The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience depend...The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization (MDO) method "Bi-Level Integrated System Collaborative Optimization (BLISCO)" is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO.展开更多
This paper studies the molecular rotational excitation and field-free spatial alignment in a nonresonant intense laser field numerically and analytically by using the time-dependent SchrSdinger equation. The broad rot...This paper studies the molecular rotational excitation and field-free spatial alignment in a nonresonant intense laser field numerically and analytically by using the time-dependent SchrSdinger equation. The broad rotational wave packets excited by the femtosecond pulse are defined in conjugate angle space, and their coefficients are obtained by solving a set of coupled linear equations. Both single molecule orientation angles and an ensemble of O2 and CO molecule angular distributions are calculated in detail. The numerical results show that, for single molecule highest occupied molecular orbital (HOMO) symmetry σ tends to have a molecular orientation along the laser polarization direction and the permanent dipole moment diminishes the mean of the orientation angles; for an ensemble of molecules, angular distributions provide more complex and additional information at times where there are no revivals in the single molecule plot. In particular, at the revival peak instant, with the increase of temperature of the molecular ensemble, the anisotropic angular distributions with respect to the laser polarization direction of the πg orbital gradually transform to the symmetrical distributions regarding the laser polarization vector and for two HOMO configurations angular distributions of all directions are confined within a smaller angle when the temperature of the molecular ensemble is higher.展开更多
The highest occupied molecular orbital(HOMO) energies of fullerenes are found by quantitative first-principles calculations to be raised by negative charging, and the rising rate rank of the fullerenes is C60 >C7...The highest occupied molecular orbital(HOMO) energies of fullerenes are found by quantitative first-principles calculations to be raised by negative charging, and the rising rate rank of the fullerenes is C60 >C70 >C80 >C90>C100 >C180. Then we compare fullerenes with carbon nanotubes(CNTs) and graphene sheets(GSs) and find that the increase of the HOMO energy of a fullerene is much faster than that of CNTs and graphene sheets with the same number of C atoms. The rising rate rank is fullerene>CNT>GS, which holds no matter what the number of C atoms is or which structure the fullerene isomer is. This work paves a new path for developing all-carbon devices with low-dimensional carbon nanomaterials as different functional elements.展开更多
The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of ...The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of electrides are thus of both scientific and technological significance.Here,we employ first-principles calculations to investigate Mott-insulating Ae_(5)X_(3)(Ae=Ca,Sr,and Ba;X=As and Sb)electrides with Mn_(5)Si_(3)-type structure,in which half-filled interstitial electrons serve as ions and are spin-polarized.The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons,resulting in spin splitting and a separation between occupied and unoccupied states.The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials.Compared with that in intermetallic electrides,the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak,leading to highly localized magnetic centers and pronounced correlation effects.Therefore,the Mott-insulating electrides Ae_(5)X_(3)have very large indirect bandgaps(0.30 eV).In addition,high pressure is found to strengthen the strong correlation effects and enlarge the bandgap.The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.展开更多
I read a story from an interesting book.The story said that once there was a king in Scotland whose name was Robert Bruce.His homeland was occupied by the king of England.He was driven out of his land.He tried six tim...I read a story from an interesting book.The story said that once there was a king in Scotland whose name was Robert Bruce.His homeland was occupied by the king of England.He was driven out of his land.He tried six times to fight back but failed.One rainy day,he was tired and sick.When he lay on the ground and was ready to give up,he saw a spider over his head.Six times the spider tried to throw its thread.展开更多
