通过倾斜多晶硅p-n结光电器件提高光电转换性能

本研究针对多晶硅p—n结光伏器件开展工作。基于倾斜光电转换器件的思想^[1]，倾斜本研究采用的光电转换器件使入射光线与器件表面法线成75度的夹角，从而使红外光在器件内形成多次全反射。这种内部全反射增加了光在器件内的光程，使得光在器件内的吸收得以增加。从采光的角度上发现，倾斜多晶硅光电转换器件可使器件的光电转换效率提高15％。此外，还发现了由倾斜器件造成开路电压稍微减小的现象并给予了解释。     

Reversible Diffraction Efficiency of Photochromic Polymer Gratings Related to Photoinduced Dimensional Changes

In this Full Paper, the possibility of reversibly changing the diffraction efficiency of gratings, fabricated by soft molding lithography on polymer films, containing photochromic molecules, is demonstrated. In particular, alternating UV and visible laser irradiation of the gratings causes the doped photochromic molecules to undergo transformations, which induce reversible dimensional changes to the samples. As a result, reversible changes are monitored in the intensity of the beams of a diode laser, transmitted and diffracted from the gratings. These changes affect the diffraction efficiency, which is increased upon irradiation with UV and decreased after irradiation with visible laser light. Such gratings are promising candidates for the fabrication of modern optical components such as optical switching devices.     

数字/频率、频率/数字转换电路的应用

介绍了数字／频率转换(D／F)一频率／电压转换(F／V)的数据发送方法和电压／频率转换(v／F)一频率／数字转换(F／D)的数据采集方法,并对D／F、F／D电路以及F／V、V／F电路进行了详细介绍。总结了相对于模拟／数字转换(A／D)、数字／模拟转换(D／A)的数据传送方式,D／F、F／D电路的优缺点。     

Preparation and Photoelectric Conversion Mechanism of Semiconducting ITO/Cu2O Electrodes

Semiconducting cuprous oxide films were electrodeposited onto conducting glasses coated with Indium Tin Oxide （ITO） using potentiostatic method. The electrodes were examined by means of X-Ray Diffraction （XRD） and X-ray Photoelectron Spectrum （XPS）. The results indicate that the prepared films are cubic Cu2O crystals, and annealing enhances the size and preferred orientation of the films. The photoelectric conversion mechanism of semiconducting ITO/Cu2O electrodes in 0.1 mol/L potassium sulfate （K2SO4） solution is further discussed by using Linear Sweep Voltammetry （LSV） method. The differences of photoelectric conversion of electrodes are reasonably deduced and proved through surfactant modifying, annealing or not, respectively.     

Preparation and Photoelectric Conversion Mechanism of Semiconducting ITO/Cu2O Electrodes

Semiconducting cuprous oxide films were electrodeposited onto conducting glasses coated with Indium Tin Oxide (ITO) using potentiostatic method. The electrodes were examined by means of X-Ray Diffraction (XRD) and X-ray Photoelectron Spectrum (XPS). The results indicate that the prepared films are cubic Cu2O crystals, and annealing enhances the size and preferred orientation of the films. The photoelectric conversion mechanism of semiconducting ITO/Cu2O electrodes in 0.1 mol/L potassium sulfate (K2SO4) solution is further discussed by using Linear Sweep Voltammetry (LSV) method. The differences of photoelectric conversion of electrodes are reasonably deduced and proved through surfactant modifying, annealing or not, respectively.     

In Situ Growth of Imine-Bridged Anion-Selective COF/AAO Membrane for Ion Current Rectification and Nanofluidic Osmotic Energy Conversion

Facing the energy crisis, using the salinity gradient between seawater and freshwater for osmotic energy conversion is a direct way to obtain energy. So far, most nanofluidic membranes utilized for osmotic energy generation are cation-selective. Given that both anion- and cation-selective membranes have the identical importance for energy conversion devices, it is of great significance to develop anion-selective membranes. Herein, an anion-selective membrane is synthesized by in situ growth of imine-bridged covalent organic framework (COF) on ordered anodic aluminum oxide (AAO) at room temperature. The imine groups and residual amino groups of COF can combine with protons in neutral solution, enabling the COF positively charged and efficiently transport of anions. Particularly, due to the asymmetry in the charge and structure of COF/AAO, the as-prepared membrane exhibits excellent ionic current rectification property, which can inhibit ion concentration polarization effectively and possess high ion selectivity and permeability. Using the present COF/AAO membrane, salinity gradient energy can be successfully harvested from solutions with high salt content, and the output power density reached 17.95W m⁻² under a 500-fold salinity gradient. The study provides a new avenue for construction and application of anion-selective membranes in the smart ion transport and efficient energy conversion.     

