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Evolution of Coulomb failure stress in Sulaiman Lobe,Pakistan,and its implications for seismic hazard assessment
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作者 Aiza Amjad Muhammad Shahid Riaz +2 位作者 Urooj Shakir Muhammad Younis Khan Muhammad Ali Shah 《Earth and Planetary Physics》 EI CSCD 2023年第2期282-294,共13页
In this research work,we present the evolution of Coulomb failure stress(CFS)in the Sulaiman Lobe and its implications for seismic hazard assessment.The Chaman transform fault,~1,000 km long,is the major active fault ... In this research work,we present the evolution of Coulomb failure stress(CFS)in the Sulaiman Lobe and its implications for seismic hazard assessment.The Chaman transform fault,~1,000 km long,is the major active fault that marks the western boundary between Pakistan and Afghanistan on the Indian Plate.To date,few studies have been conducted to unveil the interactions among earthquakes and the implications of these interactions for seismic hazard assessment in the region.We thoroughly investigated the published and online catalog to construct a sequence of major earthquakes that occurred in this region during the past.The final earthquake sequence was composed of 15 earthquakes of M_(w)≥6.0,beginning with the 1888 earthquake.We used the stress-triggering theory to numerically simulate the evolution of CFS caused by these earthquakes.The numerical results revealed that 8 out of 15earthquakes were triggered by the preceding earthquakes.The earthquakes in 1908,1910,1935,1966,and 1997 were rather independent earthquakes in this sequence.Although the epicenters of the 1975a and 1975b earthquakes were in the stress shadow zone,the partial rupture segments of both these earthquakes were in high-CFS regions.The CFS induced by the 1935 earthquake was notable,as it later triggered the 2008 doublet.Moreover,our results revealed that the northern segment of the Chaman Fault,the southern segment of the Ghazaband Fault,and the northwestern segment of the Urghargai Fault demonstrated a high change in CFS that could trigger seismicity in these regions.The necessary arrangements must therefore be made to mitigate any possible seismic hazards in the region. 展开更多
关键词 Sulaiman Thrust Sulaiman Lobe earthquake triggering Coulomb failure stress seismic hazard assessment
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Size control synthesis of sulfur doped titanium dioxide (anatase) nanoparticles,its optical property and its photo catalytic reactivity for CO_2 + H_2O conversion and phenol degradation 被引量:8
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作者 S. Tajammul Hussain Khaiber Khan R. Hussain 《Journal of Natural Gas Chemistry》 CAS CSCD 2009年第4期383-391,共9页
Sulfur doped anatase TiO2 nanoparticles (3 nm- 12 nm) were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photoc... Sulfur doped anatase TiO2 nanoparticles (3 nm- 12 nm) were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles (24 nm). The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2+H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used. 展开更多
关键词 S doped TiO2 PHOTOCATALYST CO2 conversion phenol degradation UV IR radiation
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Detailed investigation of optimized alkali catalyzed transesterification of Jatropha oil for biodiesel production 被引量:5
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作者 Waqas Ahmed Muhammad Faizan Nazar +2 位作者 Syed Danish Ali Usman Ali Rana Salah Ud-Din Khan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第3期331-336,共6页
The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyz... The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyzed transesterification route.The biophysical characteristics of Jatropha oil were found within the optimal range in accordance with ASTM standards as a substitute diesel fuel.The chemical composition and production yield of as-synthesized biodiesel were confirmed by various analytical techniques such as FT-IR,1H NMR,13 C NMR and gas chromatography coupled with mass spectrometry.A high percentage conversion,~96.09%,of fatty acids into esters was achieved under optimized transesterification conditions with 6 :1 oil to methanol ratio and 0.9 wt% Na OH for 50 min at ~60°C.Moreover,twelve fatty acids methyl esters(FAME) were quantified in the GC/MS analysis and it was interesting to note that the mass fragmentation pattern of saturated,monounsaturated and diunsaturated FAME was comparable with the literature reported values. 展开更多
