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Completing the Standard Model with Gravity by General Relativizing Quantum Physics (RQP) (Coupling Spin-2 Gravitons with Spin-0 Particles to Generate Higgs Mass)
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作者 Walter James Christensen Jr. 《Journal of Modern Physics》 2015年第13期1969-1985,共17页
After a straightforward general relativistic calculation on a modified flat-spacetime metric (developed from the fluctuating vacuum energy interacting with a graviton field), a pair of n-valued covariant and contravar... After a straightforward general relativistic calculation on a modified flat-spacetime metric (developed from the fluctuating vacuum energy interacting with a graviton field), a pair of n-valued covariant and contravariant energy momentum tensors emerged analogous to quantized raising and lower operators. Detaching these operators from the general relativistic field equations, and then transporting them to act on extreme spacetimes, these operators were able to generate fundamental particle boson masses. In particular, the operators precisely generated Higgs mass. Then by applying a consistency approach to the gravitational field equations—similar to how Maxwell applied to the electromagnetic ones—it allowed for the coupling of spin-to-mass, further restricting the particle mass to be in precise agreement with CODATA experimental values. Since this is a massless field approach integrated discretely with a massive one, it overcomes various renormalizing difficulties;moreover it solves the mass hierarchal problem of the Standard Model of particle physics, and generates its spin and therefore shows quantum physics to be a subset of General Relativity, just as Einstein had first imagined. 展开更多
关键词 Standard Model Particle PHYSICS GENERAL Relativity Geometric PARTICLES Higgs MASS Relativized Quantum PHYSICS RQP Graviton Gravitational Lagrangian Consistency Formulation for GRAVITY MASS Hierarchal Problem
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Bandgap engineering to tune the optical properties of Be_xMg_(1-x)X(X=S, Se, Te) alloys 被引量:1
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作者 B Sabir N A Noor +3 位作者 M Rashid Fasih Ud Din Shahid M Ramay Asif Mahmood 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期415-423,共9页
Structural, electronic, and optical properties of alloys BexMgl-xX (X = S, Se, Te) in the assortment 0 〈 x 〈 1 were theoretically reported for the first time in zinc-blende (ZB) phase. The calculations were carr... Structural, electronic, and optical properties of alloys BexMgl-xX (X = S, Se, Te) in the assortment 0 〈 x 〈 1 were theoretically reported for the first time in zinc-blende (ZB) phase. The calculations were carried out by using full-potential linearized augmented plane wave plus local orbitals (FP-LAPW+lo) formalism contained by the framework of density functional theory (DFT). Wu--Cohen (WC) generalized gradient approximation (GGA), based on optimization energy, has been applied to calculate these theoretical results. In addition, we used Becke and Johnson (mBJ-GGA) potential, modified form of GGA functional, to calculate electronic structural properties up to a high precision degree. The alloys were composed with the concentrations x = 0.25, 0.5, and 0.75 in pursuance of 'special quasi-random structures' (SQS) approach of Zunger for the restoration of disorder around the observed site of alloys in the first few shells. The structural parameters have been predicted by minimizing the total energy in correspondence of unit cell volume. Our alloys established direct band gap at different concentrations that make their importance in optically active materials. Furthermore, density of states was discussed in terms of the contribution of Be and Mg s and chalcogen (S, Se, and Te) s and p states and observed charge density helped us to investigate the bonding nature. By taking into consideration of immense importance in optoelectronics of these materials, the complex dielectric function was calculated for incident photon energy in the range 0--15 eV. 展开更多
关键词 BexMgl-xX (X = S SE Te) alloys zinc-blende (ZB) phase density functional theory (DFT) electronic and optical properties
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Design and calibration of a high-sensitivity and high-accuracy polarimeter based on liquid crystal variable retarders 被引量:1
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作者 Jing Guo De-Qing Ren +4 位作者 Cheng-Chao Liu Yong-Tian Zhu Jiang-Pei Dou Xi Zhang Christian Beck 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第1期87-96,共10页
