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开源立本 节时共读——小学语文链接式阅读教学策略研究 被引量:2
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作者 刘尧 《当代家庭教育》 2020年第35期186-187,共2页
小学语文链接形式阅读教学,是以教材为基本框架,反复斟酌文章中所含的文化内涵并通过开源立本节时共读策略实施。不仅如此,链接是所要阅读的文章与相关文章相关联的阅读方式,是课内与课外不同阅读类型的有机结合。它是在注重课文教材的... 小学语文链接形式阅读教学,是以教材为基本框架,反复斟酌文章中所含的文化内涵并通过开源立本节时共读策略实施。不仅如此,链接是所要阅读的文章与相关文章相关联的阅读方式,是课内与课外不同阅读类型的有机结合。它是在注重课文教材的基础之上进行的课外延伸,这种阅读方式在教学当中起着无可替代的作用,激发学生大脑活跃度,并且可以拓宽学生的视角、让学生的语文水平得到质的提升。 展开更多
关键词 小学语文 开源立本节时共 链接阅读
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挑战现实理性构建浪漫真实——接受美学观照下的非虚构小说在美国的时兴 被引量:1
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作者 李家君 《沈阳工程学院学报(社会科学版)》 2006年第2期188-190,共3页
20世纪60年代,非虚构小说的文学样式在美国发展起来。它在报道真人真事时,融入了小说的写作技巧。非虚构小说之所以能时兴并形成巨大的文学潮流,与读者的接受是密不可分的。论文从接受美学的角度对其加以观照,以便更好的理解它。
关键词 非虚构小说 接受美学 时共
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Precipitation hardening behavior of dilute binary Al-Yb alloy 被引量:6
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作者 唐超兰 周德敬 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2326-2330,共5页
The precipitation hardening behavior in dilute Al-Yb alloys upon annealing at different temperatures was investigated to shed light on the mechanism of micro-alloying element in aluminum alloys. When aging at differen... The precipitation hardening behavior in dilute Al-Yb alloys upon annealing at different temperatures was investigated to shed light on the mechanism of micro-alloying element in aluminum alloys. When aging at different temperatures, the samples showed their corresponding peak hardness in the range of 400-416 MPa due to the precipitation of Al3Yb with L 12 crystal structure. The coarsening kinetics of the Al3Yb precipitates obeyed the LSW theory, which indicated that the coarsening process was controlled by the diffusion of Yb. The coherence between Al3Yb particles and matrix was maintained until the particle size reached 11 nm. When the particle size increased to about 2 nm, the shearing mechanism started to change to Orowan mechanism. 展开更多
关键词 aluminum alloy MICROALLOYING YTTERBIUM AGING COHERENCY precipitation hardening
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Amplitude preserved VSP reverse time migration for angle-domain CIGs extraction 被引量:2
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作者 孙文博 孙赞东 朱兴卉 《Applied Geophysics》 SCIE CSCD 2011年第2期141-149,177,178,共11页
An improved method of generating angle-domain common-image gathers(ADCIGs) by VSP reverse time migration(RTM) is introduced in this paper.The formula which is used to compute the receiver wavefield for VSP RTM is ... An improved method of generating angle-domain common-image gathers(ADCIGs) by VSP reverse time migration(RTM) is introduced in this paper.The formula which is used to compute the receiver wavefield for VSP RTM is modified by adding an amplitude correction term in order to conveniently output amplitude-preserved ADCIGs.Compared with the surface seismic data,VSP data contains much richer wavefields.However,the direct and downgoing waves can bring about serious imaging artifacts in ADCIGs,especially the direct wave.The feasibility and validity of this method is demonstrated by both numerical and real VSP data from western China.Thus,the ADCIGs from this method can provide reliable basic data for VSP migration velocity analysis,VSP AVO/AVA analysis,and inversion. 展开更多
关键词 VSP reverse time migration angle-domain common-image gathers(ADCIGs) amplitude preservation
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TR-ESR Investigation on Reaction of Vitamin C with Excited Triplet of 9,10-phenanthrenequinone in Reversed Micelle Solutions 被引量:1
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作者 许新胜 史蕾 +2 位作者 刘毅 季学韩 崔执凤 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第2期150-154,I0003,共6页