关键词 Jatropha oil methyl esters TRANSESTERIFICATION biodiesel fuel gas chromatography mass spectrometry
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Effect of surface structure on the catalytic behavior of Ni:Cu/Al and Ni:Cu:K/Al catalysts for methane decomposition 被引量:1
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作者 S.Tajammul Hussain Sheraz Gul +2 位作者 Muhammed Mazhar Dalaver H.Anjum Faical Larachi 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2008年第4期374-382,共9页
Methane decomposition using nickel, copper, and aluminum (Ni:Cu/Al) and nickel, copper, potassium, and aluminum (Ni:Cu:K/Al) modified nano catalysts has been investigated for carbon fibers, hydrogen and hydroca... Methane decomposition using nickel, copper, and aluminum (Ni:Cu/Al) and nickel, copper, potassium, and aluminum (Ni:Cu:K/Al) modified nano catalysts has been investigated for carbon fibers, hydrogen and hydrocarbon production. X-ray photoelectron spectroscopy (XPS), static secondary ion mass spectrometry (SSIMS), thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), secondary electron microscopy/X-ray energy dispersive (SEM-EDX), and temperature programmed desorption (TPD) were used to depict the chemistry of the catalytic results. These techniques revealed the changes in surface morphology and structure of Ni, Cu, Al, and K, and formation of bimetallic and trimetallic surface cationic sites with different cationic species, which resulted in the production of graphitic form of pure carbon on Ni:Cu/Al catalyst. The addition of K has a marked effect on the product selectivity and reactivity of the catalyst system. K addition restricts the formation of carbon on the surface and increases the production of hydrogen and C2, C3 hydrocarbons during the catalytic reaction whereas no hydrocarbons are produced on the sample without K. This study completely maps the modified surface structure and its relationship with the catalytic behavior of both systems. The process provides a flexible route for the production of carbon fibers and hydrogen on Ni:Cu/Al catalyst and hydrogen along with hydrocarbons on Ni:Cu:K/Al catalyst. The produced carbon fibers are imaged using a transmission electron microscope (TEM) for diameter size and wall structure determination. Hydrogen produced is COx free, which can be used directly in the fuel cell system. The effect of the addition of Cu and its transformation and interaction with Ni and K is responsible for the production of CO/CO2 free hydrogen, thus producing an environmental friendly clean energy. 展开更多
关键词 bimetallic catalysts methane decomposition carbon fibers HYDROGEN higher hydrocarbons
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Suppression of methane formation during Fisher-Tropsch synthesis using manganese-cobalt oxide supported on H-5A zeolite as a catalyst
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作者 Syed Tajammul Hussain Muhammad Mazhar Muhammad Arif Nadeem 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2009年第2期187-190,共4页
In Fischer-Tropsch synthesis reaction, methane formation is one of the side reactions which must be suppressed in order to get better catalytic selectivity for light olefins. In the present study, we have modified cob... In Fischer-Tropsch synthesis reaction, methane formation is one of the side reactions which must be suppressed in order to get better catalytic selectivity for light olefins. In the present study, we have modified cobalt based Fischer-Tropsch catalyst and developed a process to minimize methane production, consequently to produce maximum yield of light olefins. Manganese-cobalt oxide supported on H-5A zeolite catalyst was synthesized using modified H-5A zeolite, to increase its surface acid sites. Increased acidity of zeolite plays a major part in the suppression of methane formation during the Fischer-Tropsch reaction. The modified zeolite results in the electronic modification of catalyst surface by creating new active catalytic sites. The results are compared with other supported catalysts along with unmodified zeolite. Appreciable reduction in methane formation is achieved on modified zeolite supported catalyst in comparison with unsupported catalyst. 展开更多
关键词 methane formation Fisher-Tropsch synthesis MANGANESE COBALT SUPPRESSION
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The Strategic Form of Quantum Prisoners' Dilemma
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作者 Ahmad Nawaz 《Chinese Physics Letters》 SCIE CAS CSCD 2013年第5期4-9,共6页
