检索结果-南通市图书馆

Preparation of ammonium nitrate-based solid composite propellants supplemented with polyurethane/nitrocellulose blends binder and their thermal decomposition behavior

引用

Defence Technology（防务技术） 2022年第11期18卷 2023-2033页

作者： Sabri Touidjine Moulai Karim Boulkadid Djalal Trache Samir Belkhiri abderrahmane Mezroua Mohamed Islam Aleg Afaf Belkebiche Energetic Propulsion Laboratory Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj-El-Bahri16046AlgiersAlgeria Energetic Materials Laboratory Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj-El-Bahri16046AlgiersAlgeria

To improve the performance of solid composite propellants(SCPs)supplemented with ammonium nitrate(AN)as an oxidizer,the incorporation of energetic ingredients such as explosives,energetic binders or catalysts is a common effective *** this purpose,polyurethane(PU),a typical inert binder,was mixed with nitrocellulose(NC)as an energetic *** composite solid propellant compositions based on AN and NC-modified polyurethane binder with different NC ratios were *** prepared formulations were characterized using Fourier transform infrared spectroscopy(FTIR),RAMAN spectroscopy,X-ray diffraction(XRD),electron densimetry,thermogravimetric(TG)analysis,and differential scanning calorimetry(DSC).A kinetic study was then performed using the iterative KissingerAkahira-Sunose(It-KAS),Flynn-Wall-Ozawa(It-FWO),and non-linear Vyazovkin integral with compensation effect(VYA/CE)*** theoretical performances,such as theoretical specific impulse,adiabatic flame temperature,and ideal exhaust gaseous species,were also determined using the NASA Lewis Code,Chemical Equilibrium with Application(CEA).Spectroscopic examinations revealed the existence of NC and full polymerization of PU in the prepared *** to density tests,the density of the propellant increases as the nitrocellulose component *** to the thermal analysis and kinetics study,the increase in NC content catalyzed the thermal decomposition of the AN-based composite solid *** on the theoretical study,increasing the amount of NC in the propellant increased the specific impulse and,as a result,the overall performance.

关键词： Composite propellants Polyurethane Nitrocellulose Ammonium nitrate Decomposition kinetics Thermal decomposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Matched Asymptotic Expansions of the Eigenvalues of a 3-D Boundary-Value Problem Relative to Two Cavities Linked by a Hole of Small Size

引用

Communications in Computational Physics 2012年第2期11卷 456-471页

作者： abderrahmane Bendali M’Barek Fares Abdelkader Tizaoui Sebastien Tordeux Electromagnetism and Acoustics CERFACS42 Avenue Gaspard CoriolisF-31100 ToulouseFrance Toulouse University INSA-ToulouseMathematical Institute of ToulouseUMR-CNRS 5219135 avenue de RangueilF-31077 ToulouseFrance Laboratoire de Mathematiques et de leurs Applications UMR-CNRS 5142Universite de Pau et des Pays de l’AdourF-64013 PauFrance Project Team MAGIQUE-3D INRIA Bordeaux-Sud-OuestF-64013 PauFrance

In this article,we consider a domain consisting of two cavities linked by a hole of small *** derive a numerical method to compute an approximation of the eigenvalues of an elliptic operator without refining in the ne... 详细信息

关键词： Elliptic operator matched asymptotic expansions eigenvalue problem finite elements

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical evaluation of radiation and optical coupling occurring in optical coupler

引用

Chinese Optics Letters 2017年第2期15卷 35-39页

作者： Mansour Bacha abderrahmane Belghoraf Electronics Department University of Sciences and Technology of Oran Mohamed Boudiaf Oran M'Naouer BP 1505 Algeria Centre of Satellites Development Ibn Rochd USTO Oran BP 4065 Algeria

We present in this work a new mathematical model to analyze and evaluate optical phenomena occurring in the nonuniform optical waveguide used in integrated optics as an optical coupler. By introducing some modifications to the intrinsic integral, we perfectly assess the radiation field present in the adjacent medium of the waveguide and, thus, follow the evolution of the optical coupling from the taper thin film to the substrate and cladding until there is a total energy transfer. The new model that is introduced can be used to evaluate electromagnetic field distribution in three mediums that constitute any nonuniform optical couplers presenting great or low wedge angles.