Polarimetry plays an important role in the measurement of solar magnetic fields. We devel- oped a high-sensitivity and high-accuracy polarimeter (HHP) based on nematic liquid crystal variable retarders (LCVRs), wh... Polarimetry plays an important role in the measurement of solar magnetic fields. We devel- oped a high-sensitivity and high-accuracy polarimeter (HHP) based on nematic liquid crystal variable retarders (LCVRs), which has a compact setup and no mechanical moving parts. The system design and calibration methods are discussed in detail. The azimuth error of the transmission axis of the polarizer as well as the fast axes of the two LCVRs and the quarter-wave plate were determined using dedicated procedures. Linearly and circularly polarized light were employed to evaluate the performance of the HHP. The experimental results indicate that a polarimetric sensitivity of better than 5.7 × 10-3 can be achieved by using a single short-exposure image, while an accuracy on the order of 10-5 can be reached by using a large number of short-exposure images. This makes the HHP a high-performance system that can be used with a ground-based solar telescope for high-precision solar magnetic field investigations. 展开更多
关键词 instrumentation polarimeters - methods laboratory - Sun magnetic fields - tech-niques polarimetric
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The Arithmetic Mean Standard Deviation Distribution: A Geometrical Framework 被引量:1
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作者 R. Caimmi 《Applied Mathematics》 2013年第11期1-10,共10页
The current attempt is aimed to outline the geometrical framework of a well known statistical problem, concerning the explicit expression of the arithmetic mean standard deviation distribution. To this respect, after ... The current attempt is aimed to outline the geometrical framework of a well known statistical problem, concerning the explicit expression of the arithmetic mean standard deviation distribution. To this respect, after a short exposition, three steps are performed as 1) formulation of the arithmetic mean standard deviation, , as a function of the errors, , which, by themselves, are statistically independent;2) formulation of the arithmetic mean standard deviation distribution, , as a function of the errors,;3) formulation of the arithmetic mean standard deviation distribution, , as a function of the arithmetic mean standard deviation, , and the arithmetic mean rms error, . The integration domain can be expressed in canonical form after a change of reference frame in the n-space, which is recognized as an infinitely thin n-cylindrical corona where the symmetry axis coincides with a coordinate axis. Finally, the solution is presented and a number of (well known) related parameters are inferred for sake of completeness. 展开更多
关键词 Standard Deviation n-Spaces Direction Cosines QUADRICS
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Theories and Simulations in Substorm Research:A Review
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作者 R.A.WOLF 《空间科学学报》 CAS CSCD 北大核心 2011年第2期125-149,共25页
Both theory and simulation have played important roles in defining and illuminating the key mechanisms involved in substorms.Basic theories of magnetic reconnection and of interchange and ballooning instabilities were... Both theory and simulation have played important roles in defining and illuminating the key mechanisms involved in substorms.Basic theories of magnetic reconnection and of interchange and ballooning instabilities were developed more than 50 years ago,and these plasma physical concepts have been central in discussions of substorm physics.A vast amount of research on reconnection,including both theoretical and computational studies,has helped provide a picture of how reconnection operates in the collisionless environment of the magnetosphere.Still,however,we do not fully understand how key microscale processes and large-scale dynamics work together to determine the location and rate of reconnection.While in the last twenty years,it has become clear that interchange processes are important for transporting plasma through the plasma sheet in the form of bursty bulk flows and substorm expansions,we still have not reached the point where simulations are able to realistically and defensibly represent all of the important aspects of the phenomenon.More than two decades ago it was suggested that the ballooning instability,the basic theory for which dates from the 1950s,may play an important role in substorms.Now the majority of experts agree that regions of the plasma sheet are often linearly unstable to ideal-MHD ballooning.However,it is also clear that kinetic effects introduce important modifications to the MHD stability criterion.It is still uncertain whether ballooning plays a leading role in substorms or has just a minor part.Among the different types of simulations that have been applied to the substorm problem,global MHD codes are unique in that,in a sense, they represent the entire global substorm phenomenon,including coupling to the solar wind and ionosphere, and the important mechanisms of reconnection,interchange,and ballooning.However,they have not yet progressed to the point where they can accurately represent the whole phenomenon,because grid-resolution problems limit the accuracy with which they can solve the equations of ideal MHD and the couphng to the ionosphere,and they cannot accurately represent small-scale processes that violate ideal MHD. 展开更多