In a normal form, prisoners' dilemma (PD) is represented by a payoff matrix showing players' strategies and payoffs. To obtain the distinguishing trait and strategic form of PD, certain constraints are imposed... In a normal form, prisoners' dilemma (PD) is represented by a payoff matrix showing players' strategies and payoffs. To obtain the distinguishing trait and strategic form of PD, certain constraints are imposed on the elements of its payoff matrix. We quantize PD by a generalized quantization scheme to analyze its strategic behavior in the quantum domain. The game starts with a general entangled state of the form |ψ>=cos(ξ/2)|00>+sin(ξ/2)|11> and the measurement for payoffs is performed in entangled and product bases. We show that for both measurements, there exist respective cutoff values of entanglement of the initial quantum state up to which the strategic form of the game remains intact. Beyond these cutoffs the quantized PD behaves like the chicken game (CG) up to another cutoff value. For the measurement in the entangled basis the dilemma is resolved for sinξ >1/7 with Q⊗Q as a Nash Equilibrium (NE). However, the quantized game behaves like PD when sinξ >1/3;whereas in the range 1/7<sinξ <1/3 it behaves like CG with Q⊗Q as an NE. For the measurement in the product basis the quantized PD behaves like classical PD for sin^(2)(ξ/2) <1/3 with D⊗D as an NE. In region 1/3<sin^(2)(ξ/2)<3/7, the quantized PD behaves like classical CG with C⊗D and D⊗C as NEs. 展开更多
关键词 BASES behave STRATEGIC
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Ionospheric precursors of strong earthquakes observed using six GNSS stations data during continuous five years(2011-2015) 被引量:1
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作者 H.E.Eshkuvatov B.J.Ahmedov +3 位作者 Y.A.Tillayev M.Arslan Tariq M.Ali Shah Libo Liu 《Geodesy and Geodynamics》 CSCD 2023年第1期65-79,共15页
This study reports the morphological characteristics of anomalous variations in Global Navigation Satellite System Total Electron Content(GNSS-TEC) prior to the strong local earthquakes(EQ) that occurred during the pe... This study reports the morphological characteristics of anomalous variations in Global Navigation Satellite System Total Electron Content(GNSS-TEC) prior to the strong local earthquakes(EQ) that occurred during the period of 2011-2015.We have analyzed 20 earthquakes of magnitude M> 5.6.A statistical technique is implemented on the data of six GNSS stations located in Tashkent,Kitab,and Maidanak in Uzbekistan,and Islamabad,Multan,Quetta in Pakistan.The results show continuous anomalous variations in TEC during 24 h befo re the occupancy of local earthquakes.It is shown that the precursors before the occurrence of strong earthquakes,in particular of magnitude 5.7,7.7,7.5,7.8 and 7.3 are detected near Eastern Uzbekistan(26 May 2013),Southwestern Pakistan(24 September 2013),Hindukush region of Afghanistan(26 October 2015),and Central Nepal(25 April 2015) and(12 May 2015),respectively.The ionospheric anomalies appearing before the strong earthquakes at six GNSS stations are registered in 14cases(70%) out of 20 selected EQs.It is depicted that anomalies referred to as ionospheric precursors appeared about 1-7 days prior to the occurrence of strong earthquakes. 展开更多
关键词 GNSS TEC EARTHQUAKES Ionospheric precursors
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Greenhouse Gas Emissions from Agro-Ecosystems and Their Contribution to Environmental Change in the Indus Basin of Pakistan 被引量:7
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作者 M. Mohsin IQBAL M. Arif GOHEER 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2008年第6期1043-1052,共10页
There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissi... There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissions and the relative importance of different sources vary widely, regionally and locally. The Indus Basin of Pakistan is the food basket of the country and agricultural activities are vulnerable to the effects of global warming due to accelerated emissions of GHGs. Many developments have taken place in the agricultural sector of Pakistan in recent decades in the background of the changing role of the government and the encouragement of the private sector for investment in new ventures. These interventions have considerable GHG emission potential. Unfortunately, no published information is currently available on GHG concentrations in the Indus Basin to