大功率集成LED光转换光源的研制

介绍了一种应用远程激发技术的大功率集成LED光转换光源,通过使用固晶区无绝缘层的镜面铝基板进行集成封装蓝光LED光源,即COB光源。所制蓝光光源与远程激发荧光粉模块结合制成LED光转换光源。利用镜面铝基板的高导热系数,解决多种LED封装形式下芯片点亮温度过高、光源衰减快的问题。采用LED荧光高分子模块与蓝光芯片分离结合的远程激发技术制成白光光源,解决荧光粉分布不均、热老化、色偏移问题。通过与传统粉胶封装方式制得的大功率集成LED器件比较测试,该种光源具有防眩光、光色均匀度高、长寿命、节能和环保的优点,从而具有更广泛的用途。     

Alloyable Viscous Fluid for Interface Welding of Garnet Electrolyte to Enable Highly Reversible Fluoride Conversion Solid State Batteries

The garnet-type solid-state Li-metal batteries are promising to develop into the high-energy-density system when coupled with the high-capacity conversion reaction cathodes. However, the high interfacial resistance and poor contact between garnet electrolyte and Li anode are still a challenge. Here, an alloyable viscous fluid strategy is proposed for Li/garnet interface welding to enable highly reversible fluoride conversion solid-state batteries. The super-assembled phenide polymer with liquid metal property can serve as “oily” interlayer to in situ construct an ionic/electronic mixed conduction network by thermal and electrochemical lithiation. The resultant healing effect of contact voids between garnet and Li enables a dramatic reduction of interfacial resistance to 6 Ω cm². The confinement and compaction of conversion products by garnet electrolyte endow the FeF₃ based batteries with long-cycling and high-rate performance (520 and 330 mAh g⁻¹ at 0.2 and 2 C respectively). This ceramic configuration also endows the CuF₂ conversion battery with much better rechargeability (instead as widely known primary battery).     

Gate‐Induced Massive and Reversible Phase Transition of VO2 Channels Using Solid‐State Proton Electrolytes

The use of gate bias to control electronic phases in VO₂, an archetypical correlated oxide, offers a powerful method to probe their underlying physics, as well as for the potential to develop novel electronic devices. Up to date, purely electrostatic gating in 3‐terminal devices with correlated channel shows the limited electrostatic gating efficiency due to insufficiently induced carrier density and short electrostatic screening length. Here massive and reversible conductance modulation is shown in a VO₂ channel by applying gate bias V_G at low voltage by a solid‐state proton (H⁺) conductor. By using porous silica to modulate H⁺ concentration in VO₂, gate‐induced reversible insulator‐to‐metal (I‐to‐M) phase transition at low voltage, and unprecedented two‐step insulator‐to‐metal‐to‐insulator (I‐to‐M‐to‐I) phase transition at high voltage are shown. V_G strongly and efficiently injects H⁺ into the VO₂ channel without creating oxygen deficiencies; this H⁺‐induced electronic phase transition occurs by giant modulation (≈7%) of out‐of‐plane lattice parameters as a result of H⁺‐induced chemical expansion. The results clarify the role of H⁺ on the electronic state of the correlated phases, and demonstrate the potentials for electronic devices that use ionic/electronic coupling.     

