Investigating the Effects of Eichhornia Crassipes Biodiesel and Liquefied Petroleum Gas on the Performance and Emissions of a Dual-Fuel Engine

This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(DFM)and equipped with an Exhaust gas recirculation technique(EGR).In particular,a single-cylinder,four-stroke,water-cooled diesel engine was utilized and four modes of fuel operation were considered:mode I,the engine operated with an ordinary diesel fuel;mode II,the engine operated with the addition of 2.4 L/min of lique-fied petroleum gas(LPG)and 20%EGR;mode III,20%ECB with 2.4 L/min LPG and 20%EGR;mode IV,40%ECB with 2.4 L/min LPG and 20%EGR.The operation conditions were constant engine speed(1500 rpm),var-iation of load(25%,50%,75%,and 100%),full load,with a compression ratio of 18,and a time injection of 23°BTDC(Before top died center).With regard to engine emissions,carbon dioxide(CO_(2)),carbon monoxide(CO),hydrocarbons(UHC),and nitrogen oxide(NOX)were measured using a gas analyzer.The smoke opacity was measured using an OPABOX smoke meter.By comparing the results related to the different modes with mode I at full load,the BTE(Brake thermal efficiency)increased by 20.17%,11.45%,and 12.66%with modes II,III,and IV,respectively.In comparison to the results for mode II,the BTE decreased due to the combustion of ECB blends by 7.26%and 6.24%for mode III and mode IV,respectively,at full load.In comparison to mode II,the Brake specific energy consumption(BSEC)increased with the ECB substitution.With ECB blends,there is a noticeable decrease in the CO,CO_(2),and UHC emissions at a partial load.Furthermore,the 20%ECB has no effect on CO emissions at full load.For modes II and IV,the CO_(2)increased by 33.33%and 19%,respectively,while the UHC emissions were reduced by 14.49%for mode III and 26.08%for mode IV.The smoke of mode III was lower by 7.21%,but for mode IV,it was higher by 12.37%.In addition,with mode III and mode IV,the NOx emissions increased by 30.50%and 18.80%,respectively.

THE THEORY AND APPLICATION OF THE STRUCTURE LIGHT ENGINEERING SURVEYING BASED ON A LASER THEODOLITE WITH THREE FREEDOMS OF ROTATION

The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning modes and their mathematical models based on laser theodolite with three freedoms of rotation are discussed.According to the features of a huge object,,the structure light engineering surveying based on laser theodolite with three freedoms of rotation is determined as the main method in an actual application.The observation of four sound concrete posts and forced centering plates.Subsequently,it is transformed into the huge object coordinate system.The scanning mode with plumb plane is selected as the main mode in the whole work.And other assistant methods,such as close range photogrammetry and the method of using reflection sheet,are applied to the work of “scanning dead angle”.At last,a surveying accuracy estimation of this method is done and a surveying accuracy test is finished.It can be concluded that the structure light engineering surveying based on laser theodolite with three freedoms of rotation is considered to be an effective and applied method,and has many superiority to some other surveying methods in the work of surveying “confining structure”.

Application of Landscape Smart Lighting in Construction Projects

Currently,to effectively construct high-quality smart cities and achieve comprehensive governance goals,various industries must embrace the transformation and upgrading of traditional management methods through the integration of new technologies.Among these,landscape smart lighting serves as a crucial tool for advancing smart city development.By judiciously applying this technology,it is possible to enhance traditional lighting methods and offer people novel experiences in their daily lives.Recognizing this importance,this article analyzes and organizes the content of landscape smart lighting,delves into its system characteristics,and summarizes its principles and practices in the field of architectural engineering as practical references for application scenarios.

Materials and device engineering to achieve high-performance quantum dots light emitting diodes for display applications

Quantum dots(QDs)have attracted wide attention from academia and industry because of their advantages such as high emitting efficiency,narrow half-peak width,and continuously adjustable emitting wavelength.QDs light emitting diodes(QLEDs)are expected to become the next generation commercial display technology.This paper reviews the progress of QLED from physical mechanism,materials,to device engineering.The strategies to improve QLED performance from the perspectives of quantum dot materials and device structures are summarized.

