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行走在“变现”与“储值”间的阅读价值意识
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作者 宋凯 《小学教学参考(综合版)》 2012年第2期14-14,共1页
小学语文阅读课堂由于学生的阅读视界、生活经验等因素的限制,学生对文本的理解与体验是无法齐步划一的。这就要求教师在教学中通过教学智慧,有意识地给学生提供阅读方法,渗透阅读的价值取向,找准阅读的切入点,为学生的阅读调好节... 小学语文阅读课堂由于学生的阅读视界、生活经验等因素的限制,学生对文本的理解与体验是无法齐步划一的。这就要求教师在教学中通过教学智慧,有意识地给学生提供阅读方法,渗透阅读的价值取向,找准阅读的切入点,为学生的阅读调好节奏,导好方向,引领、帮助学生激活已有的知识储备,唤醒学生的阅读经验,让学生凭借文本去跨越时空,进入作者描写的场景中,触摸作品人物的内心。 展开更多
关键词 阅读课堂 价值意识 “储值” 变现 教学智慧 小学语文 生活经验 阅读方法
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农村学校应在“储值”中创特色
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作者 陈有国 陈勇 《湖北教育(综合资讯)》 2011年第9期43-44,共2页
学校如何发展,学生如何培养,教师如何培育,这是校长面临的共同课题。在人人争创特色的大环境中,农村学校如何开辟自己的特色发展之路?笔者认为,农村学校要学会“储值”,即立足当地实际,找准自身优势,全方位挖掘、储存发展潜能... 学校如何发展,学生如何培养,教师如何培育,这是校长面临的共同课题。在人人争创特色的大环境中,农村学校如何开辟自己的特色发展之路?笔者认为,农村学校要学会“储值”,即立足当地实际,找准自身优势,全方位挖掘、储存发展潜能,如此才能让学校走上特色之路,学生成为特长之才,教师成为特色之师。 展开更多
关键词 农村学校 “储值” 特色发展 发展潜能 学生 教师 校长
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为农村孩子终身发展“储值” 被引量:2
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作者 吴可发 《人民教育》 CSSCI 北大核心 2010年第19期22-23,共2页
在多年的农村教育与管理实践中,我一直在思考:基础教育如何为孩子的终身发展“储值”?让孩子在未来的学习、生活和工作中,能够从几年、十几年的基础教育的积累中提取他们高效人生所需的源源不竭的“储蓄”,为其生活带来快乐,为其... 在多年的农村教育与管理实践中,我一直在思考:基础教育如何为孩子的终身发展“储值”?让孩子在未来的学习、生活和工作中,能够从几年、十几年的基础教育的积累中提取他们高效人生所需的源源不竭的“储蓄”,为其生活带来快乐,为其家庭创造幸福,为国家和社会作出贡献。 展开更多
关键词 农村孩子 “储值” 终身发展 基础教育 管理实践 农村教育 生活 学习
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电子货币时代货币发行的分散化趋势 被引量:3
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作者 朱雪莲 吴秋实 《金融理论与实践》 北大核心 2003年第2期11-13,共3页
从电子货币的职能与特性、电子货币的发行主体等方面来看,进入电子货币时代后,货币的发行权将趋于分散化。
关键词 分散化趋势 电子货币 货币发行权 中央银行 支付制度 “储值” 通货 安全性
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电子货币发展的风险与对策
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作者 陈颖 岳方 《集团经济研究》 北大核心 2006年第08X期250-251,共2页
电子货币是指在零售支付机制中,通过销售终端、不同的电子设备之间以及在公开网络上执行支付的“储值”和预付支出机制。电子货币是一种以电子脉冲代替纸张进行资金传输和存储的信用货币,它的使用和结算不受金额对象和区域的限制,信... 电子货币是指在零售支付机制中,通过销售终端、不同的电子设备之间以及在公开网络上执行支付的“储值”和预付支出机制。电子货币是一种以电子脉冲代替纸张进行资金传输和存储的信用货币,它的使用和结算不受金额对象和区域的限制,信息流、资金流在网上传递非常迅速。从目前电子货币的发行机构来看,电子货币目前大部分是由不同信用机构自行开发设计的带有各自特征的产品,更多地是商业银行等金融机构、甚至是成立特别发行公司的非银行机构,其担保主要依赖于各个发行者自身的信誉和资产规模,消费者和商家拥有选择的自由。 展开更多
关键词 电子货币 风险 支付机制 非银行机构 销售终端 “储值” 电子设备 信用货币 网上传递 发行机构
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EDLC charging performance for microgrid applications 被引量:9
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作者 徐青山 卞海红 赵伟然 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期415-420,共6页
In order to review storage performance of the electric double layer capacitor (EDLC) in microgrid applications, charging time and storage efficiency issues are mainly studied aiming at three different charging modes... In order to review storage performance of the electric double layer capacitor (EDLC) in microgrid applications, charging time and storage efficiency issues are mainly studied aiming at three different charging modes, including the constant voltage charging mode (CVCM), the constant current charging mode (CCCM) and the constant power charging mode (CPCM), based on the practical EDLC product. Numerical calculation methods are presented for different charging modes, and the charging efficiency is also reviewed with strict mathematical deductions, which is validated to be accurate enough and applicable through a simple case with the PV/EDLC system illustration. Finally, trade-off problems between charging time and energy loss are also studied. Research results show that the CPCM is more suitable for microgrid networks compared with the traditional constant-voltage and constant-current charging modes. The hybrid charging method is recommended to save energy and keep high efficiency relatively at the same time. However, how to manage the combination percentage of different charging modes in a reasonable way should be dealt with according to the practical requirements. 展开更多