关键词： Numerical evaluation of radiation and optical coupling occurring in optical coupler

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

WEIGHTED PSEUDO ALMOST-PERIODIC SOLUTIONS OF SHUNTING INHIBITORY CELLULAR NEURAL NETWORKS WITH MIXED DELAYS

引用

Acta Mathematica Scientia 2016年第6期36卷 1662-1682页

作者： Mohammed Salah M'HAMDI Chaouki AOUITI abderrahmane TOUATI Adel M. ALIMI Vaclav SNASEL Department of Mathematics University of Carthage Faculty of Sciences of Bizerta BP W 7021 Zarzouna Bizerta Tunisia REGIM-lab: Research Groups on Intelligent Machines University of Sfax National Engineering School of Sfax (ENIS) BP 1173 Sfax 3038 Tunisia VSB Technical University of Ostrava Czech Republic

In this paper, we prove the existence and the global exponential stability of the unique weighted pseudo almost-periodic solution of shunting inhibitory cellular neural networks with mixed time-varying delays comprising different discrete and distributed time delays. Some sufficient conditions are given for the existence and the global exponential stability of the weighted pseudo almost-periodic solution by employing fixed point theorem and differential inequality techniques. The results of this paper complement the previously known ones. Finally, an illustrative example is given to demonstrate the effectiveness of our results.

关键词： weighted pseudo almost-periodic solution shunting inhibitory cellular neuralnetworks mixed delays global exponential stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An incommensurate fractional discrete macroeconomic system:Bifurcation,chaos,and complexity

引用

Chinese Physics B 2023年第3期32卷 58-67页

作者： abderrahmane Abbes Adel Ouannas Nabil Shawagfeh Department of Mathematics University of JordanAmman 11942Jordan Department of Mathematics and Computer Science University of Larbi Ben M'hidiOum El Bouaghi 04000Algeria

This study proposes a novel fractional discrete-time macroeconomic system with incommensurate *** dynamical behavior of the proposed macroeconomic model is investigated analytically and *** particular,the zero equilibrium point stability is investigated to demonstrate that the discrete macroeconomic system exhibits chaotic *** using bifurcation diagrams,phase attractors,the maximum Lyapunov exponent and the 0–1 test,we verified that chaos exists in the new model with incommensurate fractional ***,a complexity analysis is carried out utilizing the approximation entropy(ApEn)and C_(0)complexity to prove that chaos ***,the main findings of this study are presented using numerical simulations.

关键词： chaos macroeconomic system discrete fractional calculus complexity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

MCNP Dose Calculations in a CT Phantom for Therapeutic External Photon Beam

引用

原子核物理评论 2011年第2期28卷 236-240页

作者： Lamyae El Gonnouni Tarek El Bardouni Mariam Zoubair Mohamed Idaomar abderrahmane Senhoo University Abdelmalek Essaadi Faculty of Sciences ERSN-LMR Department of Physics Tetuan Morocco University Abdelmalek Essaadi Faculty of Sciences BCM Department of Biology Tetuan Morocco National Institute of Oncology NIO Rabat Morocco

In this paper,we have addressed the problem of the radiation transport with the Monte Carlo N-particle(MCNP) *** is a general-purpose Monte Carlo tool designed to transport neutron,photon and electron in three dimensional *** examine the performance of MCNP5 code in the field of external radiotherapy,we performed the modeling of an Electron Density phantom(EDP) irradiated by photons from 60Co *** model was used to calculate the Percent Depth Dose(PDD) at different depths in an *** field size for PDD has been examined.A 60Co photons source placed at 80 cm source to surface distance(SSD).The results of calculations were compared to TPS data obtained at National Institute of Oncology of Rabat.

关键词： Monte Carlo method Monte Carlo N-particle electron density phantom radiotherapy CT percent depth dose

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cavity-Mode Properties of Semiconductor Lasers Operating in Strong-Feedback Regime

引用

Journal of Physical Science and Application 2015年第3期5卷 209-219页

作者： Qin Zou abderrahmane Brezini Departement Electronique et Physique Institut Mines-Telecom UMR 5157 CNRS 9 rue Charles Fourier 91011 Evry CedexFrance CEA Saclay Nano-lnnov PC 176 Bat. 861 91191 Gif sur Yvette Cedex France Departement de Chimie Faculte des Sciences Universite d 'Oran BP 1524 Oran El M 'Naouer 31000 Oran Algerie

This paper investigates the modal properties of semiconductor lasers operating in the strong-feedback regime. Analytical expressions are developed based on an iterative travelling-wave model, which enable a complete and quantitative description of a compound cavity mode in its steady state. Additional information is provided about the physical inside into a compound laser system, such as a bifurcation diagram of the compound cavity modes for full variation range （from 0 to 1） of the external reflection coefficient and a more general shape for the diagram of photon density versus mode phase - this latter will reduce to the classical ＂ellipse＂ in the weak-feedback regime. It is shown that in the strong-feedback regime, a feedback laser is characterized by a small mode number and a high density of photons. This behavior confirms previous experimental observations, showing that beyond the coherence-collapse regime, the compound laser system could be re-stabilized, and that as a result power-enhanced low-noise stable laser operation with quasi-uniform pulsation is possible with external-mirror reflectivity close to 1. Moreover, it is also shown that for a compound system operating in the strong-feedback regime, an anti-reflection treatment of a laser can significantly reduce its current threshold, and that in the absence of this treatment excitation of a minimum-linewidth mode with higher output power would be possible inside such a system. Finally, it is shown that in the weak-feedback regime except for a phase shift the iterative travelling-wave model will reduce to the Lang-Kobayashi model in cases where the product of the feedback rate and the internal round-trip time is much less than unity （that would mean in situations of as-cleaved lasers）.