Time-resolved electron spin resonance has been used to study quenching reactions between the antioxidant Vitamin C (VC) and the triplet excited states of 9,10-phenanthrenequinone (PAQ) in ethylene glycol-water (E... Time-resolved electron spin resonance has been used to study quenching reactions between the antioxidant Vitamin C (VC) and the triplet excited states of 9,10-phenanthrenequinone (PAQ) in ethylene glycol-water (EG-H2O) homogeneous and inhomogeneous reversed micelle solutions. Reversed micelle solutions were used to be the models of physiological environment of biological cell and tissue. In PAQ/EG-H2O homogeneous solution, the excited triplet of PAQ (3PAQ*) abstracts hydrogen atom from solvent EG. In PAQ/VC/EG-H2O solution, 3pAQ* abstracts hydrogen atom not only from solvent EG but also from VC. The quenching rate constant of 3pAQ* by VC is close to the diffusion-controlled value of 1.41 × 108 L/(mol.s). In hexadecyltrimethylammonium bromide (CTAB)/EG-H2O and aerosol OT (AOT)/EG- H2O reversed micelle solutions, 3pAQ* and VC react around the water-oil interface of the reversed micelle. Exit of 3pAQ* from the lipid phase slows down the quenching reaction. For Triton X-100 (TX-100)/EG-H2O reversed micelle solution, PAQ and VC coexist inside the hydrophilic polyethylene glycol core, and the quenching rate constant of 3pAQ* by VC is larger than those in AOT/EG-H2O and CTAB/EG-H2O reversed micelle solutions, even a little larger than that in EG-H2O homogeneous solution. The strong emissive chemically induced dynamic electron polarization of As'- resulted from the effective TM spin polarization transfer in hydrogen abstraction of 3pAQ* from VC. 展开更多
关键词 9 10-phenanthrenequinone Vitamin C Time-resolved electron spin resonance Reversed micelle
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Conjugate gradient and cross-correlation based least-square reverse time migration and its application 被引量:1
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作者 孙小东 李振春 葛中慧 《Applied Geophysics》 SCIE CSCD 2017年第3期381-386,460,共7页
Although conventional reverse time migration can be perfectly applied to structural imaging it lacks the capability of enabling detailed delineation of a lithological reservoir due to irregular illumination. To obtain... Although conventional reverse time migration can be perfectly applied to structural imaging it lacks the capability of enabling detailed delineation of a lithological reservoir due to irregular illumination. To obtain reliable reflectivity of the subsurface it is necessary to solve the imaging problem using inversion. The least-square reverse time migration (LSRTM) (also known as linearized refleetivity inversion) aims to obtain relatively high-resolution amplitude preserving imaging by including the inverse of the Hessian matrix. In practice, the conjugate gradient algorithm is proven to be an efficient iterative method for enabling use of LSRTM. The velocity gradient can be derived from a cross-correlation between observed data and simulated data, making LSRTM independent of wavelet signature and thus more robust in practice. Tests on synthetic and marine data show that LSRTM has good potential for use in reservoir description and four-dimensional (4D) seismic images compared to traditional RTM and Fourier finite difference (FFD) migration. This paper investigates the first order approximation of LSRTM, which is also known as the linear Born approximation. However, for more complex geological structures a higher order approximation should be considered to improve imaging quality. 展开更多
关键词 Reverse time migration reflectivity Hessian matrix conjugate gradient
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Bus transit travel time reliability evaluation based on automatic vehicle location data 被引量:4
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作者 严亚丹 过秀成 +2 位作者 李岩 孔哲 何明 《Journal of Southeast University(English Edition)》 EI CAS 2012年第1期100-105,共6页
In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed a... In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed and evaluated based on automatic vehicle location (AVL) data. Based on the statistical analysis of the bus transit travel time, six indices including the coefficient of variance, the width of travel time distribution, the mean commercial speed, the congestion frequency, the planning time index and the buffer time index are proposed. Moreover, a framework for evaluating bus transit travel time reliability is constructed. Finally, a case study on a certain bus route in Suzhou is conducted. Results show that the proposed evaluation index system is simple and intuitive, and it can effectively reflect the efficiency and stability of bus operations. And a distinguishing feature of bus transit travel time reliability is the temporal pattern. It varies across different time periods. 展开更多
关键词 bus transit travel time reliability evaluation andanalysis automatic vehicle location data statistical analysis
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The role of physical activity and exercise in obesity and weight management: Time for critical appraisal 被引量:1
