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基于证人不可区分的通用可复合安全并行可否认认证 被引量:5
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作者 冯涛 马建峰 《软件学报》 EI CSCD 北大核心 2007年第11期2871-2881,共11页
针对并行可否认认证问题,在UC(universally composable)安全框架中,基于WI(witnessindistinguishable)提出了一种新的研究思路和解决方法.根据可否认认证的安全目标,形式化地建立了UC安全的并行可否认认证模型.利用可验证平滑投影哈希... 针对并行可否认认证问题,在UC(universally composable)安全框架中,基于WI(witnessindistinguishable)提出了一种新的研究思路和解决方法.根据可否认认证的安全目标,形式化地建立了UC安全的并行可否认认证模型.利用可验证平滑投影哈希函数和非承诺加密体制,构造了一类新的并行可否认认证协议结构,基于确定性复合剩余假设和确定性Diffie-Hellman假设,实现了一个具体的协议方案.在公共参考串模型中,利用UC框架解决并行协议仿真问题与定时假设和公共目录方案相比,不需要限定攻击者能力.新方案具备前向可否认性,是自适应攻击者UC安全的.不同于CCA2加密体制结构或多陷门承诺结构的并行可否认认证,协议效率得到了改善. 展开更多
关键词 信息安全:并行可否认认证 通用可复合安全 证人不可区分 可验证平滑投影哈希函数
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通用可复合的ElGamal型广播多重签密协议 被引量:4
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作者 李建民 俞惠芳 谢永 《计算机研究与发展》 EI CSCD 北大核心 2019年第5期1101-1111,共11页
多重签密是指2个以上参与方对同一则消息进行签密,并且要求签密结果不能因为签密者数目增多而呈线性增长.普通的ElGamal型多重签名虽然具有不可伪造性,但不能抵制多个签名者的联合攻击.为了克服现有ElGamal型多重签名的缺点,将ElGamal... 多重签密是指2个以上参与方对同一则消息进行签密,并且要求签密结果不能因为签密者数目增多而呈线性增长.普通的ElGamal型多重签名虽然具有不可伪造性,但不能抵制多个签名者的联合攻击.为了克服现有ElGamal型多重签名的缺点,将ElGamal型多重签名和公钥签密组合在一起研究.提出了一种新的ElGamal型广播多重签密(ElGamal broadcasting multi-signcryption, EBMSC)协议,并给出了该协议的算法定义和安全模型,也在随机预言模型中证明了该协议在离散对数和计算性Diffie-Hellman假设下是语义安全的;然后在通用可复合框架下定义了ElGamal型广播多重签密协议的理想函数和现实协议,进而证明了现实协议能够实现广播多重签密协议的理想功能,同时还证明了现实协议是满足选择消息攻击下的不可伪造性;最后给出了ElGamal型广播多重签密协议与其他协议的效率比较.结果表明:该协议不仅在效率上要优于现有方案,而且在通用可复合框架下实现了多重签密功能.该协议适合应用在电子商务、合同签署、网上交易和财务出账等方面. 展开更多
关键词 ElGamal多重签名 ElGamal型广播多重签密 语义安全 随机预言模型 通用可复合安全
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基于密钥循环的通用可复合符号分析 被引量:1
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作者 付浩 肖建新 《计算机与数字工程》 2017年第8期1586-1591,共6页
针对目前越来越复杂的安全协议,在建立计算可靠的安全协议符号分析方法的深入研究,提出了一种解决该问题的新方法,即通用可复合符号分析方法。通过扩展现有通用可复合符号分析方法,使其可以分析基于双线性对的密钥交换协议,并在保证计... 针对目前越来越复杂的安全协议,在建立计算可靠的安全协议符号分析方法的深入研究,提出了一种解决该问题的新方法,即通用可复合符号分析方法。通过扩展现有通用可复合符号分析方法,使其可以分析基于双线性对的密钥交换协议,并在保证计算可靠性的同时,还可以保证可复合安全性。将符号模型中的密码学抽象操作与UC模型中的理想功能进行了结合,并且证明了如果协议在符号模型下满足了相应的安全性质,则在UC模型下一定安全的实现了相应的理想功能。 展开更多
关键词 安全协议 密钥循环 通用可复合 双线性对
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可信计算平台信任链安全性分析 被引量:18
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作者 徐明迪 张焕国 +2 位作者 赵恒 李峻林 严飞 《计算机学报》 EI CSCD 北大核心 2010年第7期1165-1176,共12页
可信计算规范是指导可信计算产品研制的依据,可信计算规范本身的安全性需要得到验证.信任链是可信计算平台中保障系统安全可靠的主要技术手段,它是可信计算平台整个系统安全的中心问题.针对可信计算平台信任链规范的信息流安全问题,文... 可信计算规范是指导可信计算产品研制的依据,可信计算规范本身的安全性需要得到验证.信任链是可信计算平台中保障系统安全可靠的主要技术手段,它是可信计算平台整个系统安全的中心问题.针对可信计算平台信任链规范的信息流安全问题,文中通过安全进程代数对信任链系统接口进行形式化建模,用可复合的不可演绎模型刻画信任链实体间的交互关系,把规范定义的信任链行为特性抽象为多级安全输入输出集,在讨论高级和低级输入输出依赖关系的基础之上,对信任链复合系统进行信息流分析,并给出结论和证明. 展开更多
关键词 信任链 安全进程代数 可复合的不可演绎模型
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存量背景下既有校园空间更新研究 被引量:2
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作者 武泽 许傲 +1 位作者 石妍 杨柯 《建筑与文化》 2020年第10期83-85,共3页
应对目前高等院校的快速发展与扩张,既有校园空间及环境亟须不断地改善,并向多样化需求转变。文章基于大学生行为需求的调研分析,提出校园空间低利用、可复合、弹性生长三类空间更新途径,提高校园空间的使用合理性、可达性、舒适性,从... 应对目前高等院校的快速发展与扩张,既有校园空间及环境亟须不断地改善,并向多样化需求转变。文章基于大学生行为需求的调研分析,提出校园空间低利用、可复合、弹性生长三类空间更新途径,提高校园空间的使用合理性、可达性、舒适性,从而为未来校园可持续发展提供一定借鉴作用。 展开更多
关键词 既有校园 低利用 可复合 弹性生长
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Ternary Ag/AgCl/BiOIO_3 composites for enhanced visible-light-driven photocatalysis 被引量:13
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作者 熊婷 张会均 +1 位作者 张育新 董帆 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2155-2163,共9页
Ternary Ag/AgC l/BiO IO3 composite photocatalysts are prepared by a facile method. Enhanced visible-light absorption and charge carrier separation are achieved after the introduction of Ag/AgC l particles into BiO IO3... Ternary Ag/AgC l/BiO IO3 composite photocatalysts are prepared by a facile method. Enhanced visible-light absorption and charge carrier separation are achieved after the introduction of Ag/AgC l particles into BiO IO3 systems,as revealed by ultraviolet-visible diffuse-reflectance spectrometry,photocurrent response and electrochemical impedance spectroscopy. The Ag/AgC l/BiO IO3 composites are applied to the visible-light photocatalytic oxidization of NO in air and exhibit an enhanced activity for NO removal in comparison with Ag/AgC l and pure BiO IO3. A possible photocatalytic mechanism for Ag/AgC l/BiO IO3 is proposed,which is related to the surface plasmon resonance effects of Ag metal and the effective carrier separation ability of BiO IO3. This work provides insight into the design and preparation of BiO IO3-based materials with enhanced visible-light photocatalysis ability. 展开更多
