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Experimental measurement of growth patterns on fossil corals:Secular variation in ancient Earth-Sun distances

Chinese Science Bulletin 2010年第35期55卷 4010-4017页

作者： ZHANG WeiJia1,3.4,LI ZhengBin2,3.& LEI Yang1 1 Department of Physics,peking university,beijing 100871,china 2 Department of Electrical Engineering and Computer Science,peking university,beijing 100871,china 3.state key laboratory of advanced optical communication systems & networks,peking university,beijing 100871,china 4 Committee of Yuanpei Honors Program,peking university,beijing 100871,china Department of Physics Peking University Beijing 100871 China state key laboratory of {3. optical communication systems & networks Peking University Beijing 100871 China Committee of Yuanpei Honors Program Peking University Beijing 100871 China Department of Electrical Engineering and Computer Science Peking University Beijing 100871 China

In recent years,much attention has been given to the increase in the Earth-Sun distance,with the modern rate reported as 5-15 m/cy on the basis of astronomical ***,traditional methods cannot measure the ancient leaving rates,so a myriad of research attempting to provide explanations were met with unmatched *** this paper we consider that the growth patterns on fossils could reflect the ancient Earth-Sun *** mechanical analysis of both the Earth-Sun and Earth-Moon systems,these patterns confirmed an increase in the Earth-Sun *** a large number of well-preserved specimens and new technology available,both the modern and ancient leaving rates could be measured with high precision,and it was found that the Earth has been leaving the Sun over the past 0.53.billion *** Earth's semi-major axis was 146 million kilometers at the beginning of the Phanerozoic Eon,equating to 97.6% of its current *** modern leaving rates are 5-14 m/cy,whereas the ancient rates were much *** results indicate a special expansion with an average expansion coefficient of 0.57H0 and deceleration in the form of Hubble *** the basis of experimental results,the Earth's semi-major axis could be represented by a simple formula that matches fossil measurements.

关键词：地球太阳古代距离生长模式实验石珊瑚量化

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Optimal Configuration of Multiple Pump Powers and Wavelengths for Balanced Pre- and Post-pumped Raman Fiber Amplifiers

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Chinese Journal of Lasers 2002年第2期11卷 13-17页

作者： YAN Minhui CHEN Jianping LI Jianlang JIANG WenningCHEN Junfeng LI Xin( The state key laboratory on Fiber-Optic Local Area {3. networks and advanced optical {3. systems, Shanghai Jiao Tong university,Shanghai 20003., china) Shanghai Jiao Tong Universit The State Key Laboratory on Fiber-Optic Local Area Communication Networks and Advanced Optical Communication Systems 上海 200030

A novel configuration algorithm for bi-directionally pumped Raman amplifier is developed by adopting simulated annealing algorithm. Automatic design of optical fiber Raman amplifier using 10 laser diode pumps with different wavelengths and powers is demonstrated for 64 channels DWDM systems. The resulted gain ripple is less than 2.6 dB in amplification bandwidth of more than 50 nm for a transmission span of more than 3.0 km. The algorithm can be practically applied to desired signal channel number and gain profile.

关键词： optical Raman amplifiers simulated annealing pumps dense wavelength division multiplexing

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An integrated quantum secure communication system

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Science china(Information Sciences) 2011年第12期54卷 2598-2611页

作者： DAI WenChao, LU Yuan, ZHU Jun & ZENG GuiHua state key Lab of advanced {3. communication systems and networks, Department of Electronic Engineering Shanghai Jiaotong university, Shanghai 200240, china 1. state key Lab of advanced {3. communication systems and networks Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China

In this paper, we investigate experimentally an integrated quantum secure communication system using weak coherent state. Two modules are involved in the presented system. One is used for generating the secret key which is obtained using continuous variable quantum key distribution scheme, and the other serves to encrypt and decrypt the real-time private data using a pure quantum cryptographic algorithm. The sifted key rate with reverse reconciliation is 8.6 and 3.9 kb/s in the quantum key distribution scheme under the individual attack and the collective attack, respectively. The system uses an all-fiber dual unbalance beam Mach-Zehnder interferometer, and is implemented with a 500 kb/s modulation rate over 27.2 km of optical fiber.

关键词： quantum key distribution quantum stream encryption integrated system

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Analysis of Pulse Tolerance to Pump Depletion Induced Noise in DWDM systems Using Distributed Fiber Raman Amplifiers

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Chinese Journal of Lasers 2002年第3期11卷 60-63页

作者： YAN Minhui CHEN Jianping LI Jianlang JINAG Wenning CHEN Junfeng LI Xin (The state key laboratory on Fiber Optic Local Area {3. networks and advanced optical {3. systems, Shanghai Jiao Tong university, Shanghai 20003., china) 上海交通大学 The State Key Laboratory on Fiber-Optic LocalArea Communication Networks and Advanced Optical Communication Systems 上海 200030

In distributed optical fiber Raman amplifiers, instantaneous pump power depletion is related to patterns of input DWDM signals and results in extra optical noise and crosstalk. This noise has different effects on non return to zero (NRZ) and return to zero (RZ) pulse forms. These phenomena are compared with present simulation results.

关键词： Raman scattering optical amplifiers dense wavelength division multiplexing crosstalk optical noise

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Compensating for Nonlinear Effects in Coherent-Detection optical Transmission systems

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ZTE communications 2012年第1期10卷 45-49页

作者： Fan Zhang (state key laboratory of {3. optical communication systems & networks, peking university, beijing 100871, P.R.china)

Fiber nonlinearity is one of the most important limiters of capacity in coherent optical communications. In this paper, we review two nonlinear compensation methods： digital backward propagation （BP） and nonlinear electrical equalizer （NLEE） based on the timedomain Volterra series. These compensation algorithms are implemented in a singlechannel 50 Gb/s coherent optical singlecarrier frequency division multiplexed （CO-SCFDM） system transmitting over 10 × 80 km of standard singlemode fiber （SSMF）.