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作者 Petri Wiklund 《Journal of Sport and Health Science》 SCIE 2016年第2期151-154,共4页
The prevalence of overweight and obesity has increased dramatically during last 3 decades with devastating consequences to public health. Recommended strategies to reduce obesity have focused on healthier diet and phy... The prevalence of overweight and obesity has increased dramatically during last 3 decades with devastating consequences to public health. Recommended strategies to reduce obesity have focused on healthier diet and physical activity (PA). Clearly, these approaches have not been successful, but whether this is due to failure to restrict energy intake or to maintain high levels of energy expenditure has been the subject of great controversy. Consequently, there has been a great deal of confusion about the role of PA and exercise in obesity and weight management. In this article, the theoretical basis for considering reduced PA and energy expenditure as the cause of obesity is appraised. Further, the role of PA in food intake and weight control is examined. The idea that obesity is caused by consistent deeline in daily energy expenditure is not supported either by objective measures of energy expenditure or physiological theory of weight gain alone. However, since voluntary exercise is the most important discretionary component of total daily energy expenditure, it can affect energy balance. Therefore, PA and exercise hold potential as part of the solution for the ongoing obesity epidemic. 展开更多
关键词 Energy expenditure EXERCISE OBESITY OVERWEIGHT Physical activity
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Single-trial EEG-based emotion recognition using temporally regularized common spatial pattern
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作者 成敏敏 陆祖宏 王海贤 《Journal of Southeast University(English Edition)》 EI CAS 2015年第1期55-60,共6页
This study addresses the problem of classifying emotional words based on recorded electroencephalogram (EEG) signals by the single-trial EEG classification technique. Emotional two-character Chinese words are used a... This study addresses the problem of classifying emotional words based on recorded electroencephalogram (EEG) signals by the single-trial EEG classification technique. Emotional two-character Chinese words are used as experimental materials. Positive words versus neutral words and negative words versus neutral words are classified, respectively, using the induced EEG signals. The method of temporally regularized common spatial patterns (TRCSP) is chosen to extract features from the EEG trials, and then single-trial EEG classification is achieved by linear discriminant analysis. Classification accuracies are between 55% and 65%. The statistical significance of the classification accuracies is confirmed by permutation tests, which shows the successful identification of emotional words and neutral ones, and also the ability to identify emotional words. In addition, 10 out of 15 subjects obtain significant classification accuracy for negative words versus neutral words while only 4 are significant for positive words versus neutral words, which demonstrate that negative emotions are more easily identified. 展开更多
关键词 emotion recognition temporal regularization common spatial patterns(CSP) two-character Chinese words permutation test
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Synchronous hybrid transport network design 被引量:1
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作者 李夏苗 曾明华 +1 位作者 傅白白 朱晓立 《Journal of Central South University》 SCIE EI CAS 2009年第2期332-338,共7页
Delay,as an inevitable real-world phenomenon,is usually ignored in transport network design.A model of urban hybrid transport system with stochastic delay was created on the basis of the idealized public transport sys... Delay,as an inevitable real-world phenomenon,is usually ignored in transport network design.A model of urban hybrid transport system with stochastic delay was created on the basis of the idealized public transport system design.After formulating the total trip time cost composed of accessing time in the sub-region of the city,waiting time at the public transport station,and in-vehicle time in the public transit network,the analytical properties of the total trip time cost function were investigated.The results show that in the urban hybrid transport network design,the total trip time cost reaches its approximate minimum in a δ-neighbourhood of buffer time of 1.5 min,and that through modelling optimal delay in hybrid transport system,the maximal synchronization can be achieved and operational efficiency and passenger satisfaction can be improved.The proposed modelling and analytical investigations are attempts to contribute to more realistic modelling of future idealized public transport system that involves more practical constraints. 展开更多
