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Stoichiometry of a semi-aquatic plethodontid salamander: Intraspecific variation due to location, size and diet

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Integrative Zoology 2014年第5期9卷 613-622页

作者： Joseph R.MILANOVICH Matthew E.HOPTON United States Environmental Protection Agency Office of Research and DevelopmentSustainable Technology DivisionNational Risk Management Research LaboratorySustainable Environments BranchCincinnatiOhioUSA Department of Biology Loyola University Chicago1032 West Sheridan Rd.ChicagoIL 60660USA.

Ecological stoichiometry provides a framework to investigate an organism’s relationship to nutrient *** organism’s stoichiometry is thought to constrain its contribution to nutrient cycles(recycling or storage),and to limit its growth and *** that influence the stoichiometry of a consumer are largely unstudied,but what is known is that consumer stoichiometry is influenced by the elemental requirements of the consumer(*** growth,reproduction and cell maintenance)and the availability of *** examined whole-body stoichiometry of larval southern two-lined salamanders(Eurycea cirrigera)and described the influence of location,body size,stoichiometry of diet items,and environmental nutrient supply on whole-body *** composition of phosphorous was 2.6%,nitrogen was 11.3%,and carbon was 39.6%,which are similar for other aquatic vertebrate *** most significant predictor of whole-body stoichiometry was the site where the samples were collected,which was significant for each nutrient and nutrient *** size and stoichiometry of diet items were also predictors of Eurycea cirrigera *** study suggests that spatial differences in environmental nutrient supply have a stronger influence on consumer whole-body stoichiometry among similar-sized larvae compared to life history traits,such as body size or diet.

关键词： carbon Eurycea cirrigera nitrogen phosphorus stream

Interpreting the dynamic effect of internal heat integration on reactive distillation columns

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Chinese Journal of Chemical Engineering 2017年第1期25卷 89-102页

作者： Yang Yuan Liang Zhang Haisheng Chen Shaofeng Wang Kejin Huang Huan Shao College of Information Science and technology Beijing University of Chemical Technology Patent Examination Cooperation Center of the Patent office SIPO

In this work,the impact of internal heat integration upon process dynamics and controllability by superposing reactive section onto stripping section,relocating feed locations,and redistributing catalyst within the reactive section is explored based on a hypothetical ideal reactive distillation system containing an exothermic reaction:A + BC + *** state operation analysis and closed-loop controllability evaluation are carried out by comparing the process designs with and without the consideration of internal heat *** superposing reactive section onto stripping section,favorable effect is aroused due to its low sensitivities to the changes in operating *** ascending the lower feed stage,somewhat detrimental effect occurs because of the accompanied adverse internal heat integration and strong sensitivity to the changes in operating *** descending the upper feed stage,serious detrimental effect happens because of the introduced adverse internal heat integration and strong sensitivity to the changes in operating *** redistributing catalyst in the reactive section,fairly small negative influence is aroused by the sensitivity to the changes in operating *** reinforcing internal heat integration with a combinatorial use of these three strategies,the decent of the upper feed stage should be avoided in process *** the conclusions are derived based on the hypothetical ideal reactive distillation column studied,they are considered to be of general significance to the design and operation of other reactive distillation columns.

关键词： Reactive distillation column Internal heat integration Process design Process dynamics Process control

Regeneration of waste SCR catalyst by air lift loop reactor

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Journal of Central South University 2013年第5期20卷 1314-1318页

作者： LEE Jung-bin EOM Yong-seok KIM Jun-han CHUN Sung-nam technology Commercialization office Korea Electric Power Research Institute

A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.

关键词： nitrogen oxide regeneration selective catalyst reduction air lift loop reactor catalyst

Multi-objective optimization of space station short-term mission planning

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Science China(Technological Sciences) 2015年第12期58卷 2169-2185页

作者： BU HuiJiao ZHANG Jin LUO YaZhong ZHOU JianPing College of Aerospace Science and Engineering National University of Defense Technology Chinese Manned Space Engineering office

