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Analyzing sustainability of construction equipment in the state of california

Frontiers of Engineering Management 2017年第2期4卷 138-145页

作者： Hakob AVETISYAN Miroslaw SKIBNIEWSKI Mohammad MOZAFFARPOUR Department of Civil and Environmental Engineering California State University Fullerton Department of Civil and Environmental Engineering University of Maryland College Park

Construction equipment encompasses highly polluting machines adversely affecting the *** tools are necessary for sustainability assessment of construction equipment fleets to allow contractors to reduce their emissions and comply with local or federal regulations. In addition to management tools, there is a need for a metrics that will allow companies to accurately assess the sustainability of their construction equipment fleets. The state of california USA is adopting innovative approaches to reduce adverse impact of humans on the environment. Once successfully implemented, the chances are that such practices attract other states to adopt similar approaches. This paper presents an evaluation of construction equipment fleets and data analysis. When measured and recorded, such results can be used along with decisionsupport tools for selection and utilization of construction equipment. The metrics for construction equipment evaluation as well as the tool for sustainable decisionmaking are developed based on readily available data from manufacturers or maintenance shops without a need for additional effort by contractors or government agencies for their adoption. The metrics developed and the decision support tool incorporate logical strategies of supply chain management for optimal selection of construction equipment for construction site while taking into account the availability, cost, and mobilization related constraints. The metrics and the model can benefit both the government agencies responsible for inspection of fleets and owners of construction companies in their decision-making processes related to environmental sustainability.

关键词： Construction equipment greenhouse gas emissions sustainability index sustainable construction

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Full time adult credential students?instructional preferences at california state University, Long Beach: pedagogy or andragogy?

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2004年第3期5卷 116-121页

作者： WANG Victor Occupational Studies Department California State University

This study investigated the instructional preferences of full time adult credential students after they took a live course called Principles of Adult Education at california state University, Long Beach (CSULB) in the fall semester of 2002. These full time adult credential students had been working on their adult teaching credentials to meet the competencies specified by the california Commission on Teacher Credentialing. The course introduced students to Andragogy developed by Malcolm Knowles out of the andragogical model developed by Lindeman (1926). The study used Principles of Adult Learning Scales (PALS), advanced by Gary Conti in 1983 to measure instructional preferences. Data were collected from 30 (100% of 30) full time adult credential students enrolled in a live course to determine their instructional preferences of helping adults learn. The results of the study showed in most cases these adult learning professionals taught adult students andragogically; in some cases they taught adult students pedagogically.

关键词： Andragogy Principles of Adult Learning Scales (PALS) Instructional preferences california state University

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Improving hydrogen evolution reaction efficiency through lattice tuning

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Nano Research 2024年第7期17卷 5907-5913页

作者： Zipeng Zhao Haotian Liu Wenpei Gao Praveen Kolla Wang Xue Zeyan Liu Jinghua Guo Sanjeev Mukerjee Xiaoqing Pan Qingying Jia Xiangfeng Duan Yu Huang Department of Materials Science and Engineering University of CaliforniaLos AngelesCalifornia 90095USA Department of Chemical Engineering and Materials Science University of CaliforniaIrvineCalifornia 92697USA Materials Science and Engineering North Carolina State UniversityRaleighNorth Carolina 27695USA Department of Chemistry and Chemical Biology Northeastern UniversityBostonMassachusetts 02115USA Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCalifornia 90095USA Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCalifornia 94720USA Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCalifornia 95064USA Department of Physics and Astronomy University of CaliforniaIrvineCalifornia 92697USA california Nanosystems Institute University of CaliforniaLos AngelesCalifornia 90095USA

The intermittent nature of renewable energy sources sets a requirement for efficient energy storage to mitigate the conflict between energy supply and *** is a promising choice for energy storage due to its high energy ***,the conversion of electrical energy to chemical energy stored in hydrogen through water electrolysis suffers from low efficiency,and the electricity cost dominates the total cost of hydrogen ***,we report the study of improving the hydrogen evolution reaction activity of Pt-based catalysts by building a nanoscale surface NiO and Pt interface,further optimizing the performance via tuning the lattice parameter of the core of nanoparticles,which can be achieved by varying the dealloying annealing *** optimized PtCuNi-O/C and PtNi-O/C catalysts are demonstrated to be one of the best catalysts,with a mass activity(MA)of 9.1 and 8.7 mA/μgPt,which is 9.9-fold and 9.5-fold of that of Pt/C,respectively.

