用光路转换器技术实现红外/激光兼容的方法

对目标进行昼夜观、瞄、测距的最有效手段是红外与激光的组合使用。８～１２μｍ热象仪和ＣＯ２激光测距机因在技术上有许多共同点，使两者能够实现高程度的组合兼容。本文简要分析了这两种系统可能的组合形式。

激光血管、神经环型吻合仪光转换头的设计

目的 设计并制作激光环形血管、神经吻合仪中起光路转换作用的关键部分光转换头 .方法 使用柱透镜和金属反射面等光学材料组成光转换头将普通激光束转变为环形激光束 .结果 由该光反射头组成的激光血管、神经环形吻合仪能够成功地吻合家兔颈动脉 .结论 这种光反射头能使激光在血管或神经待吻合处的一周形成一个环形照射光束 ,从而一次完成吻合 ,比普通激光吻合速度快 ,损伤小 ,操作方便 ,吻合均匀 .

Wavelet method for processing white light interferogram from optical fiber interferometer

A method based on the wavelet transform is proposed for processing white light Interferograms from optical fiber interferometers.With this method,the envelope and the zero optical path difference(ZOPD) of white light interferograms are obtained with high accuracy.The results agree well with those obtained by the method of center of gravity.Reasons for the insensitivity to noises of this method are discussed.The method is expected to be useful when processing white light interferograms from optical fiber interferometers,especially with low signal-to-noise ratio.

Multiplexing Technique Applied in the Optically Powered Oil-tank Detection System

The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and error code correcting techniques, it realizes optically powered multiple channel and parameters detection, and successfully applied in the oil tanks for temperature, pressure, liquid level and reserve measurings.

Solar-Powered Direct-Current Loads in Small Buildings

Traditional light bulbs （e.g., incandescent, fluorescent） use too much electricity, convert very little energy into light of sufficient quality and in their production use toxic contaminants. During the last few years, a new type of light source, LED （light emitting diode） bulb, has gained increasing popularity and its costs are set to plunge even further. LED bulbs offer many advantages over traditional sources, and they can be used as a direct replacement to existing lighting. This paper will use a spreadsheet-based analysis with hourly solar data supplied by Ecotect to show that, the efficiency of LED installations can be increased when used in conjunction with photovoltaic modules, as the two generate （and use） DC （direct-current） electricity, thereby eliminating intermediate-level losses in the electronic circuitry. If a storage battery is included, the solar panels generate electricity during the times when the occupants are not necessarily using the lighting, but the stored electricity can be used to power the lighting when the energy is required. The latest results demonstrate that, a slight reduction in the required floor area to be lit allows the solar-battery-LED system to be implemented in small buildings using a storage battery size that is within the range of present commercial devices.

A newly-designed self-powered electrochromic window

By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light.The device consists of a working electrode with planar integration of photovoltaic(PV)and electrochromic(EC)elements on one electrode,a platinum counter electrode and a redox electrolyte comprising Br^-/Br_3^-couple.A high transmittance modulation of 41%at 582 nm is obtained.Electrical energy converted from light is not only sufficient to drive the device,but also can be outputted to the external circuit.

CsPbBrI perovskites with low energy loss for high-performance indoor and outdoor photovoltaics

Over the years,the efficiency of inorganic perovskite solar cells(PSCs)has increased at an unprecedented pace.However,energy loss in the device has limited a further increase in efficiency and commercialization.In this work,we used(NH4)2C2O4·H2O to treat CsPbBrI2 perovskite film during spin-coating.The CsPbBrI2 underwent secondary crystallization to form high quality films with micrometer-scale and low trap density.(NH4)2C2O4·H2O treatment promoted charge transfer capacity and reduced the ideal factor.It also dropped the energy loss from 0.80 to 0.64 eV.The resulting device delivered a power conversion efficiency(PCE)of 16.55%with an open-circuit voltage(Voc)of 1.24 V,which are largely improved compared with the reference device which exhibited a PCE of 13.27%and a Voc of 1.10 V.In addition,the optimized treated device presented a record indoor PCE of 28.48%under a fluorescent lamp of 1000 lux,better than that of the reference device(19.05%).

Alloy-like ternary polymer solar cells with over 17.2% efficiency

Ternary strategy has been considered as an efficient method to achieve high performance polymer solar cells(PSCs). A power conversion efficiency(PCE) of 17.22% is achieved in the optimized ternary PSCs with10 wt% MF1 in acceptors. The over 8% PCE improvement by employing ternary strategy is attributed to the simultaneously increased JSCof 25.68 mA cm^-2, VOCof 0.853 V and FF of 78.61% compared with Y6 based binary PSCs. The good compatibility of MF1 and Y6 can be confirmed from Raman mapping, contact angle,cyclic voltammetry and morphology, which is the prerequisite to form alloy-like state. Electron mobility in ternary active layers strongly depends on MF1 content in acceptors due to the different lowest unoccupied molecular orbital(LUMO) levels of Y6 and MF1, which can well explain the wave-like varied FF of ternary PSCs. The third-party certified PCE of 16.8% should be one of the highest values for single bulk heterojunction PSCs. This work provides sufficient references for selecting materials to achieve efficient ternary PSCs.

