为了保护带电作业人员的安全,计算分析了≥750 k V交流电压等级线路和±660 k V、±800 k V直流线路电位转移过程中的暂态能量,并开展了导电手套放电试验研究。理论和试验研究结果表明,当放电系统能量为1.37 J时,放电电弧的根...为了保护带电作业人员的安全,计算分析了≥750 k V交流电压等级线路和±660 k V、±800 k V直流线路电位转移过程中的暂态能量,并开展了导电手套放电试验研究。理论和试验研究结果表明,当放电系统能量为1.37 J时,放电电弧的根部直接作用在导电手套上,将导电手套烧蚀,对作业人员产生伤害。考虑实际作业安全裕度,在规定的电位转移距离下,≥750 k V交流线路和±660 k V、±800 k V直流线路电位转移的暂态能量>1.0 J时,需使用电位转移棒进行电位转移,确保电位转移人员的安全。展开更多
A shift sampling theory established by author （1997a） is a generalization of Fourier transform computation theory. Based on this theory, I develop an Algorithm-Error （A-E） equation of potential field transformatio...A shift sampling theory established by author （1997a） is a generalization of Fourier transform computation theory. Based on this theory, I develop an Algorithm-Error （A-E） equation of potential field transformations in the wavenumber domain, which not only gives a more flexible algorithm of potential field transformations, but also reveals the law of error of potential field transformations in the wavenumber domain. The DFT0η η（0.5, 0.5） reduction-to-pole （RTP） technique derived from the A-E equation significantly improves the resolution and accuracy of RTP anomalies at low magnetic latitudes, including the magnetic equator. The law （origin, form mechanism, and essential properties） of the edge oscillation revealed by the A-E equation points out theoretically a way of improving the effect of existing padding methods in high-pass transformations in the wavenumber domain.展开更多
Potential Natural Vegetation(PNV)represents the climax of vegetation succession in a natural environment,free from significant disturbances.The reconstruction of PNV is widely used to study climate-vegetation relation...Potential Natural Vegetation(PNV)represents the climax of vegetation succession in a natural environment,free from significant disturbances.The reconstruction of PNV is widely used to study climate-vegetation relationships and predict future vegetation distributions.However,fine-scale PNV maps with high accuracy are still rare in biodiversity hotspots due to the complexity of ecosystems and limited field observations.In this study,we mapped the spatiotemporal distribution of 16 PNV types using adequate field and literature data,and an improved Comprehensive and Sequential Classification System(CSCS)approach under current(2005-2016)and future(2021-2080)climate scenarios in Yunnan province,Southwest China.We found that 1)from T0(2005-2016)to T3(2021-2080),regions with cold alpine PNV types,such as mid-mountain humid evergreen broad-leaved forests(EBLF),are projected to experience more significant temperature increases compared to regions with warm PNV types,like tropic rainforests and monsoon rainforests.High-emission scenarios(SSP585)are expected to result in temperature increases approximately 2°C higher than low-emission scenarios(SSP126).Precipitation is projected to increase for water-deficient PNV types(e.g.,monsoon rainforest and semi-humid EBLF)but decrease for humid PNV types(e.g.,rainforest and mountain mossy EBLF).The SSP370 scenario predicts a slightly smaller increase in precipitation compared to other scenarios.2)All PNV types are expected to shift to higher latitudes(by an average of 0.86°)and higher elevations(by an average of 454 m)by T3,based on their current niches.Alpine PNV types are more sensitive to climate change and are projected to shift more prominently than other types.For example,mountain mossy EBLF is expected to move 1.78°northward,while mid-mountain moist EBLF is projected to rise by 578 m.3)Cold PNV types are likely to be replaced by warm types both in latitude and altitude.Semi-humid EBLF is projected to shrink the most,by 57,984 km2(51.5%of its present range),while monsoon EBLF展开更多
The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,ev...The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,even in regions where the magnetic field B is zero.This effect demonstrates that quantum particles are influenced not only by the fields directly present but also by the potentials associated with those fields.In the AB effect,an electron beam is split into two paths,with one path encircling a solenoid and the other bypassing it.Despite the absence of a magnetic field in the regions traversed by the beams,the vector potential A associated with the magnetic flux Φ through the solenoid induces a phase shift in the electron’s wave function.This phase shift,quantified by △φ=qΦ/hc,manifests as a change in the interference pattern observed in the detection screen.The phenomenon underscores the principle of gauge invariance in QED(quantum electrodynamics),where physical observables remain invariant under local gauge transformations of the vector and scalar potentials.This reinforces the notion that the vector potential A has a profound impact on quantum systems,beyond its classical role.This article outlines the AB effect,including its theoretical framework,experimental observations,and implications.The focus on the role of the vector potential in quantum mechanics provides a comprehensive understanding of this important phenomenon.展开更多
