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“Partial pressures” of humid air in wide pressure and temperature ranges

Zidong WANG, Hanping CHEN, Shilie WENG

《能源前沿（英文）》 2013年 第7卷 第4期   页码 511-517 doi: 10.1007/s11708-013-0281-7

摘要： “Partial pressure” in humid air is a question very much concerned by scientists and no satisfactory answer has been found to date. This paper proposes a novel method to obtain the “partial pressures” of the water vapor and dry air in humid air. The results obtained by the proposed method are quite different from that obtained by Dalton’s partial pressure law. The fundamental behaviors of water vapor and dry air are studied in depth in wide pressure and temperature ranges. Semi-permeable membrane models are proposed and applied for both saturated and unsaturated humid air. “Improvement factors” are developed to quantitatively describe the magnitude of the interaction between dissimilar molecules. One discovery is that the “partial pressure” of the water vapor in saturated humid air equals , rather than ( · ) which was formerly believed. The other is that the interaction between dissimilar molecules may be omitted when temperature is above “cutting-off temperature” for unsaturated humid air. This paper satisfactorily answers the quest of “partial pressures” in humid air from a new perspective.

关键词： partial pressure     Dalton’s partial pressure law     humid air     saturated     unsaturated    

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Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

《结构与土木工程前沿（英文）》 2021年 第15卷 第6期   页码 1480-1493 doi: 10.1007/s11709-021-0776-y

摘要： In waterfront geotechnical engineering, seismic and drainage conditions must be considered in the design of retaining structures. This paper proposes a general analytical method to evaluate the seismic active earth pressure on a retaining wall with backfill subjected to partial steady seepage flow under seismic conditions. The method comprises the following steps: i) determination of the total head, ii) upper bound solution of seismic active earth thrust, and iii) deduction for the earth pressure distribution. The determination of total head h(x,z) relies on the Fourier series expansions, and the expressions of the seismic active earth thrust and pressure are derived by using the upper bound theorem. Parametric studies reveal that insufficient drainage and earthquakes are crucial factors that cause unfavorable earth pressure. The numerical results confirm the validity of the total head distribution. Comparisons indicate that the proposed method is consistent with other relevant existing methods in terms of predicting seismic active earth pressure. The method can be applied to the seismic design of waterfront retaining walls.

关键词： seismic active earth pressure     partial seepage flow     pore pressure     anisotropy     upper bound theorem    

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分形方法导出改进的牛顿第二定律及万有引力定律

付昱华

《中国工程科学》 2003年 第5卷 第6期   页码 55-58

摘要：

牛顿第二定律及万有引力定律是根据实验结果总结出来的。为了探讨从理论上导出这两个定律的可能性，根据能量守恒定律，给出用变维分形方法针对一个实例（小球沿长斜面滚下）导出改进的牛顿第二定律及万有引力定律的方法。具体给出了适用于实例的常维分形结果：改进的万有引力定律F=-GMm / r1.99989和改进的牛顿第二定律F=ma1.01458。

关键词： 分形方法     牛顿第二定律     万有引力定律     理论推导    

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China’s Ministry of Environmental Protection Adopted Draft Amendment to the Law on Prevention and Control

Fu Sun,Yi Liu

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0890-6

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First law-based thermodynamic analysis on Kalina cycle

ZHANG Ying, HE Maogang, JIA Zhen, LIU Xun

《能源前沿（英文）》 2008年 第2卷 第2期   页码 145-151 doi: 10.1007/s11708-008-0021-6

摘要： Based on the first law of thermodynamics, and adopting the Peng-Robinson equation (P-R equation) as the basic equation for the properties of ammonia-water mixtures, a thermodynamic analysis on a single-stage distillation Kalina cycle is presented. A program to calculate the thermodynamic properties of ammonia-water mixtures, and that for calculating the performance of Kalina cycles, were developed, with which the heat-work conversion particulars of Kalina cycles were theoretically calculated. The influences on the cycle performance of key parameters, such as the pressure and temperature at the inlet of the turbine, the back pressure of the turbine, the concentration of the working solution, the concentration of the basic solution and the cycle multiplication ratio, were analyzed.

