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Control of atmospheric CO_2 concentrations by 2050: A calculation on the emission rights of different countries

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Science china Earth Sciences 2009年第10期52卷 1447-1469页

作者： DING ZhongLi1, DUAN XiaoNan2, GE QuanSheng3 & ZHANG ZhiQiang4 1 institute of Geology and Geophysics, chinese academy of Sciences, beijing 100029, china 2 The General Office of chinese academy of Sciences, beijing 100864, china 3 institute of Geographic Sciences and Natural resources research, chinese academy of Sciences, beijing 100101, china 4 The Lanzhou Branch of the National Science Library, the Scientific information Center for resources and Environment, Lanzhou 730000, china institute of Geology and Geophysics Chinese Academy of Sciences Beijing China The General Office of chinese academy of Sciences Beijing China institute of Geographic Sciences and Natural resources research Chinese Academy of Sciences Beijing China The Lanzhou Branch of the National Science Library the Scientific Information Center for Resources and Environment Lanzhou China

This paper is to provide quantitative data on some critical issues in anticipation of the forthcoming international negotiations in Denmark on the control of atmospheric CO2 concentrations. Instead of letting only a small number of countries dominate a few controversial dialogues about emissions reductions, a comprehensive global system must be established based on emissions allowances for different countries, to realize the long-term goal of controlling global atmospheric CO2 concentrations. That a system rooted in "cumulative emissions per capita," the best conception of the "common but differentiated responsibilities" principle affirmed by the Kyoto Protocol according to fundamental standards of fairness and justice, was demonstrated. Based on calculations of various countries' cumulative emissions per capita, estimates of their cumulative emissions from 1900 to 2005, and their annual emissions allowances into the future (2006―2050), a 470 ppmv atmospheric CO2 concentration target was set. According to the following four objective indicators―total emissions allowance from 1900 to 2050, actual emissions from 1900 to 2005, emissions levels in 2005, and the average growth rate of emissions from 1996 to 2005―all countries and regions whose population was more than 300000 in 2005 were divided into four main groups: countries with emissions deficits, countries and regions needing to reduce their gross emissions, countries and regions needing to reduce their emissions growth rates, and countries that can maintain the current emissions growth rates. Based on this proposal, most G8 countries by 2005 had already expended their 2050 emissions allowances. The accu-mulated financial value based on emissions has reached more than 5.5 trillion US dollars (20 dollars per ton of CO2). Even if these countries could achieve their ambitious emissions reduction targets in the future, their per capita emissions from 2006 to 2050 would still be much higher than those of developing coun

关键词： international negotiations on climate change cumulative emissions per capita emission allowance

Digital Cancellation Scheme and Hardware Implementation for High-Order Passive Intermodulation Interference Based on Hammerstein Model

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china Communications 2019年第9期16卷 165-176页

作者： Xiaqing Miao Lu Tian School of information and Electronics Beijing Institute of TechnologyBeijing 100081China china academy of Electronics and information technology Beijing 100041China

Passive intermodulation(PIM)interference urgently needs to be solved in the satellite communication system,owing to degrading the whole *** research contributions to the cancellation method for PIM were focused on the analog domain,however,the PIM distortion cannot be eliminated completely with the ***,some researchers attempt to tackle the problem through digital signal processing,nevertheless,the proposed methods were not suitable for the practical satellite communication *** this paper,we present a general scheme for the adaptive feedforward PIM ***-order PIM signals at baseband are estimated by modeling the PIM distortion with Hammerstein model in the digital *** on the reconstructed PIM signal,we adopt the least mean square algorithm to adaptively mitigate the PIM interference for tracking the variation of *** time and frequency synchronization of PIM are based on the correlation of the peak of received signals with the corresponding reconstructed PIM *** experimental results show that the scheme can effectively cancel the PIM interference,and achieve an interference suppression gain more than 20dB.

关键词： satellite communication passiveintermodulation interference digital cancellation Hammerstein model

research progress in terahertz quantum cascade lasers

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Science china(information Sciences) 2012年第1期55卷 16-26页

作者： CAO JunCheng Key Laboratory of Terahertz Solid-State technology,Shanghai institute of Microsystem and information technology,chinese academy of Sciences,Shanghai 200050,china Key Laboratory of Terahertz Solid-State technology Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China

The terahertz(THz)quantum cascade laser(QCL)is a coherent THz source based on intersubband transitions of unipolar *** semiconductor lasers,THz QCLs are solid-state,electrically pumped,tunable,and can be easily *** paper reviews the state of the art for the design,operation temperature,and output power of THz *** applications in THz communication and imaging are also discussed.