In a fragmented wartime China(1931—45),the levels of violence,suffering,and resistance varied in|different regions.The Anti-Japanese War left people with different experiences and memories.To date,both Chinese-and En...In a fragmented wartime China(1931—45),the levels of violence,suffering,and resistance varied in|different regions.The Anti-Japanese War left people with different experiences and memories.To date,both Chinese-and English-language scholarship have paid insufficient attention to the more than two hundred million common Chinese who stayed in Japanese-occupied areas.To help fill this gap,this study provides a thematic analysis of interviews conducted by the author with six Chinese women of the urban middle-class about their experiences in the Japanese-occupied areas.It adds voices and perspectives of ordinary,middle-class women to the rich tapestry of everyday life of wartime China.The oral narratives of these women are everyday accounts of uncertainty,fear,and survival.More important,they are testimonies to the evolution of their gender consciousness and their determination to pursue an education as a means of resisting gender inequality.In addition,these oral narratives show how these women developed strategies in their marriages,work,and political views to reconcile with the reality of living with the enemy.Their everyday forms of resistance helped them maintain dignity in the face of foreign imperialism.展开更多
The Book of Zambasta(abbreviated‘Z’)is a long poem in Old Khotanese which has been described as’a veritable Manual of Buddhism’.[1]The best-preserved copy,sometimes referred to as‘Z1’,seems to have formed part o...The Book of Zambasta(abbreviated‘Z’)is a long poem in Old Khotanese which has been described as’a veritable Manual of Buddhism’.[1]The best-preserved copy,sometimes referred to as‘Z1’,seems to have formed part of a manuscript miscellany,in which the 24 chapters of Z occupied folios 143 verso to 440 recto.Of these 298 folios,more than two thirds are still extant in whole or part.In Z1each verse is written on a single line,with six lines to the page.The text is presented in four columns separated by spaces which in principle correspond to the caesurae between the four padas(‘abcd’)of the verse.The verse number is frequently indicated at the end of the line,often in abbreviated form(e.g.‘2’in place of‘52’,or‘52’in place of‘152’).展开更多
The year 2022 is a rough patch for domestic beauty makeups.When major overseas brands have occupied the first echelon of the area list on each major platform,new domestic brands have no confidence to take COVID-19 pan...The year 2022 is a rough patch for domestic beauty makeups.When major overseas brands have occupied the first echelon of the area list on each major platform,new domestic brands have no confidence to take COVID-19 pandemic as a fig leaf for the stagnant sales volume.Some professional managers find pessimistically that Generation Z groups,which new brands take as main clients,should have turned to grand brands without hesitation.A severe fact has been placed before the Chinese beauty makeup market-the marketing method that domestic cosmetics rely on for starting up is no longer a secret key for competition,and it seems very difficult for the weak product power to resist the overwhelming grand brands.展开更多
The China Jinping Underground Laboratory phaseⅡ[1](CJPL-Ⅱ)is the expansion project following the success of CJPL-I.A temporary usage in the year 2020–2021 enabled the Underground Nuclear Astrophysics Experiment in ...The China Jinping Underground Laboratory phaseⅡ[1](CJPL-Ⅱ)is the expansion project following the success of CJPL-I.A temporary usage in the year 2020–2021 enabled the Underground Nuclear Astrophysics Experiment in China(JUNA)phase I experiments presented here.Once commissioned in 2023,CJPL-Ⅱwill occupy a much larger underground space(300000 m^(3)in volume)for conducting experiments and is planned to house CDEX-Ⅱ。展开更多
Significant interest has been focused on graphene materials for their unique properties as Hydrogen storage materials. The development of their abilities by modifying their configuration with doped or decorated transi...Significant interest has been focused on graphene materials for their unique properties as Hydrogen storage materials. The development of their abilities by modifying their configuration with doped or decorated transition metals </span><span style="font-family:Verdana;">was also of great interest. In this work</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> using the DFT/B3LYP/6-31G/LanL2DZ</span><span style="font-family:Verdana;"> level of theory, graphene sheet (GS) as one of the materials of interest was doped with two transition metals, Osmium (Os) and Tungsten (W). Two active sites on the GS were tested (C4 and C16) resulted into adsorbed systems, H2@C4-GS and H2@C16-GS. C16 position showed the largest adsorption energy compared to that at C4. Therefore, C4 was replaced by the two metals and two adsorbed systems were formed</span><span style="font-family:Verdana;">: </span><span style="font-family:Verdana;">H</span><sub><span style="font-family:Verdana;vertical-align:sub;">2</span></sub><span style="font-family:Verdana;">@Os-GS and H2@W-GS. The binding energy of H</span><sub><span style="font-family:Verdana;vertical-align:sub;">2</span></sub><span style="font-family:Verdana;">@Os-GS was found to be greater than that of H2@W-GS.展开更多