The electromagnetic shift of energy levels of H-atom electrons is determined by calculating an electron coupling to the Gibbons-Hawking ectromagnetic field thermal bath. Energy shift of electrons in H-atom is determin...The electromagnetic shift of energy levels of H-atom electrons is determined by calculating an electron coupling to the Gibbons-Hawking ectromagnetic field thermal bath. Energy shift of electrons in H-atom is determined in the framework of non-relativistic quantum mechanics.展开更多
The relationship between phase shifts produced by two supersymmetric (SUSY) partner potentials has been examined critically. Phase shifts produced by two SUSY partner potentials bear a simple relation irrespective of ...The relationship between phase shifts produced by two supersymmetric (SUSY) partner potentials has been examined critically. Phase shifts produced by two SUSY partner potentials bear a simple relation irrespective of being shape invariant potential (SIP) or not (non-SIP). In general, the phase shift cannot be obtained algebraically, even for standard SIPs except the Coulomb potential.展开更多
A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous author’ viewpoints, the 1,2-shift can be divi...A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous author’ viewpoints, the 1,2-shift can be divided into two categories. 1,2-electron-deficient shift is that the electronic configuration of the atom which accepts the migrating group is a cation or an electron-deficient atom, and 1,2-anion shift is the one that the accepted atom of the migration group is a negative ion. In terms of the experimental facts and the calculation of the potential surfaces, in electron-deficient shift such as Beckmann or Baeyer-Villiger rearrangement, the migration occurs through a transition complex formed between the π-bond and the cation or electron-deficient migrating group, but in anion shift such as Wittig or Stevens rearrangement, the electron pair in π-orbit excites at first to π orbit, and then the migration occurs through the new formed complex between the anion migration group and the vacant π orbit. The above mechanisms explain reasonably the intramolecular properties, the configuration retentions of the migration group, and the corresponding migratory aptitudes of the two type 1, 2-shifts. The partial and less important free radical reaction of 1, 2-anion shift has been explained by the π-complex mechanism too.展开更多
We indicated in our previous work that for QED the role of the scalar potential which appears at the loop level is much smaller than that of the vector potential and is in fact negligible. But the situation is differe...We indicated in our previous work that for QED the role of the scalar potential which appears at the loop level is much smaller than that of the vector potential and is in fact negligible. But the situation is different for QCD, one reason is that the loop effects are more significant because as is much larger than a, and second the non-perturbative QCD effects may induce a sizable scalar potential. In this work, we study phenomenologically the contribution of the scalar potential to the spectra of charmonia, bottomonia and bC（bc） families. Taking into account both vector and scalar potentials, by fitting the well measured charmonia and bottomonia spectra, we re-fix the relevant parameters and test them by calculating other states of not only the eharmonia and bottomonia families, but also the bc family. We also consider the Lamb shift of the spectra.展开更多
文摘为了保护带电作业人员的安全,计算分析了≥750 k V交流电压等级线路和±660 k V、±800 k V直流线路电位转移过程中的暂态能量,并开展了导电手套放电试验研究。理论和试验研究结果表明,当放电系统能量为1.37 J时,放电电弧的根部直接作用在导电手套上,将导电手套烧蚀,对作业人员产生伤害。考虑实际作业安全裕度,在规定的电位转移距离下,≥750 k V交流线路和±660 k V、±800 k V直流线路电位转移的暂态能量>1.0 J时,需使用电位转移棒进行电位转移,确保电位转移人员的安全。
文摘A shift sampling theory established by author （1997a） is a generalization of Fourier transform computation theory. Based on this theory, I develop an Algorithm-Error （A-E） equation of potential field transformations in the wavenumber domain, which not only gives a more flexible algorithm of potential field transformations, but also reveals the law of error of potential field transformations in the wavenumber domain. The DFT0η η（0.5, 0.5） reduction-to-pole （RTP） technique derived from the A-E equation significantly improves the resolution and accuracy of RTP anomalies at low magnetic latitudes, including the magnetic equator. The law （origin, form mechanism, and essential properties） of the edge oscillation revealed by the A-E equation points out theoretically a way of improving the effect of existing padding methods in high-pass transformations in the wavenumber domain.
