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Advances and challenges in developing cocatalysts for photocatalytic conversion of carbon dioxide to fuels

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Nano Research 2022年第12期15卷 10090-10109页

作者： Qian Wang Zhenhua pan Graduate School of Engineering Nagoya UniversityFuro-choChikusa-kuNagoya464-8603Japan Institute for Advanced Research Nagoya UniversityFuro-choChikusa-kuNagoya464-8601Japan Department of Applied Chemistry Faculty of Science and TechnologyChuo University1-13-27 KasugaBunkyoTokyo112-8551Japan

The global adoption of efficient sustainable energy sources is a crucial step toward meeting energy demands while achieving carbon emission reduction *** energy has become a clean and cost-competitive alternative to traditional fossil fuels,but the intermittent nature of sunlight results in challenges associated with energy storage and *** carbon dioxide reduction intends to mimic natural photosynthesis for utilizing sunlight to chemically convert water and CO_(2) into *** this process,the solar energy is captured and stored in fuels,so-called solar fuels,for widespread on-demand *** solar fuel production systems are multi-component,comprising light-harvesting(photosensitizer)and catalytic(cocatalyst)*** are indispensable for photocatalytic CO_(2) reduction systems,which promote charge carrier separation and transport,reduce the reaction activation energy,and alter the reaction route,thereby enhancing the activity and selectivity of the photocatalytic *** review presents a comprehensive summary of the recent advancements in cocatalysts for photocatalytic CO_(2) reduction reaction(CO_(2)RR),with the purpose of providing new insights and guidance to the field with regard to research directions and best *** summarize how various cocatalysts including inorganic nanoparticles,metal complexes,enzymes,and bacteria can be combined with semiconductor photosensitizer for light-driven photocatalytic CO_(2)***-by-side comparisons reveal the strengths and limitations of each kind of cocatalysts and how lessons extracted from studying natural photosynthetic systems can be applied to investigations of artificial photosynthesis,presenting an outlook discussing possible future concepts for a more effective photocatalytic CO_(2) reduction process.

关键词： photocatalysis cocatalyst carbon dioxide reduction artificial photosynthesis solar fuel production

Effect of Rotor-stator Axial Gap on the Tip Seal Leakage Flow of a Steam Turbine

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Journal of Thermal Science 2021年第3期30卷 973-982页

作者： LI pan CAO Lihua School of Energy and Power Engineering Northeast Electric Power UniversityJilin 132012China

The tip leakage flow in different axial gaps is numerically investigated based on the Reynolds-Averaged Navier-Stokes equations and k-ω SST turbulent model using commercial CFD software ANSYS *** characteristics of vortexes in the flow field of tip seal and the distribution law of rotor tip leakage loss are analyzed under the change of axial *** results show that the flow field in the blade tip seal undergoes complex changes with the increase of axial *** are two opposite vortices in the seal cavity with small axial gap,namely,the large vortex in the cavity and the small vortex near the wall of the *** small vortex gradually disappears with the increase of the axial *** the axial gap is increased to a certain value,the reverse large vortex is formed in the cavity behind the low teeth of seal,and the leakage rate increases significantly;the steam flow angle and the mixing loss also show different *** on the traditional calculation formula of tip leakage rate,a more accurate calculation formula of tip leakage rate is constructed by introducing equivalent labyrinth seal teeth to consider the variation of axial gap.

关键词： steam turbine axial gap tip leakage labyrinth seal prediction formulation

Red/NIR/SWIR multi-band persistent luminescent nanoparticles as ultrasensitive multi-channel tracers in water and crude oil/water emulsions

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Nano Research 2023年第11期16卷 12706-12712页

作者： Yafei Chen Zhengwei pan Center for Integrative Petroleum Research College of Petroleum Engineering and GeosciencesKing Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia

We report the use of CaTiO_(3):Pr^(3+)multiband persistent luminescent nanoparticles,which can simultaneously emit red(610 nm),near-infrared(893 nm),and short-wave infrared(1040 nm)photoluminescence and persistent luminescence,as the tracer nanoagents for water tracer *** using a spectrofluorometer,an Si charge-coupled device(CCD)camera and an InGaAs array camera as the detection tools,we evaluated the sensing capabilities of the three emission bands of CaTiO_(3):Pr^(3+)nanoparticles in brine water solutions and crude oil/brine water emulsions in both photoluminescence mode and persistent luminescence *** these different detection combinations,the persistent luminescence-based Si CCD camera imaging exhibits the best sensing performance with the detection limits being at a single-digit ppb level for the 610 and 893 nm bands and about 100–200 ppb for the 1040 nm band in both water solutions and crude oil/water emulsions,while the photoluminescencebased Si CCD camera imaging has a much higher detection limit of~10 ppm in water solutions and of~200 ppm in oil/water *** persistent luminescence-based InGaAs array camera imaging to the 1040 nm band has the worst performance with the detection limits higher than 200 ppm for both *** sensing performances of the spectrofluorometer to photoluminescence signals and persistent luminescence signals in the two solutions are about the same,with the detection limits being around 100–200 ppm.

