利用红外热像仪检测玻璃钢内部缺陷

实验表明，红外热成像技术可以有效地检查玻璃钢内部脱胶。对玻璃钢内部缺陷的检测来说，本方法优于其它常规方法。     

解密车载玻璃钢天线

近年来业余无线电市场上上悄然出现一类车载型玻璃钢天线,其外形与基地玻璃钢类似,只是直径要细一些,同时重量也轻一些。很多销售商家都向HAM推销这种天线,并称这种天线采用特殊结构,效果比传统钢线制成的车载天线要好,就像固定架设的玻璃钢"棒子"天线一样。那么,事实是否如此呢?车载玻璃钢天线与以钢线为主体的传统车载天线孰优孰劣,下文中笔者将为大家一窥究竟。车载型玻璃钢天线在网上几乎找不到任何制作资料和内部结构图,为了探究车载玻璃钢天线的内部真实结构,笔者在市场购买了一付有一定知名度品牌的高增益玻璃钢车载天线进行测试和解剖。     

漫谈天线性能测试

以常见的玻璃钢垂直天线为例,其内部电气结构与天线的射频性能密切相关,每一单元振子的尺寸决定了天线的工作频率,阵列单元数量决定了天线的增益,阵列结构与实现方法决定了带宽,整体结构形式决定了天线波瓣特性,部件的耐压水平和连接固定工艺决定了天线的最大承受功率。     

基于红外脉冲相位热成像技术的玻璃钢深度测量

为探索红外热成像技术用于玻璃钢材料厚度测量的方法,文中使用闪光灯脉冲激励热成像的方法对玻璃钢平底洞标准件进行检测,通过脉冲相位法(PPT)进行数据处理,提取频域信息、消除噪声,并在试验设备采样频率不能满足盲频测量要求的限制条件下,建立相位阈值,完成了厚度测量。试验结果表明,玻璃钢试件的物理特性会对测量结果造成误差,但经数值优化后可在一定厚度范围内得到和实际深度接近的探测值,该方法可以作为玻璃钢厚度测量的有效手段。     

树脂含量对裱糊玻璃钢的影响

通过对手工裱糊成型工艺中玻璃钢树脂含量的实验，研究玻璃钢树脂含量对裱糊成型工艺中出现的玻璃钢制品发白现象的影响，确定了裱糊工艺的树脂用量，对玻璃钢手工裱糊工艺有一定指导作用。     

变频器在玻璃钢化设备中的应用

本文主要讲述了玻璃钢化的主要原理及变频调速技术在玻璃钢化设备中的应用。     

玻璃钢内衬式人井施工技术

玻璃钢内衬式人井,其玻璃钢内衬具有防污水腐蚀、抗冲刷和寿命长的特点,主要运用于城市给排水设施中的排污管道。本文主要介绍国外城市管网工程中的玻璃钢内衬式人井的施工技术,以供同行参考。     

脉冲红外热波检测技术的影响因素分析

利用ANSYS有限元仿真与试验研究了脉冲红外热波检测技术的影响因素。以玻璃钢、碳纤维及热障涂层三种材料为例进行了仿真,重点研究了环境、被测材料自身缺陷等因素对脉冲红外热波检测的影响,并对玻璃钢和碳纤维两种材料的检测能力进行了判定。对碳纤维和玻璃钢材料进行了试验,研究了实验条件对检测效果的影响,并给出了玻璃钢和碳纤维两种材料的最佳实验参数。     

五米通信天线面板玻璃钢铆胎的设计和制造

采用玻璃钢成型工艺技术制造天线面板铆胎有许多优点，它不仅缩短制造周期而且降低了生产成本。本文从设计和制造两个方面总结了五米通信天线面板玻璃钢铆胎研制过程，研制出的玻璃钢铆胎型面精度为0.2mm(r.m.s.)，达到了设计要求。     

聚脂树脂玻璃钢在卫星电视接收天线中的应用

本文介绍了聚脂树脂玻璃钢天线的结构设计、性能、制造工艺，以及在卫星电视接收天线中的应用情况，供大家广开思路，拓展聚脂树脂玻璃钢的应用领域。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its