The Shipborne acoustic communication system of the submersible Shenhai Yongshi works in vertical, horizontal and slant channels according to the relative positions. For ease of use, an array combined by a vertical-con...The Shipborne acoustic communication system of the submersible Shenhai Yongshi works in vertical, horizontal and slant channels according to the relative positions. For ease of use, an array combined by a vertical-cone directional transducer and a horizontal-toroid one is installed on the mothership. Improved techniques are proposed to combat adverse channel conditions, such as frequency selectivity, non-stationary ship noise, and Doppler effects of the platform’s nonlinear movement. For coherent modulation, a turbo-coded single-carrier scheme is used. In the receiver, the sparse decision-directed Normalized Least-Mean-Square soft equalizer automatically adjusts the tap pattern and weights according to the multipath structure, the two receivers’ asymmetry, the signal’s frequency selectivity and the noise’s spectrum fluctuation. The use of turbo code in turbo equalization significantly suppresses the error floor and decreases the equalizer’s iteration times, which is verified by both the extrinsic information transfer charts and bit-error-rate performance. For noncoherent modulation, a concatenated error correction scheme of nonbinary convolutional code and Hadamard code is adopted to utilize full frequency diversity. Robust and lowcomplexity synchronization techniques in the time and Doppler domains are proposed. Sea trials with the submersible to a maximum depth of over 4500 m show that the shipborne communication system performs robustly during the adverse conditions. From the ten-thousand communication records in the 28 dives in 2017, the failure rate of the coherent frames and that of the noncoherent packets are both below 10%, where both synchronization errors and decoding errors are taken into account.展开更多
As a coprocessor, field-programmable gate array (FPGA) is the hardware computing processor accelerating the computing capacity of coraputers. To efficiently manage the hardware free resources for the placing of task...As a coprocessor, field-programmable gate array (FPGA) is the hardware computing processor accelerating the computing capacity of coraputers. To efficiently manage the hardware free resources for the placing of tasks on FPGA and take full advantage of the partially reconfigurable units, good utilization of chip resources is an important and necessary work. In this paper, a new method is proposed to find the complete set of maximal free resource rectangles based on the cross point of edge lines of running tasks on FPGA area, and the prove process is provided to make sure the correctness of this method.展开更多
Iridium(Ⅲ)complexes with 2−phenylpyridine(ppy)have been demonstrated as a type of promising phosphorescence dopant in emitting layers of organic light emitting diodes(OLEDs).In most iridium(III)complexes,there exist ...Iridium(Ⅲ)complexes with 2−phenylpyridine(ppy)have been demonstrated as a type of promising phosphorescence dopant in emitting layers of organic light emitting diodes(OLEDs).In most iridium(III)complexes,there exist the strong spin−orbit coupling betweenπ−orbitals of cyclometalated ligands and 5d orbitals of the centric iridium.We study a novel iridium(Ⅲ)complex(ppy)2Ir(4−TfmBTZ)with ppy as cyclometalated ligands and 2-(4-trifluoromethyl-2-hydroxylphenyl)benzothiazole(4-TfmBTZ)as an ancillary ligand using the Gaussian 03 program.The geometries,electronic structures and spectroscopic properties of this iridium(Ⅲ)complex are investigated by density functional theory(DFT)and time−dependent density functional theory(TD-DFT).The results show that the spin-orbit coupling occurs not only between ppy and iridium atom but also between 4-TfmBTZ and iridium atom in this complex.The highest occupied molecular orbital is dominantly localized on the Ir atom and 4-TfmBTZ ligand,while the lowest unoccupied molecular orbital on 4-TfmBTZ ligand.The triplet lowest-lying transition is attributed to the Ir-to-4-TfmBTZ charge-transfer(3MLCT)transition while the sub−low-lying transitions are assigned to the 3MLCT transitions of Ir(ppy)2.The nature of the lowest unoccupied orbital changes from ppy−localized to 4-TfmBTZ-localized and reveals that phosphorescent color of Ir(Ⅲ)complex can be controlled by the ancillary ligand and substituent.展开更多
The wolverine, Gulogulo, is an endangered species in China. This is the first report of the overall status of wolverines in China. The geographic distribution and population sizes of wolverines in the Greater Khingan ...The wolverine, Gulogulo, is an endangered species in China. This is the first report of the overall status of wolverines in China. The geographic distribution and population sizes of wolverines in the Greater Khingan and Altai Mountains were surveyed by line transect from1996–2000 and in 2011, respectively. We identified two geographically distinct groups in the Great Khingan Mountains, with a total population size of about 200 individuals throughout the region(approximately80,000 km^2). Wolverines were also confirmed to be present in the Altai Mountains, where about 100 individuals occupied approximately 28,000 km^2 of mountain forest and tundra. Prey depletion and habitat loss, which are correlated with increasing human activities, are the main reasons for wolverine population declines in China.展开更多
