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31.
This work follows a series of experiments carried out earlier at INSA of Rouen (Hassan, T., Taleb, L., Krishna, S., 2008. Influence of non-proportional loading paths on ratcheting responses and simulations by two recent cyclic plasticity models. Int. J. Plast. 24, 1863–1889). It investigates the elastoplastic cyclic behavior of a 304L stainless steel at room temperature. In a first step the cross path effect on ratcheting is confirmed, as well as the crucial role of the loading path non-proportionality. Strain controlled tests are also conducted for different strain amplitudes and loading paths. Cross-hardening effect appears more important when the shearing sequence is followed by the axial one. Moreover for alternating axial and shearing cycles, this phenomenon occurs after each crossing sequence leading to a very significant strain hardening, at least of the same order as the one obtained after a circular strain path. Yet, the magnitude of the observed over hardening does not necessarily seem a function of the cumulated plastic strain. 相似文献
32.
Gioria Esteban Signorini Chiara Taleb María C. Thomas Arne Mihályi Magdolna R. Gutierrez Laura 《Cellulose (London, England)》2021,28(14):9135-9147
Cellulose - Palladium was incorporated into carboxymethylated cellulose fibers as a support, thereby becoming an efficient and stable catalyst for low temperature gas phase reaction. Thus, NO was... 相似文献
33.
Nasreddine Ennaceur Khaled Jarraya Anu Singh Isabelle Ledoux-Rak Tahar Mhiri 《Journal of Physics and Chemistry of Solids》2012,73(3):418-422
Aiming at the development of new proton conducting solids, recent studies of the NaH2PO4·H2O–NaH2AsO4·H2O system have lead to the synthesis of a new compound NaH2(PO4)0.48(AsO4)0.52·H2O (NDAP). Calorimetric studies have confirmed the presence of four reversible phase transitions (abbreviated by PhT), at 257/270 (PhT, IV), 261/290 (PhT, III), 267/301 (PhT, II) and 317/317.5 K (PhT, I) (for cooling/heating processes, respectively). It is shown that the III and IV phase transitions are of a first order type, with a “order-disorder and displacive” character, accompanied by specific dielectric anomalies. The behavior of the dielectric constant ε′r and of tan δ shows that, at 272 K, the (PhT, IV) could be ferroelectric–paraelectric. As for the (PhT, III) at 296 K, it leads to a superionic–protonic phase; a jump in the conductivity is associated to this transition with an unusual high value of conductivity 1.07×10?4 Ω?1 cm?1 and a low activation energy 0.39 eV (Kh. Jarraya et al.). Quandratic nonlinear (NLO) properties of NDAP powder was confirmed efficiency of the grown crystal by the Kurtz and Perry second harmonic generation (SHG) technique. 相似文献
34.
Dr. Gourishetty Srikanth Dr. Anil Ravi Dr. Anusha Sebastian Jobi Joseph Prof. Monther A. Khanfar Prof. Mohammed I. El-Gamal Prof. Raed A. Al-Qawasmeh Prof. Imad A. Abu-Yousef Prof. Amin F. Majdalawieh Prof. Taleb H. Al-Tel 《European journal of organic chemistry》2023,26(9):e202201354
Azepino[3,4,5-cd]indole derivatives represent the core scaffold of important natural products and biologically relevant compounds. Therefore, the establishment of step- and atom-economic strategies to access this class of compounds is of paramount importance. To this end, complexity-to-diversity (CtD) strategy has become one of the most important tools that transforms complex molecules into diverse skeleta. However, many of the reactions that could be employed in CtD are restricted by the functional handles exist in these molecules. This limits the achievement of the desired skeletal diversity. Herein, an efficient and step-economic strategy to access a diverse collection of azepino-[3,4,5-cd]indole architectures through a cascade that combines Pictet-Spengler with Michael addition, is described. This was achieved by reacting cyclohexadienone acetaldehydes 2 a – 2 d with indolyl-4-ethyl amine 1 . Employing a CtD strategy on the developed azepino-[3,4,5-cd]indoles, a rapid rearrangement reaction that provided a modular, chemo- and diastereoselective access to diverse collection of spiro azepinocarbazole nature-inspired frameworks, was encountered. 相似文献
35.