基金The Major Program for Basic Research Project of Yunnan Province,No.202101B C070002The Second Comprehensive Scientific Expedition of the Qinghai-Tibet Plateau,No.2019QZKK 04020101。
文摘Potential Natural Vegetation(PNV)represents the climax of vegetation succession in a natural environment,free from significant disturbances.The reconstruction of PNV is widely used to study climate-vegetation relationships and predict future vegetation distributions.However,fine-scale PNV maps with high accuracy are still rare in biodiversity hotspots due to the complexity of ecosystems and limited field observations.In this study,we mapped the spatiotemporal distribution of 16 PNV types using adequate field and literature data,and an improved Comprehensive and Sequential Classification System(CSCS)approach under current(2005-2016)and future(2021-2080)climate scenarios in Yunnan province,Southwest China.We found that 1)from T0(2005-2016)to T3(2021-2080),regions with cold alpine PNV types,such as mid-mountain humid evergreen broad-leaved forests(EBLF),are projected to experience more significant temperature increases compared to regions with warm PNV types,like tropic rainforests and monsoon rainforests.High-emission scenarios(SSP585)are expected to result in temperature increases approximately 2°C higher than low-emission scenarios(SSP126).Precipitation is projected to increase for water-deficient PNV types(e.g.,monsoon rainforest and semi-humid EBLF)but decrease for humid PNV types(e.g.,rainforest and mountain mossy EBLF).The SSP370 scenario predicts a slightly smaller increase in precipitation compared to other scenarios.2)All PNV types are expected to shift to higher latitudes(by an average of 0.86°)and higher elevations(by an average of 454 m)by T3,based on their current niches.Alpine PNV types are more sensitive to climate change and are projected to shift more prominently than other types.For example,mountain mossy EBLF is expected to move 1.78°northward,while mid-mountain moist EBLF is projected to rise by 578 m.3)Cold PNV types are likely to be replaced by warm types both in latitude and altitude.Semi-humid EBLF is projected to shrink the most,by 57,984 km2(51.5%of its present range),while monsoon EBLF
文摘The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,even in regions where the magnetic field B is zero.This effect demonstrates that quantum particles are influenced not only by the fields directly present but also by the potentials associated with those fields.In the AB effect,an electron beam is split into two paths,with one path encircling a solenoid and the other bypassing it.Despite the absence of a magnetic field in the regions traversed by the beams,the vector potential A associated with the magnetic flux Φ through the solenoid induces a phase shift in the electron’s wave function.This phase shift,quantified by △φ=qΦ/hc,manifests as a change in the interference pattern observed in the detection screen.The phenomenon underscores the principle of gauge invariance in QED(quantum electrodynamics),where physical observables remain invariant under local gauge transformations of the vector and scalar potentials.This reinforces the notion that the vector potential A has a profound impact on quantum systems,beyond its classical role.This article outlines the AB effect,including its theoretical framework,experimental observations,and implications.The focus on the role of the vector potential in quantum mechanics provides a comprehensive understanding of this important phenomenon.
文摘The electromagnetic shift of energy levels of H-atom electrons is determined by calculating an electron coupling to the Gibbons-Hawking ectromagnetic field thermal bath. Energy shift of electrons in H-atom is determined in the framework of non-relativistic quantum mechanics.
文摘The relationship between phase shifts produced by two supersymmetric (SUSY) partner potentials has been examined critically. Phase shifts produced by two SUSY partner potentials bear a simple relation irrespective of being shape invariant potential (SIP) or not (non-SIP). In general, the phase shift cannot be obtained algebraically, even for standard SIPs except the Coulomb potential.
文摘A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous author’ viewpoints, the 1,2-shift can be divided into two categories. 1,2-electron-deficient shift is that the electronic configuration of the atom which accepts the migrating group is a cation or an electron-deficient atom, and 1,2-anion shift is the one that the accepted atom of the migration group is a negative ion. In terms of the experimental facts and the calculation of the potential surfaces, in electron-deficient shift such as Beckmann or Baeyer-Villiger rearrangement, the migration occurs through a transition complex formed between the π-bond and the cation or electron-deficient migrating group, but in anion shift such as Wittig or Stevens rearrangement, the electron pair in π-orbit excites at first to π orbit, and then the migration occurs through the new formed complex between the anion migration group and the vacant π orbit. The above mechanisms explain reasonably the intramolecular properties, the configuration retentions of the migration group, and the corresponding migratory aptitudes of the two type 1, 2-shifts. The partial and less important free radical reaction of 1, 2-anion shift has been explained by the π-complex mechanism too.
基金Supported by National Natural Science Foundation of China (NSFC) (10775073, 11005079)Special Grant for Ph.D. Program of Ministry of Eduction of P.R. China (20070055037, 20100032120065)
文摘We indicated in our previous work that for QED the role of the scalar potential which appears at the loop level is much smaller than that of the vector potential and is in fact negligible. But the situation is different for QCD, one reason is that the loop effects are more significant because as is much larger than a, and second the non-perturbative QCD effects may induce a sizable scalar potential. In this work, we study phenomenologically the contribution of the scalar potential to the spectra of charmonia, bottomonia and bC（bc） families. Taking into account both vector and scalar potentials, by fitting the well measured charmonia and bottomonia spectra, we re-fix the relevant parameters and test them by calculating other states of not only the eharmonia and bottomonia families, but also the bc family. We also consider the Lamb shift of the spectra.