I.Introduction Chinese culture,characterized by strong nationality and heredity,is created and shared by Chinese people in the worldwide.Along the coure of human being`s evolution,China plays a role of critical signif...I.Introduction Chinese culture,characterized by strong nationality and heredity,is created and shared by Chinese people in the worldwide.Along the coure of human being`s evolution,China plays a role of critical significance all the time.In the vast extensive territory,our ancestors and countrymen have interpreted wonderful magic of Chinese culture,and make a great contribution to the world.In the long course of history,culture of Central Plains always occupied the dominating position in China,enjoying a cutting edge over minority ethnic groups.Unlike western countries展开更多
At 02:30 am Baghdad time on January 17, the U. S. and allied forces carried out 1000 sorties air and 100 ship-launcnea cruise missile strikes, blasting Iraqi targets to free Kuwait from Iraqi occupation. The attack be...At 02:30 am Baghdad time on January 17, the U. S. and allied forces carried out 1000 sorties air and 100 ship-launcnea cruise missile strikes, blasting Iraqi targets to free Kuwait from Iraqi occupation. The attack began less than 19 hours after the expiration of the UN-mandated deadline. From the following day to the end of the month, the U.S.-led allied air forces continued massive bombing&against targets in Iraq and occupied Kuwait. From展开更多
A shift about 0.3eV to higher binding energy is reported in the valence band and Cls core level of Kx C_(60)(x<0.2).Analysis shows that the result could not be interpreted by a mixture of C_(60) and K3 C_(60).A dul...A shift about 0.3eV to higher binding energy is reported in the valence band and Cls core level of Kx C_(60)(x<0.2).Analysis shows that the result could not be interpreted by a mixture of C_(60) and K3 C_(60).A dulite K-doped phase and fermi level pinning near the lowest unoccupied molecular orbital derived band caused by K-doping are proposed.展开更多
The electronic structures of small aluminum clusters,Al_(n)(n=5-24),are investigated by a localized-orbital theory based on the tight-binding approximation.Magic-numbered clusters each exhibit a HOMO-LUMO gap maximum,...The electronic structures of small aluminum clusters,Al_(n)(n=5-24),are investigated by a localized-orbital theory based on the tight-binding approximation.Magic-numbered clusters each exhibit a HOMO-LUMO gap maximum,and simultaneously an s-p gap minimum,but not necessarily an ionization potential maximum,where HOMO-LUMO gap denotes the energy gap between the highest occupied orbital and the lowest unoccupied orbital of the cluster.Also revealed is an irregular odd-even alternation in HOMO-LUMO gaps for Al_(n)(n=7-24).Cluster geometry either contributes to or dominates these findings.展开更多
For submonolayer amounts of C_(60)condensed on Sn substrate,the peaks derived from top two occupied molecular orbitals were broadened by 0.3eV in comparison with solid C_(60).For coverageθ<1 monolayer,the broadeni...For submonolayer amounts of C_(60)condensed on Sn substrate,the peaks derived from top two occupied molecular orbitals were broadened by 0.3eV in comparison with solid C_(60).For coverageθ<1 monolayer,the broadenings are independent of the coverage.It indicates that the delocalizations of electrons in valence bands of C_(60)are weak and the widths do not reflect the true band dispersions.展开更多
Thermally activated delayed fluorescence(TADF)emitter is a promising organic light-emitting diode(OLED)material due to low cost,wide luminous color gamut and 100%exciton utilization efficiency[1].To achieve high TADF ...Thermally activated delayed fluorescence(TADF)emitter is a promising organic light-emitting diode(OLED)material due to low cost,wide luminous color gamut and 100%exciton utilization efficiency[1].To achieve high TADF performance,a feasible strategy is to construct a twisted donor–acceptor(D–A)unit,decreasing the overlap between the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO),and minimizing the energy gap(∆E_(ST))between the lowest singlet(S_(1))and triplet(T_(1))states[2,3].However,this long-range charge transfer feature is often disadvantageous for achieving high oscillator strengths(f)and radiative transition rates(k_(r))[4](Fig.1(a)).展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.51109132)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110073120015)
文摘The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization (MDO) method "Bi-Level Integrated System Collaborative Optimization (BLISCO)" is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO.