关键词 transport network design DELAY SYNCHRONIZATION total trip time cost
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Research on TDM approach of sharing BRT-lane supported by vehicle-infrastructure integration 被引量:2
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作者 Dong Hongzhao Ling Yue +1 位作者 Liu Dongxu Guo Mingfei 《Engineering Sciences》 EI 2013年第5期77-83,共7页
In order to increase the availability of the part-time idle bus rapid transit lane(BRT-lane),a time division multiplexing(TDM) method to share BRT-lane with the vehicles besides BRT buses is proposed based on vehicle-... In order to increase the availability of the part-time idle bus rapid transit lane(BRT-lane),a time division multiplexing(TDM) method to share BRT-lane with the vehicles besides BRT buses is proposed based on vehicle-road collaboration. The TDM control strategy is established under the circumstance of vehicle-infrastructure integration(VII). The algorithm is given to forecast the segmented BRT travel time. According to the real time traffic information,a comprehensive model is given to estimate the vehicles' lane-changing time from/to the BRTlane to/from its neighbor lane and determine the timing sequence for vehicles collaboration. Finally,the experiment demonstrates that the predicted value of the travel time and lane-changing time is much close to the true value. The control strategy of the vehicles collaboration could promise the non-BRT vehicles to share BRT-lane without disturbing BRT's priority. 展开更多
关键词 vehicle-infrastructure integration(VII) vehicles collaboration BRT-lane time division multiplexing (TDM) lane-changing time model
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Pancreatic carcinoma coexisting with chronic pancreatitis versus tumor-forming pancreatitis:Diagnostic utility of the time-signal intensity curve from dynamic contrast-enhanced MR imaging 被引量:29
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作者 Yoshitsugu Tajima Tamotsu Kuroki +3 位作者 Ryuji Tsutsumi Ichiro Isomoto Masataka Uetani Takashi Kanematsu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第6期858-865,共8页
AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially... AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially pancreatic carcinoma coexisting with chronic pancreatitis and tumor-forming pancreatitis. METHODS: Forty-eight consecutive patients who underwent surgery for a focal pancreatic mass, including pancreatic ductal carcinoma (n = 33), tumor-forming pancreatitis (n = 8), and islet cell tumor (n = 7), were reviewed. Five pancreatic carcinomas coexisted with longstanding chronic pancreatitis. The pancreatic TICs were obtained from the pancreatic mass and the pancreatic parenchyma both proximal and distal to the mass lesion in each patient, prior to surgery, and were classified into 4 types according to the time to a peak: 25 s and 1, 2, and 3 min after the bolus injection of contrast material, namely, type-Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively, and were then compared to the corresponding histological pancreatic conditions. RESULTS: Pancreatic carcinomas demonstrated type-Ⅲ (n = 13) or Ⅳ (n = 20) TIC. Tumor-forming pancreatitis showed type-Ⅱ (n = 5) or Ⅲ (n = 3) TIC. All islet cell tumors revealed type-Ⅰ. The type-Ⅳ TIC was only recognized in pancreatic carcinoma, and the TIC of carcinoma always depicted the slowest rise to a peak among the 3 pancreatic TICs measured in each patient, even in patients with chronic pancreatitis.CONCLUSION: Pancreatic TIC from dynamic MRI provides reliable information for distinguishing pancreatic carcinoma from other pancreatic masses, and may enable us to avoid unnecessary pancreatic surgery and delays in making a correct diagnosis of pancreatic carcinoma, especially, in patients with longstanding chronic pancreatitis. 展开更多
关键词 Pancreatic carcinoma Chronic pancreatitis Focal pancreatic mass Tumor-forming pancreatitis Differential diagnosis Dynamic magnetic resonance imaging Time-signal intensity curve