assess their magnitude and emission trends. The present study is an attempt to estimate GHG (CO2, CH4 and N2O) emissions arising from different agro-ecosystems of Indus Basin. The GHGs were estimated mostly using the IPCC Guidelines and data from the published literature. The results showed that CH4 emissions were the highest (4.126 Tg yr^-1) followed by N20 (0.265 Tg yr^-1) and CO2 (52.6 Tg yr^-1). The sources of CH4 are enteric fermentation, rice cultivation and cultivation of other crops. N2O is formed by microbial denitrification of NO3 produced from applied fertilizer-N on cropped soils or by mineralization of native organic matter on fallow soils. CO2 is formed by the burning of plant residue and by soil respiration due to the decomposition of soil organic matter. 展开更多
关键词 greenhouse gases AGRICULTURE Indus Basin Pakistan
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Optimization Study of Pulsed DC Nitrogen-Hydrogen Plasma in the Presence of an Active Screen Cage 被引量:3
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作者 A.SAEED A.W.KHAN +5 位作者 F.JAN H.U.SHAH M.ABRAR M.ZAKA-UI-ISLAM M.KHALID M.ZAKAULLAH 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第5期460-464,共5页
A glow discharge plasma nitriding reactor in the presence of an active screen cage is optimized in terms of current density,filling pressure and hydrogen concentrations using optical emission spectroscopy(OES).The s... A glow discharge plasma nitriding reactor in the presence of an active screen cage is optimized in terms of current density,filling pressure and hydrogen concentrations using optical emission spectroscopy(OES).The samples of AISI 304 are nitrided for different treatment times under optimum conditions.The treated samples were analyzed by X-ray diffraction(XRD) to explore the changes induced in the crystallographic structure.The XRD pattern confirmed the formation of iron and chromium nitrides arising from incorporation of nitrogen as an interstitial solid solution in the iron lattice.A Vickers microhardness tester was used to evaluate the surface hardness as a function of treatment time(h).The results showed clear evidence of improved surface hardness and a substantial amount of decrease in the treatment time compared with the previous work. 展开更多
关键词 optical diagnostics plasma nitriding austenitic stainless steel
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Precise Seismic Substructural Model of the Eocene Chorgali Limestone in the Turkwal Oil Field, Central Potwar, Pakistan 被引量:1
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作者 Khawar Ashfaq AHMED Sarfraz KHAN +3 位作者 Mahmood SULTAN UMAIR Bin Nisar Kalim ULLAH Al-Hseinat MU’AYYAD 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第6期1711-1720,共10页
The precise seismic substructural interpretation of the Turkwal oil field in the Central Potwar region of district Chakwal of Pakistan has been carried out. The research work was confined to the large fore-thrust that... The precise seismic substructural interpretation of the Turkwal oil field in the Central Potwar region of district Chakwal of Pakistan has been carried out. The research work was confined to the large fore-thrust that serves as an anticlinal structural trap through ten 2 D seismic lines. A precise seismic substructural model of the Eocene Chorgali Limestone with precise orientation of thrust and oblique slip faults shows the presence of a huge fracture, which made this deposit a good reservoir. The abrupt surface changes in dip azimuth for the Eocene Chorgali Limestone verifies the structural trends and also the presence of structural traps in the Turkwal field. The logs of three wells(Turkwal deep X-2, Turkwal-01 and Fimkassar-01) were analyzed for petrophysical studies, well synthetic results and generation of an Amplitude Versus Offset(AVO) model for the area. The AVO model of Turkwal deep X-2 shows abrupt changes in amplitude, which depicts the presence of hydrocarbon content. Well correlation technique was used to define the overall stratigraphic setting and the thickness of the reservoir formation in two wells, Turkwal-01 and Turkwal deep X-2. The Eocene Chorgali Limestone in Turkwal-01 is an upward thrusted anticlinal structure and because of the close position of both wells to the faulted anticlinal structure, its lesser thickness differs compared to Turkwal deep X-2. The overall results confirm that the Turkwal field is comparable to several similar thrust-bound oil-bearing structures in the Potwar basin. 展开更多
