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The passive measurements of object's directional emissivity in laboratory

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Science China(Technological Sciences) 2000年第S1期43卷 55-61页

作者：徐希孺陈良富庄家礼 Institute of RS & GIS Peking University Beijing China

In 1991, J. Labed, et al. offered a formula of passive measurement of directional emissiv-ity of object in laboratory. It is based on two preconditions, blackbody background radiation and the temperature of target (T,) different to background temperature (Tb) and the bigger the difference Δ T=Tt-Tb) is , the higher the accuracy of measurement will be. In fact, only approximate black-body exists, as Tt≠Tb, it is more difficult to satisfy the precondition of "blackbody background radiation". Authors of this paper re-deduce this formula under the condition of non-blackbody background and a new concept of effective emissivity. Our results had been proven by Monte Carlo’s simulation and experiments. We re-explain the experimental results offered by J. Labed et al. and why εr, 3.7(θ) reduces more rapidly than εr1 10.6(θ) and εr1 12(θ) as θincreases.

关键词： emissivity passive measurement.

Coherent passive optical network for 5G and beyond transport

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Optoelectronics Letters 2021年第9期17卷 546-551页

作者： Waseem W.Shbair Fady I.El-Nahal KN Group Dublin D22 YP38Ireland Islamic University of Gaza Gaza P.O.Box 108Palestine

Building low-latency and high-capacity optical networks is vital for new high-speed cellular *** wavelength division multiplexing passive optical networks(WDM-PONs)are expected to play a key role in these *** this article,an overview of PON technologies for the 5 th generation(5 G)transport systems has been ***,a modified scheme based on coherent WDM-PON has been investigated using a dual polarization quadrature phase shift keying(DP-QPSK)*** aim of the scheme is to build a 1600 Gbit/s network that will be used in the construction of the transport architecture of 5 G and beyond cellular networks either in mobile front haul(MFH)or mobile back haul(MBH).The results indicate that the proposed scheme offers a promising solution for future 5 G transport systems.

关键词： passive network beyond

Research of Application of passive Natural Ventilated Strategies of High-Density Urban Area

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Journal of Harbin Institute of Technology(New Series) 2014年第5期21卷 59-65页

作者： De-Xuan Song Shao-Yu Liu Si-Jie Liu College of Architecture and Urban Planning Tongji University College of Architecture Hongkong University

High-density development is becoming an inevitable tendency in Chinese urbanization. In this study,the application of natural ventilation in high-density urban development is discussed. Based on the domestic and foreign study on natural ventilation,indoor and outdoor natural ventilated strategies,and the application on natural ventilation in underground space development are analyzed. From the study,the relationship between passive and active ventilated technologies is interpreted into what is described to be synergistic,complementary and additive.

关键词： high-density natural ventilation passive strategies

Enhancing the Stability of passive Film on 304 SS by Chemical Modification in Alkaline Phosphate–Molybdate Solutions

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Transactions of Tianjin University 2020年第2期26卷 135-141页

作者： Chengcheng Pan Yang Song Weixian Jin Zhenbo Qin Shizhe Song Wenbin Hu Da-Hai Xia Tianjin Key Laboratory of Composite and Functional Materials Tianjin 300354China School of Materials Science and Engineering Tianjin UniversityTianjin 300354China Zhoushan Marine Corrosion Institute of Central Research Institute of Iron and Steel Zhoushan 316003China

The purpose of this work was to enhance the corrosion resistance of the passive fi lm on 304 stainless steel(SS)by chemical modifi cation in alkaline phosphate–molybdate *** 304 SS was passivated in both phosphate and phosphate–molybdate mixed solutions to investigate the eff ect of molybdate on its corrosion *** experimental results indicated that the passive fi lm showed better corrosion resistance in Cl?-containing solutions after modifi cation in phosphate–molybdate solutions than in phosphate-only ***-dispersive spectroscopy analyses revealed that the passive fi lm formed in phosphate–molybdate solutions contained Mo and P after modifi cation,which is the reason for the enhanced corrosion resistance.

关键词： passive fi lm 304 SS Corrosion Phosphate Molybdate

Measurement　of　Excursion　of　Finger　Flexor　Tendons　Produced　by　a　Continuous　passive　Motion　Machine

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中华骨科杂志 1995年第2期15卷 76-83页

作者： Yoshida E Dent JA Rowley JI From the Department of Orthopaedic and Trauma Surgery University of Dundee Scotland

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ＭｅａｓｕｒｅｍｅｎｔｏｆＥｘｃｕｒｓｉｏｎｏｆＦｉｎｇｅｒＦｌｅｘｏｒＴｅｎｄｏｎｓＰｒｏｄｕｃｅｄｂｙａＣｏｎｔｉｎｕｏｕｓＰａｓｓｉｖｅＭｏｔｉｏｎＭａｃｈｉｎｅＹｏｓｈｉｄａＥ；ＤｅｎｔＪＡ；ＲｏｗｌｅｙＪＩＲｅｃｅｉｖｅｄ９Ａｕｇｔｔｓｔ１...

