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柴达木盆地西部和北缘天然气中C_(5)—C_(7)轻烃地球化学特征

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天然气地球科学 2024年第2期35卷 344-356页

作者：张臣张道勇周世新李靖陈克非周立明谷宇峰自然资源部油气资源战略研究中心北京100034 中国科学院西北生态环境资源研究院/甘肃省油气资源研究重点实验室甘肃兰州730000 中国石油勘探开发研究院北京100083

近些年在柴达木盆地西部和北缘油气勘探获得了新进展,但新勘探区块油气来源仍存在较大争议。C_(5)—C_(7)轻烃可作为很好的补充,为判识天然气来源提供新信息。系统采集了柴西和柴北缘主要油气田的天然气样品,分析其中轻烃的组分和单体... 详细信息

近些年在柴达木盆地西部和北缘油气勘探获得了新进展,但新勘探区块油气来源仍存在较大争议。C_(5)—C_(7)轻烃可作为很好的补充,为判识天然气来源提供新信息。系统采集了柴西和柴北缘主要油气田的天然气样品,分析其中轻烃的组分和单体烃碳同位素。结果显示:柴西天然气的轻烃具有高含量的正庚烷,柴北缘天然气的轻烃具有高含量的甲基环己烷和甲苯。柴西天然气中轻烃的δ^(13)C_(MCC5)值和δ^(13)C_(MCC6)值分别分布在-23‰~-18‰和-24‰~-20‰之间,柴北缘天然气中轻烃的δ^(13)C_(MCC5)值和δ^(13)C_(MCC6)值分别分布在-28‰~-22‰和-26‰~-23‰之间。这些特征反映出柴西地区天然气中轻烃主要来源于古近系—新近系咸水湖相泥岩,柴北缘地区天然气中轻烃主要来源于侏罗系煤系烃源岩。此外,结合天然气和原油地球化学特征,对南翼山和东坪地区油气来源开展了进一步研究。南翼山地区天然气可能有来自侏罗系和古近系—新近系煤系烃源岩的贡献,原油主要来自古近系—新近系烃源岩。东坪地区天然气主要来源于侏罗系煤系烃源岩,轻烃和凝析油主要来源于侏罗系泥岩。

关键词：柴达木盆地天然气 C_(5)-C_(7)轻烃组分碳同位素

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温室大棚溶解混施智能施肥机设计与实现

农机化研究 2024年第2期46卷 91-96页

作者：王铁广李文勤陈可飞邢凯肖洒方赛银李明西南林业大学机械与交通学院昆明650224 安徽工程大学电气工程学院安徽芜湖241000

为了实现固体水溶性肥料高效溶解与精准施肥,设计了一种温室大棚溶解混施智能施肥机,主要由肥料搅拌单元、供水单元、吸肥单元及控制单元组成,水肥配比采用模糊PID控制调节方式。首先,依据固体水溶性肥料的自身特点搭建带有肥料搅拌装... 详细信息

为了实现固体水溶性肥料高效溶解与精准施肥,设计了一种温室大棚溶解混施智能施肥机,主要由肥料搅拌单元、供水单元、吸肥单元及控制单元组成,水肥配比采用模糊PID控制调节方式。首先,依据固体水溶性肥料的自身特点搭建带有肥料搅拌装置的施肥设备硬件系统;然后,根据施肥设备混肥特性,建立肥料EC值调控模型,设计PID控制器;最后,采用模糊控制方法自适应调节PID参数,提出模糊PID控制系统设计方法。试验结果表明:使用模糊PID控制策略能够显著提高系统性能,特别是在减少系统滞后时间和保持系统稳定性方面。

关键词：智能施肥机固体水溶性肥料温室率模糊PID控制

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Quantitative Gas-in-place Comparison of Original and Bitumen-free Lacustrine Shale

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Acta Geologica Sinica(English Edition) 2022年第2期96卷 559-570页

作者： LI Jing ZHOU Shixin FU Deliang chen kefei ZHANG chen SUN Zexiang LI Pengpeng Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou 730000China Key Laboratory of Petroleum Resources Gansu ProvinceLanzhou 730000China Key Laboratory of Coal Exploration and Comprehensive Utilization Ministry of Nature and ResourcesShaanxi Coal Geology Group CoLtd.Xi’an 710021China University of Chinese Academy of Sciences Beijing 100101China