基金supported by the Program of Excellent Team in Harbin Institute of Technologythe Program for New Century Excellent Talents in University (NCET)National Natural Science Foundation of China (Grant Nos 10774033,60878018 and 10674036)
文摘This paper studies the molecular rotational excitation and field-free spatial alignment in a nonresonant intense laser field numerically and analytically by using the time-dependent SchrSdinger equation. The broad rotational wave packets excited by the femtosecond pulse are defined in conjugate angle space, and their coefficients are obtained by solving a set of coupled linear equations. Both single molecule orientation angles and an ensemble of O2 and CO molecule angular distributions are calculated in detail. The numerical results show that, for single molecule highest occupied molecular orbital (HOMO) symmetry σ tends to have a molecular orientation along the laser polarization direction and the permanent dipole moment diminishes the mean of the orientation angles; for an ensemble of molecules, angular distributions provide more complex and additional information at times where there are no revivals in the single molecule plot. In particular, at the revival peak instant, with the increase of temperature of the molecular ensemble, the anisotropic angular distributions with respect to the laser polarization direction of the πg orbital gradually transform to the symmetrical distributions regarding the laser polarization vector and for two HOMO configurations angular distributions of all directions are confined within a smaller angle when the temperature of the molecular ensemble is higher.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11374174,51390471,51527803,and 51701143the National Basic Research Program of China under Grant No 2015CB654902+4 种基金the National Key Research and Development Program under Grant No 2016YFB0700402the Foundation for the Author of National Excellent Doctoral Dissertation under Grant No 201141the National Program for Thousand Young Talents of China,the Tianjin Municipal Education Commissionthe Tianjin Municipal Science and Technology Commissionthe Fundamental Research Fund of Tianjin University of Technology
文摘The highest occupied molecular orbital(HOMO) energies of fullerenes are found by quantitative first-principles calculations to be raised by negative charging, and the rising rate rank of the fullerenes is C60 >C70 >C80 >C90>C100 >C180. Then we compare fullerenes with carbon nanotubes(CNTs) and graphene sheets(GSs) and find that the increase of the HOMO energy of a fullerene is much faster than that of CNTs and graphene sheets with the same number of C atoms. The rising rate rank is fullerene>CNT>GS, which holds no matter what the number of C atoms is or which structure the fullerene isomer is. This work paves a new path for developing all-carbon devices with low-dimensional carbon nanomaterials as different functional elements.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.12204419 and 12074013)。
文摘The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of electrides are thus of both scientific and technological significance.Here,we employ first-principles calculations to investigate Mott-insulating Ae_(5)X_(3)(Ae=Ca,Sr,and Ba;X=As and Sb)electrides with Mn_(5)Si_(3)-type structure,in which half-filled interstitial electrons serve as ions and are spin-polarized.The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons,resulting in spin splitting and a separation between occupied and unoccupied states.The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials.Compared with that in intermetallic electrides,the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak,leading to highly localized magnetic centers and pronounced correlation effects.Therefore,the Mott-insulating electrides Ae_(5)X_(3)have very large indirect bandgaps(0.30 eV).In addition,high pressure is found to strengthen the strong correlation effects and enlarge the bandgap.The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.
文摘I read a story from an interesting book.The story said that once there was a king in Scotland whose name was Robert Bruce.His homeland was occupied by the king of England.He was driven out of his land.He tried six times to fight back but failed.One rainy day,he was tired and sick.When he lay on the ground and was ready to give up,he saw a spider over his head.Six times the spider tried to throw its thread.