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Co-precipitation preparation and burning performance test of delay composition containing barium chromate 被引量:3
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作者 QI Yi WANG Jin-ying +2 位作者 ZHANG Xin YU Shuo YU Hui-qin 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第1期73-77,共5页
In order to optimize the performance of delay composition containing barium chromate,the preparation conditions of barium chromate were optimized,and S/BaCrO 4/KClO 4 delay composition was prepared by co-precipitation... In order to optimize the performance of delay composition containing barium chromate,the preparation conditions of barium chromate were optimized,and S/BaCrO 4/KClO 4 delay composition was prepared by co-precipitation using barium chromate as precipitant.Then,the ignition temperature,delay time and other burning performance were tested.The results show that the ignition temperature of S/BaCrO 4/KClO 4 delay composition prepared by co-precipitation method is higher than that by traditional mechanical mixing method;the burning rate is faster and the burning time precision is higher because co-precipitation method can make the components mix more evenly.This co-precipitation method with barium chromate can be extended to the preparation of other mixed explosive agents containing barium chromate. 展开更多
关键词 barium chromate CO-PRECIPITATION delay composition delay time
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Raman Scattering at Resonant or Near-Resonant Conditions: A Generalized Short-Time Approximation
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作者 Abdelsalam Mohammed 孙玉萍 +2 位作者 苗泉 Hans Agren Faris Gel'mukhanov 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第1期31-47,I0003,共18页
We investigate the dynamics of resonant Raman scattering in the course of the frequency de- tuning. The dephasing in the time domain makes the scattering fast when the photon energy is tuned from the absorption resona... We investigate the dynamics of resonant Raman scattering in the course of the frequency de- tuning. The dephasing in the time domain makes the scattering fast when the photon energy is tuned from the absorption resonance. This makes frequency detuning to act as a camera shutter with a regulated scattering duration and provides a practical tool of controlling the scattering time in ordinary stationary measurements. The theory is applied to resonant Raman spectra of a couple of few-mode model systems and to trans-1,3,5-hexatriene and guanine-cytosine (G-C) Watson-Crick base pairs (DNA) molecules. Besides some particular physical effects, the regime of fast scattering leads to a simplification of the spectrum as well as to the scattering theory itself. Strong overtones appear in the Raman spectra when the photon frequency is tuned in the resonant region, while in the mode of fast scattering, the overtones are gradually quenched when the photon frequency is tuned more than one vibra- tional quantum below the first absorption resonance. The detuning from the resonant region thus leads to a strong purification of the Raman spectrum from the contamination by higher overtones and soft modes and purifies the spectrum also in terms of avoidance of dissociation and interfering fluorescence decay of the resonant state. This makes frequency detuning a very useful practical tool in the analysis of the resonant Raman spectra of complex systems and considerably improves the prospects for using the Raman effect for detection of foreign substances at ultra-low concentrations. 展开更多
关键词 Resonant Raman Scattering duration Hexatriene Short time approximation
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Quantum Polynomial-Time Fixed-Point Attack for RSA 被引量:3
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作者 Yahui Wang Huanguo Zhang Houzhen Wang 《China Communications》 SCIE CSCD 2018年第2期25-32,共8页
Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography. In particular, the security of widely used public-key cryptosystems merits d... Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography. In particular, the security of widely used public-key cryptosystems merits deep research to protect against new types of attacks. It is therefore highly meaningful to research cryptanalysis in the quantum computing environment. Shor proposed a wellknown factoring algorithm by finding the prime factors of a number n =pq, which is exponentially faster than the best known classical algorithm. The idea behind Shor's quantum factoring algorithm is a straightforward programming consequence of the following proposition: to factor n, it suffices to find the order r; once such an r is found, one can compute gcd( a^(r/2) ±1, n)=p or q. For odd values of r it is assumed that the factors of n cannot be found(since a^(r/2) is not generally an integer). That is, the order r must be even. This restriction can be removed, however, by working from another angle. Based on the quantum inverse Fourier transform and phase estimation, this paper presents a new polynomial-time quantum algorithm for breaking RSA, without explicitly factoring the modulus n. The probability of success of the new algorithm is greater than 4φ( r)/π~2 r, exceeding that of the existing quantum algorithm forattacking RSA based on factorization. In constrast to the existing quantum algorithm for attacking RSA, the order r of the fixed point C for RSA does not need to be even. It changed the practices that cryptanalysts try to recover the private-key, directly from recovering the plaintext M to start, a ciphertext-only attack attacking RSA is proposed. 展开更多
关键词 information security cryptogra-phy RSA fixed-point quantum computing
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A Subsection Shared Restoration Method for Long-Haul WDM Networks
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作者 贺辉 范戈 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第1期44-47,共4页
A novel restoration scheme, Parted Path Shared Restoration (PPSR), was proposed. The major idea of PPSR is the strategy of ‘parted disposal’. PPSR keeps the advantage of Path Based Shared Restoration (PBSR) in utili... A novel restoration scheme, Parted Path Shared Restoration (PPSR), was proposed. The major idea of PPSR is the strategy of ‘parted disposal’. PPSR keeps the advantage of Path Based Shared Restoration (PBSR) in utilization of capacity. In addition, the restoration time of PPSR is much less than that of PBSR. Furthermore, a satisfaction function was proposed to estimate the performance of PPSR. This function takes the utilization of capacity and restoration time into a harmonious and uniform frame. Through theoretical analysis and computer simulation, the performance of PPSR was demonstrated. 展开更多
关键词 WDM networks parted shared restoration restoration time reserved capacity
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Estimating model for urban carrying capacity on bike-sharing 被引量:1
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作者 YU Jia-jie JI Yan-jie +1 位作者 YI Chen-yu LIU Yang 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第6期1775-1785,共11页
As the demand for bike-sharing has been increasing,the oversupply problem of bike-sharing has occurred,which leads to the waste of resources and disturbance of the urban environment.In order to regulate the supply vol... As the demand for bike-sharing has been increasing,the oversupply problem of bike-sharing has occurred,which leads to the waste of resources and disturbance of the urban environment.In order to regulate the supply volume of bike-sharing reasonably,an estimating model was proposed to quantify the urban carrying capacity(UCC)for bike-sharing through the demand data.In this way,the maximum supply volume of bike-sharing that a city can accommodate can be obtained.The UCC on bike-sharing is reflected in the road network carrying capacity(RNCC)and parking facilities’carrying capacity(PFCC).The space-time consumption method and density-based spatial clustering of application with noise(DBSCAN)algorithm were used to explore the RNCC and PFCC for bike-sharing.Combined with the users’demand,the urban load ratio on bike-sharing can be evaluated to judge whether the UCC can meet users’demand,so that the supply volume of bike-sharing and distribution of the related facilities can be adjusted accordingly.The application of the model was carried out by estimating the UCC and load ratio of each traffic analysis zone in Nanjing,China.Compared with the field survey data,the effect of the proposed algorithm was verified. 展开更多
关键词 bike-sharing urban carrying capacity space-time consumption method density-based spatial clustering of application with noise(DBSCAN)algorithm
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Resonance Raman Spectroscopic and Theoretical Study of Geometry Distortion of Thiourea in 2^1A State