关键词 2D seismic well correlation fore-thrust structural traps AVO model Eocene Chorgali Limestone and Basement Potwar
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Evolutionarily Stable Strategies in Quantum Hawk-Dove Game
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作者 Ahmad Nawaz A. H. Toor 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第5期12-15,共4页
我们使量子化由使用一个纯起始的状态的最一般的形式调查纯、混合的 evolutionarily 稳定的策略(S 字) 的存在的鹰鸽子比赛。一个例子被认为拉比较在之间古典并且比赛的量版本。我们最一般的起始的量状态的选择使我们能使比赛对称或不... 我们使量子化由使用一个纯起始的状态的最一般的形式调查纯、混合的 evolutionarily 稳定的策略(S 字) 的存在的鹰鸽子比赛。一个例子被认为拉比较在之间古典并且比赛的量版本。我们最一般的起始的量状态的选择使我们能使比赛对称或不对称。我们显示出那因为在那里存在的比赛参数的一个特别集合仅仅在比赛的古典版本混合了 S 字,量子化允许甚至纯策略是为除了混合 S 字的对称的比赛的 S 字。在另一方面,仅仅纯的策略 S 字能为鹰鸽子比赛的不对称的量版本存在。[从作者抽象] 展开更多
关键词 进化稳定策略 量子态 博弈 ESS公司 混合对称 初始状态 不对称
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Shocks and Solitons in Ultradense Degenerate Electron-Positron-Ion Plasmas
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作者 S.A.Khan Arshad M.Mirza 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第1期151-157,共7页
震动和 solitons 的形成和繁殖被雇用 Thomas 费密模型在 unmagnetized,包含电子和正电子的退化费密气体的 ultradense 血浆,和古典离子气体调查。为这个目的,一个使变形的 Korteweg-de Vries 冰山(dKdVB ) 方程为冷、断热、等温的... 震动和 solitons 的形成和繁殖被雇用 Thomas 费密模型在 unmagnetized,包含电子和正电子的退化费密气体的 ultradense 血浆,和古典离子气体调查。为这个目的,一个使变形的 Korteweg-de Vries 冰山(dKdVB ) 方程为冷、断热、等温的离子用减少的 perturbative 技术被导出。在平面几何学的 dKdVB 方程的局部性的分析答案为分散以及驱散被获得主导的案例。为 nonplanar (圆柱、球形) 几何学,改变 dKdVB 方程的数字冲击波答案的时间被发现。它导致 soliton 答案的主导的大小写也是的分散讨论了。离子温度,正电子集中和驱散的效果在这些非线性的结构上被发现重要。到科学兴趣的系统的结果的关联被指出。 展开更多
关键词 正负电子对 等离子体 孤子解 超密 KdVB方程 等离子气体 退化 KDV方程
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Structural and optical analysis of Cr_2N thin films prepared by DC magnetron sputtering
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作者 Shakil Khan A.Mahmood +3 位作者 A.Shah Qaiser Raza Muhammad Asim Rasheed Ishaq Ahmad 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第2期197-202,共6页
Chromium nitride (Cr2N) thin films were prepared by a DC magnetron sputtering technique. The deposition temperature was raised from 50 to 300℃, and its influence on the film structure and refractive index was inves... Chromium nitride (Cr2N) thin films were prepared by a DC magnetron sputtering technique. The deposition temperature was raised from 50 to 300℃, and its influence on the film structure and refractive index was investigated. X-ray diffraction analysis shows that the crystalline strucure of the films transforms from the (101) to (002) oriented hexagonal CrzN phase as the increase of substrate tempera- ture above 50℃, and a highly texatred film grows at 100℃. An empirical relation between the crystalline orientation and infrared active modes of the films is obtained, i.e., the Fourier transform infrared (FTIR) spectrum of the film prepared at 50℃ exhibits only A1 (TO) mode. The prominent peak in the FTIR spectra of the film prepared above 50℃is assigned to the E1 (TO) mode and is correlated with the (002) or c-axis oriented hexagonal wurtzite phase of Cr2N. In the surface analysis of atomic force microscopy, a transformation from the featureless surface to columnar-type morphology is observed with the increase of substrate temperature from 50 to 100℃, exhibiting c-axis oriented crystallite growth. A further increase in substrate temperature to 200℃ causes the c-axis crystallites to merge, resulting in the formation of voids. The refractive index (n) of the deposited films is obtained using spectroscopic ellipsometry. 展开更多
关键词 chromium nitride thin films magnetron sputtering structural analysis optical analysis refractive index
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The charge state distribution of B, C, Si, Ni, Cu and Au ions on 5 MV pelletron accelerator
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作者 Ali Awais Javaid Hussain +5 位作者 Muhammad Usman Waheed Akram Kashif Shahzad Turab Ali Ishaq Ahmad Malik Maaza 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第5期43-47,共5页