关键词 Ag/AgCl/BiOIO3 Ternary composite Visible-light photocatalysis Nitrogen oxide removal Charge seperation
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Three-dimensional MoS_2/reduced graphene oxide aerogel as a macroscopic visible-light photocatalyst 被引量:4
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作者 张瑞阳 万文超 +2 位作者 李大为 董帆 周莹 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第2期313-320,共8页
Photocatalysis is regarded as an ideal technology for solving the urgent environmental and energy issues that we face today.Among the reported photocatalysts,molybdenum disulfide(MoS2) is very promising for applicat... Photocatalysis is regarded as an ideal technology for solving the urgent environmental and energy issues that we face today.Among the reported photocatalysts,molybdenum disulfide(MoS2) is very promising for applications in hydrogen production and pollutant photodegradation.However,its lack of active sites and the difficulty of recovering catalysts in powder form have hindered its wide application.Here,we report the successful preparation of a macroscopic visible-light responsive MoS2/reduced graphene oxide(MoS2/RGO) aerogel.The obtained MoS2/RGO aerogel exhibits enhanced photocatalytic activity towards hydrogen production and photoreduction of Cr(Ⅵ) in comparison with the MoS2 powder.In addition,the low density(56.1 mg/cm^3) of the MoS2/RGO aerogel enables it to be used as an efficient adsorption material for organic pollutants.Our results demonstrate that this very promising multifunctional aerogel has potential applications in environmental remediation and clean energy production. 展开更多
关键词 Molybdenum disulfide/reduced graphene oxide aerogel Composite PHOTOCATALYSIS Visible light Adsorption
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不可区分属性的计算可靠性分析方法研究
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作者 胡亚希 《电脑知识与技术》 2021年第32期40-43,共4页
针对目前越来越复杂的安全协议,在计算可靠的安全协议符号分析方法的基础上,提出了一种计算可靠且支持双线性对、对称加密以及密钥循环的安全协议符号模型,该模型明确指定双线性对实例生成器和加密算法需要满足的安全属性,并证明了在满... 针对目前越来越复杂的安全协议,在计算可靠的安全协议符号分析方法的基础上,提出了一种计算可靠且支持双线性对、对称加密以及密钥循环的安全协议符号模型,该模型明确指定双线性对实例生成器和加密算法需要满足的安全属性,并证明了在满足这些安全属性的条件下,符号方法分析的不可区分属性蕴含计算方法分析的不可区分属性,这保证了该模型具有计算可靠性。同时,该模型通过增强攻击者对密钥循环的控制能力去除了无密钥循环的限制。 展开更多
关键词 安全协议 符号方法 计算可靠性 通用可复合 双线性对
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Characteristics of Soluble and Exchangeable Acidity inan Extremely Acidified Acid Sulfate Soil 被引量:4
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作者 C.Lin M.D.MELVILLE 《Pedosphere》 SCIE CAS CSCD 1999年第4期323-330,共8页
An extremely acidified acid sulfate soil (ASS) was investigated to characterize its soluble and exchangeableacidity. The results showed that soluble acidity of a sample determined by titration with a KOH solutionwas m... An extremely acidified acid sulfate soil (ASS) was investigated to characterize its soluble and exchangeableacidity. The results showed that soluble acidity of a sample determined by titration with a KOH solutionwas much significantly greater than that indicated by pH measured using a PH meter, particularly for theextremely acidic soil samples. This is because the total soluble acidity of the extremely acidic soil sampleswas mainly composed of various soluble Al and Fe species, possibly in forms of Al sulfate complexes (e.g.,AISO4) and ferrous Fe (Fe2+). It is therefore suggested not to use pH alone as an indicator of soluble acidityin ASS, particularly for extremely acidic ASS. It is also likely that AISO4+ actively pericipated in cationexchange reactions. It appears that the possible involvement of this Al sulfate canon in the canon adsorptionhas significant effect on increasing the amount of acidity being adsorbed by the soils. 展开更多
