Field dependence/independence in Language Acquisition are discussed by many language learners.In this article,we will mainly focus on talking about the cognitive style,including the concept of Field-dependence/indepen...Field dependence/independence in Language Acquisition are discussed by many language learners.In this article,we will mainly focus on talking about the cognitive style,including the concept of Field-dependence/independence,their character istics and differences and functions in language acquisition.展开更多
In this paper, we give the algebraic independence measures for the values ofMahler type functions in complex number field and p-adic number field, respectively.
Ralph Waldo Emerson 's essay Self-reliance is one of the major writings that helped carve the ethnic American individualism and form the intellectual basis of today's writers.Self-reliant individuals are so cl...Ralph Waldo Emerson 's essay Self-reliance is one of the major writings that helped carve the ethnic American individualism and form the intellectual basis of today's writers.Self-reliant individuals are so closely associated with the society that people involved in it must learn how to deal with the relationship with it.Total independence is an illusion,an illusion which blinds us to the realities and the deficiencies of our dependencies and the dependencies of others upon us.展开更多
The phase field method for fracture integrates the Griffith theory and damage mechanics approach to predict crack initiation and propagation within one framework.It replaced the discrete representation of crack by dif...The phase field method for fracture integrates the Griffith theory and damage mechanics approach to predict crack initiation and propagation within one framework.It replaced the discrete representation of crack by diffusive damage and solved it based on a minimization of the global energy storage functional.As a result,no crack tracking topology is needed,and complex crack shapes can be captures without user intervention.However,it is also reported to have an inconsistency between the predicted fracture toughness and the material strength.Recently,a novel energetic degradation function was proposed in literature to handle this issue.This research does some further modifications to the global energy storage functional so that Newton's method can be directly used to solve the energy minimization.With the new energy form,direct implementation of the length-scale independent phase field method into finite element packages like LS-DYNA becomes possible.This paper presents the framework and details of implementing the length-scale independent phase field method into LS-DYNA through a user-defined element and material subroutine.Several numerical examples are presented to compare with the experiment crack shape.Most importantly,this paper is one of the first ones to quantitatively predict accurate force response compared to experiments.These examples verify the accuracy of the new energy form and implementation.展开更多
Taking into account the interaction of an electron with both bulk longitudinaloptical (LO) and interfaceoptical(IO) phonons, we investigate the magnetic field and temperature dependence of the properties of a magnetop...Taking into account the interaction of an electron with both bulk longitudinaloptical (LO) and interfaceoptical(IO) phonons, we investigate the magnetic field and temperature dependence of the properties of a magnetopolaron at the interface of polarpolar crystals in an external magnetic field by using the generalized Haga perturbation method. The results reveal that as the magnetic field B is lower than critical strengths BCL and BCI, the selftrapping of the interface magnetopolaron weakens with increasing temperature, but it strengthens with the rising temperature when B is higher than BCL and BCI. The effect of temperature becomes striking while B is close to BCL or BCI. The results also show that the farther from the interface the electron, the more markedly the electronLO phonon interction changes with the variation of temperature. On the other hand, the nearer from the interface the electron, the more distinctly the electronIO phonon interaction changes with varying temperature.展开更多