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作者 张海波 赵彦英 郑旭明 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第1期1-10,I0003,共11页
The A-band resonance Raman spectra of thiourea were obtained in water and acetonitrile solution. B3LYP/6-311++G(3df,3pd) and RCIS/6-311++G(3df,3pd) calculations were done to elucidate the ultraviolet electroni... The A-band resonance Raman spectra of thiourea were obtained in water and acetonitrile solution. B3LYP/6-311++G(3df,3pd) and RCIS/6-311++G(3df,3pd) calculations were done to elucidate the ultraviolet electronic transitions, the distorted geometry structure and the saddle point of thiourea in 21A excited state, respectively. The resonance Raman spectra were assigned. The absorption spectrum and resonance Raman intensities were modeled using Heller's time-dependent wavepacket approach to resonance Raman scattering. The results indicate that largest change in the displacement takes place with the C--S stretch mode u6 (|△|=0.95) and noticeable changes appear in the H5N3H6+H8N4H7 wag v5 (|△|=0.19), NCN symmetric stretch^-C--S stretch+N3H6+H8N4 wag v4 (|△|=0.18), while the moderate intensities of 2-15 and 4-15 are mostly due to the large excited state frequency changes of v15, but not due to its significant change in the normal mode displacement. The mechanism of the appearance of even overtones of the S-CN2 out of plane deformation is explored. The results indicate that a Franck-Condon region saddle point is the driving force for the quadric phonon mechanism within the standard A-term of resonance Raman scattering, which leads to the pyramidalization of the carbon center and the geometry distortion of thiourea molecule in 21A excited state. 展开更多
关键词 THIOUREA Excited state structural dynamics Resonance Raman Timedependent wavepacket approach Density functional theory
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Perturbation Theory for Dual Cosine Function(Ⅱ)—Time-dependent Perturbation in the Sun-reflexive Case
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作者 丁天彪 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第2期82-84,共3页
In this paper,we proved that the infinitesimal generator of a strongly continuous cosine operator function is preserved under the time-dependent perturbation in the sun-reflexive case,where the perturbed operator is ... In this paper,we proved that the infinitesimal generator of a strongly continuous cosine operator function is preserved under the time-dependent perturbation in the sun-reflexive case,where the perturbed operator is a bounded linear operator from X into a bigger space Xθ(not X),then the corresponding 2-order abstract Cauchy problem is uniformly well-posed. 展开更多
关键词 dual cosine operator function time-dependent perturbation θ-reflexivity
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Stochastic Resonance in a Bistable System with Time-Delayed Feedback Loops
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作者 LI Dong-Xi XU Wei WANG Liang XU Yong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第8期396-402,共7页
The phenomenon of stochastic resonance of a bistable system subjected to linear time-delayed feedback loops driven by multiplieative Gaussian coloured noise and additive Gaussian white noise is investigated. Firstly, ... The phenomenon of stochastic resonance of a bistable system subjected to linear time-delayed feedback loops driven by multiplieative Gaussian coloured noise and additive Gaussian white noise is investigated. Firstly, the analytic expression of the quasi-steady distribution function Ps (x, t) is derived by applying the unified coloured noise approximation and the Novikov Theorem; Secondly, the expression of the signal-to-noise ratio (SNR) is obtained in the adiabatic limit to quantify the stochastic resonance. Finally, tile effects of the linear coefficient a, the nonlinear coefficient b, the linear time-delayed feedback coefficient c and the delay time r on Ps(x,t) and SNR^± are discussed. It is found that the effects of the linear coefficient and the nonlinear coefficient, the positive linear time-delayed feedback coefficient and the negative linear time-delayed feedback coefficient, the positive delayed time and the negative delayed time on Ps(x,t) and SNR^± are different, respectively. This discussion would be helpful to the study of the system reliability and controlling stochastic resonance. 展开更多
关键词 stochastic resonance linear time-delayed feedback loops bistable system
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