关键词 electric double layer capacitor (EDLC) energy storage charge evaluation numerical calculation trade-off
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只想理个发,能不能别叫我办卡?
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作者 胡姚雨 《课堂内外(高中版)(A版)》 2022年第3期12-13,共2页
为什么一定要叫我办卡?--从“现金”到“储值”这世上有两个地方能让人改头换面,一个是监狱,一个是……理发店。推开玻璃门的那一刻,人们就会想起曾经被Tony老师支配的恐惧--不光在于他那手起刀落、“亲妈不认”的狂野剪法,更在于他巧... 为什么一定要叫我办卡?--从“现金”到“储值”这世上有两个地方能让人改头换面,一个是监狱,一个是……理发店。推开玻璃门的那一刻,人们就会想起曾经被Tony老师支配的恐惧--不光在于他那手起刀落、“亲妈不认”的狂野剪法,更在于他巧舌如簧、舌灿莲花的一顿游说,让你恨不得当场掏出500块,大吼一声“办”! 展开更多
关键词 玻璃门 理发店 监狱 改头换面 “储值”
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NUMERICAL SIMULATION STUDY ON WUQING GEOTHERMAL RESERVOIR,TIANJIN
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作者 李新国 赵军 《Transactions of Tianjin University》 EI CAS 2001年第3期197-201,共5页
In this paper the computer code of AUTOUGH2 is used to carry out numerical simulation study on the Wuqing geothermal reservoir for evaluating reservoir performance upon different exploitation schemes.The simulating ca... In this paper the computer code of AUTOUGH2 is used to carry out numerical simulation study on the Wuqing geothermal reservoir for evaluating reservoir performance upon different exploitation schemes.The simulating calculation and analysis of two main cases,production without reinjection and production with reinjection,were carried out to illuminate and compare the temperature and pressure profiles with distance and time.The water level or pressure will decrease with the time of production,and the reinjection will cause the cooling effect of reinjection on the production zone. 展开更多
关键词 numerical simulation AUTOUGH2 RESERVOIR water level decrease pressure decrease REINJECTION cooling effect
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Prediction of the Mooring Force of a 2-D Floating Oil Storage Tank 被引量:4
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作者 CHU Xinjie DONG Sheng ZHAO Xizeng 《Journal of Ocean University of China》 SCIE CAS 2014年第6期901-910,共10页
A Constrained Interpolation Profile (CIP)-based model is developed to predict the mooring force of a two-dimensional floating oil storage tank under wave conditions, which is validated against to a newly performed e... A Constrained Interpolation Profile (CIP)-based model is developed to predict the mooring force of a two-dimensional floating oil storage tank under wave conditions, which is validated against to a newly performed experiment. In the experiment, a box-shaped floating oil storage apparatus is used. Computations are performed by an improved CIP-based Cartesian grid model, in which the THINC/SW scheme (THINC: tangent of hyperbola for interface capturing; SW: Slope Weighting), is used for interface capturing. A multiphase flow solver is adopted to treat the water-air-body interactions. The Immersed Boundary Method (IBM) is implemented to treat the body surface. Main attention is paid to the sum force of mooring line and velocity field around the body. It is found that the sum force of the mooring line increases with increasing wave amplitude. The body suffers from water wave impact and large body motions occur near the free surface. The vortex occurs near the sharp edge, i.e., the sharp bottom comers of the float- ing oil storage tank and the vortex shedding can be captured by the present numerical model. The present model could be further improved by including turbulence model which is currently under development. Comparison between the computational mooring forces and the measured mooring forces is presented with a reasonable agreement. The developed numerical model can predict the mooring line forces very well. 展开更多
关键词 floating oil storage mooring line force CIP method numerical method Immersed Boundary Method
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Storage and Density of Soil Organic Carbon in Urban Topsoil of Hilly Cities:A Case Study of Chongqing Municipality of China 被引量:7