Reversible Conversion Reactions and Small First Cycle Irreversible Capacity Loss in Metal Sulfide‐Based Electrodes Enabled by Solid Electrolytes

Solid‐state batteries can potentially enable new classes of electrode materials which are unstable against liquid electrolytes. Here, SnS nanocrystals, synthesized by a wet chemical method, are used to fabricate a Li‐ion electrode, and the electrochemical properties of this electrode are examined in both solid and liquid electrolyte designs. The SnS‐based solid‐state cell delivers a capacity of 629 mAh g^?1 after 100 cycles and exhibits an unprecedentedly small irreversible capacity in the first cycle (8.2%), while the SnS‐based liquid cell shows a rapid capacity decay and large first cycle irreversible capacity (44.6%). Cyclic voltammetry (CV) experiments show significant solid electrolyte interphase (SEI) formation in the liquid cell during the first discharge while SEI formation by electrolyte reduction in the solid‐state cell appears negligible. Along with CV, X‐ray photoelectron spectroscopy and energy dispersive spectroscopy are used to investigate the differences between the solid‐state and liquid cells. The reaction chemistry of SnS in solid‐state cells is also studied in detail by ex situ X‐ray diffraction and X‐ray absorption spectroscopy. The overarching findings are that use of a solid electrolyte suppresses materials degradation and electrolyte reduction which leads to a small first cycle irreversible capacity and stable cycling.     

Physical Properties of Water under the Action by Electricity and Light

The significance of research of water system is demonstrated by the expriments and statistical data.Some physical and chemical properties of water system affected by various factors in the nature are given.It also points out that further research of the effect on extremely complicated water system caused by electricity,magnetic field,sound and light now becomes an important research subject.     

High‐Yield Fabrication,Activation, and Characterization of Carbon Nanotube Ion Channels by Repeated Voltage‐Ramping of Membrane‐Capillary Assembly

The interior channels of carbon nanotubes are promising for studying transport of individual molecules in a 1D confined space. However, experimental investigations of the interior transport have been limited by the extremely low yields of fabricated nanochannels and their characterization. Here, this challenge is addressed by assembling nanotube membranes on glass capillaries and employing a voltage‐ramping protocol. Centimeter‐long carbon nanotubes embedded in an epoxy matrix are sliced to hundreds of 10 µm‐thick membranes containing essentially identical nanotubes. The membrane is attached to glass capillaries and dipped into analyte solution. Repeated ramping of the transmembrane voltage gradually increases ion conductance and activates the nanotube ion channels in 90% of the membranes; 33% of the activated membranes exhibit stochastic pore‐blocking events caused by cation translocation through the interiors of the nanotubes. Since the membrane‐capillary assembly can be handled independently of the analyte solution, fluidic exchange can be carried out simply by dipping the capillary into a solution of another analyte. This capability is demonstrated by sequentially measuring the threshold transmembrane voltages and ion mobilities for K⁺, Na⁺, and Li⁺. This approach, validated with carbon nanotubes, will save significant time and effort when preparing and testing a broad range of solid‐state nanopores.     

MPEG-2到MPEG-4转换编码中场-帧编码宏块转换及运动矢量优化算法

本文针对MPEG-2到MPEG-4转换编码中存在的场、帧编码宏块的不兼容问题,提出了场-帧编码宏块的转 换方法,并重点研究了场-帧转换后的运动矢量生成和优化问题,提出了一种基于残差图像DCT交流系数权重的自适应场 -帧运动矢量优化算法,实验表明其性能良好。     

Pechini法制备TiO_2薄膜及其在染料敏化太阳电池中的应用

用Pechini法在FTO导电玻璃上制备不同厚度的TiO2薄膜,并组装成染料敏化太阳能电池。XRD结果表明,在450℃退火1h得到了主相为锐钛矿的TiO2。SEM结果表明,TiO2薄膜表面疏松多孔,粒径均匀,厚度在6~15μm。紫外-可见光谱分析表明,TiO2薄膜染料的吸附量随薄膜厚度的增加而增加。光电性能研究表明,在0.005W/cm2的弱光照下,膜1(厚6μm)和膜2(厚15μm)光阳极的光电转换效率分别为6.85%和11.83%;在0.1 W/cm2的模拟标准太阳光照下,膜1和膜2光阳极的光电转换效率分别为1.72%和2.39%。     

透镜与电池间距对聚光光伏系统特性影响的实验研究

实验研究了聚光太阳电池上光照强度、短路电流、开路电压、电池温度和光电转换效率随菲涅耳透镜与电池的距离变化关系。结果表明,聚光条件下,太阳电池性能的提高主要源于短路电流的变化,而不是开路电压;聚光后,太阳电池与透镜距离为焦长时,输出功率可以达到最大值;太阳电池的最大单位光强转换效率需要把太阳电池放到透镜焦点前。本文研究结果对于聚光光伏系统的研制具有指导意义。     