关键词 SUBSTORM RECONNECTION INTERCHANGE Simulations
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Theoretical investigation of optical properties and band gap engineering for Zn1-xTMxTe(TM=Fe,Co)alloys by modified Becke-Johnson potential
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作者 Q Mahmood M Yaseen +2 位作者 M Hassan Shahid M Ramay Asif Mahmood 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期491-498,共8页
The direct band gap ZnTe with transition metal (TM) impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson (mBJ) functional fo... The direct band gap ZnTe with transition metal (TM) impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson (mBJ) functional for performing the structural computations and detailed investigations of the optical characters in Zn1_xTMxTe (TM = Fe, Co) alloys with 0 ≤ x ≤1. By employing the FP-LAPW method, we determine various optical parameters for the ternary alloys and for the end binaries. The calculated static dielectric constants and optical band gaps for Zn1_xTMxTe (TM = Fe, Co) have an inverse relation that verifies the Penn model. We find that the static dielectric constant is nearly equal to the square of the static refractive index, and both increase with TM content. Furthermore, we also find a slight shift of peaks to a higher energy region with increasing TM concentration. The decreasing band gap and high value of the absorption in the visible region of electromagnetic spectrum make these alloys suitable for photonic and solar cell applications. 展开更多
关键词 amorphous semiconductors transition metal-doped ZnTe structural computation optical property
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Magnetism,optical,and thermoelectric response of CdFe_2O_4by using DFT scheme
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作者 Q Mahmood M Yaseen +3 位作者 K C Bhamu Asif Mahmood Y Javed Shahid M Ramay 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第3期376-383,共8页
Comparative analysis of electronic, magnetic, optical, and thermoelectric properties of CdFe2O4, calculated by em- ploying PBEsol + mBJ has been done. The PBEsol reveals metallic nature, while TB-mBJ illustrates ferr... Comparative analysis of electronic, magnetic, optical, and thermoelectric properties of CdFe2O4, calculated by em- ploying PBEsol + mBJ has been done. The PBEsol reveals metallic nature, while TB-mBJ illustrates ferromagnetic semiconducting behavior. The reasons behind the origin of ferromagnetism are explored by observing the exchange, crystal field, and John-Teller energies. The optical nature is investigated by analyzing dielectric constants, refraction, absorption coefficient, reflectivity, and optical conductivity. Finally, thermoelectric properties are elaborated by describing the electri- cal and thermal conductivities, Seebeck coefficient, and power factor. The strong absorption for the visible energy and high power factor suggest CdFe2O4 as the potential candidate for renewable energy applications. 展开更多
关键词 frustrated magnetism density functional theory John-Teller distortion Hund's rule
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The Weighted Mean Standard Deviation Distribution: A Geometrical Framework
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作者 R. Caimmi 《Applied Mathematics》 2015年第3期520-546,共27页
The current attempt is aimed to extend previous results, concerning the explicit expression of the arithmetic mean standard deviation distribution, to the general case of the weighted mean standard deviation distribut... The current attempt is aimed to extend previous results, concerning the explicit expression of the arithmetic mean standard deviation distribution, to the general case of the weighted mean standard deviation distribution. To this respect, the integration domain is expressed in canonical form after a change of reference frame in the n-space, which is recognized as an infinitely thin n-cylindrical corona where the axis coincides with a coordinate axis and the orthogonal section is an infinitely thin, homotetic (n-1)-elliptical corona. The semiaxes are formulated in two different ways, namely in terms of (1) eigenvalues, via the eigenvalue equation, and (2) leading principal minors of the matrix of a quadratic form, via the Jacobi formulae. The distribution and related parameters have the same formal expression with respect to their counterparts in the special case where the weighted mean coincides with the arithmetic mean. The reduction of some results to ordinary geometry is also considered. 展开更多
关键词 Standard Deviation n-Spaces Direction Cosines QUADRATIC FORMS MATRIX Theory
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Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications
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作者 Tahir Iqbal M.Irfan +4 位作者 Shahid M.Ramay Abdullah Alhamidi Hamid Shaikh Murtaza Saleem Saadat A.Siddiqi 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第6期743-748,I0003,共7页
Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,ma... Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions. 展开更多
关键词 Dilute magnetic semiconductors X-ray di raction UV-Vis spectrophotometry Magnetic properties PHOTO-CATALYSIS
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Electronic and thermoelectric properties of alkali metal-based perovskites CsYbF3 and RbYbF3
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作者 Q Mahmood N A Noor +3 位作者 T Ghrib Nessrin A Kattan Asif Mahmood Shahid M Ramay 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第11期473-478,共6页
The electronic and thermoelectric properties of alkali metal-based fluorides CsYbF3 and RbYbF3 are studied by using Wien2k and BoltzTraP codes.The structural and thermodynamic stability of these materials are confirme... The electronic and thermoelectric properties of alkali metal-based fluorides CsYbF3 and RbYbF3 are studied by using Wien2k and BoltzTraP codes.The structural and thermodynamic stability of these materials are confirmed by tolerance factor(0.94 and 0.99 for RbYbF3 and CsYbF3)and negative formation energy.The optimized lattice constants and bulk moduli are consistent with the results reported in the literature.The reported band gap for RbYbF3 is 0.86 eV which decreases to 0.83 eV by the replacement of Cs with Rb.The electrical and thermal conductivities along with Seebeck coefficients decrease with temperature rising from 0 K to 800 K.The large values of thermoelectric parameters for positive chemical potentials show that the character is dominated by electrons.The studied materials have figures of merit 0.82 and 0.81 at room temperature respectively,for RbYbF3 and CsYbF3 and increase with temperature rising.Therefore,the materials under study may have potential application values in thermoelectric generators and refrigerators. 展开更多
关键词 density functional theory thermodynamic stability electrical conductivity figure of merit
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Ab-initio calculations of bandgap tuning of In1-xGaxY(Y=N,P)alloys for optoelectronic applications
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作者 Muhammad Rashid Jamil M +3 位作者 Mahmood Q Shahid M Ramay Asif Mahmood A Ghaithan H M 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第11期467-474,共8页
The III–V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few decades.In the present article,the bandgap tuning and its influen... The III–V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few decades.In the present article,the bandgap tuning and its influence on optical properties of In1-xGaxN/P,where(x=0.0,0.25,0.50,0.75,and 1.0)alloys are comprehensively analyzed by density functional theory based on full-potential linearized augmented plane wave method(FP-LAPW)and modified Becke and Johnson potentials(TB-mBJ).The direct bandgaps turn from 0.7 eV to 3.44 eV,and 1.41 eV to 2.32 eV for In1-xGaxN/P alloys,which increases their potentials for optoelectronic devices.The optical properties are discussed such as dielectric constants,refraction,absorption,optical conductivity,and reflection.The light is polarized in the low energy region with minimum reflection.The absorption and optical conduction are maxima in the visible region,and they are shifted into the ultraviolet region by Ga doping.Moreover,static dielectric constant e1(0)is in line with the bandgap from Penn’s model. 展开更多
关键词 density functional theory direct bandgap III-V semiconductors tuning of optical band gap solar cell applications
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Einstein’s Gravitational Field Approach to Dark Matter and Dark Energy—Geometric Particle Decay into the Vacuum Energy Generating Higgs Boson and Heavy Quark Mass
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作者 Walter James Christensen 《Journal of Modern Physics》 2015年第10期1421-1439,共19页
During an interview at the Niels Bohr Institute David Bohm stated, “according to Einstein, particles should eventually emerge … as singularities, or very strong regions of stable pulses of (the gravitational) field... During an interview at the Niels Bohr Institute David Bohm stated, “according to Einstein, particles should eventually emerge … as singularities, or very strong regions of stable pulses of (the gravitational) field” [1]. Starting from this premise, we show spacetime, indeed, manifests stable pulses (n-valued gravitons) that decay into the vacuum energy to generate all three boson masses (including Higgs), as well as heavy-quark mass;and all in precise agreement with the 2010 CODATA report on fundamental constants. Furthermore, our relativized quantum physics approach (RQP) answers to the mystery surrounding dark energy, dark matter, accelerated spacetime, and why ordinary matter dominates over antimatter. 展开更多