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作者 LIU Yong WANG Cheng +1 位作者 YUE Wenze HU Yanyan 《Chinese Geographical Science》 SCIE CSCD 2013年第1期26-34,共9页
Rapid urbanization results in the conversion of natural soil to urban soil,and consequently,the storage and density of the soil carbon pools change.Taking Chongqing Municipality of China as a study case,this investiga... Rapid urbanization results in the conversion of natural soil to urban soil,and consequently,the storage and density of the soil carbon pools change.Taking Chongqing Municipality of China as a study case,this investigation attempts to better understand soil carbon pools in hilly cities.First,the vegetated areas in the study area were derived from QuickBird images.Then,topsoil data from 220 soil samples(0-20 cm) in the vegetated areas were collected and their soil organic carbon(SOC) densities were analyzed.Using the Kriging interpolation method,the spatial pattern of SOC was estimated.The results show that the SOC density exhibited high spatial variability in the urban topsoil of Chongqing.First,the SOC density in topsoil decreased according to slope in the order 2°-6° < 25°-90° < 0°-2° < 6°-15° < 15°-25°.Second,the newly developed areas during 2001-2010 had a lower SOC density than the areas built before 1988.Third,urban parks and gardens had a higher SOC density in topsoil,residential green land followed,and scattered street green land ranked last.For hilly cities,the variability of terrain affects the distribution of SOC.The Kriging results indicate that Kriging method combining slope with SOC density produced a high level of accuracy.The Kriging results show that the SOC density to the north of the Jialing River was higher than the south.The vegetated areas were estimated to amount to 73.5 km2 across the study area with an SOC storage of 0.192 Tg and an average density of 2.61 kg/m2. 展开更多
关键词 soil organic carbon (SOC) TOPSOIL hilly city Kriging interpolation
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Effect of Storage Time and Temperature on Phenolic, Flavonoid Contents and Antioxidant Properties of Milled Rice
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作者 Pimpaporn Thanajiruschaya Wathinee Doksaku +1 位作者 Phanee Rattanachaisit Jirasak Kongkiattikajorn 《Journal of Life Sciences》 2011年第6期447-453,共7页
The objective of this study was to determine the phenolic, flavonoid contents and amioxidant properties in the milled rice cv. Khaw Dawk Mali 105 during storage for 0-7 months at different temperatures. The total phen... The objective of this study was to determine the phenolic, flavonoid contents and amioxidant properties in the milled rice cv. Khaw Dawk Mali 105 during storage for 0-7 months at different temperatures. The total phenolic content of non-stored rice was 17.02 mg/g and 7-month stored rice at 25℃ was 6.07 + 0.01 mg/g while storage for 7 months at 37 ℃, the phenolic contents was 7.29±0.35 mg/g. The total flavonoid content of non-stored rice was 13.26 ± 0.01 mg/g and 7 month stored rice at 25 ℃ was 6.74±0.01 mg/g while storage for 7 months at 37℃, the flavonoid content was 6.45 ± 0.12 mg/g. The antioxidant property determined by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical expressed in the value of EC50 (DPPH) of non-stored rice was 0.27 mg/mL and 7-month stored rice at 25℃ was 12.15 mg/mL while storage for 7 months at 37℃, the antioxidant property was 6.34 mg/mL. The antioxidant property determined by lipid peroxidation expressed in the value of EC50 (lipid peroxidation) of non-stored rice was 0.12 mg/mL and 7 month stored rice at 25℃ was 1.18 rag/mL while storage for 7-months at 37 ℃, the antioxidant property was 1.10 mg/mL. The results showed that storage time at 25℃ and 37 ℃ caused decrease of extractable phenolic and flavonoid contents and antioxidant activities of the milled rice however 7-month stored milled rice at 37 ℃ milled rice at 25 ℃. 展开更多
关键词 ANTIOXIDANT PHENOLIC flavonoid RICE storage.