关键词 acid sulfate soils aluminium sulfate complex exchangeable acidity HYDROLYSIS soluble acidity
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Predicting Complex Word Emotions and Topics through a Hierarchical Bayesian Network 被引量:2
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作者 Kang Xin Ren Fuji 《China Communications》 SCIE CSCD 2012年第3期99-109,共11页
In this paper, we provide a Word Emotion Topic (WET) model to predict the complex word e- motion information from text, and discover the dis- trbution of emotions among different topics. A complex emotion is defined... In this paper, we provide a Word Emotion Topic (WET) model to predict the complex word e- motion information from text, and discover the dis- trbution of emotions among different topics. A complex emotion is defined as the combination of one or more singular emotions from following 8 basic emotion categories: joy, love, expectation, sur- prise, anxiety, sorrow, anger and hate. We use a hi- erarchical Bayesian network to model the emotions and topics in the text. Both the complex emotions and topics are drawn from raw texts, without con- sidering any complicated language features. Our ex- periment shows promising results of word emotion prediction, which outperforms the traditional parsing methods such as the Hidden Markov Model and the Conditional Random Fields(CRFs) on raw text. We also explore the topic distribution by examining the emotion topic variation in an emotion topic diagram. 展开更多
关键词 word emotion classification complex e-motion emotion intensity prediction emotion-topicvariation hierarchical Bayesian network
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In-situ route for the graphitized carbon/TiO composite photocatalysts with enhanced removal efficiency to emerging phenolic pollutants 被引量:3
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作者 Yunqing Liu Peiyu Xia +4 位作者 Lingyu Li Xinyue Wang Jiaqi Meng Yuxin Yang Yihang Guo 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第9期1378-1392,共15页
TiO2 is the most photoactive material because of its superstrong photooxidizing ability,and TiO2 photocatalysis has been widely applied in sustainable water treatment and environmental remediation.However,poor sunligh... TiO2 is the most photoactive material because of its superstrong photooxidizing ability,and TiO2 photocatalysis has been widely applied in sustainable water treatment and environmental remediation.However,poor sunlight or visible-light harvesting efficiency and fast recombination rate of the photogenerated charge carriers severely limit the practical applications of TiO2.To overcome these problems,the present work demonstrates a facile in-situ co-condensation method combined with hydrothermal treatment to prepare a series of graphitized carbon/TiO2 composite photocatalysts,and anatase TiO2 phase andp-p-conjugated polycyclic aromatic carbon structure are created simultaneously.As-prepared TiO2/C composites exhibit remarkably high visible-light photocatalytic activity in the degradation of aqueous emerging phenolic pollutants,acetaminophen(APAP)and methylparaben(MPB),and apparent rate constant of the TiO2/C composite with carbon doping level of 10.3%for APAP and MPB removal is 7.6 and 2.8 times higher than that of bare TiO2,and 6.2 and 2.6 times higher than that of Degussa P25 TiO2.Based on the results of photoelectrochemical experiments,indirect chemical probe measurements,and ESR spectroscopy,it is verified that doping TiO2 with graphitized carbon is responsible for this enhanced photocatalytic activity,which renders the improved visible-light harvesting ability,the accelerated separation of the photogenerated charge carriers,and enlarged BET surface areas.Through analyzing the intermediates yielded in the photodegradation process,the pathway of visible-light photocatalytic degradation of APAP and MPB over the TiO2/C composite is proposed. 展开更多