关键词： lattice tuning Pt-based catalyst hydrogen evolution reaction electrocatalysis

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Stable hydrogen-bonded organic frameworks and their photo-and electro-responses

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Nano Research 2024年第8期17卷 7675-7699页

作者： Ying Hou Xin-Song Huang Sheng-Hao Gong Chen Liu Yangyang Liu Tian-Fu Liu state Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Department of Chemistry and Biochemistry California State UniversityLos AngelesCalifornia 90032USA College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China

Hydrogen-bonded organic frameworks(HOFs)are a recent class of porous materials that have garnered considerable research interest owing to their distinctive *** can be constructed through judicious selection of H-bonding motifs,which are further enforced by other weak intermolecular interactions such asπ–πstacking,van der Waals forces,and framework *** advantage of these interactions,we can expand the functional field of HOFs by introducing active ***,researchers have made substantial advancements in using HOFs for chemical sensing,catalysis,proton conduction,biological applications,and *** low bonding energy of H-bonds allows for precise control over the concentration of ligands in solvents,forming diverse HOF *** varied structures offer significant advantages for producing HOFs with photo-responsive and electro-responsive ***,the presence of H-bonds in HOFs results in their inherent lower stability compared to metal-organic frameworks(MOFs)and covalent-organic frameworks(COFs)formed via coordination and covalent bonds,*** a result,the pursuit of stable and innovative HOF materials with novel functional sites remains an ongoing *** review provides an overview of recent research progress in the development of new strategies for stable HOF synthesis and applications of HOFs with stimuli-responsive *** first classified all synthetic methods reported to date and discussed the stable HOFs synthesized,as well as their unique properties and *** addition,we summarized the applications of HOFs utilizing their synergistic responses to external stimuli,including photo,electrical,pressure,and chemical *** systematically reviewed stable HOF synthesis and applications,which may lead to a deeper understanding of the structure–activity relationship for these materials and guide future HOF design.

关键词： stable hydrogen-bonded organic frameworks(HOFs) photo-response electro-response photoelectric synergistic response

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Research progress on electrolyte key salts for sodium-ion batteries

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Progress in Natural Science:Materials International 2024年第02期34卷 263-273页

作者： weimin Zhao Miao Wang Haichen Lin Kangwoon Kim Rongkai He Shijie Feng Haodong Liu College of Chemical Engineering and Safety Binzhou University Center for Memory and Recording Research Building University of California San Diego state GRID Liaocheng Power Supply Company

Sodium-ion batteries(SIBs) are considered potential successors to lithium-ion batteries in the fields of energy storage and low-speed vehicles, thanks to their advantages such as abundant raw material sources, high energy density, and a wide operational temperature range. However, several scientific and engineering challenges still require attention in the development of sodium-ion batteries. Electrolyte salts, as a key component of sodium-ion battery electrolytes, play a critical role in battery performance. This paper provides a brief overview of the research progress on different electrolyte salt systems in sodium-ion batteries. It discusses characteristics such as ionic conductivity, electrochemical windows, electrochemical performance, and thermal safety in various solvent systems. Furthermore, the paper summarizes a series of strategies for controlling electrolyte and electrode interfaces, offering references for addressing the challenges in the mass production and application of sodium-ion batteries.

关键词： Electrochemical performance Electrolyte Electrolyte salts Sodium ion batteries

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Nonlinear Extrapolation Estimates of π

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 91-108页

作者： Wen-qing Xu Sha-sha Wang Da-chuan Xu Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing100124China Department of Mathematics and Statistics California State UniversityLong BeachCalifornia90840USA Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang050043China

The classical Archimedean approximation of π uses the semiperimeter or area of regular polygons inscribed in or circumscribed about a unit circle in R~2 and it is well-known that by using linear combinations of these basic estimates,modern extrapolation techniques can greatly speed up the approximation ***,when n vertices are randomly selected on the circle,the semiperimeter and area of the corresponding random inscribed and circumscribing polygons are known to converge to π almost surely as n→∞,and by further applying extrapolation processes,faster convergence rates can also be achieved through similar linear combinations of the semiperimeter and area of these random *** this paper,we further develop nonlinear extrapolation methods for approximating π through certain nonlinear functions of the semiperimeter and area of such *** focus on two types of extrapolation estimates of the forms χ_n=S_n~αA_n~β and Y_n(p)=(αS_n~p+βA_n~p)~(1/p) where α+β=1,p≠0,and Sn and An respectively represents the semiperimeter and area of a random n-gon inscribed in the unit circle in R~2,and Xn may be viewed as the limit of Y_n(p) when p→*** deriving probabilistic asymptotic expansions with carefully controlled error estimates for Xn and Y_n(p),we show that the choice α=4/3,β=-1/3 minimizes the approximation error in both cases,and their distributions are also asymptotically normal.