Residual bitumen in organic-rich shale of oil windows exists widely, and its effect on the gas storage capacity of shale could be two-fold. Bitumen could occupy and block the nanopores of shale, thereby reducing the gas storage capacity. On the other hand, gas could be dissolved in bitumen in shale gas reservoirs, leading to enhanced gas storage capacity. To quantify the effect of bitumen on the gas-in-place(GIP) estimation of lacustrine organic-rich shale, the micropore characteristics and methane sorption capacity of original and bitumen-free shale from the Triassic Yangchang Formation of the Ordos Basin, combined with the methane dissolution capacity for the isolated bitumen, were analyzed and compared. GIP for the original and bitumen-free shale in the depth range of 500–2500 m was evaluated. The results show that micropores in the shale samples were mainly related to organic matter. Clay mineral-hosted pores contributed slightly to microporosity. Bitumen significantly reduced the micropore surface area and volume of the original shale, with average percentages of 28.09% and 51.26%, respectively. The methane sorption capacity decreased after bitumen removal. When normalized to the original shale mass, the sum of the methane sorption capacity for bitumen-free shale and the methane dissolution capacity for isolated bitumen was similar to the methane sorption capacity of the original shale, indicating that the lack of methane absorbed on bitumen is the main reason for the decrease in methane sorption capacity after bitumen removal. The contribution of absorbed methane on bitumen to sorbed methane in shale could be higher than 36.23%. Dual effects of bitumen on shale GIP were observed. A high content of bitumen(1.12%) increased the GIP of the shale samples, with an average percentage of 23.5% in the depth range of 500–2500 m, while a low content of bitumen(0.06%) decreased the GIP, with an average percentage of 13.6%.

关键词： lacustrine shale gas-in-place bitumen methane sorption methane dissolution

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Anonymous handover authentication protocol for mobile wireless networks with conditional privacy preservation

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Science China(Information Sciences) 2017年第5期60卷 113-129页

作者： Debiao HE Ding WANG Qi XIE kefei chen State Key Laboratory of Software Engineering Computer School Wuhan University State Key Laboratory of Cryptology School of Electronics Engineering and Computer Science Peking University Hangzhou Key Laboratory of Cryptography and Network Security Hangzhou Normal University

With the development of the wireless communication technology and the popularity of mobile devices, the mobile wireless network(MWN) has been widely used in our daily life. Through the access point(AP), users could access the Internet anytime and anywhere using their mobile devices. Therefore, MWNs can bring much convenience to us. Due to the limitation of AP’s coverage, the seamless handover frequently occurs in practical applications. How to guarantee the user’s privacy and security and identify the real identity when he/she brings harm to the system becomes very challenging. To achieve such goals, many anonymous handover authentication(AHA) protocols have been proposed in the last several years. However, most of them have high computation costs because mobile nodes need to carry out the bilinear pairing operations or the hash-to-point operations. Besides, most of them cannot satisfy some critical requirements, such as non-traceability and perfect forward secrecy. In this paper, we first outline the security requirements of AHA protocols, and then propose a new AHA protocol to eliminate weaknesses existing in previous AHA protocols. Based on the hardness of two famous mathematical problems, we demonstrate that the proposed AHA protocol is secure against different kinds of attacks and can meet a variety of security requirements. It can be seen from the details of implementations that the proposed AHA protocol also has much less computation cost than three latest AHA protocols.

关键词： mobile wireless network handover authentication anonymity conditional privacy preservation provable security

Efficient identity-based threshold decryption scheme from bilinear pairings

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Frontiers of Computer Science 2018年第1期12卷 177-189页

作者： Wei GAO Guilin WANG kefei chen Xueli WANG School of Mathematics and Statistics Ludong University Yantai 264025 China School of Computer and Software Nanjing University of Information Science & Technology Nanjing 210044 China Key Laboratory of Information Security Guangzhou University Guangzhou 510006 China Shield Lab Singapore Research Center of Huawei Singapore 117674 Singapore Department of Mathematics Hangzhou Normal University Hangzhou 311121China School of Mathematics South China Normal University Guangzhou 510631 China

Using Shamir＇s secret sharing scheme to indi- rectly share the identity-based private key in the form of a pairing group element, we propose an efficient identity-based threshold decryption scheme from pairings and prove its se- curity in the random oracle model. This new paring-based scheme features a few improvements compared with other schemes in the literature. The two most noticeable features are its efficiency, by drastically reducing the number of pair- ing computations, and the ability it gives the user to share the identity-based private key without requiring any access to a private key generator. With the ability it gives the user to share the identity-based private key, our ID-based threshold decryption （IBTD） scheme, the second of its kind, is signif- icantly more efficient than the first scheme, which was de- veloped by Baek and Zheng, at the expense of a slightly in- creased ciphertext length. In fact, our IBTD scheme tries to use as few bilinear pairings as possible, especially without depending on the suite of Baek-Zheng secret sharing tools based on pairings.