关键词： Semiconductor lasers external optical feedback compound cavity modes weak-feedback regime strong-feedbackregime coherence collapse iterative travelling-wave model Lang-Kobayashi model.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Effects of Magnetic Dopant on the Structural and Electrical Properties in Superconducting YBaCu<sub>3</sub>O<sub>7-δ</sub>Ceramic

引用

Advances in Chemical Engineering and Science 2018年第1期8卷 1-10页

作者： Souheila Chamekh abderrahmane Bouabellou Thin Films and Interfaces Laboratory University of Constantine Constantine Algeria

The work reported in this paper aims at a better understanding of the magnetic doping effects on the structural and electrical properties for a series of YBa2(Cu1-xCox)3O7-δ ceramics. The Co doped YBa2Cu3O7-δ are (YBCO) prepared by conventional solid state reaction method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), differential thermal analysis (DTA) and resistivity measurements. The crystal lattice parameters are found to change due to the cobalt doping and tendency to a structure phase transition from orthorhombic to tetragonal, which is confirmed by the decrease of the degree of orthorhombicity. The morphology examination with SEM revealed gradual increases of grain size with x = 0.02 Co, a high porosity is observed in the doped samples compared to the pure one. The decomposition temperature of YBCO is pushed from temperatures above 975°C to lower temperatures of 945°C. The resistivity measurements of doped samples with x = 0.04 and 0.06;shows a deviation in from T-linear behavior due to the opening of a pseudogap.

关键词： YBCO Doped Co Electrical Properties Phase Transition High Tc Superconductivity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Dormancy of Fig Cultivated under Moroccan Conditions

引用

American Journal of Plant Sciences 2012年第4期3卷 473-479页

作者： Ahmed Oukabli abderrahmane Mekaoui Plant Breeding and Genetic Resources Regional Agricultural Research Centre of Meknes Meknes Morocco

Fig (Ficus carica L.) is a deciduous species well adapted to Mediterranean conditions but its chilling requirement is still not well understood. The present study examines the pattern of bud-break in seven fig cultivars over two years under Moroccan conditions. Evaluation of dormancy behavior was made using a biological test known as “single node cuttings” carried out under controlled conditions. The responses of cultivars from Morocco, Italy, Spain and France were assessed. The period from full leaf fall to bud-break was characterized by a small variation (10 - 20 days) which did not appear to reflect the origin of the cultivars. Steady-sates were at high level in the middle of December or in January depending on the year. During the cold period, MTB didn’t exceed 200 days for “Borjassate noire”, “Ournakssi” and “Kadota” and varied from 100 to 128 days for the other cultivars. Therefore, dormancy was not deep and its period was short. Forcing bud during the coldest period allowed to a bud break but it didn’t exceed 10% and dormancy wasn’t complete. Missing bud break wasn’t observed and the geographic origin of examined cultivars didn’t seem to determine the length, and the deepness of bud dormancy. Bud-break occurred within a month of last leaf fall in the cultivars, indicating that they were all suited to commercial production in Morocco. Apparently, bud-break is more reliable in fig than it is in other Rosaceous species in this environment.

关键词： Fig Dormancy Bud Break Varieties Behaviour

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Note on the Orchids of the Moutas Hunting Reserve--- Tlemcen （Western Algeria）

引用

Journal of Life Sciences 2013年第4期7卷 410-415页

作者： Brahim Babali abderrahmane Hasnaoui Mohammed Bouazza Laboratory of Ecology and Management of the Natural Ecosystems Department of Ecology and Environment Aboubakr BelkaidUniversity Tlemcen 13000 Algeria

Through the Algerian orchid flora, several rare species remain endemic in the Maghreb. This note on the orchids will enrich the already existing data on the area of Tlemcen. Currently, the coexistence of orchids and species （such as Quercus faginea subsp. tlemcenensis （DC.） M., Lonicera implexa L. and Ruscus aculeatus L.） indicates an ecological environment of dominant forest. Nevertheless, the significant frequency of fires and human pressure is leading to erosion of this area orchids richness. This work enabled us to establish a complete inventory of the orchids species that exist, with an estimate of the populations and a taxon illustration for each of them. Fourteen species （14） were indexed, during the period of spring 2011 only, in this reserve and the scoured areas which do not exceed 2000 ha, representing 29% of the total Algerian orchids species. Among the rare taxa signed ourselves： Ophrys subfusca subsp. battandieri （Rchb.） Batt. and Dactylorhiza durandii （Boiss. and Reuter） M. Lainz in Oranie （O）＊

关键词： Biodiversity orchidaceae mounts of Tlemcen moutas Ophrys Dactylorhiza rare species inventory.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：