关键词： Archimedean polygons random polygons approximations ofπ extrapolation processes asymptotic convergence

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High temperature superconductor Na2B2H stabilized by hydrogen intercalation under ambient pressure

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Science China(Physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 145-152页

作者： Wendi Zhao Defang Duan Zhengtao Liu Zihao Huo Shumin Guo Decheng An Maosheng Miao Tian Cui state Key Laboratory of Superhard Materials Key Laboratory of Material Simulation Methods & Software of Ministry of Education College of Physics Jilin University Department of Chemistry and Biochemistry California State University Department of Earth Science University of California Institute of High Pressure Physics School of Physical Science and Technology Ningbo University

Hydrogenated metal borides have attracted much attention due to their potential high-temperature superconductivity. Here, we propose a new strategy for hydrogen intercalation tuning the stability and superconductivity of the boron honeycomb sublattice,and predict an unprecedented layered compound Na2B2H, which hosts excellent superconductivity. Strikingly, the superconducting transition temperature（Tc） of Na2B2H reaches 42 K at ambient pressure. The Tcvalue can be further increase to 63 K under 5% biaxial tensile strain. The excellent superconductivity originates from the strong electron-phonon coupling between theσ-bonding bands near the Fermi level and the B-B stretching optical E modes. The interstitial electron localization and crystal orbitals of the H-intercalated Na ion layer well match the boron honeycomb lattice and act as a chemical template to stabilize the B layer. Furthermore, the introduction of hydrogen tuned the Fermi level, and the coupling vibration of Na and H ions effectively enhanced the dynamic stability of the structure. Na2B2H represents a new family of layered high-temperature superconductors,and the strategy of stabilizing the honeycomb boron sublattice via chemical template hosts great potential for application to more layered compounds.

关键词： superconductivity hydrogenation metal borides electron-phonon coupling

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Nonlinear encoding in diffractive information processing using linear optical materials

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Light(Science & Applications) 2024年第8期13卷 1675-1688页

作者： Yuhang Li Jingxi Li Aydogan Ozcan Electrical&Computer Engineering Department University of CaliforniaLos AngelesCA 90095USA Bioengineering Department University of CaliforniaLos AngelesCA 90095USA california NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCA 90095USA

Nonlinear encoding of optical information can be achieved using various forms of data ***,we analyze the performances of different nonlinear information encoding strategies that can be employed in diffractive optical processors based on linear materials and shed light on their utility and performance gaps compared to the state-of-the-art digital deep neural *** a comprehensive evaluation,we used different datasets to compare the statistical inference performance of simpler-to-implement nonlinear encoding strategies that involve,e.g.,phase encoding,against data repetition-based nonlinear encoding *** show that data repetition within a diffractive volume(e.g.,through an optical cavity or cascaded introduction of the input data)causes the loss of the universal linear transformation capability of a diffractive optical ***,data repetition-based diffractive blocks cannot provide optical analogs to fully connected or convolutional layers commonly employed in digital neural ***,they can still be effectively trained for specific inference tasks and achieve enhanced accuracy,benefiting from the nonlinear encoding of the input *** results also reveal that phase encoding of input information without data repetition provides a simpler nonlinear encoding strategy with comparable statistical inference accuracy to data repetition-based diffractive *** analyses and conclusions would be of broad interest to explore the push-pull relationship between linear material-based diffractive optical systems and nonlinear encoding strategies in visual information processors.

关键词： nonlinear simpler Nonlinear

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Low phase noise K-band signal generation using polarization diverse single-soliton integrated microcombs

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Photonics Research 2024年第6期12卷 1175-1185页

作者： ALWALEED ALDHAFEERI HSIAO-HSUAN CHIN TRISTAN MELTON DONG IL LEE ALLEN CHU WENTING WANG MINGBIN YU PATRICK GUO-QIANG LO DIM-LEE KWONG CHEE WEI WONG Fang Lu Mesoscopic Optics and Quantum Electronics Laboratory University of CaliforniaLos AngelesCalifornia 90095USA Institute of Microelectronics A*STARSingapore 117865Singapore state Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technologyand Shanghai Industrial Technology Research InstituteShanghai 200050China

Frequency microcombs with microwave and millimeter-wave repetition rates provide a compact solution for coherent communication and information *** implementation of these microcombs using a CMOS-compatible platform further paves the way for large-scale photonic integration and ***,we demonstrate free-running soliton microcombs with K-band repetition rates with very low phase noise over a 4 GHz pump detuning range reaching−117(−123)dBc/Hz at 10 kHz offset for a 19.7(10)GHz carrier without active pump stabilization,exceeding commercial electronic microwave oscillators at frequency offsets above 40 *** minimum laser noise to soliton microwave signal transduction factor observed is−*** noise performance is achieved using a hybridized dual-mode for soliton generation to achieve passive thermal stabilization and minimal soliton spectrum shift from prior Raman scattering and dispersive wave *** further examine the locking of the repetition rate to an external ultrastable photonic oscillator to illustrate the feasibility of phase noise suppression below the thermorefractive noise limits of microresonator frequency combs.

关键词： pump polarization millimeter

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Universal insertion of molecules in ionic compounds under pressure

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National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng Yanming Ma Chris J.Pickard Hanyu Liu Maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge state Key Laboratory of Superhard Materials & Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of Materials Science & Metallurgy University of Cambridge Advanced Institute for Materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

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