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Defence Technology（防务技术） 2019年第2期15卷 233-240页

作者： hamid reza Pouretedal Sajjad Damiri Ali Zandi Department of Chemistry Faculty of Science Malek-Ashtar University of Technology

The unfavorable growth and agglomeration of micro-particles of RDX explosive was almost observed in manufacture process. For preventing of growth of micro-particles and agglomeration in anti-solvent crystallization process, the effect of additives glucose, sucrose and poly ethylene glycol-2000 and wetting solvent of isopropyl alcohol were studied. Taguchi experimental design was used for optimization of the operating conditions. The type of additive, the amount of additive(%wt.), solvent of wetting and wetting time were selected for optimization of the conditions. By using 4 factor and 3 levels, 27 experiments were conducted(L27). Results showed that in the presence of 2 %wt. of sucrose additive and isopropyl alcohol solvent, the agglomerations of particles were decreased so that a decrease 30-50% in the average of particles size was seen. Addition additives were effective in storage container and for reduce the agglomeration of particles during storage. Also, the agglomeration rate of particles was reduced over time at optimized conditions. Imaging optical microscopy, scanning electron microscopy(SEM), and particle size analyzer(PSA) methods were used for particles size analyzing as a response in statistical optimization and quality control of the final product. The sensitivity to some mechanical and shock stimuli on the RDX in presence of sucrose additive was tested and the obtained results showed the insignificant effect of additive on the safety properties of pure RDX.

关键词： RDX explosive Taguchi experimental design Agglomeration Additive Anti-solvent

Bifurcation in a 3-DOF Airfoil with Cubic Structural Nonlinearity

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Chinese Journal of Aeronautics 2011年第3期24卷 265-278页

作者： Saied IRANI hamid SARRAFZADEH Mohammad reza AMOOZGAR Department of Aerospace Engineering K.N.Toosi University of Technology

Limit cycle oscillations （LCOs） as well as nonlinear aeroelastic analysis of a 3-DOF aeroelastic airfoil motion with cubic restoring moments in the pitch degree of freedom are investigated. Aeroelastic equations of an airfoil with control surface in an incompressible potential flow are presented in the time domain. The harmonic balance （HB） method is utilized to calculate the LCO frequency and amplitude for the airfoil. Also the semi-analytical method has revealed the presence of stable and unstable limit cycles, along with stability reversal in the neighborhood of a Hopf bifurcation. The system response is determined by nu- merically integrating the governing equations using a standard Runge-Kutta algorithm and the obtained results are compared with the HB method. Also the results by the third order HB （HB3） method for control surface are consistent with the other numerical solution. Finally, by combining the numerical and the HB methods, types of bifiarcation, be it supercritical, subcritical, or diver- gent flutter area are identified.

关键词： flutter bifurcation cubic nonlinearity limit cycle oscillations harmonic balance method

Increasing of photostability of HNS explosive in the presence of UV photostabilizers

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Defence Technology（防务技术） 2021年第2期17卷 338-342页

作者： hamid reza Pouretedal Sajjad Damiri Zynab Karami Faculty of Applied Sciences Malek Ashtar University of TechnologyIran

The photostabilies of hexanitrostillbene(HNS)were studied at 1%*** *** photostabilizers of Chiguard BP-12(UV-531),ADK STAB LA-326(UV-326),ADK STAB LA-32(UV-P),Irganox 1010 and Everstab LS944 were used in this study.A photoreactor including a 30 W monochromatic UV lamp was used for investigation of photodegradations of solid *** changes in surface area of HNS peak in HPLC chromatogram at time intervals of 2,4,6 and 8 h were used for calculation of kinetic rate constants of photodegradation *** compound of UV-P photostabilizer was found to have the greatest effect on enhancing photostability for HNS among the investigated *** kinetic rate constants were obtained 6.2×10^(-2) and 4.1×10^(-2)h^(-1),respectively,for photodegradation process of HNS in absence and in presence of UV-P.