Stripper gas and terminal potential play a key role for the charge state distribution in a tandem pelletron accelerator. The knowledge of this distribution is important for experiments performed on tandem accelerators... Stripper gas and terminal potential play a key role for the charge state distribution in a tandem pelletron accelerator. The knowledge of this distribution is important for experiments performed on tandem accelerators. The charge state distribution of B, C, Si, Ni, Cu and Au beams is measured by using Ar as stripper gas, and terminal potential is varied from 0.3 to 3.0 MV on 5UDH-2 tandem pelletron accelerator installed at the National Centre for Physics, Islamabad. The individual charge state is measured after the switching magnet at 15° in high-energy portion. It is observed that the higher charge states are stable in the range of lower and middle atomic masses of periodic table, whereas higher atomic mass(Au) shows beam current instability in higher charge states. For carbon,the charge distribution at 1.7 MV terminal potential by varying stripper gas pressure is also studied, which resulted in decreased overall transmission with good current value for higher charge states. 展开更多
关键词 Pelletron ACCELERATOR Charge state DISTRIBUTION STRIPPER gas TERMINAL potential
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Electric-field induced fluctuations in laser generated plasma plume
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作者 Rizwan AHMED Abdul JABBAR +1 位作者 Zeshan Adeel UMAR Muhammad Aslam BAIG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第4期83-89,共7页
The effect of an external electric field on laser-generated plasma has been studied.It is observed that the laser-generated plasma can be used for the ignition of a spark in the presence of a low voltage external elec... The effect of an external electric field on laser-generated plasma has been studied.It is observed that the laser-generated plasma can be used for the ignition of a spark in the presence of a low voltage external electric field.An eight-fold emission intensity enhancement in Cu I spectral lines are measured as compared to the signal intensity in the absence of an external electric field.The plasma parameters remain the same initially,up to a few microseconds after the generation of plasma,and this feature makes it more interesting for the quantitative analysis of any sample using laser induced breakdown spectroscopy(LIBS).In the presence of an external electric field,fluctuations(contraction and expansion)in the laser-generated plasma are observed which increase the plasma decay time and consequently result in enhanced signal intensity. 展开更多
关键词 LIBS laser produced plasma effect of external electric plasma parameters
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Quantum State Tomography and Quantum Games
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作者 Ahmad Nawaz 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第3期37-40,共4页
A technique is developed for single qubit quantum state tomography using the mathematical setup of generalized quantization scheme for games.In this technique,Alice sends an unknown pure quantum state to Bob who appen... A technique is developed for single qubit quantum state tomography using the mathematical setup of generalized quantization scheme for games.In this technique,Alice sends an unknown pure quantum state to Bob who appends it with|0><0|and then applies the unitary operators on the appended quantum state and finds the payoffs for Alice and himself.It is shown that for a particular set of unitary operators,these payoffs are equal to Stokes parameters for an unknown quantum state.In this way an unknown quantum state can be measured and reconstructed.Strictly speaking,this technique is not a game as no strategic competitions are involved. 展开更多
关键词 STATE QUANTUM OPERATORS
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Effects of electron trapping on nonlinear electron-acoustic waves excited by an electron beam via particle-in-cell simulations
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作者 A A ABID 陆全明 +3 位作者 陈华岳 柯阳光 S ALI 王水 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第5期93-101,共9页
By performing one-dimensional particle-in-cell simulations,the nonlinear effects of electronacoustic(EA)waves are investigated in a multispecies plasma,whose constituents are hot electrons,cold electrons,and beam elec... By performing one-dimensional particle-in-cell simulations,the nonlinear effects of electronacoustic(EA)waves are investigated in a multispecies plasma,whose constituents are hot electrons,cold electrons,and beam electrons with immobile neutralized positive ions.Numerical analyses have identified that EA waves with a sufficiently large amplitude tend to trap cold electrons.Because EA waves are dispersive,where the wave modes with different wavenumbers have different phase velocities,the trapping may lead to the nlixing of cold electrons.The cold electrons finally get thermalized or heated.The investigation also shows that the excited EA waves give rise to a broad range of wave frequencies,which may be helpful for understanding the broadband-electrostatic-noise spectrum in the Earth's auroral region. 展开更多
