照明价值的关键要素:单位光成本与平均光效的研究

从科学客观的角度,以光价值为基础,探讨分析"光成本"这一评价依据,提出高能效、单位光成本、平均光效等检验光成本的核心参数,分析决定照明价值的关键要素。

照明价值的关键要素单位光成本与平均光效的研究

从科学客观的角度,以光价值为基础,探讨分析"光成本"这一评价依据,提出提高能效、照明的核心以人为本的光、单位光成本、平均光效等检验光成本的核心参数,分析决定照明价值的关键要素。

基于加权光流能量的异常行为检测

为了减少光线突变对光流提取的干扰,实时、可靠地提取运动目标前景,采用双背景模型方法,即自适应的滑动平均背景更新算法融合HSV颜色空间背景模型提取前景。在运动目标前景的最小邻接矩形区域内,采用Lucas-Kanade方法计算光流信息,通过光流信息计算出运动目标的单位加权光流能量来判断是否发生异常行为。在室内外环境的实验结果表明:该方法能够稳定地检测人的异常行为,鲁棒性较高,计算复杂度较低,能够满足实时性要求。

光伏发电单元系统中电池组件功能和进展研究

文章针对光伏发电单元系统中电池组件的进展情况进行分析,结合光伏发电单元系统中电池组件功能分析,包括EVA材料、玻璃盖板、硅电池片、背板材料、密封条与边框等,通过研究影响光伏发电单元系统中电池组件应用效率的因素,包括表面积灰、阴影遮挡、组件性能不匹配等,目的在于提升光伏发电单元系统的工作效率,提高光伏发电厂的工作效率。

首届“奥力杯”中国焊接摄影大赛作品欣赏(之一)

这里,有焊花飞舞的灵动,有弧光铁水的神韵,有写满激情的乐章……您还犹豫什么?只待,用艺术的眼光欣赏焊接!用跳跃的心灵感受焊接!用灵巧的双手描摹焊接!生产中,只要定格美丽瞬间!生活中,只要挥毫泼墨!旅程里,只要有感而发!摄影、诗词、书法、绘画……"焊接艺苑",都为您留有一片自由发挥的"艺术天地"!

Relations Between Red Edge Characteristics and Agronomic Parameters of Crops

The hyperspectral reflectance of the canopy and the leaves on the main stemfor six varieties, two each of rice corn, and cotton crops, were measured at different growth stageswith an ASD FieldSpec Pro FR^(TM) to analyze red edge characteristics forleaf area indices (LAI),aboveground biomass, as well as the chlorophyll, carotenoid, and nitrogen content, emphasizingcomparative differences on the red edge parameters. The results showed a 'double peak' phenomenonfor the red edge of the canopy spectra but not for the leaves. There were 'increase' and 'decrease'change rules for the red edge position, lambda_r, the red edge slope, D lambda_r, and the red edgearea, S_r, of the canopy spectra for all 3 crops with a 'blue shift' for lambda_r of the leafspectra for all 3 crops as the development stages progressed. For rice, corn, and cotton the LAI andfresh leaf mass had highly significant correlations (P < 0.01) to the red edge parameters lambda_r,D lambda_r, and S_r of their canopy spectra. Additionally, for all crops the chlorophyll-a,chlorophyll-b, total chlorophyll, and carotenoid content of the leaves all had highly significant (P< 0.01) correlations to their lambda_r. For rice, the nitrogen content of the leaves in g kg^(-1)and phytomassfor a unit area of land in g m^(-2) also had a highly significant (P < 0.01)correlation to lambda_r, D lambda_r lambda_r, and S_r of the canopy spectra.

Effect of Initial Frequency Chirp on Supercontinuum Generation in Dispersion-flattened Fibers

Supercontinuum generation in dispersion-flattened fibers is studied theoretically. It is found that the flat spectral width of the supereontinuum generation in normal dispersion-flattened fiber can be increased from 66 nm to over 100 nm when the absolute value of the initial frequency chirps is increased from zero to 10. It is further found that initial frequency chirps are adverse to flat and wideband supercontinuum generation in anomalous dispersion-flattened fiber, and when the absolute value of the frequency chirps is increased to a certain degree, supercontinuum spectrum even can not be achieved.