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A NOVEL MULTI-VALUED BAM MODEL WITH IMPROVED ERROR-CORRECTING CAPABILITY
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作者 Zhang Daoqiang Chen Songcan (College of Info. Sci. Tech., Nanjing Univ. of Aeronautics and Astronautics, Nanjing 210016) 《Journal of Electronics(China)》 2003年第3期220-223,共4页
A Hyperbolic Tangent multi-valued Bi-directional Associative Memory (HTBAM) model is proposed in this letter. Two general energy functions are defined to prove the stability of one class of multi-valued Bi-directional... A Hyperbolic Tangent multi-valued Bi-directional Associative Memory (HTBAM) model is proposed in this letter. Two general energy functions are defined to prove the stability of one class of multi-valued Bi-directional Associative Mernorys(BAMs), with HTBAM being the special case. Simulation results show that HTBAM has a competitive storage capacity and much more error-correcting capability than other multi-valued BAMs. 展开更多
关键词 Bi-directional associative memory Recurrent neural network Multi-value
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Numerical Simulation of Sloshing in Rectangular Storage Tank Using Coupled FEM-BEM 被引量:6
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作者 Hassan Saghi Mohammad Javad Ketabdari 《Journal of Marine Science and Application》 2012年第4期417-426,共10页
Sloshing of liquid can increase the dynamic pressure on the storage sidewalls and bottom in tanker ships and LNG careers. Different geometric shapes were suggested for storage tank to minimize the sloshing pressure on... Sloshing of liquid can increase the dynamic pressure on the storage sidewalls and bottom in tanker ships and LNG careers. Different geometric shapes were suggested for storage tank to minimize the sloshing pressure on tank perimeter. In this research, a numerical code was developed to model liquid sloshing in a rectangular partially filled tank. Assuming the fluid to be inviscid, Laplace equation and nonlinear free surface boundary conditions are solved using coupled FEM-BEM. The code performance for sloshing modeling is validated against available data. To minimize the sloshing pressure on tank perimeter, rectangular tanks with specific volumes and different aspect ratios were investigated and the best aspect ratios were suggested. The results showed that the rectangular tank with suggested aspect ratios, not only has a maximum surrounded tank volume to the constant available volume, but also reduces the sloshing pressure efficiently. 展开更多
关键词 rectangular storage tank sloshing phenomenon aspect ratio coupled FEM-BEM
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Dynamic response of fixed-roof oil-storage tank structure under blast loading
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作者 路胜卓 王伟 《Journal of Southeast University(English Edition)》 EI CAS 2012年第1期58-63,共6页
In order to investigate the damage and deformation mechanism of large scale steel fixed-roof oil-storage tanks under the combustible gas explosion, a series of explosion experiments of scaled models are conducted. Th... In order to investigate the damage and deformation mechanism of large scale steel fixed-roof oil-storage tanks under the combustible gas explosion, a series of explosion experiments of scaled models are conducted. The l: 25 scaled numerical models of oil-storage tanks with a capacity of 5 000 m3 are also set up by ANSYS/LS-DYNA software, and their damage processes under the blast impact are numerically simulated. Both the experimental results and the numerical simulations show that the blast loading curve displays a pressure jump instantaneously at the moment of contact with the experimental models, and the overpressure peaks at the stagnation area of the outer surface on the blast side. The yield range first appears at the stagnation area and then propagates to the neighboring parts, and the irregular plastic hinge circle obviously appears around the deformation area, which results in the concaved buckling of the tank inner surface. During the whole process, the inner liquid not only impacts on the structures, but also absorbs and consumes part of the blast energy. 展开更多
关键词 fixed-roof oil-storage tank combustible gasexplosion numerical simulation and analysis impact loading dynamic strain
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Towards a cure for HIV: the identification and characterization of HIV reservoirs in optimally treated people