关键词： water tracer CaTiO_(3):Pr^(3+)nanoparticles photoluminescence persistent luminescence crude oil/water emulsion detection limit

Third-order unconditional positivity-preserving schemes for reactive flows keeping both mass and mole balance

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Chinese Journal of Aeronautics 2023年第11期36卷 24-41页

作者： Jianhua pan Luxin Li Zhejiang Provincial Engineering Research Center for the Safety of Pressure Vessel and Pipeline Ningbo UniversityNingbo 315211China Key Laboratory of Impact and Safety Engineering Ministry of EducationNingbo UniversityNingbo 315211China

In this paper,the previously proposed second-order process-based modified Patankar Runge-Kutta schemes are extended to the third order of *** to the process-based implicit handling of reactive source terms,the mass conservation,mole balance and energy conservation are kept simultaneously while the positivity for the density and pressure is preserved unconditionally even with stiff reaction *** is proved that the first-order truncation terms for the Patankar coefficients must be zero to achieve a prior third order of accuracy for most cases.A twostage Patankar procedure for each Runge-Kutta step is designed to eliminate the first-order truncation terms,accomplish the prior third order of accuracy and maximize the Courant number which the total variational diminishing property *** the same approach as the second-order schemes,the third-order ones are applied to Euler equations with chemical reactive source *** studies including both 1D and 2D ordinary and partial differential equations are conducted to affirm both the prior order of accuracy and the positivity-preserving property for the density and pressure.

关键词： Chemical reactions Positivity-preserving Patankar schemes Mass conservation Mole balance Third-order schemes

Foot use and hand preference during feeding in captive black-and-white snub-nosed monkeys(Rhinopithecus bieti)

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Integrative Zoology 2013年第4期8卷 378-388页

作者： Jing pan Wen XIAO Matthew h.TALBERT Matthew B.SCOTT Institute of Eastern-himalaya Biodiversity Research Dali UniversityDaliYunnanChina Department of Psychology University of GeorgiaAthensGeorgiaUSA School of Life Sciences University of Science and Technology of ChinaHefeiAnhuiChina Kunming Institute of Zoology Chinese Academy of SciencesKunmingYunnanChina College of Engineering University of GeorgiaAthensGeorgiaUSA

Postural origin theory predicts that body postures are related to hand preference in nonhuman primates due to hemispheric *** preference,especially in manipulating objects,is also a good predictor of hemispheric specialization in *** studied limb(hand and foot)preferences in 11 captive adult black-and-white snub-nosed monkeys(Rhinopithecus bieti)to see how limb preference is influenced by postures and foot *** preference was significantly different for this group between quadrupedal standing and clinging postures,and sitting and clinging postures,but not between bipedal standing and clinging *** were significantly more likely to use the right hand in the clinging posture than in quadrupedal standing or sitting *** the sitting posture,individuals maintained their respective hand preference even when the food was on the other side of the *** was a gender difference in the sitting posture,where females preferred their right hand but males preferred their *** who did not routinely use their feet to manipulate objects,compared to those who did,shifted to greater right hand use from the clinging posture to the bipedal *** male individual and his offspring were more likely to use their feet to manipulate objects than the rest of the *** the present study,we reveal the first evidence of a postural effect on hand preference in *** as well as a foot preference in this *** results mostly agree with the postural origin theory and hemispheric specialization.

关键词： bipedal standing foot preference gender difference limb preference postural origin theory

Lightweight privacy-preserving truth discovery for vehicular air quality monitoring

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Digital Communications and Networks 2023年第1期9卷 280-291页

作者： Rui Liu Jianping pan Department of Computer Science University of VictoriaVictoriaBCV8P 5C2Canada

Air pollution has become a global concern for many *** crowdsensing systems make it possible to monitor air quality at a fine *** better utilize the sensory data with varying credibility,truth discovery frameworks are ***,in urban cities,there is a significant difference in traffic volumes of streets or blocks,which leads to a data sparsity problem for truth *** the privacy of participant vehicles is also a crucial *** first present a data masking-based privacy-preserving truth discovery framework,which incorporates spatial and temporal correlations to solve the sparsity *** further improve the truth discovery performance of the presented framework,an enhanced version is proposed with anonymous communication and data *** frameworks are more lightweight than the existing cryptography-based *** also evaluate the work with simulations and fully discuss the performance and possible extensions.