Optical Fiber Instrument for Single-point Multi-parameter Measurement

A novel kind of optical fiber instrument for two channel measurement of temperature and displacement was developed. Four channel quartz fiber optics were employed to measure two channel signals of temperature and displacement simultaneously, and the operating efficiency of this instrument was greatly improved.

Heterogeneous N-coordinated single-atom photocatalysts and electrocatalysts

Single-atom catalysts(SACs)have been widely used in heterogeneous catalysis owing to the maximum utilization of metal-active sites with controlled structures and well-defined locations.Upon tailored coordination with nitrogen atom,the metal-nitrogen(M-N)-based SACs have demonstrated interesting physical,optical and electronic properties and have become intense in photocatalysis and electrocatalysis in the past decade.Despite substantial efforts in constructing various M–N-based SACs,the principles for modulating the intrinsic photocatalytic and electrocatalytic performance of their active sites and catalytic mechanism have not been sufficiently studied.Herein,the present review intends to shed some light on recent research made in studying the correlation between intrinsic electronic structure,catalytic mechanism,single-metal atom(SMA)confinement and their photocatalytic and electrocatalytic activities(conversion,selectivity,stability and etc).Based on the analysis of fundamentals of M–N-based SACs,theoretical calculations and experimental investigations,including synthetic methods and characterization techniques,are both included to provide an integral understanding of the underlying mechanisms behind improved coordination structure and observed activity.Finally,the challenges and perspectives for constructing highly active M–N based photocatalysis and electrocatalysis SACs are provided.In particular,extensive technical and mechanism aspects are thoroughly discussed,summarized and analyzed for promoting further advancement of M-N-based SACs in photocatalysis and electrocatalysis.

Synthesis and characterization of red-emission PPV copolymers containing fluorenone unit

Two soluble copolymers of fluorenone and dioctoxylbenzene （PFN） or anthracene （PFNAn） were synthesized through Heck polymerization, and were characterized by gel permeation chromatography （GPC）, FT-IR, IH-NMR, elemental analysis and thermogravimetric analysis. The polymers possess good solubility in common organic solvents and high thermal stability with the Onset decomposition temperature at higher than 410 ℃. The photophysical properties of the polymers were investigated in both solutions and spin-coated films. Cyclic voltammetry results revealed that the copolymers possess higher electron affinity and reversible reduction/re-oxidation processes. Their electroluminescent properties were further investigated. PFN and PFNAn show stable and saturated red light emission with high thermal stability and high electron injection ability. This type of conjugated polymers may be promising for the applications as electron acceptors in polymer photovoltaic cells and electron transporting materials.

The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

An indoor positioning system for mobile target tracking based on VLC and IMU fusion

An indoor positioning system( IPS) is designed to realize positioning and tracking of mobile targets,by taking advantages of both the visible light communication( VLC) and inertial measurement unit( IMU). The platform of the IPS is designed,which consists of the light-emitting diode( LED)based transmitter,the receiver and the positioning server. To reduce the impact caused by measurement errors,both inertial sensing data and the received signal strength( RSS) from the VLC are calibrated. Then,a practical propagation model is established to obtain the distance between the transmitter and the receiver from the RSS measurements. Furthermore,a hybrid positioning algorithm is proposed by using the adaptive Kalman filter( AKF) and the weighted least squares( WLS)trilateration to estimate the positions of the mobile targets.Experimental results show that the developed IPS using the proposed hybrid positioning algorithm can extend the localization area of VLC,mitigate the IMU drifts and improve the positioning accuracy of mobile targets.

Consideration of Shape Characteristics for Apartments Incorporating Daylight and Energy Performance

The objective of this paper is to design units with well-lighted environment and low-energy consumption in the apartment building. Their daylight and energy performance can be determined by the building shape and orientation. The paper initially produced the results of illuminations and energy efficiency using the daylight and thermal simulations by Autodesk ＂ECOTECT＂. It then provided the comparison on simulation results of two type buildings： Flat-type and L-type apartment. The available options for the design incorporating the environmental performance have less flexibility in fiat-type apartments than in L-type ones. The best unit in the fiat apartment is fixed from -45 to 45 degrees rotation, however, that in the L-type one can change depending on rotating the building. Moreover, if the upper level units had the appropriate environment, the lower level could have larger window areas in order to meet those daylight performance needs. Results show that the facade design should have the different window areas depending on the location of each unit. It can assist in the comfort and low-energy consumption design by using simulation tools that achieve the more predictable understandings.