关键词：掌指关节指尖手指指间关节指关节 Continuous Excursion Finger Flexor Machine Measurement Motion passive Produced Tendons

Practical Performance of passive Thermal Catalysis for Indoor Formaldehyde

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Journal of Harbin Institute of Technology(New Series) 2019年第2期26卷 55-60页

作者： Ge Zhang Yan Li Jiao Bai Qunli Zhang Jing Liu School of Civil and Resource Engineering University of Science and Technology Beijing Beijing Key Lab of Heating Gas SupplyVentilating and Air Conditioning EngineeringBeijing University of Civil Engineering and Architecture School of Civil Engineering Henan Polytechnic University

The purpose of this study is to investigate the practical performance of passive thermal catalysis for indoor formaldehyde. A heating plate coated with noble metal catalyst Pt/TiO_2 was made to simulate the radiators with a passive thermal catalysis function. The formaldehyde degradation rate in the presence of the simulated radiator was measured in a stainless-steel chamber under controlled temperature and compared with that in the presence of catalyst powder. The influence of temperature and the concentration of formaldehyde on the degradation performance was measured thoroughly and fitted in the polynomial form. It was found that the degradation capability of the coated catalyst dropped from that of the catalyst power, and the degradation capability trends of both materials in various temperatures were different. The clean air delivery rate(CADR) was found to be merely the function of temperature and irrelevant to indoor formaldehyde concentration in the investigated range.

关键词： formaldehyde Pt/TiO2 degradation passive thermal catalysis CADR

Package-level passive equalization technology enabling DML-based 112 Gbps/λ PAM4 transmission

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Chinese Optics Letters 2019年第12期17卷 15-20页

作者： Zhike Zhang Jinye Li Zeping Zhao Jianguo Liu Xingjun Wang State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871China Frontiers Science Center for Nano-optoelectronics Peking UniversityBeijing 100871China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

We demonstrate a package-level passive equalization technology in which the wire-bonding-induced resonance effect is used to compensate for the limited gain strength within the Nyquist *** corresponding gain strength under various inductance and capacitance combinations could be quantitatively determined using a numerical *** the increase in the Nyquist frequency,the capacitance shows a greater effect on the gain strength than the ***,the parasitic capacitance should be decreased to realize the desired gain strength at a higher Nyquist *** this equalization technology,gain strength of 5.8 dB is obtained at 22 GHz,which can compensate for the limited bandwidth for the 112 Gbps pulse amplitude modulation(PAM4)*** experimental results show that 112 Gbps/λ PAM4 transmission based on a directly modulated laser(DML)module can be realized with a bit error rate of 1×10^-3 at a received optical power of 3d Bm.

关键词： passive Gbps capacitance

Tensor feature extraction of underwater passive sonar target based on auditory model

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Chinese Journal of Acoustics 2020年第3期39卷 341-350页

作者： KANG Chunyu XIA Zhijun ZHANG Xinhua ZHANG Yi GUO Dexin Department of Underwater Weaponry and Chemical Defense Dalian Navy AcademyDalian 116018 Department of Graduate Student Dalian Navy AcademyDalian 116018

Feature extraction is a key step for underwater passive sonar target classification and recognition.A kind of tensor feature extraction method based on auditory PattersonHoldsworth cochlear model is ***,the filter impulse response of the cochlear model is regarded as the basis function of signal decomposition,and the center frequency of different channels is determined according to the nonlinear scale or conventional linear scale of the auditory ***,the gain and bandwidth of the corresponding channel are calculated,and the order and phase parameters of the impulse response are quantified to obtain a relatively complete signal decomposition *** according to the principle of signal decomposition,the third-order tensor features of channel number-order number-phase number are ***,the classification and recognition of the underwater passive sonar target is realized by calculating the similarity between the testing sample tensor feature and training sample tensor *** experiment on passive sonar target classification and recognition shows that the extracted tensor features have better classification and recognition performance,and the equivalent rectangular bandwidth scale of the auditory model is better than the linear scale to divide the center frequency,which can improve the target indication ability of passive sonar.

关键词： auditory underwater passive

Cr^(4+):YAG as a passive Q-Switch in a Diode-Pumped cw Nd:YVO_(4) Laser

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Chinese Physics Letters 1998年第12期15卷 883-885页

作者： HE Jing-liang HOU Wei ZHANG Heng-li WU Ling-an XU Zu-yan YANG Guo-zhen DENG Pei-zhen XU Jun QIAO Jing-wen Laboratory of Optical Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800

The performance of a passively Q-switched all-solid-state Nd:YVO_(4) laser using Cr^(4+):YAG as saturable absorber is *** coupling operation at 1064nm resulted in 70ns pulses at 40kHz repetition rates with average out... 详细信息

关键词： Nd: switched passive