关键词 DARK Energy DARK Matter Einstein Higgs PARTICLE GEOMETRIC Particles Fundamental Quanta General Relativity BOSONS Quarks Mass Hierarchy Problem Accelerated Spacetime Standard Model of PARTICLE PHYSICS Relativized Quantum PHYSICS RQP BOHM Consistency Condition
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The Mind-Brain Problem Bose-Einstein Statistics, Temperature, Heat, Entropy God and Other Elementary Particles
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作者 Walter J. Christensen Jr. 《Journal of Modern Physics》 2020年第9期1330-1360,共31页
The purpose of this research is to apply the Einstein’s principle of relativity to solve the mind-brain problem and to generate all Standard Model Particle masses. Our approach is somewhat analogous to the dualistic ... The purpose of this research is to apply the Einstein’s principle of relativity to solve the mind-brain problem and to generate all Standard Model Particle masses. Our approach is somewhat analogous to the dualistic idea of Descartes. Instead of a pineal gland, wherein the brain interacts with the mind, we propose during the developmental stages of the human fetus the tiny brain begins to communicate with the smallest structures of spacetime. This interaction occurs as the fetus brain begins to emit thermodynamic low heat energies, which are then absorbed into the smallest structures of spacetime saturating the interstices of the fetus brain. Think of these heat-energies like Morse code instructions. Since these kinds of interaction involve spacetime, with brain matter-energy, and that our main guiding principle is that of relativity, our research resulted in a general relativistic wave equation, wherein the n-valued heat-energies emitted by the brain-field-matrix <em style="white-space:normal;">B</em><sub style="white-space:normal;"><span style="white-space:nowrap;"><em>μ</em></span><em></em><em>v</em></sub>, is identified as the energy momentum tensor of general relativity. The spacetime mind-matrix (<em style="white-space:normal;">M</em><sub style="white-space:normal;"><em><em>μ</em><em></em><em>v</em></em></sub>) is likewise identified as the Riemannian curvature matrix. Together they form a general relativistic expression given by: <em>M</em><sub><em><span style="font-size:10px;"><em>μ</em></span><em style="font-size:10px;white-space:normal;"></em><em style="font-size:10px;white-space:normal;">v</em><span style="font-size:10px;white-space:normal;"> </span></em></sub>+<em>P</em><sub><em><span style="font-size:10px;"><em>μ</em></span><em style="font-size:10px;white-space:normal;"></em><em style="font-size:10px;white-space:normal;">v</em><span style="font-size:10px;white-space:normal;"> </span></em></sub><em>M=cB<sub><span style="font-size:10px;"><em>μ</em></span><em style="font-size:10px;white-space:normal;"></em><em style="font-size:10px;white-space:normal;">v</em></sub></em>. Here <em>c</em> represents the combined general relativistic constants. By detaching the energy momentum tensor <em>B</em><sub><span style="white-space:nowrap;"><em>μ</em></span><em></em><em>v</em> </sub>from the general relativistic wave equation, converting it to an operator, and then combining the time component with the Bose-Einstein equation, resulted in a brain temperature function capable of calculating precise heat-energies emitted by the brain during the formation of the fetus mind. As the fetus brain becomes more complex, it further organizes the mind. At some point self-aware consciousness is evoked within the spacetime mind. The same equation (<em>relabeled to distinguish it from the mind-brain equation</em>) can be applied to generate all Standard Model Particle masses. 展开更多
关键词 Mind-Body Problem Thermodynamics Heat Energy General Relativity Particle Mass Problem Hydrogen Spectra Consciousness God Particle Neuro-Fields Spacetime Mind Neuroscience NEUROTROPHINS
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Gravitation, Holographic Principle, and Extra Dimensions
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作者 Roberto Caimmi 《Journal of Modern Physics》 2016年第5期426-434,共9页
Within the context of Newton’s theory of gravitation, restricted to point-like test particles and central bodies, stable circular orbits in ordinary space are related to stable circular paths on a massless, unmovable... Within the context of Newton’s theory of gravitation, restricted to point-like test particles and central bodies, stable circular orbits in ordinary space are related to stable circular paths on a massless, unmovable, undeformable vortex-like surface, under the action of a tidal gravitational field along the symmetry axis. An interpretation is made in the light of a holographic principle, in the sense that motions in ordinary space are connected with motions on a selected surface and vice versa. Then ordinary space is conceived as a 3-hypersurface bounding a n-hypervolume where gravitation