关键词： terahertz quantum cascade laser communication imaging

CMQV+:An authenticated key exchange protocol from CMQV

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Science china(information Sciences) 2012年第7期55卷 1666-1674页

作者： LI Hui 1,2 & WU ChuanKun 1 1 State Key Laboratory of information Security,institute of Software,chinese academy of Sciences,beijing 100190,china 2 Graduate University of chinese academy of Sciences,beijing 100049,china State Key Laboratory of information Security Institute of Software Chinese Academy of Sciences Beijing China Graduate University of chinese academy of Sciences Beijing China

Ustaoglu presents a secure and efficient key exchange protocol named CMQV,based on the design rationales of HMQV and *** with the latter two protocols,on one hand,CMQV achieves high performance of HMQV,and on the other,it is proven secure in eCK model as NAXOS ***,CMQV enjoys the security proof under gap Diffie-Hellman assumption as indicated by its *** this paper,we propose a variant of CMQV,called CMQV+,which is proven secure under a weaker assumption (*** Diffie-Hellman assumption) in eCK model with random oracles while maintaining the high-performance feature of CMQV as much as possible.

关键词： key exchange eCK model trapdoor-test technique provable security CDH assumption

A two-round honest-verifier zero-knowledge protocol

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Science china(information Sciences) 2010年第5期53卷 954-963页

作者： LIU HanWu 1,2 & LIN DongDai 1 1 The State Key Laboratory of information Security, institute of Software, chinese academy of Sciences, beijing 100190, china 2 Graduate University of the chinese academy of Sciences, beijing 100049, china The State Key Laboratory of information Security Institute of Software Chinese Academy of Sciences Beijing China Graduate University of the chinese academy of Sciences Beijing China

Since the concept of zero-knowledge protocols was introduced, it has attracted a lot of attention and in turn showed significant effect on the development of cryptography, complexity theory and other areas. The round complexity of a zero-knowledge protocol is a very important efficiency consideration, and it is required to be as small as possible. Generally, it is desirable to have zero-knowledge protocols with constant numbers of rounds. Goldreich and Oren proved that only languages in BPP have one-round and two-round zero-knowledge protocols. Moreover, they also showed that only languages in BPP have one-round honest-verifier zero-knowledge protocols. The notion of honest-verifier zero-knowledge protocols is highly non-trivial and fascinating itself, and has many other uses. Thus, the problem as to whether there exist two-round honest-verifier zero-knowledge protocols becomes an important open problem. In this paper, we introduce a new simulation technique and present a two-round honest-verifier zero-knowledge protocol for any language in N P under a standard complexity assumption based on this technique.

关键词： proof system argument system zero-knowledge witness indistinguishability black-box one-way permutation commitment scheme zap

Oxygen and hydrogen isotopic compositions of coexistent minerals of the Tasigake alkali granite pluton,northern Xinjiang:constraints upon the cause of ^(18)O-D depletion and the ^(18)O/^(16)O exchange kinetics

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chinese Science Bulletin 1999年第12期44卷 1086-1093页

作者： LIU Wei, ZHAO Zhenhua ZHANG Fuqin research Center of Mineral resources Exploration, institute of Geophysics , chinese academy of Sciences , beijing 100101, china Guangzhou institute of Geochemistry, chinese academy of Sciences , Guangzhou 510640, china research Center of Mineral resource Exploration Institute of Geophysics Chinese Academy of Science Beijing China Guangzhou institute of Geochemistry Chinese Academy of Sciences Guangzhou China

Oxygen and hydrogen isotopic compositions have been determined of three coexistent mineral triplets of alkali feldspar, quartz, arfvedsonite of 11 samples collected from the Tasigake alkali granite pluton, Ulungur River region, northern Xinjiang. Isotopic exchange with meteoric water during subsolidus cooling caused strong 18O-D depletion and the remarkable nonequilibrium 18O/16O relation between coexistent minerals. 18O/16O exchange kinetic effects of the three minerals are simultaneously and consistently modelled. Exsolution and microtextural reorganization of alkali feldspar, and infiltration of water have been mutually facilitated by each other. Shallow intrusion, and circulation of meteoric water throughout the pluton cool it effectively. As a result, the "heat engine" is rapidly extinguished, and the nonequilibrium 18O/16O relation is frosen.