文摘In a fragmented wartime China(1931—45),the levels of violence,suffering,and resistance varied in|different regions.The Anti-Japanese War left people with different experiences and memories.To date,both Chinese-and English-language scholarship have paid insufficient attention to the more than two hundred million common Chinese who stayed in Japanese-occupied areas.To help fill this gap,this study provides a thematic analysis of interviews conducted by the author with six Chinese women of the urban middle-class about their experiences in the Japanese-occupied areas.It adds voices and perspectives of ordinary,middle-class women to the rich tapestry of everyday life of wartime China.The oral narratives of these women are everyday accounts of uncertainty,fear,and survival.More important,they are testimonies to the evolution of their gender consciousness and their determination to pursue an education as a means of resisting gender inequality.In addition,these oral narratives show how these women developed strategies in their marriages,work,and political views to reconcile with the reality of living with the enemy.Their everyday forms of resistance helped them maintain dignity in the face of foreign imperialism.
文摘The Book of Zambasta(abbreviated‘Z’)is a long poem in Old Khotanese which has been described as’a veritable Manual of Buddhism’.[1]The best-preserved copy,sometimes referred to as‘Z1’,seems to have formed part of a manuscript miscellany,in which the 24 chapters of Z occupied folios 143 verso to 440 recto.Of these 298 folios,more than two thirds are still extant in whole or part.In Z1each verse is written on a single line,with six lines to the page.The text is presented in four columns separated by spaces which in principle correspond to the caesurae between the four padas(‘abcd’)of the verse.The verse number is frequently indicated at the end of the line,often in abbreviated form(e.g.‘2’in place of‘52’,or‘52’in place of‘152’).
文摘The year 2022 is a rough patch for domestic beauty makeups.When major overseas brands have occupied the first echelon of the area list on each major platform,new domestic brands have no confidence to take COVID-19 pandemic as a fig leaf for the stagnant sales volume.Some professional managers find pessimistically that Generation Z groups,which new brands take as main clients,should have turned to grand brands without hesitation.A severe fact has been placed before the Chinese beauty makeup market-the marketing method that domestic cosmetics rely on for starting up is no longer a secret key for competition,and it seems very difficult for the weak product power to resist the overwhelming grand brands.
基金the National Natural Science Foundation of China(Grant No.11490560)the CNNC innovation fundthe CAS instrument fund。
文摘The China Jinping Underground Laboratory phaseⅡ[1](CJPL-Ⅱ)is the expansion project following the success of CJPL-I.A temporary usage in the year 2020–2021 enabled the Underground Nuclear Astrophysics Experiment in China(JUNA)phase I experiments presented here.Once commissioned in 2023,CJPL-Ⅱwill occupy a much larger underground space(300000 m^(3)in volume)for conducting experiments and is planned to house CDEX-Ⅱ。
文摘Significant interest has been focused on graphene materials for their unique properties as Hydrogen storage materials. The development of their abilities by modifying their configuration with doped or decorated transition metals </span><span style="font-family:Verdana;">was also of great interest. In this work</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> using the DFT/B3LYP/6-31G/LanL2DZ</span><span style="font-family:Verdana;"> level of theory, graphene sheet (GS) as one of the materials of interest was doped with two transition metals, Osmium (Os) and Tungsten (W). Two active sites on the GS were tested (C4 and C16) resulted into adsorbed systems, H2@C4-GS and H2@C16-GS. C16 position showed the largest adsorption energy compared to that at C4. Therefore, C4 was replaced by the two metals and two adsorbed systems were formed</span><span style="font-family:Verdana;">: </span><span style="font-family:Verdana;">H</span><sub><span style="font-family:Verdana;vertical-align:sub;">2</span></sub><span style="font-family:Verdana;">@Os-GS and H2@W-GS. The binding energy of H</span><sub><span style="font-family:Verdana;vertical-align:sub;">2</span></sub><span style="font-family:Verdana;">@Os-GS was found to be greater than that of H2@W-GS.