Lyase Activities of Heterologous CpcS and CpcT for Phycocyanin Holo-β-subunit from Arthrospira platensis in Escherichia coli

Arthrospira platensis is an economically important cyanobacterium; and it has been used widely in food and pharmaceutical industries. The phycocyanin(PC) from A. platensis is extremely valuable in medicine and molecular biology due to its antioxidation and anti-tumoring activity and applicability as fluorescence protein tag. In present study, two recombinant plasmids, one contained the phycocyanobilin(PCB)-producing genes(hox1 and pcyA) while the other contained the phycobiliprotein gene(cpcB) and the lyase gene(either cpcS/U or cpcT), were constructed and synchronically transferred into E. coli in order to test the the activities of relevant lyases for catalysing PCB addition to CpcB during synthesizing fluorescent PC holo-β-subunit(β-PC) of A. platensis. As was evidenced by the fluorescence emitted at a peak specific for PC, CpcB was successfully synthesized in E. coli, to which co-expressed PCBs attached though at a relatively low efficiency. The results showed that the attachment of PCBs to CpcB were carried out mainly by co-expressed CpcS/U but CpcB also showed some autocatalytic activity. Currently, no CpcT activity was detected in this E. coli expression system. Further studies will be conducted to improve the efficiency of fluorescent PC synthesis in E. coli.

42英寸彩色壁挂显示屏将于今年面市

多年来,显示屏制造商早巳预告壁挂式扁平电视美化全世界起居室的一天将来临。随着宽屏幕电视在日本和大屏幕电视在美国日益流行,显示屏已变得越来越大和越来越扁平。如今富士通公司已开发出对角线42英寸的宽屏幕彩色等离子体显示屏(PDP)。它夸耀这种75毫米厚的显示屏能与最好的阴极射线管媲美:1670万种彩色、每平方米300新烛光(光强单位)和对比度系数为70:1。

Teleportation of Bipartite Entangled State Without Joint Measurement

In this paper, we present a probabilistic teleportation scheme for unknown bipartite entangled state. By using linear optical elements, we convert the Bell-state measurement into separated single-qubit measurements.

Tracking Submicron Particles in Microchannel Flow by Microscopic Holography

Three-dimensional tracking of submicron particles in flows in a micro-channel was carried out using in-line holographic microscopy.A fixed single 0.5 μm fluorescent particle was identified and isolated from dust particles or overlapped particle pair using the laser induced fluorescent(LIF) method.Then in-line microscopic holograms of the fixed single particle were obtained at different positions on the optical axis,i.e.the defocus distances.The holograms of the single particle were used as the model templates with the known defocus distances.The particles in the in-line microscopic holograms of flow in the microchannel were then identified and located to obtain their two-dimensional positions.The defocus distances of those particles were determined by matching each hologram pattern to one of the model templates obtained in the single particle test.Finally the three-dimensional position and velocity of each particle were obtained.

Rest Thallium-201/Stress Technetium-99m Sestamibi Dual-Isotope Myocardial Perfusion Single-Photon Emission Computed Tomography in Detecting of Chronic Coronary Artery Disease

To investigate diagnostic accuracy of 2-hour protocol of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT in chronic coronary artery disease. Sixty-seven patients with suspected CAD were enrolled in the prospective study. All patients underwent myocardial perfusion scintigraphy in SPECT with dual isotopes of T1-201 and dipyridamole stress Tc-99m sestamibi. Rest and stress imaging protocol were performed in 2 hours by dose of 3 mCi TI-201 and 25 mCi Tc-99m sestamibi. The acquisition parameters includes LEHR collimator, energy peak of 72 and 167 keV for T1-201 and 140 keV for Tc-99m, 180-degree rotation from RAO to LPO, matrix size 64x64, and 25second/frame/64 frames. The 20-segment model of left ventricle was used in automatic quantitation software. Coronary angiography was used as gold standard. CAD was defined as 50% of lumen stenosis on coronary angiography. Rest TI-201/stress tc-99m sestamibi dual-isotope SPECT demonstrated a sensitivity of 94.59% and specificity of 70%, positive predictive value of 79.54% and negative predictive value of 91.3% in detection of coronary artery disease. Sensitivity and specificity for detecting multi-vessel coronary artery disease were 82.75% and 81.57% for the left anterior descending, 77.77% and 91.83% for left circumflex and 94.11% and 82% for right coronary artery. 2-hour protocol of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT has high sensitivity, specificity, positive predictive value and negative predictive value in detecting chronic coronary artery disease with greater than 50% stenosis assessed by coronary angiography Moreover, this imaging protocol gives high imaging quality, time-saving and convenience.