关键词： HNS explosive Photodegradation Photostabilizer Kinetic rate constant

Seismic progressive-failure analysis of tall steel structures under beam-removal scenarios

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 904-917页

作者： Behrouz BEHNAM Fahimeh SHOJAEI hamid reza RONAGH School of Civil and Environmental Engineering Amirkabir University of Technology Tehran 13496 Iran Independent Researcher Earthquake Engineer Parand 37611 Iran Centre for Infrastructure Engineering Western Sydney University NSW 2751 Australia

Investigating progressive collapse of tall structures under beam removal scenarios after earthquake is a complex subject because the earthquake damage acts as an initial condition for the subsequent scenario. An investigation is performed here on a 10 story steel moment resisting structure designed to meet the life safety level of performance when different beam removal scenarios after earthquake are considered. To this end, the structure is first subjected to the design earthquake simulated by Tabas earthquake acceleration. The beam removal scenarios are then considered at different locations assuming that both ends connections of the beam to columns are simultaneously detached from the columns;thus the removed beam falls on the underneath floor with an impact. This imposes considerable loads to the structure leading to a progressive collapse in all the scenarios considered. The results also show that the upper stories are much more vulnerable under such scenarios than the lower stories. Hence, more attention shall be paid to the beam-to-column connections of the upper stories during the process of design and construction.

关键词： progressive collapse tall steel moment-resisting frames non-linear dynamic analysis beam-removal scenario impact

Multiple damage detection in complex bridges based on strain energy extracted from single point measurement

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Frontiers of Structural and Civil Engineering 2020年第3期14卷 722-730页

作者： Alireza ARABHA NAJAFABADI Farhad DANESHJOO hamid reza AHMADI Department of Structural Engineering RoadHousing&Urban Development Research CenterTehran 13145-1696Iran Department of Structural Engineering Faculty of Civil and Environmental EngineeringTarbiat Modares UniversityTehran 14115-397Iran Department of Civil Engineering Faculty of EngineeringUniversity of MaraghehMaragheh 55136-553Iran

Strain Energy of the structure can be changed with the damage at the damage *** accurate detection of the damage location using this index in a force system is dependent on the degree of accuracy in determining the structure deformation function before and after *** use of modal-based methods to identify damage in complex bridges is always associated with problems due to the need to consider the effects of higher modes and the adverse effct of operational conditions on the extraction of structural modal *** this paper,the deformation of the structure was determined by the concept of influence line using the Betti-Maxwell *** two damage detection indicators were developed based on strain energy *** indices were presented separately for bending and torsion *** element analysis of a five-span concrete curved bridge was done to validate the stated *** was simulated by decreasing stiffness at different sections of the *** response regarding displacement ofa point on the deck was measured along each span by passing a moving load on the bridge at very low *** of the strain energy extracted from displacement influence line and the strain energy extracted from the rotational displacement influence line(SERIL)were calculated for the studied *** results show that the proposed methods have well identified the location of the damage by significantly reducing the number of sensors required to record the ***,the location of symmetric damages is detected with high resolution using SERIL.

关键词： damage detection strain energy infuence line complex bridges rotation displacement

A Convenient Method for the Preparation of 1,5-Diaryl-3-（arylamino）-I H-pyrrol-2（5 H）-ones

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Chinese Journal of Chemistry 2011年第9期29卷 1851-1855页

作者： Ghashang, Majid Shaterian, hamid reza~ Department of Chemistry Faculty of Sciences University of Sistan and Baluchestan PO Box 98135-674 Zahedan Iran

A simple and eco-friendly method for the preparation of 1,5-diaryl-3-（arylamino）-lH-pyrrol-2（5H）-ones via the cyclo-condensation reaction of aldehydes, amines and ethyl pyruvate in the presence of silica supported ferric chlo- ride （SiO2-FeCl3） as reusable heterogeneous catalyst is described. The present methodology offers several advantages such as excellent yields, simple procedure and short reaction times.