关键词 Titanium dioxide CARBON Visible-light photocatalysis COMPOSITE Phenolic compound Water treatment
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BiOCl-Bi12O17Cl2 nanocomposite with high visible-light photocatalytic activity prepared by an ultrasonic hydrothermal method for removing dye and pharmaceutical 被引量:11
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作者 Zeqing Long Guang Xian +2 位作者 Guangming Zhang Tao Zhang Xuemei Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第3期464-473,共10页
A BiOCl-Bi12O17Cl2 nanocomposite with a high visible-light response and a low photoinduced electron-hole pair recombination rate was successfully synthesized using an ultrasonic-hydrothermal method.The texture,structu... A BiOCl-Bi12O17Cl2 nanocomposite with a high visible-light response and a low photoinduced electron-hole pair recombination rate was successfully synthesized using an ultrasonic-hydrothermal method.The texture,structure,optical,and photocatalytic properties of the composite were characterized.The results showed that the composite had a sheet flower-like structure with a large specific surface area.Ultraviolet-visible diffuse reflection spectra and photoluminescence spectra showed that the composite had an excellent visible-light response and a low recombination rate of photoinduced electron hole pairs.The photocatalytic property of the composite was evaluated by the removal efficiency of rhodamine B and ciprofloxacin under visible-light illumination.The composite’s reaction rate constant of removing rhodamine B(/ciprofloxacin)was approximately 8.14(/4.94),42.63(/11.91)and 64.66(/36.07)times that of Bi12O17Cl2,P25,and BiOCl,respectively.Furthermore,the composite showed a wide applicable pH range and excellent reusability.Mechanism analysis showed that photogenerated holes played a dominant role and·O2–also contributed to photocatalytic degradation.In summary,this study presents a high-efficiency photocatalyst for wastewater treatment. 展开更多
关键词 BiOCl-Bi12O17Cl2 NANOCOMPOSITE Green technology Visible-light photocatalysis
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Higher-Dimensional Integrable Systems Arising from Motions of Curves on S^2(R)and S^3(R) 被引量:2
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作者 QU Chang-Zheng LI Yan-Yan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期841-843,共3页
We show that higher-dimensional integrable systems including the (2+1)-dimensional generalized sine-Gordon equation and the (2+1)-dimensional complex mKdV equation are associated with motions of surfaces inducedby end... We show that higher-dimensional integrable systems including the (2+1)-dimensional generalized sine-Gordon equation and the (2+1)-dimensional complex mKdV equation are associated with motions of surfaces inducedby endowing with an extra space variable to the motions of curves on S^2(R) and S^3(R). 展开更多
关键词 higher-dimensional integrable system motion of curve sine-Gordon equation complex mKdV equation
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Recurrent giant fibrovascular polyp of the esophagus 被引量:7
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作者 Ser Yee Lee Weng Hoong Chan +2 位作者 Ranjiv Sivanandan Dennis Teck Hock Lim Wai Keong Wong 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第29期3697-3700,共4页