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作者 Adewunmi Onafuwa-Nugal Lucy A McNamara Kathleen L Collins 《Cell Research》 SCIE CAS CSCD 2010年第11期1185-1187,共3页
Currently available anti-HIV-1 drugs suppress viral replication and maintain viral levels below the detection threshold of most assays but do not eliminate cellular reservoirs. As a result, very low levels of circulat... Currently available anti-HIV-1 drugs suppress viral replication and maintain viral levels below the detection threshold of most assays but do not eliminate cellular reservoirs. As a result, very low levels of circulating virus can be detected in most people despite long-term treatment with potent anti-HIV drug combinations. Not surprisingly, viral levels rebound with discontinuation of treatment. New evidence indicates that there is a viral reservoir in bone marrow progenitor cells. 展开更多
关键词 HIV LATENCY bone marrow stem cells CD34
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电子货币对货币供应量统计的影响 被引量:1
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作者 代林玲 连小辉 《中国经贸导刊》 北大核心 2009年第15期54-54,共1页
一、电子货币的概念及货币供应量统计 何谓电子货币,1998年,巴塞尔银行监管委员会(BCBS)将电子货币定义为:在零售支付机制中,通过销售终端、各类电子设备,以及在公开网络上执行支付的“储值”产品和预付支付机制。所谓“储值”... 一、电子货币的概念及货币供应量统计 何谓电子货币,1998年,巴塞尔银行监管委员会(BCBS)将电子货币定义为:在零售支付机制中,通过销售终端、各类电子设备,以及在公开网络上执行支付的“储值”产品和预付支付机制。所谓“储值”产品,是指保存在物理介质(硬件或卡介质)中可用来支付的价值,这种物理介质可以是Mondex智能卡、多功能信用卡、“电子钱包”等,所储价值使用后,可以通过电子设备追加。 展开更多
关键词 货币供应量 电子货币 统计 巴塞尔银行监管委员会 支付机制 电子设备 “储值” 货币定义
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Improved multilevel storage capacity in Ge_(2)Sb_(2)Te_(5)-based phase-change memory using a high-aspect-ratio lateral structure 被引量:1
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作者 Ruizhe Zhao Mingze He +4 位作者 Lun Wang Ziqi Chen Xiaomin Cheng Hao Tong Xiangshui Miao 《Science China Materials》 SCIE EI CAS CSCD 2022年第10期2818-2825,共8页
Further improvement of storage density is a key challenge for the application of phase-change memory(PCM)in storage-class memory.However,for PCM,storage density improvements include feature size scaling down and multi... Further improvement of storage density is a key challenge for the application of phase-change memory(PCM)in storage-class memory.However,for PCM,storage density improvements include feature size scaling down and multilevel cell(MLC)operation,potentially causing thermal crosstalk issues and phase separation issues,respectively.To address these challenges,we propose a high-aspect-ratio(25:1)lateral nanowire(NW)PCM device with conventional chalcogenide Ge_(2)Sb_(2)Te_(5)(GST-225)to realize stable MLC operations,i.e.,low intra-and inter-cell variability and low resistance drift(coefficient=0.009).The improved MLC performance is attributed to the high aspect ratio,which enables precise control of the amorphous region because of sidewall confinement,as confirmed by transmission electron microscopy analysis.In summary,the NW devices provide guidance for the design of future high-aspect-ratio threedimensional PCM devices with MLC capability. 展开更多
关键词 multilevel cell high aspect ratio NANOWIRES 3D phase-change memory Ge_(2)Sb_(2)Te_(5)
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Conductive Ni3(HITP)2 MOFs thin films for flexible transparent supercapacitors with high rate capability 被引量:4
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作者 Weiwei Zhao Tiantian Chen +7 位作者 Weikang Wang Beibei Jin Jiali Peng Shuaihang Bi Mengyue Jiang Shujuan Liu Qiang Zhao Wei Huang 《Science Bulletin》 SCIE EI CAS CSCD 2020年第21期1803-1811,M0003,M0004,共11页
The flexible transparent supercapacitors have been considered as one of the key energy-storage components to power the smart portable electronic devices.However,it is still a challenge to explore flexible transparent ... The flexible transparent supercapacitors have been considered as one of the key energy-storage components to power the smart portable electronic devices.However,it is still a challenge to explore flexible transparent capacitive electrodes with high rate capability.Herein,conductive Ni3(HITP)2(HITP=2,3,6,7,10,11-hexaiminotriphenylene)thin films are adopted as capacitive electrodes in flexible transparent supercapacitors.The Ni3(HITP)2 electrode possesses the excellent optoelectronic property with optical transmittance(T)of 78.4%and sheet resistance(Rs)of 51.3Ωsq-1,remarkable areal capacitance(CA)of 1.63 mF cm^-2and highest scan rate up to 5000 mV s-1.The asymmetric Ni3(HITP)2//PEDOT:PSS supercapacitor(T=61%)yields a high CA of 1.06 mF cm^-2at 3μA cm-2,which maintains 77.4%as the current density increases by 50 folds.The remarkable rate capability is ascribed to the collaborative advantages of low diffusion resistance and high ion accessibility,resulting from the intrinsic conductivity,short oriented pores and large specific areas of Ni3(HITP)2 films. 展开更多