Scaling law of hydrogen evolution reaction for InSe monolayer with 3d transition metals doping and strain engineering

Recently, two dimensional In Se attracts great attentions as potential hydrogen production photocatalysts.Here, comprehensive investigations on the hydrogen evolution reaction activity of In Se monolayer with3 d transition metal doping and biaxial strain were performed based on the density functional theory.Transition metal dopants significantly increase the bonding strength between H and Se, and then adjust the hydrogen adsorption free energy to 0.02 e V by Zn doping. The enhanced hydrogen evolution reaction activity results from less electron occupying H 1 s-Se 4 pzanti-bonding states, which is well correlated with the pzband center level. Importantly, the universal scalling law was proposed to descript the evolution of hydrogen adsorption free energy including both doping and strain effects. Moreover, with appropriate band alignment, optical absorption, and carriers separation ability, Zn doped In Se monolayer is considered as a promising candidate of visible-light photocatalyst for hydrogen production.

一种基于随机森林和Light GBM的房产估价模型

针对商品房评估方法中存在数据源单一,考虑影响因素理想化,特征工程过分依赖主观经验等问题,结合随机森林和Light GBM模型,提出了一种RF_LightGBM模型用于房产价值评估。首先,通过随机森林对特征进行重要度排序,将影响房产价格因素较小的特征排除,使用网格搜索算法对模型进行优化,最后将该方法用于房产价值评估。在真实的房价数据集上进行的实验表明,相较于随即森林,XGBoost等传统模型,RF_LightGBM模型的评估精度提高了1.7%,且百分误差在0%~10%以内的评估结果占比88.38%。说明所用模型可以很好地应用于房产价值评估,得到的评估结果更加准确。

S vacancy modulated Zn_(x)Cd_(1-x)S/CoP quantum dots for efficient H_(2) evolution from water splitting under visible light

Energy band structure and interfacial compatibility of heterojunctions are crucial for photocatalysts in promoting photogene rated charge separation and transfer.Here,a combined strategy of vacancy engineering and quantum effect via a facile phosphating process is reported,for the first time,to modulate the energy band structure and the interface of Zn_(x)Cd_(1-x)S/CoP quantum dots(ZCS_(v)/CoP QDs)heterojunction.The combined experimental and theoretical investigation revealed that phosphating process transformed CoO_(x) QDs to CoP QDs,and more importantly,generated considerable amount of sulfur vacancies in ZCS_(v).As a result,a TypeⅡZCS_(v)/CoP QDs heterojunction with compatible interfaces was constructed via in-situ generated P-Zn,P-Cd and S-Co bonds,which facilitated the separation and transfer of the photogenerated charge and thus resulted in a high ability towards hydrogen evolution under visible light(17.53 mmol g^(-1) h^(-1)).This work provides an effective and adaptable strategy to modulate band structure and interfacial compatibility of heterojunctions via vacancy engineering and quantum effect.

Assessing Lateral Continuity within the Yammama Reservoir in the Foroozan Oilfield, Offshore Iran: An Integrated Study

Located in Iranian sector of the Persian Gulf, Foroozan Oilfield has been producing hydrocarbons via seven different reservoirs since the 1970 s. However, understanding fluid interactions and horizontal continuity within each reservoir has proved complicated in this field. This study aims to determine the degree of intra-reservoir compartmentalization using gas geochemistry, light hydrocarbon components, and petroleum bulk properties, comparing the results with those obtained from reservoir engineering indicators. For this purpose, a total of 11 samples of oil and associated gas taken from different producing wells in from the Yammama Reservoir were selected. Clear distinctions, in terms of gas isotopic signature and composition, between the wells located in northern and southern parts of the reservoir(i.e. lighter δ13 C1, lower methane concentration, and negative sulfur isotope in the southern part) and light hydrocarbon ratios(e.g. nC 7/toluene, 2,6-dmC7/1,1,3-tmcyC5 and m-xylene/4-mC8) in different oil samples indicated two separate compartments. Gradual variations in a number of petroleum bulk properties(API gravity, V/Ni ratios and asphaltene concentration) provided additional evidence on the reservoir-filling direction, signifying that a horizontal equilibrium between reservoir fluids across the Yammama Reservoir is yet to be achieved. Finally, differences in water-oil contacts and reservoir types further confirmed the compartmentalization of the reservoir into two separate compartments.