基金financially supported by the National Natural Science Foundation of China(Grant No.61471351)the National Key Research and Development Program of China(Grant Nos.2016YFC0300300 and 2016YFC0300605)the National High Technology Research and Development Program of China(863 Program,Grant No.2009AA093301)
文摘The Shipborne acoustic communication system of the submersible Shenhai Yongshi works in vertical, horizontal and slant channels according to the relative positions. For ease of use, an array combined by a vertical-cone directional transducer and a horizontal-toroid one is installed on the mothership. Improved techniques are proposed to combat adverse channel conditions, such as frequency selectivity, non-stationary ship noise, and Doppler effects of the platform’s nonlinear movement. For coherent modulation, a turbo-coded single-carrier scheme is used. In the receiver, the sparse decision-directed Normalized Least-Mean-Square soft equalizer automatically adjusts the tap pattern and weights according to the multipath structure, the two receivers’ asymmetry, the signal’s frequency selectivity and the noise’s spectrum fluctuation. The use of turbo code in turbo equalization significantly suppresses the error floor and decreases the equalizer’s iteration times, which is verified by both the extrinsic information transfer charts and bit-error-rate performance. For noncoherent modulation, a concatenated error correction scheme of nonbinary convolutional code and Hadamard code is adopted to utilize full frequency diversity. Robust and lowcomplexity synchronization techniques in the time and Doppler domains are proposed. Sea trials with the submersible to a maximum depth of over 4500 m show that the shipborne communication system performs robustly during the adverse conditions. From the ten-thousand communication records in the 28 dives in 2017, the failure rate of the coherent frames and that of the noncoherent packets are both below 10%, where both synchronization errors and decoding errors are taken into account.
基金Project supported by the Shanghai Leading Academic Discipline Project(Grant No.J50103)the Natural Science Foundation of Jiangxi Province(Grant No.2010GZS0031)the Science Technology Project of Jiangxi Province(Grant No.2010BGB00604)
文摘As a coprocessor, field-programmable gate array (FPGA) is the hardware computing processor accelerating the computing capacity of coraputers. To efficiently manage the hardware free resources for the placing of tasks on FPGA and take full advantage of the partially reconfigurable units, good utilization of chip resources is an important and necessary work. In this paper, a new method is proposed to find the complete set of maximal free resource rectangles based on the cross point of edge lines of running tasks on FPGA area, and the prove process is provided to make sure the correctness of this method.
基金by the National Natural Scientific Foundation of China under Grant Nos 60976018 and 21071108Key Program of Science and Technology of Ministry of Education(207015)+1 种基金Program for Changjiang Scholar and Innovative Research Team in University(IRT0972)Shanxi Natural Scientific Foundation(2008011008).
文摘Iridium(Ⅲ)complexes with 2−phenylpyridine(ppy)have been demonstrated as a type of promising phosphorescence dopant in emitting layers of organic light emitting diodes(OLEDs).In most iridium(III)complexes,there exist the strong spin−orbit coupling betweenπ−orbitals of cyclometalated ligands and 5d orbitals of the centric iridium.We study a novel iridium(Ⅲ)complex(ppy)2Ir(4−TfmBTZ)with ppy as cyclometalated ligands and 2-(4-trifluoromethyl-2-hydroxylphenyl)benzothiazole(4-TfmBTZ)as an ancillary ligand using the Gaussian 03 program.The geometries,electronic structures and spectroscopic properties of this iridium(Ⅲ)complex are investigated by density functional theory(DFT)and time−dependent density functional theory(TD-DFT).The results show that the spin-orbit coupling occurs not only between ppy and iridium atom but also between 4-TfmBTZ and iridium atom in this complex.The highest occupied molecular orbital is dominantly localized on the Ir atom and 4-TfmBTZ ligand,while the lowest unoccupied molecular orbital on 4-TfmBTZ ligand.The triplet lowest-lying transition is attributed to the Ir-to-4-TfmBTZ charge-transfer(3MLCT)transition while the sub−low-lying transitions are assigned to the 3MLCT transitions of Ir(ppy)2.The nature of the lowest unoccupied orbital changes from ppy−localized to 4-TfmBTZ-localized and reveals that phosphorescent color of Ir(Ⅲ)complex can be controlled by the ancillary ligand and substituent.