Giant fibrovascular polyps of the esophagus and hypopharynx are rare benign esophageal tumors. They arise most commonly in the upper esophagus and may, rarely, originate in the hypopharynx. They can vary significantly... Giant fibrovascular polyps of the esophagus and hypopharynx are rare benign esophageal tumors. They arise most commonly in the upper esophagus and may, rarely, originate in the hypopharynx. They can vary significantly in size. Even though they are benign, they may be lethal due to either bleeding or, rarely, asphyxiation if a large polyp is regurgitated. Patients commonly present with dysphagia or hematemesis. The polyps may not be well visualized on endoscopy and imaging plays a vital role in aiding diagnosis as well as providing important information for preoperative planning, such as the location of the pedicle, the vascularity of the polyp and the tissue elements of the mass. They can also be recurrent in rare cases, especially if the resection margins of the base are involved. We review the recent literature and report a case of a 61-year-old man with a recurrent giant esophageal fibrovascular polyp with illustrative contrast barium swallow, CT and intra-operative images, who required several surgeries via a combination of endoscopic, trans-oral, trans-cervical, trans-thoracic and trans-abdominal approaches. 展开更多
关键词 Giant fibrovascular polyp ESOPHAGUS Esophageal polyp Fibroepithelial polyps
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In-situ polymerization for PPy/g-C_3N_4 composites with enhanced visible light photocatalytic performance 被引量:4
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作者 Hongju Han Min Fu +3 位作者 Yalin Li Wei Guan Peng Lu Xueli Hu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期831-840,共10页
Polypyrrole‐modified graphitic carbon nitride composites(PPy/g‐C3N4)are fabricated using an in‐situ polymerization method to improve the visible light photocatalytic activity of g‐C3N4.The PPy/g‐C3N4 is applied t... Polypyrrole‐modified graphitic carbon nitride composites(PPy/g‐C3N4)are fabricated using an in‐situ polymerization method to improve the visible light photocatalytic activity of g‐C3N4.The PPy/g‐C3N4 is applied to the photocatalytic degradation of methylene blue(MB)under visible light irradiation.Various characterization techniques are employed to investigate the relationship between the structural properties and photoactivities of the as‐prepared composites.Results show that the specific surface area of the PPy/g‐C3N4 composites increases upon assembly of the amorphous PPy nanoparticles on the g‐C3N4 surface.Owing to the strong conductivity,the PPy can be used as a transition channel for electrons to move onto the g‐C3N4 surface,thus inhibiting the recombination of photogenerated carriers of g‐C3N4 and improving the photocatalytic performance.The elevated light adsorption of PPy/g‐C3N4 composites is attributed to the strong absorption coefficient of PPy.The composite containing 0.75 wt%PPy exhibits a photocatalytic efficiency that is 3 times higher than that of g‐C3N4 in 2 h.Moreover,the degradation kinetics follow a pseudo‐first‐order model.A detailed photocatalytic mechanism is proposed with·OH and·O2-radicals as the main reactive species.The present work provides new insights into the mechanistic understanding of PPy in PPy/g‐C3N4 composites for environmental applications. 展开更多
关键词 PPy/g‐C3N4 composites In‐situ polymerization Visible light photocatalysis Mechanism Environmental remediation
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Thermal stability of degradable composite from ultrafine coal powder and polyethylene
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作者 杨伏生 周安宁 +1 位作者 杨志远 郑茂盛 《Journal of Coal Science & Engineering(China)》 2006年第2期84-87,共4页
Thermal degradation processes and kinetics of composites based on ultrafine coal powder and high density polyethylene (HDPE), linear low density polyethylene (LLDPE) or low density polyethylene (LDPE) at differe... Thermal degradation processes and kinetics of composites based on ultrafine coal powder and high density polyethylene (HDPE), linear low density polyethylene (LLDPE) or low density polyethylene (LDPE) at different compositions were studied by means of thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) in present work, to improve understandings in stabilization or degradation control of the composite. The results