takes origin, within a n-hyperspace. The extension of the holographic principle to extra dimensions implies the existence of a minimum distance where test particles may still be considered as distinct from the central body. Below that threshold, it is inferred test particles lose theirs individuality and “glue” to the central body via unification of the four known interactions and, in addition, 1) particles can no longer be conceived as point-like but e.g., strings or membranes, and 2) quantum effects are dominant and matter turns back to a pre-big bang state. A more detailed formulation including noncircular motions within the context of general relativity, together with further knowledge on neutron stars, quark stars and black holes, would provide further insight on the formulation of quantum gravity. 展开更多
关键词 Newtionian Theory of Gravitation Holographic Principle Extra Dimensions
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Atomic Dispersed Hetero‑Pairs for Enhanced Electrocatalytic CO_(2)Reduction
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作者 Zhaoyong Jin Meiqi Yang +13 位作者 Yilong Dong Xingcheng Ma Ying Wang Jiandong Wu Jinchang Fan Dewen Wang Rongshen Xi Xiao Zhao Tianyi Xu Jingxiang Zhao Lei Zhang David J.Singh Weitao Zheng Xiaoqiang Cui 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期55-67,共13页
Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,in... Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,increasing the binding of the*COOH to the active site will generally increase the*CO desorption energy.Breaking this relationship may be expected to dramatically improve the intrinsic activity of CO_(2)RR,but remains an unsolved challenge.Herein,we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier.This system shows an unprecedented CO_(2)RR intrinsic activity with TOF of 3336 h−1,high selectivity toward CO production,Faradaic efficiency of 95.96%at−0.60 V and excellent stability.Theoretical calculations show that the Mo-Fe diatomic sites increased the*COOH intermediate adsorption energy by bridging adsorption of*COOH intermediates.At the same time,d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of*CO intermediates.Thus,the undesirable correlation between these steps is broken.This work provides a promising approach,specifically the use of di-atoms,for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale. 展开更多
关键词 CO_(2)reduction reaction Atomic dispersed catalyst Hetero-diatomic pair Ad-desorption energy Linear scaling relation
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Theoretical Investigation on THz Generation from Optical Rectification with Tilted-Pulse-Front Excitation 被引量:1
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作者 牡海伟 杨楠 《Chinese Physics Letters》 SCIE CAS CSCD 2014年第12期49-51,共3页
The Terahertz (THz) wave is a special electro- magnetic wave with frequency between 0.1 10THz (1 THz=1012 Hz), which has been widely used in spec- troscopy, imaging and remote sensing. There are several THz wave s... The Terahertz (THz) wave is a special electro- magnetic wave with frequency between 0.1 10THz (1 THz=1012 Hz), which has been widely used in spec- troscopy, imaging and remote sensing. There are several THz wave sources based on ultrashort laser pulses, including photoconductor antenna, optical Dember effect, air-plasma and optical rectification. For THz generation from optical rectification, phase- matching condition between pump laser pulses and THz pulses has to be fulfilled to obtain a high con- version efficiency. 展开更多
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Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) perovskite solar cell by surface passivation using iso-butyl ammonium iodide
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作者 Wakul Bumrungsan Kritsada Hongsith +4 位作者 Vasan Yarangsi Pisith Kumnorkeaw Sukrit Sucharitakul Surachet Phaduangdhitidhada Supab Choopun 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第11期1963-1970,共8页
Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of pero... Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of perovskite solar cell devices was fabricated with the structure of FTO/SnO_(2)/Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3)(FTO,i.e.,fluorine doped tin oxide)and IBA/Spiro-OMeTAD/Ag.The effect of different weights of IBA passivated on Cs-doped perovskite solar cells(PSCs)was systematically investigated and compared with non-passivated devices.It was found that the 5-mg IBA-passivated devices exhibited a high power conversion efficiency(PCE)of 15.49%higher than 12.64%of non-IBA-passivated devices.The improvement of photovoltaic parameters of the 5-mg IBA-passivated device can be clearly observed compared to the Cs-doped device.The better performance of the IBA-passivated device can be confirmed by the reduction of PbI_(2) phase in the crystal structure,lower charge recombination rate,lower charge transfer resistance,and improved contact angle of perovskite films.Therefore,IBA passivation on Cs_(0.1)(CH_(3)NH)_(0.9)PbI_(3) is a promising technique to improve the efficiency of Cs-doped perovskite solar cells. 展开更多