Optogenetics and its application in neural degeneration and regeneration

Neural degeneration and regeneration are important topics in neurological diseases. There are limited options for therapeutic interventions in neurological diseases that provide simultaneous spatial and temporal control of neurons. This drawback increases side effects due to non-specific targeting. Optogenetics is a technology that allows precise spatial and temporal control of cells. Therefore, this technique has high potential as a therapeutic strategy for neurological diseases. Even though the application of optogenetics in understanding brain functional organization and complex behaviour states have been elaborated, reviews of its therapeutic potential especially in neurodegeneration and regeneration are still limited. This short review presents representative work in optogenetics in disease models such as spinal cord injury, multiple sclerosis, epilepsy, Alzheimer＇s disease and Parkinson＇s disease. It is aimed to provide a broader perspective on optogenetic therapeutic potential in neurodegeneration and neural regeneration.

Novel Oxygen Storage Components Promoted Palladium Catalysts for Emission Control in Natural Gas Powered Engines

A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.

Spatial light modulation for femtosecond laser manufacturing:Current developments and challenges

Since the invention of lasers,spatial-light-modulated laser processing has become a powerful tool for various applications.It enables multidimensional and dynamic modulation of the laser beam,which significantly improves the processing efficiency,accuracy,and flexibility,and presents wider prospects over traditional mechanical technologies for machining three-dimensional,hard,brittle,or transparent materials.In this review,we introduce:(1)The role of spatial light modulation technology in the development of femtosecond laser manufacturing;(2)the structured light generated by spatial light modulation and its generation methods;and(3)representative applications of spatial-light-modulated femtosecond laser manufacturing,including aberration correction,parallel processing,focal field engineering,and polarization control.Finally,we summarize the present challenges in the field and possible future research.

Vacancy-engineering-mediated activation of excitonic transition for boosting visible-light-driven photocatalytic oxidative coupling of amines

The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompanied with unfavorable changes in redox ability and dynamics of photoinduced species that would confuse the comprehensive optimization.In this work,we propose a nontrivial excitonic transition regulation strategy for gaining sub-bandgap light absorption in low-dimensional semiconductor-based photocatalysts.Using bismuth oxybromide(BiOBr)as a model system,we highlight that the light absorption cut-off edge could be effectively extended up to 500 nm by introducing Bi vacancies.On the basis of theoretical simulations and spectroscopic analyses,we attributed the broadening of light absorption to the promotion of excitonic transition that is generally forbidden in pristine BiOBr system,associated with Bi-vacancy-induced excited-state symmetry breaking.In addition,Bi vacancy was demonstrated to implement negligible effects on other photoexcitation properties like excited-state energy-level profiles and kinetics.Benefiting from these features,the defective sample exhibits a notable advantage in gaining visible-light-driven photocatalytic reactions.

Coupling pinch analysis and rigorous process simulation for hydrogen networks with light hydrocarbon recovery

In refineries,some hydrogen-rich streams contain considerable light hydrocarbons that are important raw materials for the chemical industry.Integrating hydrogen networks with light hydrocarbon recovery can enhance the reuse of both hydrogen and light hydrocarbons.This work proposes an automated method for targeting hydrogen networks with light hydrocarbon recovery.A pinch-based algebraic method is improved to determine the minimum fresh hydrogen consumption and hydrogen sources fed into the light hydrocarbon recovery unit automatically.Rigorous process simulation is conducted to determine the mass and energy balances of the light hydrocarbon recovery process.The targeting procedures are developed through combination of the improved pinch method and rigorous process simulation.This hybrid method is realized by coupling the Matlab and Aspen HYSYS platforms.A refinery hydrogen network is analyzed to illustrate application of the proposed method.The integration of hydrogen network with light hydrocarbon recovery further reduces fresh hydrogen requirement by463.0 m^(3)·h^(-1) and recovers liquefied petroleum gas and gasoline of 1711.5 kg·h^(-1) and 643 kg·h^(-1),respectively.A payback period of 9.2 months indicates that investment in light hydrocarbon recovery is economically attractive.