Highly Stable Lithium−Sulfur Batteries Promised by Siloxene: An Effective Cathode Material to Regulate the Adsorption and Conversion of Polysulfides

Designing an appropriate cathode is still a challenge for lithium–sulfur batteries (LSBs) to overcome the polysulfides shuttling and sluggish redox reactions. Herein, 2D siloxene nanosheets are developed by a rational wet‐chemistry exfoliation approach, from which S@siloxene@graphene (Si/G) hybrids are constructed as cathodes in Li‐S cells. The siloxene possesses corrugated 2D Si backbone with abundant O grafted in Si₆ rings and hydroxyl‐functionalized surface, which can effectively intercept polysulfides via synergistic effects of chemical trapping capability and kinetically enhanced polysulfides conversion. Theoretical analysis further reveals that siloxene can significantly elevate the adsorption energies and lower energy barrier for Li⁺ diffusion. The LSBs assembled with 2D Si/G hybrid cathodes exhibit greatly enhanced rate performance (919, 759, and 646 mAh g^?1 at 4 C with sulfur loading of 1, 2.9, and 4.2 mg cm^?2, respectively) and superb durability (demonstrated by 1000 cycles with an initial capacity of 951 mAh g^?1 and negligible 0.032% decay rate at 1 C with sulfur loading of 4.2 mg cm^?2). It is expected that the study presented here may open up a new vision toward developing high‐performance LSBs with siloxene for practical applications.     

运用铬钨合金提升四层膜系结构的宽光谱光热转换效率

基于铬钨合金能带结构的研究,得到了可表述任意铬钨合金组分光学性质的数学模型,并将其应用于实际光热器件特性分析.根据由模型获得特定组分铬钨合金的光学性质,设计了一个含有单层铬钨合金吸收层的四层膜结构,显示出优异的宽光谱(300～1 000 nm)光热转换性能.     

非晶As2S3半导体薄膜在激光作用下的性能及结构研究

在激光辐照或退火作用下 ,As2 S3非晶半导体薄膜的光学吸收边出现红移现象 ,并且随着激光功率的增大和辐照时间的延长 ,红移值增大 ,并最后达到饱和。这种红移在先经过退火处理再激光辐照的薄膜中是可逆的。从扫描电镜的形貌图中也可以看出 ,经激光辐照后 ,薄膜表面有晶相出现 ,且随着激光功率的增加 ,晶相出现增多。As2 S3非晶半导体薄膜中光致效应的产生是由于光致结构变化所致 ,对其产生原因 ,进行了机理分析     

Boosting H2O2‐Guided Chemodynamic Therapy of Cancer by Enhancing Reaction Kinetics through Versatile Biomimetic Fenton Nanocatalysts and the Second Near‐Infrared Light Irradiation

Fenton reaction–based chemodynamic therapy (CDT) has attracted considerable attention for tumor treatment, because the Fenton reaction can degrade endogenous H₂O₂ within the tumor to form reactive oxygen species (ROS) to kill cancer cells. The kinetics of the Fenton reaction has significantly influenced its treatment efficacy. It is crucial to enhance the reaction kinetics at the maximum H₂O₂ concentration to quickly produce vast amounts of ROS to achieve treatment efficacy, which to date, has not been realized. Herein, reported is an efficacious CDT treatment of breast cancer using biomimetic CS‐GOD@CM nanocatalysts, which are rationally designed to significantly boost the Fenton reaction through improvement of H₂O₂ concentration within tumors, and application of the second near‐infrared (NIR‐II) light irradiation at the maximum concentration, which is monitored by photoacoustic imaging. The biomimetic nanocatalysts are composed of ultra‐small Cu_2?xSe (CS) nanoparticles, glucose oxidase (GOD), and tumor cell membrane (CM). The nanocatalysts can be retained in tumor for more than two days to oxidize glucose and produce an approximately 2.6‐fold increase in H₂O₂ to enhance the Fenton reaction under the NIR‐II irradiation. This work demonstrates for the first time the CDT treatment of cancer enhanced by the NIR‐II light.