关键词： ammonia-water     P-R     single-stage distillation     Peng-Robinson     pressure    

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Reduction kinetics of SrFeO/CaO∙MnO nanocomposite as effective oxygen carrier for chemical looping partial

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1726-1734 doi: 10.1007/s11705-022-2188-5

摘要： Chemical looping reforming of methane is a novel and effective approach to convert methane to syngas, in which oxygen transfer is achieved by a redox material. Although lots of efforts have been made to develop high-performance redox materials, a few studies have focused on the redox kinetics. In this work, the kinetics of SrFeO3−δ–CaO∙MnO nanocomposite reduction by methane was investigated both on a thermo-gravimetric analyzer and in a packed-bed microreactor. During the methane reduction, combustion occurs before the partial oxidation and there exists a transition between them. The weight loss due to combustion increases, but the transition region becomes less inconspicuous as the reduction temperature increased. The weight loss associated with the partial oxidation is much larger than that with combustion. The rate of weight loss related to the partial oxidation is well fitted by the Avrami–Erofeyev equation with n = 3 (A3 model) with an activation energy of 59.8 kJ∙mol‒1. The rate law for the partial oxidation includes a solid conversion term whose expression is given by the A3 model and a methane pressure-dependent term represented by a power law. The partial oxidation is half order with respect to methane pressure. The proposed rate law could well predict the reduction kinetics; thus, it may be used to design and/or analyze a chemical looping reforming reactor.

关键词： chemical looping reforming     SrFeO3−δ/CaO·MnO nanocomposite     reduction kinetics     Avrami–Erofeyev model     pressure-dependent term    

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Effect of Ca

Qi WANG, Hongzhi JIANG, Shengli CHEN, Mingmin ZHANG, Mingxing DING, Esheng KONG, Guangying HUANG

《医学前沿（英文）》 2009年 第3卷 第1期   页码 96-99 doi: 10.1007/s11684-009-0014-9

摘要： The aim of this paper was to explore the relationship between energy metabolism and the meridian phenomenon. The manner of change of oxygen partial pressure in acupoints and no-acupoints of the urinary bladder meridian of goats was observed with a needle-type tissue oxygen tension sensor after the acupuncture effect was blocked by Ca complexation with ethylenediamine tetraacetic acid (EDTA)-Na . The results showed that: (1) the concentration of calcium ion in urinary bladder meridian acupoints was higher than that in no-acupoints ( <0.01 or <0.05); (2) the tissue oxygen tension in urinary bladder meridian acupoints was higher than that in no-acupoints ( <0.01); (3) the oxygen partial pressure in acupoints decreased significantly after injection with EDTA-Na , compared with injection of either normal sodium or nothing ( <0.01); (4) the oxygen partial pressure in acupoints was higher than that in no-acupoints after EDTA-Na injection ( <0.01). Acupuncture could reduce oxygen partial pressure in acupoints by regulating microcirculation and increasing metabolic levels.

关键词： oxygen partial pressure     biosensor     calcium channels     acupoint    

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摩尔定律发展亟需450 mm 硅片但时间可能会推迟

屠海令

《工程（英文）》 2015年 第1卷 第2期   页码 162-163 doi: 10.15302/J-ENG-2015060

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CFD evaluation of pressure drop across a 3-D filter housing for industrial gas turbine plants