关键词 Conductive film Metal-organic frameworks Collaborative advantages Flexible transparent supercapacitors High rate capability
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A reliable power management scheme for consistent hashing based distributed key value storage systems 被引量:1
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作者 Nan-nan ZHAO Ji-guang WAN +1 位作者 Jun WANG Chang-sheng XIE 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第10期994-1007,共14页
Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing the... Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing their power consumption. In this paper, we propose GreenCHT, a reliable power management scheme for consistent hashing based distributed key value storage systems. It consists of a multi-tier replication scheme, a reliable distributed log store, and a predictive power mode scheduler (PMS). Instead of randomly placing replicas of each object on a number of nodes in the consistent hash ring, we arrange the replicas of objects on nonoverlapping tiers of nodes in the ring. This allows the system to fall in various power modes by powering down subsets of servers while not violating data availability. The predictive PMS predicts workloads and adapts to load fluctuation. It cooperates with the multi-tier replication strategy to provide power proportionality for the system. To ensure that the reliability of the system is maintained when replicas are powered down, we distribute the writes to standby replicas to active servers, which ensures failure tolerance of the system. GreenCHT is implemented based on Sheepdog, a distributed key value storage system that uses consistent hashing as an underlying distributed hash table. By replaying 12 typical real workload traces collected from Microsoft, the evaluation results show that GreenCHT can provide significant power savings while maintaining a desired performance. We observe that GreenCHT can reduce power consumption by up to 35%-61%. 展开更多
关键词 Consistent hash table (CHT) REPLICATION Power management Key value storage system Reliability
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Impact of hydraulic perforation on fracture initiation and propagation in shale rocks 被引量:4
20
作者 ZHAO Xi JU Yang +2 位作者 YANG Yong SU Sun GONG WenBo 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第5期756-762,共7页
To enhance the oil and gas recovery rate, hydraulic fracturing techniques have been widely adopted for stimulation of low-permeability reservoirs. Pioneering work indicates that hydraulic perforation and layout could ... To enhance the oil and gas recovery rate, hydraulic fracturing techniques have been widely adopted for stimulation of low-permeability reservoirs. Pioneering work indicates that hydraulic perforation and layout could significantly affect fracture initiation and propagation in low-permeability reservoir rocks subjected to complex in-situ stresses. This paper reports on a novel numerical method that incorporates fracture mechanics principles and the numerical tools FRANC3D and ANSYS to investigate the three-dimensional initiation and propagation behavior of hydro-fracturing cracks in shale rock. Considering the transverse isotropic property of shale rocks, the mechanical parameters of reservoir rocks attained from laboratory tests were adopted in the simulation. The influence of perforation layouts on the 3D initiation of hydro-fracturing fractures in reservoir rocks under geo-stresses was quantitatively illuminated. The propagation and growth of fractures in three dimensions in different perforating azimuth values were illustrated. The results indicate that: 1) the optimal perforation direction should be parallel to the maximum horizontal principal stress, 2) the crack plane gradually turns toward the direction of the maximum horizontal principal stress when they are not in parallel, 3) compared with the linear and symmetric pattern, the staggered perforation is the optimal one, 4) the proper perforation density is four to six holes per meter, 5) the optimal perforation diameter in this model is 30 ram, and 6) the influence of the perforation depth on the fracture initiation pressure is low. 展开更多
关键词 hydraulic fracturing PERFORATION shale rocks in-situ stresses numerical simulation fracture mechanics
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