关键词： coherent optical communication fiber nonlinearity digital signal processing

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Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2, CHEN ZhengHao3.& ZHANG XiaoZhong4,5 1 key laboratory of Beam Technology & Materials Modification of the Ministry of Education, Institute of Low Energy Nuclear Physics, beijing Normal {3., beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3.laboratory of optical Physics, Institute of Physics, Chinese Academy of Sciences, beijing 100080, china 4 key laboratory of advanced Materials of the Ministry of Education, Department of Materials Science and Engineering, Tsinghua {3., beijing 100084, china 5 beijing National Center for Electron Microscopy, Tsinghua {3., beijing 100084, china 1. key laboratory of Beam Technology & Materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China 2. beijing Radiation Center Beijing 100875 China 3. laboratory of optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China 4. key laboratory of advanced Materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing 100084 China 5. beijing National Center for Electron Microscopy Tsinghua University Beijing 100084 China

The LaMn1-xTexO3.δ (x=0.1, 0.2, 0.3. were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3. ions are partly converted into Mn2+ and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2+, Mn3. and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3. is much larger or less than the sum of Mn2+ and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3. is close to the sum of Mn2+ and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

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A Novel Fabrication for Method Long PeriodFiber Grating

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Chinese Journal of Lasers 2002年第2期11卷 39-42页

作者： HE Shuo LI Xinwan YE Ailun HE Wanxun SONG Hao(state key laboratory on Local Fiber {3. networks andadvanced Fiber {3. systems, optical Fiber Technology Institute,Shanghai Jiaotong university, Shanghai 20003., china) optical Fiber Technology Institute Shanghai Jiaotong University State Key Laboratory on Local Fiber Communication Networks and Advanced Fiber Communication Systems 上海 200030

A new method of fabricating all-fiber broadband-rejection filter based on long period fiber grating (LPFG) is proposed. The principle in the method is to make periodic asymmetrical deformation in the core of fiber without microbends by electrode discharging so as to induce periodic refractive index changes. Two kinds of filters whose rejection peak wavelength at 1550 nm and 13.0 nm are obtained. The insertion loss is less than 0.6 dB and 1.4 dB respectively. The 20 dB bandwidth ranges from 10 nm to 3. nm. The backward reflection loss is extremely small (less than - 70 dB). Such devices can be used as isolation filters in 13.0/1550 nm WDM system and other fields.

关键词： long period fiber grating band-rejection filter asymmetrical deformation

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Optimization of Millimeter-Wave RoF System Structure

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ZTE communications 2009年第3期7卷 25-30页

作者： Zhang Cheng,Chen Zhangyuan,Hu Weiwei(state key laboratory on {3. optical communication systems and networks,peking university,beijing 100871,P.R.china)

Based on the seamless integration of broadband optical and wireless access networks,millimeter-wave Radio over Fiber (RoF) technology is considered to be a promising solution for the next generation access networks which will provide high capacity and flexibility with low *** due to its large cost to realize,the system architecture needs to be *** the millimeter-wave optical generation part,optical heterodyning method can be introduced to generate a high-frequency millimeter-wave signal using a low-frequency signal *** the system efficiency can be greatly improved based on injection-locking of a semiconductor *** the downlink,the transmission distance can be greatly enhanced using single-sideband *** the single-mode modulation (single-sideband modulation) based on an injection-locked semiconductor laser is a much simpler *** the uplink,direct modulation of optical heterodyning signal can be used to realize the down-conversion of uplink millimeter-wave signal,which simplifies the receiver structure at the centre *** the wavelength division multiplexing millimeter-wave RoF duplex system,the wavelength reuse in both downlink and uplink can save the wavelength resource in the whole system,which improves its efficiency.

关键词： RoF Optimization of Millimeter-Wave RoF System Structure mode Radio Wave EDFA dBm Figure DFB

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A Novel Approach for TNA Address Management

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光学学报 2003年第S1期23卷 767-768页

作者： Xiaodong Wang, Yaohui Jin, Weishen Hu, Shenli Zhu state key Lab of advanced {3. communication systems and networks, Shanghai Jiao Tong university, P. R.china state key Lab of advanced {3. communication systems and networks Shanghai Jiao Tong University P. R.China

We present a new scheme to allocate/de-allocate Transport Network Assigned (TN A) address using Link Management Protocol (LMP) and to register/resolution these addresses using Lightweight Directory Access Protocol (LD... 详细信息

关键词： ASON et on A Novel Approach for TNA Address Management for OIF link LDAP LMP TNA

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A QoS-Guanranteed Scheduling Algorithm with High Throughput for Edge Nodes of optical Burst Switching networks

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光学学报 2003年第S1期23卷 747-748页

作者： Guiling Wu, Jianping Chen, Xinwang Li, Junfeng ChenThe state key laboratory on Fiber-Optic Local Area {3. networks and advanced optical {3. systems, Shanghai Jiao Tong university, Shanghai 20003., P. R. china The state key laboratory on Fiber-Optic Local Area {3. networks and advanced optical {3. systems Shanghai Jiao Tong University Shanghai 200030 P. R. China

A scheduling algorithm for the edge nodes of optical burst switching (OBS) networks is proposed to guarantee the delay requirement of services with different CoS (Class of Service) and provide lower burst loss ratio a... 详细信息

关键词： QoS of A QoS-Guanranteed Scheduling Algorithm with High Throughput for Edge Nodes of optical Burst Switching networks WDM Edge OBS for with

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