EFFIOM,Olayinka S. OHUNAKIN

《能源前沿（英文）》 2016年 第10卷 第2期   页码 192-202 doi: 10.1007/s11708-016-0406-x

摘要： This paper investigated the flow distribution and total pressure drop across a designed 3-D filter housing integrated with a 3-stage filtration system using computational fluid dynamics (CFD). The filter housing model was proposed for a heavy-duty industrial gas turbine plant operating at an average ambient temperature of 20°C.The pressure drops across the classes of filters were 652.8 Pa, 2692.2 Pa, 887.8 Pa, 776.2 Pa and 2304.2 Pa for I-GB, GB-GA, GA-FA, FA-HA, and HA-O, respectively. The results obtained indicated an acceptable total pressure drop of 7.2% for the entire filter housing before filter clean-up. Although the CFD simulation result shows that small outlet flow velocity and transonic flows exist at the outlet of the filter housing, the designed filter housing was proved compatible with the studied GT, for inlet flow conditions between 600≤ ≤610 kg/s and 60≤ ≤70 m/s for the air flow rate and velocity, respectively. Furthermore, the designed filter housing could be adopted for the studied GT and locations of Usan and Maiduguri in Nigeria, and other locations with similar environmental conditions.

关键词： computational fluid dynamics (CFD)     pressure drop     flow distribution     filter housing     gas turbine    

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Improving existing “reaching law” for better discrete control of seismically-excited building structures

Zhijun LI, Zichen DENG

《结构与土木工程前沿（英文）》 2009年 第3卷 第2期   页码 111-116 doi: 10.1007/s11709-009-0022-5

摘要： In this paper, a novel “composite reaching law” was explained in details: 1) the equation of discrete motion for a control system; 2) the design of discrete-time variable structure control. In addition, the model of a three-storey shear-type building structure was used to verify the effectiveness of the discrete variable structure control method. The results of numerical example analysis of the model show that the control law can effectively reduce the peak value of seismic response of the building structure and the chattering effect of the control system.

关键词： discrete-time variable structure control     composite reaching law     chattering effect     saturated control law    

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Methanation and chemolitrophic nitrogen removal by an anaerobic membrane bioreactor coupled partial nitrification

《环境科学与工程前沿（英文）》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1668-2

摘要：

● Efficient carbon methanation and nitrogen removal was achieved in AnMBR-PN/A system.

关键词： Anaerobic membrane bioreactor     Partial nitrification/Anammox     Carbon separation     Chemolitrophic nitrogen removal    

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How did Archimedes discover the law of buoyancy by experiment?

Hidetaka KUROKI

《机械工程前沿（英文）》 2016年 第11卷 第1期   页码 26-32 doi: 10.1007/s11465-016-0368-z

摘要：

After Archimedes and Vitruvius era, for more than 2000 years, it has been believed that the displaced water measurement of golden crown is impossible, and at his Eureka moment, Archimedes discovered the law of buoyancy (Proposition 7 of his principles) and proved the theft of a goldsmith by weighing the golden crown in water.

A previous study showed that a small amount of displaced water was able to be measured with enough accuracy by the introduced method. Archimedes measured the weight of displaced water. He did not find the law of buoyancy but rather specific gravity of things at the moment.

After which, Archimedes continued to measure the specific gravity of various solids and fluids. Through these measurements, he reached the discovery of the law of buoyancy directly by experiment. In this paper, the process to the discovery of Archimedes’ principle (Proposition 5) is presented.

关键词： Archimedes’ principle     buoyancy     specific gravity     Eureka     Vitruvius     displaced water     balance     floating body    

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Fatigue crack growth simulations of 3-D linear elastic cracks under thermal load by XFEM

SINGH,S. K. YADAV

《结构与土木工程前沿（英文）》 2015年 第9卷 第4期   页码 359-382 doi: 10.1007/s11709-015-0304-z

摘要： This paper deals with the fatigue crack growth simulations of three-dimensional linear elastic cracks by XFEM under cyclic thermal load. Both temperature and displacement approximations are extrinsically enriched by Heaviside and crack front enrichment functions. Crack growth is modelled by successive linear extensions, and the end points of these linear extensions are joined by cubic spline segments to obtain a modified crack front. Different crack geometries such as planer, non-planer and arbitrary spline shape cracks are simulated under thermal shock, adiabatic and isothermal loads to reveal the sturdiness and versatility of the XFEM approach.