Ultra-Thin Carbon-Doped Bi_(2)WO_(6) Nanosheets for Enhanced Photocatalytic CO_(2) Reduction

The photocatalytic reduction of CO_(2) is a promising strategy to generate chemical fuels.However,this reaction usually suf-fers from low photoactivity because of insuffi cient light absorption and rapid charge recombination.Defect engineering has become an eff ective approach to improve the photocatalytic activity.Herein,ultra-thin(~4.1 nm)carbon-doped Bi_(2)WO_(6) nanosheets were prepared via hydrothermal treatment followed by calcination.The ultra-thin nanosheet structure of the cata-lyst not only provides more active sites but also shortens the diff usion distance of charge carriers,thereby suppressing charge recombination.Moreover,carbon doping could successfully extend the light absorption range of the catalyst and remarkably promote charge separation,thus inhibiting recombination.As a result,the as-prepared Bi_(2)WO_(6) photocatalyst with ultra-thin nanosheet structure and carbon doping exhibits enhanced photocatalytic CO_(2) reduction performance,which is twice that of pristine ultra-thin Bi_(2)WO_(6) nanosheet.This study highlights the importance of defect engineering in photocatalytic energy conversion and provides new insights for fabricating effi cient photocatalysts.

Directional high-efficiency nanowire LEDs with reduced angular color shift for AR and VR displays

The emission wavelength of InGaN/GaN dot-in-wire LED can be tuned by modifying the nanowire diameter,but it causes mismatched angular distributions between blue,green,and red nanowires because of the excitation of different waveguide modes.Besides,the far-field radiation patterns and light extraction efficiency are typically calculated by center dipoles,which fails to provide accurate results.To address these issues,we first compare the simulation results between central dipole and dipole cloud with experimental data.Next,we calculate and analyze the display metrics for full-color nanowire LEDs by 3D dipole cloud.Finally,we achieve unnoticeable angular color shift within±20°viewing cone for augmented reality(AR)and virtual reality(VR)displays with an improved light extraction efficiency.

基于BIM技术的电力工程施工管理系统的应用及实践

为了提高电力工程项目的施工质量和施工效率,控制施工成本,提出一种基于BIM技术的电力工程施工管理系统。该系统主要由数据层、服务层、应用层构成。数据层以BIM中央数据库作为数据处理单元,存储施工资料、整个数据;服务层通过数据预处理、点云计算、点云配准、点云融合实现BIM模型的构建;应用层通过BIM模型与施工各环节建立联系,实现电力工程施工的全程管理。系统应用结果表明,经过该系统调配后,施工工作面合理、有序,可优化施工人数、提升施工质量、缩短施工周期、降低施工成本。

用于背投电视光学引擎光源的PhlatLight^(TM)光子晶体LED

在投影应用中,采用PhlatLightTM的LED使得基于微显技术的背投电视实现60in或更大屏幕显示成为可能。PhlatLightTM基于光子晶体技术,其独特的设计优化了LED器件的发光特性,使得光能量能够耦合到光学扩展量较小的光学引擎中,以得到很高的光能量利用率。

某轻型国VI CNG客车动力优化匹配

天然气汽车虽然具有良好的排放性和经济性,但也存在动力不足的缺陷,影响整车市场推广和应用。为了能解决压缩天然气(CNG)客车动力性不足的问题,在不改变原发动机结构的基础上,首先,通过调整发动机喷气压力和点火提前角,尽可能减少发动机功率和扭矩损失;然后,将该发动机搭载在轻客某车型上,通过合理设计布置燃气系统;最后,利用整车模拟软件AVLCruise,建立动力性仿真模型,匹配最优的变速箱和后桥速比组合。经过实际道路测试验证,CNG整车动力可达到同类汽油机车型的90%以上,能够满足用户实际使用需求。

基于City Engine的日照分析研究

讨论了光照分析原理以及所准备的数据,提出了基于City Engine的日照分析方法,实现了小区居民楼光照分析。也为快速构建三维大场景建筑物的光照分析提供方法。

解析一款LED成像电脑灯——Robe Robin DLS Profile

通过测试,解析一款LED成像电脑灯的构成、性能及其特点。