This paper studies the multi-objective optimization of space station short-term mission planning(STMP), which aims to obtain a mission-execution plan satisfying multiple planning demands. The planning needs to allocate the execution time effectively, schedule the on-board astronauts properly, and arrange the devices reasonably. The STMP concept models for problem definitions and descriptions are presented, and then an STMP multi-objective planning model is developed. To optimize the STMP problem, a Non-dominated Sorting Genetic Algorithm II(NSGA-II) is adopted and then improved by incorporating an iterative conflict-repair strategy based on domain knowledge. The proposed approach is demonstrated by using a test case with thirty-five missions, eighteen devices and three astronauts. The results show that the established STMP model is effective, and the improved NSGA-II can successfully obtain the multi-objective optimal plans satisfying all constraints considered. Moreover, through contrast tests on solving the STMP problem, the NSGA-II shows a very competitive performance with respect to the Strength Pareto Evolutionary Algorithm II(SPEA-II) and the Multi-objective Particle Swarm Optimization(MOPSO).

关键词： space station short-term mission planning multi-objective optimization NSGA-II

Coupled thermal-mechanical analysis of two ITER-like first wall mockups under heat shock of plasma disruptions

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Science China(Technological Sciences) 2016年第3期59卷 476-487页

作者： HUANG ShengHong ZHAO YongQiang WANG WeiHua School of Engineering Science University of Science and Technology of China Institute of Applied Physics of Army office Academic

The first wall of the fusion reactor is a plasma-facing component and is a key link to maintain the integrity of structure during thermal shock induced by plasma disruptions. Be and W/Cu functionally graded materials are two kinds of important plas- ma-facing materials （PFM） of first wall in fusion reactor currently. Previous researches seldom comparatively evaluated the normal servicing and heat shock resistance performance of first walls with those two kinds of PFMs. And also there lacks cou- pled thermal/mechanical analysis on the heat shock process in consideration of multiple thermal/mechanical phenomena, such as material melting, solidification, evaporation, etc., which is significant to further understand the heat shock damage mecha- nism of the first wall with different PFMs. With the aim of learning more detailed mechanical mechanism of thermal shock damage and then improving the thermal shock resistance performance of different first wall designs, the coupled ther- mal/mechanical response of two typical ITER-like first walls with PFM of Be and functionally graded W-Cu respectively un- der the heat shock of 1 2 GW/m2 are computed by the finite element method. Special considerations of elastic-plastic defor- mation, material melting, and solidification are included in numerical models and methods. The mechanical response behaviors of different structures and materials under the normal servicing operation as well as plasma disruption conditions are analyzed and investigated comparatively. The results reveal that heat is mainly deposited on the PFM layer in thc high energy shock pulse induced by plasma disruptions, resulting in complex thermal stress change as well as mechanical itTeversible damage of thermal elastic and plastic expansion, contraction and yielding. Compared with the first wall with Be PFM, which mitigates the damages from heat shock at most only in the PFM layer with cost of whole PFM layer plastic yielding, the first wall with graded W-Cu PFM

关键词： first wall plasma facing component plasma disruptions thermal shock resistance finite element method

Two-dimensional pixel image lag simulation and optimization in a 4-T CMOS image sensor

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Journal of Semiconductors 2010年第9期31卷 59-63页

作者：于俊庭李斌桥于平平徐江涛牟村 School of Electronics Information Engineering Tianjin University Logistics Management office Hebei University of Technology

Pixel image lag in a 4-T CMOS image sensor is analyzed and simulated in a two-dimensional *** of reducing image lag are discussed from transfer gate channel threshold voltage doping adjustment,PPD N-type doping dose/implant tilt adjustment and transfer gate operation voltage adjustment for signal electron *** the computer analysis tool ISE-TCAD,simulation results show that minimum image lag can be obtained at a pinned photodiode n-type doping dose of 7.0×10^12 cm^-2,an implant tilt of -2°,a transfer gate channel doping dose of 3.0×10^12 cm^-2 and an operation voltage of 3.4 *** conclusions of this theoretical analysis can be a guideline for pixel design to improve the performance of 4-T CMOS image sensors.