关键词： 3-D cracks     fatigue life     Paris law     thermal load     XFEM    

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Why does environmental compliance cost more than penalty? —A legal analysis on environmental acts of enterprises in China

DONG Hongwei

《环境科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 434-442 doi: 10.1007/s11783-007-0069-2

摘要： In the environmental protection field of China, due to lower law-breaking cost but higher law-abiding cost , it is a common case that the enterprise chooses to break through the law on purpose. The punishment to the unlawful pr

关键词： law-abiding     punishment     environmental protection     law-breaking     enterprise    

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Methane partial oxidation over NiO-MgO/Ce

Piyawat PUE-ON, Vissanu MEEYOO, Thirasak RIRKSOMBOOON

《化学科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 289-296 doi: 10.1007/s11705-013-1345-2

摘要： Methane partial oxidation (MPO) is considered as an alternative method to produce hydrogen because it is an exothermic reaction to afford a suitable H /CO ratio of 2. However, carbon deposition on a catalyst is observed as a major cause of catalyst deactivation in MPO. In order to find suitable catalysts that prevent the carbon deposition, NiO-MgO/Ce Zr O (CZO) supported catalysts were prepared via the co-impregnation (C) and sequential incipient wetness impregnation (S) methods. The amount of Ni loading was fixed at 15 wt-% whereas the amount of MgO loading was varied from 5 to 15 wt-%. The results revealed that the addition of MgO shifted the light-off temperatures to higher temperatures. This is because the Ni surface was partially covered with MgO, and the strong interaction between NiO and NiMgO over CZO support led to the difficulty in reducing NiO to active Ni and thus less catalytic activity. However, among the catalysts tested, the 15Ni5Mg/CZO (S) catalyst exhibited the best catalytic stability for MPO after 18 h on stream at 750°C. Moreover, this catalyst had a better resistance to carbon deposition due to its high metallic Ni dispersion at high temperature.

关键词： methane partial oxidation     NiO     ceria-zirconia     MgO     mixed oxide solid solution    

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标题 作者 时间 类型 操作

“Partial pressures” of humid air in wide pressure and temperature ranges

Zidong WANG, Hanping CHEN, Shilie WENG

期刊论文

Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

期刊论文

分形方法导出改进的牛顿第二定律及万有引力定律

付昱华

期刊论文

China’s Ministry of Environmental Protection Adopted Draft Amendment to the Law on Prevention and Control

Fu Sun,Yi Liu

期刊论文

First law-based thermodynamic analysis on Kalina cycle

ZHANG Ying, HE Maogang, JIA Zhen, LIU Xun

期刊论文

Reduction kinetics of SrFeO/CaO∙MnO nanocomposite as effective oxygen carrier for chemical looping partial

期刊论文

Effect of Ca

Qi WANG, Hongzhi JIANG, Shengli CHEN, Mingmin ZHANG, Mingxing DING, Esheng KONG, Guangying HUANG

期刊论文

摩尔定律发展亟需450 mm 硅片但时间可能会推迟

屠海令

期刊论文

CFD evaluation of pressure drop across a 3-D filter housing for industrial gas turbine plants

EFFIOM,Olayinka S. OHUNAKIN

期刊论文

Improving existing “reaching law” for better discrete control of seismically-excited building structures

Zhijun LI, Zichen DENG

期刊论文

Methanation and chemolitrophic nitrogen removal by an anaerobic membrane bioreactor coupled partial nitrification

期刊论文

How did Archimedes discover the law of buoyancy by experiment?

Hidetaka KUROKI

期刊论文

Fatigue crack growth simulations of 3-D linear elastic cracks under thermal load by XFEM

SINGH,S. K. YADAV

期刊论文

Why does environmental compliance cost more than penalty? —A legal analysis on environmental acts of enterprises in China

DONG Hongwei

期刊论文

Methane partial oxidation over NiO-MgO/Ce

Piyawat PUE-ON, Vissanu MEEYOO, Thirasak RIRKSOMBOOON

期刊论文