indicated that the coal facilitates melting of the polyethylene slightly before onset temperature, some chemical interactions were also observed in the composite. Coal participates in chain initiation, transfer and termination of the polymer, influences on thermal stability of composites lie in hydrogen acceptor effect of the coal. The thermal decomposition of the coals and the polymers can be modeled via the first order parallel reactions models in low temperatLire range. In higher temperature case, combination of aromatic macromolecular radical from coal with polymeric macromolecular radical gives rise to the greater activation energies of decomposition, thermal decomposition of the composites comply to step-by-step consecutive reactions models. Coal can be used as important degradation controlling additive to prepare functional materials. 展开更多
关键词 coal POLYETHYLENE COMPOSITE TG DSC stability
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A novel method based on entransy theory for setting energy targets of heat exchanger network 被引量:5
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作者 Li Xia Yuanli Feng +1 位作者 Xiaoyan Sun Shuguang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第8期1037-1042,共6页
A T-Q diagram based on entransy theory is applied to graphically and quantitatively describe the irreversibility of the heat transfer processes.The hot and cold composite curves can be obtained in the T-Q diagram.The ... A T-Q diagram based on entransy theory is applied to graphically and quantitatively describe the irreversibility of the heat transfer processes.The hot and cold composite curves can be obtained in the T-Q diagram.The entransy recovery and entransy dissipation that are affected by temperature differences can be obtained through the shaded area under the composite curves.The method for setting the energy target of the HENs in T-Q diagram based on entransy theory is proposed.A case study of the diesel oil hydrogenation unit is used to illustrate the application of the method.The results show that three different heat transfer temperature differences is 10 K,15 K and 20 K,and the entransy recovery is 5.498×10~7k W·K,5.377×10~7k W·K,5.257×10~7k W·K,respectively.And the entransy transfer efficiency is 92.29%,91.63%,90.99%.Thus,the energy-saving potential of the HENs is obtained by setting the energy target based on the entransy transfer efficiency. 展开更多
关键词 Heat transfer Process systems Entransy Energy target T-Qdiagram
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The Effects of Stochastic Characteristics of Materials on the Reliability of a Composite Ship Hull
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作者 张炜 唐文勇 +1 位作者 陈念众 张圣坤 《Journal of Marine Science and Application》 2011年第1期1-6,共6页
The effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials under longitudinal moment were extensively studied using reliability and sensitivity calculations of ... The effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials under longitudinal moment were extensively studied using reliability and sensitivity calculations of a composite ship hull which was sagging.The reliability indices and failure probabilities of the ship in three kinds of failure modes (buckling,material failure,and ultimate collapse) were calculated by the surface response method and JC method.The importance factors of random variables in stochastic models,such as the model errors in predicting the ultimate longitudinal strength of ship and the longitudinal bending moment that the ship withstands,as well as the stochastic characteristics of materials in the models used,were calculated.Then,the effects of these random variables,including the stochastic characteristics of materials on the reliability index and the failure probability of ships which were sagging,were discussed with their importance factors.The results show that the effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials should be considered during the reliability assessment of composite ships.Finally,some conclusions and recommendations were given for high-speed ship design and safety assessment. 展开更多