关键词： 18O-D depletion isotopic exchange kinetics alkali granite Ulungur.

research progress in studies on the coalbed gas geochemistry

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Progress in Natural Science:Materials International 2006年第3期16卷 215-220页

作者： TAO Mingxin (College of resources Sciences & technology, beijing Normal University, beijing 100875, china Key Laboratory of Gas Geochemistry, institute of Geology and Geophysics, chinese academy of Sciences, Lanzhou 730000, china) College of resources Sciences and technology Beijing Normal University Beijing 100875 China Key Laboratory of Gas Geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China

The current situation of geochemical studies on coalbed gas is reviewed in this paper. Generally, coalbed gas is composi-tionally dominated by methane with δ13C1 values ranging approximately from - 80‰ to - 10‰. However, few isotopic studies have been carried out on other components of coalbed gas except for hydrogen and carbon dioxide, whose δDCH4 values available for utilization vary from - 333‰ to - 117‰, and δ13CCO2 values from - 29. 4‰ to + 18. 6‰. Two major types of coalbed gas, thermogenic gas and secondary biogenic gas, have been identified, and there are also some other classification criteria. Compared with conventional natural gases, coalbed gas has a wide distribution range of δ13C1 and δ13CCO2 values, especially possessing some extremely heavy values. Current problems that remain unsolved in the coalbed gas geochemistry include the variation mechanism, controlling factors and application of carbon and hydrogen isotopes of methane, the relation between the values of δ13C1 and Ro, the systematic classification scheme and criterion of genetic types, and the application of the coalbed gas geochemistry in evaluating target districts of the coalbed gas exploration.

关键词： coalbed gas geochemistry isotopic composition genetic type novel resource.

Multiparty simultaneous quantum identity authentication with secret sharing

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Science china(Physics,Mechanics & Astronomy) 2008年第3期51卷 321-327页

作者： YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of Computer Science and technology,beijing University of technology,beijing 100022,china 2 State Key Laboratory of information Security (Graduate University of the chinese academy of Sciences),beijing 100049,china 3 School of Science,beijing University of Posts and Telecommunications,beijing 100876,china 4 institute of Electronic technology,information Engineering University,Zhengzhou 450004,china 5 Trusted Computing Laboratory,beijing University of technology,beijing 100022,china College of Computer Science and technology Beijing University of Technology Beijing China State Key Laboratory of information Security (Graduate University of the chinese academy of Sciences) Beijing China School of Science Beijing University of Posts and Telecommunications Beijing China institute of Electronic technology Information Engineering University Zhengzhou China Trusted Computing Laboratory Beijing University of Technology Beijing China

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.

关键词： quantum identity authentication secret sharing quantum cryptography

Giant complete automaton for uncertain multiple string matching and its high speed construction algorithm

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Science china(information Sciences) 2011年第8期54卷 1562-1571页

作者： HU Yue 1,2, GAO QingShi 1,2 ,GUO Li 2 & WANG PeiFeng 1 1 School of information Engineering,University of Science and technology beijing,beijing 100083,china 2 institute of Computing technology,chinese academy of Sciences,beijing 100190,china School of information Engineering University of Science and Technology Beijing Beijing China institute of Computing technology Chinese Academy of Sciences Beijing China

Multiple string matching is often completed under the presence of U- or V-uncertain-strings,or combinations *** large numbers of strings with U-, V-,and U-V-uncertain-strings,including the interleaving of two or more uncertain strings,is important to thoroughly gathering useful information and detecting harmful *** paper proposes a complete automaton and its high-speed construction algorithm for large-scale U-, V-,and U-V-uncertain multiple strings,including two or more uncertain strings interlaced with one *** maximum number of parallel complete automation of the V-uncertain string is also *** paper reveals that there are two kinds of pretermissions,i.e.,similarly-connected and interlaced-string pretermissions,and that mistake may appear in the matching of the regular expressions,or states in the automaton may increase in number,if the intersection of the U-uncertain strings sets and the homologous subsequent special point in the U-uncertain strings sets are not eliminated from the whole system.

关键词： multiple string matching U-uncertain-strings V-uncertain-strings U-V-uncertain-strings complete automaton