Research Progress of Optical H2O Sensor With a DFB Diode Laser

In the field of near infrared H2O sensing, the acquisition of the absorption signal usually is from a noisy background, thus it is important to adopt an effective signal demodulation method. This study introduced the research progress in the field of trace water vapor detection, covering different individual gas detection techniques. On the basis of the conventional double-beam differential absorption, the division method in voltage and the dual-peak method based on the differential value of two adjacent absorption lines have been studied. Voltage division has an excellent stability to temperature variation, mechanical extrusion, and fiber bend loss. The dual-peak method proved a linear relation with the water vapor concentration, and this method provided a way to measure the concentration at high pressure. Furthermore, the so called balanced ratiometer detection （BRD） was introduced. It has an outstanding self-adjusting capability, and it can also avoid an excess phase difference caused by the current-to-voltage converting circuit, thus this method has a high sensitivity. In addition, the second harmonic technique applied to gas detection was introduced, and for the high-frequency modulation via driving current, l/f was suppressed apparently; as a result, this technique realized a better sensitive detection by one to two orders of magnitude.

Formation of efficient dye-sensitized solar cells by introducing an interfacial layer of hierarchically ordered macro-mesoporous TiO_2 film

Hierarchically ordered macro-mesoporous TiO2 films (Ti-Ma-Me) were fabricated on fluorine-doped tin oxide (FTO) substrates through the confinement self-assembly method. The prepared Ti-Ma-Me possesses periodically ordered structure and a large specific surface area, which was applied as an interfacial layer between the nanocrystalline TiO2 film (P25-TiO2) and FTO electrode in the dye-sensitized solar cell (DSSC). The introduction of a Ti-Ma-Me interfacial layer increased the shortcircuit current density (Jsc) from 7.49 to 10.65 mA/cm2 and the open-circuit voltage (Voc) from 0.65 to 0.70 V as the result of its improved light harvesting efficiency by allowing for the high roughness factor and enhanced multiple internal reflection or scattering as well as reducing the back-transport reaction by blocking direct contact between the electrolyte and FTO electrode. Therefore, the photovoltaic conversion efficiency (η) was improved by 83% from 3.04% to 5.55%, as compared to a device using a bare P25 TiO2 photoanode.

A low-temperature TiO2/SnO2 electron transport layer for high-performance planar perovskite solar cells

Conventional titanium oxide(TiO2) as an electron transport layer(ETL) in hybrid organic-inorganic perovskite solar cells(PSCs) requires a sintering process at a high temperature to crystalize, which is not suitable for flexible PSCs and tandem solar cells with their low-temperatureprocessed bottom cell. Here, we introduce a low-temperature solution method to deposit a TiO2/tin oxide(SnO2) bilayer towards an efficient ETL. From the systematic measurements of optical and electronic properties, we demonstrate that the TiO2/SnO2 ETL has an enhanced charge extraction ability and a suppressed carrier recombination at the ETL/perovskite interface, both of which are beneficial to photo-generated carrier separation and transport. As a result, PSCs with TiO2/SnO2 bilayer ETLs present higher photovoltaic performance of the baseline cells compared with their TiO2 and SnO2 single-layer ETL counterparts. The champion PSC has a power conversion efficiency(PCE) of 19.11% with an open-circuit voltage(Voc)of 1.15 V, a short-circuit current density(Jsc) of 22.77 mA cm^-2,and a fill factor(FF) of 72.38%. Additionally, due to the suitable band alignment of the TiO2/SnO2 ETL in the device, a high Vocof 1.18 V is achieved. It has been proven that the TiO2/SnO2 bilayer is a promising alternative ETL for high efficiency PSCs.

Polypyrrole-cobalt-carbon nanocomposites as efficient counter electrode materials for dye-sensitized solar cells

In this work, we demonstrate a new kind of Pt-free counter electrode for dye-sensitized solar cells(DSCs). Polypyrrole-cobalt-carbon(PPY-Co-C) nanocomposites, with the advantages of low cost and simple preparation, show favorable catalytic activity in promoting tri-iodide reduction. The DSC composed of the PPY-Co-C nanocomposite electrode exhibits an acceptable energy conversion efficiency of 6.01%, a considerable short-circuit photocurrent of 15.33 mA cm-2, and a low charge-transfer resistance of 1.5 Ω cm2. The overall performance of PPY-Co-C is superior to the carbon counterparts and comparable with the platinum reference, rendering them efficient and promising counter electrode materials for DSCs.

Photo-stable perovskite solar cells with reduced interfacial recombination losses using a CeO interlayer

Despite demonstrating remarkable power conversion efficiencies(PCEs), perovskite solar cells(PSCs) have not yet achieved their full potential. In particular, the interfaces between the perovskite and charge transport layers account for the vast majority of the recombination losses.Interfacial contact and band alignment between the lowtemperature-processed TiO_(2) electron transport layer(ETL)and the perovskite are essential to minimize nonradiative recombination losses. In this study, a CeOx interlayer is employed to modify the perovskite/TiO_(2) interface, and the charge transport properties of the devices are investigated. The bilayer-structured TiO_(2)/CeOx ETL leads to the modification of the interface energetics, resulting in improved electron extraction and reduced nonradiative recombination in the PSCs.Devices based on TiO_(2)/CeOx ETL exhibit a high open-circuit voltage(Voc) of 1.13 V and an enhanced PCE of more than 20%as compared with Vocof 1.08 V and a PCE of approximately 18% for TiO^(2-)based devices. Moreover, PSCs based on TiO_(2)/CeOx ETL maintain over 88% of their initial PCEs after light illumination for 300 min, whereas PSCs based on TiO_(2) ETL almost failed. This study provides an efficient strategy to enhance the PCE and stability of PSCs based on a lowtemperature-processed TiO_(2) ETL.