关键词 composite material reliability analysis response-surface method sensitivity analysis
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Simulation of Land-use Scenarios for Beijing Using CLUE-S and Markov Composite Models 被引量:25
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作者 HU Yecui ZHENG Yunmei ZHENG Xinqi 《Chinese Geographical Science》 SCIE CSCD 2013年第1期92-100,共9页
This study investigated and simulated land use patterns in Beijing for the year 2000 and the year 2005 from the actual land use data for the year 1995 and the year 2000,respectively,by combining spatial land allocatio... This study investigated and simulated land use patterns in Beijing for the year 2000 and the year 2005 from the actual land use data for the year 1995 and the year 2000,respectively,by combining spatial land allocation simulation using the CLUE-S model,and numerical land demand prediction using the Markov model.The simulations for 2000 and 2005 were confirmed to be generally accurate using Kappa indices.Then the land-use scenarios for Beijing in 2015 were simulated assuming two modes of development:1) urban development following existing trends;and 2) under a strict farmland control.The simulations suggested that under either mode,urbanized areas would expand at the expense of land for other uses.This expansion was predicted to dominate the land-use conversions between 2005 and 2015,and was expected to be accompanied by an extensive loss of farmland.The key susceptible to land-use changes were found to be located at the central urban Beijing and the surrounding regions including Yanqing County,Changping District and Fangshan District.Also,the simulations predicted a considerable expansion of urban/suburban areas in the mountainous regions of Beijing,suggesting a need for priority monitoring and protection. 展开更多
关键词 CLUE-S model land use Markov model scenario simulation BEIJING
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Composite Cathode Based on Redox-Reversible Nb2TiO7 for Direct High-Temperature Steam Electrolysis
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作者 Shi-song Li Ji-gui Cheng +2 位作者 Xu-cheng Zhang Yu Wang Kui Xie 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第3期323-330,I0002,共9页
Ni/YSZ fuel electrodes can only operate under strongly reducing conditions for steam elec- trolysis in an oxide-ion-conducting solid oxide electrolyzer (SOE). In atmosphere with a low content of H2 or without H2, ca... Ni/YSZ fuel electrodes can only operate under strongly reducing conditions for steam elec- trolysis in an oxide-ion-conducting solid oxide electrolyzer (SOE). In atmosphere with a low content of H2 or without H2, cathodes based on redox-reversible Nb2TiO7 provide a promising alternative. The reversible changes between oxidized Nb2TiO7 and reduced Nbl.33Tio.6704 samples are systematically investigated after redox-cycling tests. The conductivities of Nb2TiO7 and reduced Nb1.33Tio.6704 are studied as a function of temperature and oxygen partial pressure and correlated with the electrochemical properties of the composite electrodes in a symmetric cell and SOE at 830 ℃. Steam electrolysis is then performed using an oxide-ion-conducting SOE based on a Nb1.33Ti0.6704 composite fuel electrode at 830 ℃. The current-voltage and impedance spectroscopy tests demonstrate that the reduction and activation of the fuel electrode is the main process at low voltage; however, the steam electrolysis dominates the entire process at high voltages. The Faradic efficiencies of steam electrolysis reach 98.9% when 3%H2O/Ar/4%H2 is introduced to the fuel electrode and 89% for that with introduction of 3%H2O/Ar. 展开更多
关键词 Redox-reversible Alternative fuel electrode Solid oxide electrolyzer Steamelectrolysis
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