Effect of electroacupuncture on expression of NR2B in prefrontal cortex in morphine-withdrawal rats

Objective To observe the effect of electroacupuncture （EA） on learning and memory abilities and expression of N-methyI-D-aspartate receptor subunit （NR2B） in prefrontal cortex in morphine-withdrawal rats and to investigate the molecular biological mechanisms. Methods Thirty-six male SD rats were randomly divided into four groups, namely control group （group A）, model group （group B）, model with acupuncture group （group C） and model with electroacupunture group （group D）, with 9 in each group. All rats except those in group A were subcutaneously injected with morphine hydrochloride injectio on the back with daily dosage increased day by day. Naloxone was given 3 h after the last injection to establish the models of morphinewithdrawal rats. After the models were established, the rats were treated with acupuncture and electroacupuncture respectively at bilateral ＂Shenshu＂ （肾俞 BL 23） and ＂Zusanli＂ （足三里 ST 36） for 15 min per time, once daily for 6 days. Space learning and memory abilities of the rats were measured by Morris water maze, and protein and gene expression levels of NR2B in prefrontal cortex were measured by Western Blot and RT-PCR. Results In place navigation test, the escape latency in group B, group C and group D was significantly prolonged compared with that of group A （P〈0.01）, the escape latency in group C and group D was significantly shortened compared with that of group B （P〈0.01） and the escape latency in group D was significantly shortened compared with that of group C （P〈0.05）; during spatial probe test, the number of times crossing the platform of group B, group C and group D decreased compared with that of group A （P〈0.01）, and compared with group B, the number of times crossing the platform of group C increased and the number of group D significantly increased （P〈0.01）. Decreased protein expression level of NR2B was found in group B when compared with that of group A （P〈0.01）, increased protein expression levels of NR2B were found in group C and group D when compared with that of group B （P〈0.01）, however, the expression level in group D was higher than that in group C （P〈0.01）. mRNA expression level of NR2B in prefrontal cortex in morphine-withdrawal rats decreased （P〈0.05）, however, compared with that of group B, the expression level increased in group D （P〈0.05）, and there was no statistical significance in increased expression level in group C （P〉0.05）. Conclusion Acupuncture and eletroacupunture can improve space learning and memory abilities of merphine-withdrawal rats, with better efficacy of eletroacupuncture than that of acupuncture, the mechanisms of which may be associated with the regulation of NR2B expression in prefrontal cortex.

Aggregation-enhanced emission and efficient electroluminescence of conjugated polymers containing tetraphenylethene units

Tetraphenylethene (TPE) is a popular luminogen characterized by aggregation-induced emission and has been widely used to construct solid-state emissive materials. In this work, two thermally stable polymers (P1 and P2) consisting of TPE conjugated to the 2,7-positions of fluorene and carbazole, respectively, are synthesized and characterized. Both polymers are weakly fluorescent in solutions but show greatly enhanced emission as the aggregate formation, presenting an aggregation-enhanced emission feature. Two kinds of polymer light-emitting diodes are fabricated utilizing P1 and P2 as emitters (EML) (device I: ITO/PEDOT:PSS (45 nm)/PVK:EML (1:1 wt%, 55 nm)/TPBI (38 nm)/Ca:Ag; device II: ITO/PEDOT:PSS (45 nm)/ PVK:OXD-7:EML (3:1:3 wt%, 55 nm)/TPBI (38 nm)/Ca:Ag). The device II of P2 shows the best performances, affording a maximum luminance of 6500 cd/m 2 and a high peak efficiency of 2.11 cd/A.