基金supported by the Rare and Endangered Species Investigation and Monitoring Project of the State Forestry Administration(41309408)the Heilongjiang Academy of Sciences Fund
文摘The wolverine, Gulogulo, is an endangered species in China. This is the first report of the overall status of wolverines in China. The geographic distribution and population sizes of wolverines in the Greater Khingan and Altai Mountains were surveyed by line transect from1996–2000 and in 2011, respectively. We identified two geographically distinct groups in the Great Khingan Mountains, with a total population size of about 200 individuals throughout the region(approximately80,000 km^2). Wolverines were also confirmed to be present in the Altai Mountains, where about 100 individuals occupied approximately 28,000 km^2 of mountain forest and tundra. Prey depletion and habitat loss, which are correlated with increasing human activities, are the main reasons for wolverine population declines in China.
文摘I.Introduction Chinese culture,characterized by strong nationality and heredity,is created and shared by Chinese people in the worldwide.Along the coure of human being`s evolution,China plays a role of critical significance all the time.In the vast extensive territory,our ancestors and countrymen have interpreted wonderful magic of Chinese culture,and make a great contribution to the world.In the long course of history,culture of Central Plains always occupied the dominating position in China,enjoying a cutting edge over minority ethnic groups.Unlike western countries
文摘At 02:30 am Baghdad time on January 17, the U. S. and allied forces carried out 1000 sorties air and 100 ship-launcnea cruise missile strikes, blasting Iraqi targets to free Kuwait from Iraqi occupation. The attack began less than 19 hours after the expiration of the UN-mandated deadline. From the following day to the end of the month, the U.S.-led allied air forces continued massive bombing&against targets in Iraq and occupied Kuwait. From
基金Supported in Part by the National Natural Science Foundation of China with Grant No.191174003。
文摘A shift about 0.3eV to higher binding energy is reported in the valence band and Cls core level of Kx C_(60)(x<0.2).Analysis shows that the result could not be interpreted by a mixture of C_(60) and K3 C_(60).A dulite K-doped phase and fermi level pinning near the lowest unoccupied molecular orbital derived band caused by K-doping are proposed.
基金Supported by the National Natural Science Foundation of China under Grants Nos.19574059 and 19634030.
文摘The electronic structures of small aluminum clusters,Al_(n)(n=5-24),are investigated by a localized-orbital theory based on the tight-binding approximation.Magic-numbered clusters each exhibit a HOMO-LUMO gap maximum,and simultaneously an s-p gap minimum,but not necessarily an ionization potential maximum,where HOMO-LUMO gap denotes the energy gap between the highest occupied orbital and the lowest unoccupied orbital of the cluster.Also revealed is an irregular odd-even alternation in HOMO-LUMO gaps for Al_(n)(n=7-24).Cluster geometry either contributes to or dominates these findings.
基金Supported by the National Natural Science Foundation of China No.19174003One of authors,Xun Kun,is also indebted to Shandong Province for support through Grant No.90A1111.
文摘For submonolayer amounts of C_(60)condensed on Sn substrate,the peaks derived from top two occupied molecular orbitals were broadened by 0.3eV in comparison with solid C_(60).For coverageθ<1 monolayer,the broadenings are independent of the coverage.It indicates that the delocalizations of electrons in valence bands of C_(60)are weak and the widths do not reflect the true band dispersions.
基金This work was supported by the National Natural Science Foundation of China(21975119)L.Ding thanks the open research fund of Songshan Lake Materials Laboratory(2021SLABFK02)the National Natural Science Foundation of China(51922032 and 21961160720).
文摘Thermally activated delayed fluorescence(TADF)emitter is a promising organic light-emitting diode(OLED)material due to low cost,wide luminous color gamut and 100%exciton utilization efficiency[1].To achieve high TADF performance,a feasible strategy is to construct a twisted donor–acceptor(D–A)unit,decreasing the overlap between the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO),and minimizing the energy gap(∆E_(ST))between the lowest singlet(S_(1))and triplet(T_(1))states[2,3].However,this long-range charge transfer feature is often disadvantageous for achieving high oscillator strengths(f)and radiative transition rates(k_(r))[4](Fig.1(a)).