关键词 electron acoustic waves cold ELECTRONS TRAPPING particle-in-cell(PIC)simulation
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Role of Jeans Instability in Multi-Component Quantum Plasmas in the Presence of Fermi Pressure
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作者 S.AliShan A.Mushtaq 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第7期217-220,共4页
The quantum hydrodynamic model is employed to investigate the effects of gravitational potential on multi-component dusty plasmas.The effects of Fermi temperature ratios of ions to electrons(TFi/TFe)and positrons to e... The quantum hydrodynamic model is employed to investigate the effects of gravitational potential on multi-component dusty plasmas.The effects of Fermi temperature ratios of ions to electrons(TFi/TFe)and positrons to electrons(TFp/TFe)have been calculated and presented graphically.It is observed that an increase in the Fermi temperature ratios of ions to electrons and positrons to electrons stabilizes the Jeans instability as the mode phase speed increases with these ratios.In the absence of the statistical effects due to Fermi pressure,the dispersion is weak.The stability criteria are calculated for each case separately. 展开更多
关键词 FERMI POSITRON ABSENCE
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Coherent nonlinear structures in dense electron positron plasma
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作者 S.A.Khan Z.Wazir 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期335-340,共6页
It is shown that rarefactive-type double layer structures exist in ultradense electron-positron plasma.For this purpose,an extended Korteweg de Vries equation is derived and solved analytically in the low amplitude li... It is shown that rarefactive-type double layer structures exist in ultradense electron-positron plasma.For this purpose,an extended Korteweg de Vries equation is derived and solved analytically in the low amplitude limit by employing the appropriate fluid equations.A strong influence of quantum degeneracy pressure of electrons and positrons,quantum diffraction effects and concentration of background positive ions on double layer is noticed.It is also pointed out that the amplitude and steepness of the double layer increases with an increase in ion concentration or ion charge number.The results are examined numerically for some interesting cases of dense plasmas with illustrations. 展开更多
关键词 degenerate plasma nonlinear structures double layers
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Structural and mechanical properties of Al–C–N films deposited at room temperature by plasma focus device
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作者 Z A Umar R Ahmad +3 位作者 R S Rawat M A Baig J Siddiqui T Hussain 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第7期299-304,共6页
The Al–C–N films are deposited on Si substrates by using a dense plasma focus(DPF) device with aluminum fitted central electrode(anode) and by operating the device with CH_4/N_2 gas admixture ratio of 1:1. XRD ... The Al–C–N films are deposited on Si substrates by using a dense plasma focus(DPF) device with aluminum fitted central electrode(anode) and by operating the device with CH_4/N_2 gas admixture ratio of 1:1. XRD results verify the crystalline Al N(111) and Al_3CON(110) phase formation of the films deposited using multiple shots. The elemental compositions as well as chemical states of the deposited Al–C–N films are studied using XPS analysis, which affirm Al–N, C–C, and C–N bonding. The FESEM analysis reveals that the deposited films are composed of nanoparticles and nanoparticle agglomerates. The size of the agglomerates increases at a higher number of focus deposition shots for multiple shot depositions. Nanoindentation results reveal the variation in mechanical properties(nanohardness and elastic modulus)of Al–C–N films deposited with multiple shots. The highest values of nanohardness and elastic modulus are found to be about 11 and 185 GPa, respectively, for the film deposited with 30 focus deposition shots. The mechanical properties of the films deposited using multiple shots are related to the Al content and C–N bonding. 展开更多
关键词 dense plasma focus XPS field emission scanning electron microscope elastic modulus
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