关键词 perovskite solar cell power conversion efficiency surface passivation cesium methylammonium lead iodide iso-butyl ammoni-um iodide
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Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy
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作者 W A FAROOQ M ATIF +4 位作者 W TAWFIK M S ALSALHI Z A ALAHMED M SARFRAZ J P SINGH 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第12期1141-1146,共6页
Laser-induced breakdown spectroscopy (LIBS) technique has been applied to inves- tigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrol... Laser-induced breakdown spectroscopy (LIBS) technique has been applied to inves- tigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, C1, Fe, A1, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria. 展开更多
关键词 laser induced breakdown BACTERIA bio-samples and carbon lines
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Prediction of a monolayer spin-spiral semiconductor:CoO with a honeycomb lattice
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作者 张杰 宋姝诺 +3 位作者 张艳芳 张余洋 Sokrates T.Pantelides 杜世萱 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期115-119,共5页
The recent successful fabrication of two-dimensional(2D)CoO with nanometer-thickness motivates us to investigate monolayer CoO due to possible magnetic properties induced by Co atoms.Here,we employ first-principles ca... The recent successful fabrication of two-dimensional(2D)CoO with nanometer-thickness motivates us to investigate monolayer CoO due to possible magnetic properties induced by Co atoms.Here,we employ first-principles calculations to show that monolayer CoO is a 2D spin-spiral semiconductor with a honeycomb lattice.The calculated phonon dispersion reveals the monolayer's dynamical stability.Monolayer CoO exhibits a type-I spin-spiral magnetic ground state.The spinspiral state and the direct bandgap character are both robust under biaxial compressive strain(-5%)to tensile strain(5%).The bandgap varies only slightly under either compressive or tensile strain up to 5%.These results suggest a potential for applications in spintronic devices and offer a new platform to explore magnetism in the 2D limit. 展开更多
关键词 spin-spiral semiconductor type-II multiferroic bandgap engineering monolayer CoO
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Analysis of Freely Swimming C. elegans Using Laser Diffraction
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作者 Jenny Magnes Kathleen M. Raley-Susman +4 位作者 Noureddine Melikechi Alicia Sampson Rebecca Eells Alexandra Bello Michael Lueckheide 《Open Journal of Biophysics》 2012年第3期101-107,共7页
Soil and aquatic multicellular microorganisms play a critical role in the nutrient-cycling and organismal ecology of soil and aquatic ecosystems. These organisms live and behave in a complex three-dimensional environm... Soil and aquatic multicellular microorganisms play a critical role in the nutrient-cycling and organismal ecology of soil and aquatic ecosystems. These organisms live and behave in a complex three-dimensional environment. Most studies of microorganismal behavior, in contrast, have been conducted using microscope-based approaches, which limit the movement and behavior to a narrow, nearly two-dimensional focal field. We report on a novel analytical approach that provides real-time analysis of freely swimming C elegans without dependence on microscope-based equipment. This approach consists of tracking the temporal periodicity of diffraction patterns generated by directing laser light onto nematodes in a cuvette. We measured oscillation frequencies for freely swimming nematodes in cuvettes of different sizes to provide different physical constraints on their swimming. We compared these frequencies with those obtained for nematodes swimming within a small droplet of water on a microscope slide, a strategy used by microscope-based locomotion analysis systems. We collected data from diffraction patterns using two methods: video analysis and real time data acquisition using a fast photodiode. Swimming frequencies of nematodes in a droplet of ionic solution on a microscope slide was confirmed to be 2.00 Hz with a variance of 0.05 Hz for the video analysis method and 0.03 Hz for the real time data acquisition using a photodiode;this result agrees with previously published estimates using microscope-based analytical techniques. We find the swimming frequency of unconstrained worms within larger cuvettes to be 2.37 Hz with a variance of 0.02 Hz. As the cuvette size decreased, so did the oscillation frequency, indicating a change in locomotion when physical constraints are introduced. 展开更多
关键词 DIFFRACTION C. ELEGANS FOURIER Transform FOURIER ANALYSIS MECHANOSENSATION
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