关键词： multicomponent reactions domino reactions SiO2-FeCl3 1,5-diaryl-3-(arylamino)-lH-pyrrol-2(5H)-one γ-lactam ethyl pyruvate

A low-power and low-energy flexible GF(p) elliptic-curve cryptography processor

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第9期11卷 724-736页

作者： hamid reza AHMADI Ali AFZALI-KUSHA School of Electrical and Computer Engineering University of Tehran

We investigate the use of two integer inversion algorithms,a modified Montgomery modulo inverse and a Fermat's Little Theorem based inversion,in a prime-field affine-coordinate elliptic-curve *** perform this,we present a low-power/energy GF(p) affine-coordinate elliptic-curve cryptography(ECC) processor design with a simplified architecture and complete flexibility in terms of the field and curve *** design can use either of the inversion *** on the implementations of this design for 168-,192-,and 224-bit prime fields using a standard 0.13 μm CMOS technology,we compare the efficiency of the algorithms in terms of power/energy consumption,area,and calculation *** results show that while the Fermat's theorem approach is not appropriate for the affine-coordinate ECC processors due to its long computation time,the Montgomery modulo inverse algorithm is a good candidate for low-energy *** results also show that the 168-bit ECC processor based on the Montgomery modulo inverse completes one scalar multiplication in only 0.4 s at a 1 MHz clock frequency consuming only 12.92 μJ,which is lower than the reported values for similar designs.

关键词： Elliptic-curve cryptography(ECC) Prime field Montgomery multiplication Montgomery inverse Low-energy

Complementary Inequalities to Improved AM-GM Inequality

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1609-1616页

作者： hamid reza MORADI Mohsen Erfanian OMIDVAR Department of Mathematics Mashhad Branch Islamic Azad University Mashhad Iran

Following an idea of Lin, we prove that if A and B are two positive operators such that 0 〈 mI 〈 A 〈 m＇I ≤ M＇I ≤B 〈 MI, then Ф^2（A＋B/2）≤K^2（h）/（1＋（logM＇/m＇）^2/8）^2Ф^2（A#B）,and Ф^2（A＋B/2）≤K^2（h）/（1＋（logM＇/m＇）^2/8）^2（Ф（A）#Ф（B））^2,where K（h） = （h＋1）2 /4h and h = M and Ф is a positive unital linear map.

关键词： Operator inequalities positive linear maps operator norm Kantorovich inequality Wielandt inequality

Acetalization of Carbonyl Compounds as Pentaerythritol Diacetals and Diketals in the Presence of Cellulose Sulfuric Acid as an Efficient, Biodegradable and Reusable Catalyst

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Chinese Journal of Chemistry 2012年第3期30卷 695-698页

作者： Shaterian, hamid reza Rigi, Fatemeh Department of Chemistry Faculty of Sciences University of Sistan and Baluchestan PO Box 98135-674 Zahedan Iran

This paper reports a practical and green method for the acetalization of carbonyl compounds as pentaerythritol diacetals and diketals derivatives using cellulose sulfuric acid as a biodegradable and reusable solid aci... 详细信息

关键词： synthetic method, aldehyde, cellulose sulfuric acid pentaerythritol, solvent-free, acetalization

A new impedance and robust adaptive inverse control approach for a teleoperation system with varying time delay

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Science China(Technological Sciences) 2009年第9期52卷 2629-2643页

作者： Mokhtar SHA SADEGHI hamid reza MOMENI Electrical and Electronic Engineering Department Shiraz University of TechnologyShiraz Iran Electrical Engineering Department Faculty of Engineering Tarbiat Modares UniversityTehran Iran

This paper presents a new robust adaptive inverse control approach for a force-reflecting teleoperation system with varying time delay. First,an impedance control is designed for the master robot. Second,an adaptive inverse control is proposed for the slave robot. Finally,the slave side controller is modified such that the robust stability and performance are achieved. In addition,robust stability analysis has been performed and optimal behavior is ensured by using standard characteristic polynomials. It is shown that despite of presence of randomly-varying time delay,the proposed control algorithm compensates the position drifts efficiently. Demonstrable simulation studies confirm the effectiveness of the proposed control system and its advantages over the existing sliding mode control strategies.

关键词： teleoperation bilateral force feedback adaptive inverse control time delay system