关键词： Privacy preserving Truth discovery Crowdsensing Vehicular networks

Siegmund Duality for Continuous Time Markov Chains on Z_+~d

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Acta Mathematica Sinica,English Series 2018年第9期34卷 1460-1472页

作者： pan ZhAO Department of Basic Courses Beijing Union University

For the continuous time Markov chain with transition function P（t） on Z d ＋ , we give the necessary and sufficient conditions for the existence of its Siegmund dual with transition function P - （t）. If Q, the q-matrix of P（t）, is uniformly bounded, we show that the Siegmund dual relation can be expressed directly in terms of q-matrices, and a sufficient condition under which the Q-function is the Siegnmnd dual of some Q-function is also given.

关键词： Continuous time Markov chains the Siegmund dual Mobius function ↑-Mobius mono-tonicity Feller Reuter Riley transition functions birth and death chains

A portable device for studying the effects of fluid flow on degradation properties of biomaterials inside cell incubators

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Regenerative Biomaterials 2019年第1期6卷 39-48页

作者： Wensen Jiang Jiajia Lin Alex h.Chen Jianwei pan huinan Liu Department of Bioengineering Materials Science and Engineering ProgramStem Cell Center Department of Mechanical Engineering University of CaliforniaRiversideRiversideCA 92521USA Department of Bioengineering University of CaliforniaRiversideRiversideCA 92521USA Department of Neurosurgery The First Affiliated Hospital of Zhejiang UniversityHangzhou 310003China

A portable device was designed and constructed for studying the properties of biomaterials in physiologically relevant fluids under controllable flow conditions that closely simulate fluid flow inside the *** device can fit entirely inside a cell incubator;and,thus,it can be used directly under standard cell culture *** impedance-driven pump was built in the sterile flow loop to control the flow rates of fluids,which made the device small and portable for easy deployment in the *** demonstrate the device functions,magnesium(Mg)as a representative biodegradable material was tested in the flow device for immersion degradation under flow versus static conditions,while the flow module was placed inside a standard cell *** flow rate was controlled at 0.1760.06 ml/s for this study;and,the flow rate is adjustable through the controller module outside of incubators for simulating the flow rates in the ranges of blood flow in human artery(0.050.43 ml/s)and vein(0.020.08 ml/s).Degradation of Mg under flow versus static conditions was characterized by measuring the changes of sample mass and thickness,and Mg2t ion concentrations in the immersion *** chemistry and morphology of Mg after immersion under flow versus static conditions were *** portable impedance-driven flow device is easy to fit inside an incubator and much smaller than a peristaltic pump,providing a valuable solution for studying biomaterials and implants(*** or ureteral stents)in body fluids under flow versus static conditions with or without cells.

关键词： portable flow device impedance-driven pump biomaterials body fluids magnesium(Mg)degradation

Bayesian optimization+XGBoost based life cycle carbon emission prediction for residential buildings—An example from Chengdu,China

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Building Simulation 2023年第8期16卷 1451-1466页

作者： haize pan Chengjin Wu School of Civil Engineering and Geomatics Southwest Petroleum UniversityChengdu 610500China

The large amount of carbon emissions generated by buildings during their life cycle greatly impacts the environment and poses a considerable challenge to China’s carbon reduction *** building design phase has the most significant potential to reduce building life-cycle carbon emissions(LCCO_(2)).however,the lack of detailed inventory data at the design stage makes calculating a building’s LCCO_(2) very difficult and ***,accurate prediction of building LCCO_(2) at the design stage using relevant design factors is essential to reduce carbon *** paper proposes an ensemble learning algorithm combining Bayesian optimization and extreme gradient boosting(BO-XGBoost)to predict LCCO_(2) accurately in residential ***,this study collected and calculated the LCCO_(2) of 121 residential buildings in Chengdu,***,a carbon emission prediction model was developed using XGBoost based on 15 design factors,and hyperparameter optimization was performed using the BO ***,the model performance was evaluated using two evaluation metrics,coefficient of determination(R2)and root mean square error(RMSE),and the prediction performance of other models was compared with that of the BO-XGBoost *** results show that the RMSE of the proposed BO-XGBoost for predicting LCCO_(2) in residential buildings is at least 40%lower compared to other *** method adopted in this study can help designers accurately predict building LCCO_(2) at the early design stage and provide methodological support for similar studies in the future.

关键词： building carbon emissions life cycle XGBoost Bayesian optimization predictive model