关键词： image lag two-dimensional simulation doping dose implant tilt CMOS image sensor

Nitrogen removal characteristics of heterotrophic nitrification-aerobic denitrification by Alcaligenes faecalis C16

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Chinese Journal of Chemical Engineering 2015年第5期23卷 827-834页

作者： Yuxiang Liu Yao Wang Yi Li Hua An Yongkang Lv College of Environmental Science and Engineering Taiyuan University of Technology National Major Science and technology Program Management office for Water Pollution Control and Treatment Shanxi Key Lab of Coal Science and technology Taiyuan University of Technology

Alcaligenes faecalis C16 was found to have the ability to heterotrophically nitrify and aerobically denitrify. In order to further understand its nitrogen removal ability and mechanism, the growth and ammonium removal response were investigated at different C/N ratios and ammonium concentrations in the medium with citrate and acetate as carbon source separately. Furthermore, experiments of nitrogen sources, production of nitrogen gas and enzyme assay were conducted. Results show that the bacterium converts NH+4-N and produces NH2 OH during the growing phase and nitrite accumulation is its distinct metabolic feature. A. faecalis C16 is able to tolerate not only high ammonium concentration but also high C/N ratio, and the ammonium tolerance is associated with carbon source and C/N ratio. The nitrogen balance under different conditions shows that approximately28%–45% of the initial ammonium is assimilated into the cells, 44%–60% is denitrified and several percent is converted to nitrification products. A. faecalis C16 cannot utilize hydroxylamine, nitrite or nitrate as the sole nitrogen source for growth. However, nitrate can be used when ammonium is simultaneously present in the medium. A possible pathway for nitrogen removal by C16 is suggested. The preliminary enzyme assay provides more evidence for this nitrogen removal pathway.

关键词： Heterotrophic nitrification-aerobic denitrification Alcaligenes faecalis Hydroxylamine oxidase Nitrate reductase Nitrite reductase

Deep learning to develop zero-equation based turbulence model for CFD simulations of the built environment

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Building Simulation 2024年第3期17卷 399-414页

作者： Giovanni Calzolari Wei Liu Division of sustainable Buildings Department of Civil and Architectural EngineeringKTH Royal Institute of TechnologyBrinnelvägen 23Stockholm11428Sweden

This study aims to improve the accuracy and speed of predictions for thermal comfort and air quality in built environments by creating a coupled framework between computational fluid dynamics(CFD)simulations and deep learning *** coupling approach is showcased by the development of a data-driven turbulence *** new turbulence model is built using a deep learning neural network,whose mapping structure is based on a zero-equation turbulence model for built environment simulations,and is coupled with the CFD software OpenFOAM to create a hybrid *** neural network is a standard shallow multi-layer *** number of hidden layers and nodes per layer was optimized using Bayesan optimization *** framework is trained on an indoor environment case study,as well as tested on an indoor office simulation and an outdoor building array *** show that the deep learning based turbulence model is more robust and faster than traditional two-equation Reynolds average Navier-Stokes(RANS)turbulence models,while maintaining a similar level of *** model also outperforms the standard algebraic zero-equation model due to its superior ability to generalize to various flow *** some challenges,namely the mapping constraint,the limited training dataset size and the source of generation of training data,the hybrid framework demonstrates the viability of the coupling technique and serves as a starting point for future development of more reliable and advanced models.

关键词： neural networks computational fluid dynamics(CFD) turbulence model OpenFOAM

An enhanced digital predistortion algorithm based on polynomial model identification

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Science China(Information Sciences) 2019年第2期62卷 160-168页

作者： Wanzhi MA Xin QUAN Bo ZHAO Ying LIU Wensheng PAN Shihai SHAO Youxi TANG National Key Laboratory of Science and technology on Communication University of Electronic Science and Technology of China Military Delegate office in Shijiazhuang Military Delegate Bureau of Equipment Development Department

To improve the accuracy of the nonlinear distortion correction for the radio frequency(RF)power amplifier(PA), it is necessary to precisely obtain the reverse function of the PA nonlinear ***, the direct inversion of the PA nonlinear model involves solving a high-order univariate polynomial,which is difficult to apply in engineering. In this study, based on the envelope memory polynomial(EMP)model, the high-order terms of the nonlinear model are approximated by their previously calculated values through iterations and considered as known constants in the polynomial solution finding process, thereby resulting in a significant reduction in computational complexity. Compared with the direct inversion method,model of a 9 th-order nonlinear, the proposed method reduces the calculation time in the coordinated rotation digital computer(CORDIC) algorithm by at least 80%. The simulation results show that for a long-term evolution(LTE) downlink signal, the results obtained by the proposed simplified method agree well with those obtained by direct inversion method.

关键词： digital predistortion power amplifier nonlinear distortion memory effects radio frequency