristics of a turbocharged diesel engine fueled with gas-to-liquids

WU Tao, ZHANG Wugao, FANG Junhua, HUANG Zhen

《能源前沿(英文)》 2007年 第1卷 第3期   页码 331-335 doi: 10.1007/s11708-007-0049-z

摘要: Emission characteristics of a turbocharged, inter-cooled, heavy-duty diesel engine operating on neat gas-to-liquids (GTL) and blends of GTL with conventional diesel were investigated and a comparison was made with those of diesel fuel. The results show that nitrogen oxides (NO), smoke, and particulate matter (PM) emissions can be decreased when operating on GTL and diesel-GTL blends. Engine emissions decrease with an increase of GTL fraction in the blends. Compared with diesel fuel, an engine operating on GTL can reduce NO, PM, carbon monoxide (CO), and hydrocarbon (HC) by 23.7%, 27.6%, 16.6% and 12.9% in ECE R49 13-mode procedure, respectively. Engine speed and load have great influences on emissions when operating on diesel-GTL blends and diesel fuel in the turbocharged diesel engine. The study indicates that GTL is a promising alternative fuel for diesel engines to reduce emissions.

关键词: comparison     conventional     fraction     13-mode procedure     study    

标题 作者 时间 类型 操作

Synthesis of ordered cerium-doped cubic mesoporous silica using long-chain ionic liquid as template

YUE Hongxia, ZHAO Hongmei, LIU Longjiang, WANG Siping, Ruan Qiong, WANG Tongwen

期刊论文

Systematic screening procedure and innovative energy-saving design for ionic liquid-based extractive

期刊论文

Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

期刊论文

A dynamic procedure based on the scale-similarity hypotheses for large-eddy simulation

ZHOU Bing, CUI Guixiang, CHEN Naixiang

期刊论文

新建有岩爆倾向硬岩矿床采矿技术研究工作程序

郭然,于润沧

期刊论文

过程神经元网络的若干理论问题

何新贵,梁久祯

期刊论文

三峡升船机船厢室施工程序研究

曾明

期刊论文

New concept and procedure for reliability assessment of an IEC 61850 based substation and distribution

Hosein HAYATI,Amir AHADI,Seyed Mohsen MIRYOUSEFI AVAL

期刊论文

过程神经网络的训练及其应用

何新贵,梁久祯,许少华

期刊论文

A super-element approach for structural identification in time domain

LI Jie, ZHAO Xin

期刊论文

长距离输油输气管道建设——焊接工艺制订及焊接设备选型

郭海云,李桓,李国华,胡连海

期刊论文

A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid

Tingting MA, Ying TENG, Peter CHRISTIE, Yongming LUO, Yongshan CHEN, Mao YE, Yujuan HUANG

期刊论文

Automated synthesis of steady-state continuous processes using reinforcement learning

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

Emission characteristics of a turbocharged diesel engine fueled with gas-to-liquids

WU Tao, ZHANG Wugao, FANG Junhua, HUANG Zhen

期刊论文