Zerrouki Abdelkhalek Abrigach Farid Taleb Mustapha El Kadiri Sghir 《Research on Chemical Intermediates》2020,46(2):1453-1467
Research on Chemical Intermediates - A class of novel multi-tripodal ligands has been prepared via condensation reaction between pyrazole or triazole moieties and... 相似文献
36.
Nasreddine Tabet-Aouel Demetres D. Kouvatsos 《The Journal of the Operational Research Society》1992,43(3):227-239
Analytic approximations are proposed for the mean response-times of R(≥ 2) priority classes in a stable G/G/c/PR queue with general class interarrival and service time distributions and c(≥ 2) parallel servers under pre-emptive resume (PR) scheduling. The generalized exponential (GE) distributional model is used to represent general distributions with known first two moments per class. The analysis is based on the extension of known heuristic arguments and earlier results regarding the study of the stable GE/GE/c/FCFS (c ≥ 1, single class) and GE/G/1/PR queues. Numerical examples illustrate the accuracy of the proposed approximations in relation to simulations involving different interarrival and service time distributions per class. Moreover, GE-type performance bounds on the system response time per class are defined. Comments on the role of the new mean response time expressions towards the approximation of the joint and marginal queue length distributions of a stable G/G/c/PR queue are included. 相似文献
37.
Secure IoT solution for wearable health care applications,case study Electric Imp development platform 下载免费PDF全文
Belkacem Benadda Bilal Beldjilali Abdelkrim Mankouri Omar Taleb 《International Journal of Communication Systems》2018,31(5)
Internet expansion affects currently diverse entities on the physical world and daily life. The democratization of the technology called Internet of Things (IoT) brings back many problems associated with the security of the transmitted data, autonomy, and ease of use, with the central constraint of gathering momentum. The use of an embedded development platform for IoT operating through Wi‐Fi and cloud technology is in our case the solution that fits the internet model objects for wearable health care application. This work involves the study and implementation of wearable IoT secure solution dedicated to health care devoted to old and dependent people. The proposed hardware, powered by solar cells, operate through smart sleep and wake up events. The relevant part of the developed IoT operating software exploits the multiagent behavior. Case study, based on the exploitation of the Electric Imp platform, is proposed. 相似文献
38.
Chlorobenzene and more generally, chloroarenes, can be converted into aromatic acids via catalytic reaction with aqueous methyl formate under biphasic conditions. The only efficient catalyst is [PdCl2(PCy3)2] (Cy = cyclohexyl). [RU3(CO)12] and ammonium formate improve yield and selectivity. The mechanism should involve oxidative addition of the C---Cl bond to a zero-valent Pd species followed by CO insertion. The palladium catalyst may also directly activate methyl formate. The procedure is convenient (no solvent, no initial pressurization) and at least as efficient as previously described methods. 相似文献
39.
Lighting-up the dynamics of telomerization and DNA replication by CdSe-ZnS quantum dots 总被引:7,自引:0,他引:7
Patolsky F Gill R Weizmann Y Mokari T Banin U Willner I 《Journal of the American Chemical Society》2003,125(46):13918-13919
CdSe-ZnS core-shell quantum dots (QDs) act as photochemical centers for lighting-up the dynamics of telomerization or DNA replication. 相似文献
40.
[reaction: see text] CuI.0.75DMS complex is an excellent catalyst for the direct conjugate addition of alkenyl groups from vinylzirconocene reagents to alpha,beta-unsaturated aldehydes and ketones. The presence of the catalyst with an alkenylzirconocene, at +40 degrees C in THF, circumvents the need for making discrete alkenylcopper reagents. The catalyst is superior in terms of product yields and alkene flexibility in comparison to other copper(I) sources as well as the nickel(II)-catalyzed conjugate addition. This simple one-pot procedure shows that only 1 equiv of the vinylzirconocene is needed. 相似文献