关键词： identity-based cryptography threshold cryptog-raphy provable security random oracle model bilinear pair-ing identity-based threshold decryption

Optimistic fair exchange E-commerce protocol based on secret sharing

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Journal of Systems Engineering and Electronics 2006年第4期17卷 858-863页

作者： Ma Changshe Lei Feiyu chen kefei Dept. of Computer Science and Engineering Shanghai Jiaotong Univ. Shanghai 200080 P.R.China School of Computer South China Normal Univ. Guangzhou 510631 P.R.China The State Key Lab of Information Security China Academy of Sciency Beijing 100039 P.R.China

A key problem of electronic commerce （for short e-commerce） is fair exchange which guarantees that at the end of the transaction, either both parties involved in the trausaction receive each other＇s items or none do. A non-interactive optimistic fair exchange e-commerce protocol model based on the publicly verifiable secret sharing is presented. The main idea of our exchange protocol is to interchange verifiable and recoverable keys of the symmetric encryption for participants＇ items. So it is especially suitable for exchange of large-size items. Furthermore, our protocol is efficient and simple as it does not need interactive proof system which has been adopted by a large quantity of previously proposed fair exchange protocols. Based on a modified （2,2） secret sharing scheme, a concrete non-interactive fair exchange e-commerce protocol is designed.

关键词： E-commerce optimistic fair-exchange publicly verfiable secret sharing.

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LR-RRA-CCA secure functional encryption for randomized functionalities from trapdoor HPS and LAF

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Science China(Information Sciences) 2018年第5期61卷 291-305页

作者： Huige WANG kefei chen Baodong QIN Ziyuan HU Department of Network Engineering Anhui Science and Technology University Department of Computer Science and Engineering Shanghai Jiao Tong University Department of Mathematics Hangzhou Normal University National Engineering Laboratory for Wireless Security Xi'an University of Posts and Telecommunications State Key Laboratory of Cryptology

Original public-key encryption is viewed as a tool to encrypt point-to-point *** data is aimed at a particular user,where a sender encrypts a message x under a specified public key P *** this case,only the owner of the(unique)secret key corresponding to P K can decrypt the resulting ciphertext to recover the message ***,on some occasions,encryption is necessary to implement more fine-grained control of the encrypted *** example,the sender

关键词： LAF CCA RRA

Identity-based threshold key-insulated signature

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High Technology Letters 2012年第3期18卷 275-280页

作者： chen Jianhong chen kefei Long Yu Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 P. R. China Department of Computer Engineering Huaiyin Institute of Technology Huaian 223003 P. R. China National Laboratory of Modern Communications Chengdu 610041 P. R. China

Due to the compromise of the security of the underlying system or machine stonng the key, exposure of the private key can be a devastating attack on a cryptosystem. Key insulation is an important technique to protect private keys. To deal with the private （signing） key exposure problem in identity-based signature systems, we propose an identity-based threshold key-insulated signature （IBTKIS） scheme. It strengthens the security and flexibility of existing identity-based key-insulated signature schemes. Our scheme＇ s security is proven in the random oracle model and rests on the hardness of the computational Diffie-Helhnan problem in groups equipped with a pairing. To the best of our knowledge, it is the first IBTKIS scheme up to now.

关键词： threshold key-insulated signature random oracle model

Sequential Aggregate Signatures and Multisignatures in the Plain Public Key Model

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Chinese Journal of Electronics 2015年第2期24卷 338-342页

作者： ZHOU Xuhua LAI Junzuo LIU Shengli chen kefei School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Department of Computer Science Jinan University School of Science Hangzhou Normal University

At Eurocrypt’06, Lu et al. presented the first Sequential aggregate signature(SAS) provably secure without random oracles. The drawback of their scheme is that users need long public keys and the security model makes the Knowledge of secure key(KOSK) assumption. We present the first SAS scheme, which the user needs short public keys and the security is proven without random oracles, in the plain public key model. We also present the first Multisignature(MS) scheme in the plain public key model, which the security is proven without random oracles.

关键词： Sequential aggregate signature Multisignature Plain public key model Standard model Computational Diffie-Hellman assumption