This paper reports that the blend films of poly （2-methoxy-5-（2＇-ethyl-hexyloxy）-p-phenylene vinylene） （MEH-PPV） and N,N＇-bis（1-ethylpropyl）-3,4： 9,10-perylene bis （tetracarboxyl diimide） （EP-PDI） with ...This paper reports that the blend films of poly （2-methoxy-5-（2＇-ethyl-hexyloxy）-p-phenylene vinylene） （MEH-PPV） and N,N＇-bis（1-ethylpropyl）-3,4： 9,10-perylene bis （tetracarboxyl diimide） （EP-PDI） with the weight ratio of 1：2.5 have been prepared by spin-coating from chloroform （CF） and chlorobenzene （CB） solutions respectively. The absorption spectra and the morphology of the blend films show that large crystal-like EP-PDI aggregates are formed in film prepared from CB solution, which corresponds to a new absorption shoulder near 590 nm, while there is no shoulder around 590 nm in the UV-Vis absorption spectra of the blend film from CF solution. The electric-field dependence spectra of the photocurrent generation quantum yield of the film from CB solution shows that at weak electric field the EP-PDI aggregates act as more efficient sensitizers, but at strong electric field the quantum yields become almost invariable over the entire spectral range no matter what the state of EP-PDI, monomer or aggregate. At strong electric field, the photocurrent generation yields of both films from CF and CB solution saturate and their yield spectra become spectrally similar, mentioning that at strong electric field the photoexcitons dissociate efficiently and the free charges are collected by the electrodes almost completely.展开更多
We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of ...We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of local density approximation complemented by self-interaction correction. It is found that photoelectron emission in one photon regime could be considered as a probing tool for the main character of different types of molecular orbitals （σ or π）. The pattern of emitted photoelectrons strongly depends on the polarized angle of the laser, for σ orbital, the number of photoelectron decreases with increasing the polarized angle, while for π orbital, it has the inverse relation to the polarized angle, which reveals the multi-electron effect in molecules. On the other hand, concerning the total photoelectron emission, one should take into account a few occupied orbitals instead of only the outmost one.展开更多
With the aim of understanding the relationships between organic small molecule field-effect transistors （FETs） and organic conjugated polymer FETs, we investigate the thickness dependence of surface morphology and c...With the aim of understanding the relationships between organic small molecule field-effect transistors （FETs） and organic conjugated polymer FETs, we investigate the thickness dependence of surface morphology and charge carrier mobility in pentacene and regioregular poly （3-hexylthiophene） （RR-P3HT） field-effect transistors. On the basis of the results of surface morphologies and electrical properties, we presume that the charge carrier mobility is largely related to the morphology of the organic active layer. We observe that the change trends of the surface morphologies （average size and average roughness） of pentacene and RR-P3HT thin films are mutually opposite, as the thickness of the organic layer increases. Further, we demonstrate that the change trends of the field-effect mobilities of pentacene and RR-P3HT FETs are also opposite to each other, as the thickness of the organic layer increases within its limit.展开更多
In some organic materials, varying the finite distance between adjacent carrier traps modifies the Coulomb potential around each trap, resulting in a more complex field-dependence of mobility, differing from （but not...In some organic materials, varying the finite distance between adjacent carrier traps modifies the Coulomb potential around each trap, resulting in a more complex field-dependence of mobility, differing from （but not incompatible with） the usually considered relationship of ln μ∝√E ,a relationship which has been successfully explained by the Poole-Frenkel effect. To investigate the influence of the adjacency of traps, a model system is proposed, which consists of two traps separated by distance α. Our numerical calculation shows that with increasing α, the dependence of mobility on the electric field changes from linear to exponential. Moreover, beyond a certain large α, i.e., as the distance to the nearest trap approaches infinity, the proposed model is essentially the same as the Poole-Frenkel effect. The proposed model accounts for the effect of the energy barrier shape, especially the effect of the location of the potential-energy maximum, a phenomenon which is not accommodated in the Poole-Frenkel model. Because the model assumes the Coulomb interaction between the adjacent traps, it applies to those charged traps which may exist in organic materials for various reasons.展开更多
To understand the anisotropy dependence of the damage evolution and material removal during the machining process of MgF_(2) single crystals,nanoscratch tests of MgF_(2) single crystals with different crystal planes a...To understand the anisotropy dependence of the damage evolution and material removal during the machining process of MgF_(2) single crystals,nanoscratch tests of MgF_(2) single crystals with different crystal planes and directions were systematically performed,and surface morphologies of the scratched grooves under different conditions were analyzed.The experimental results indicated that anisotropy considerably affected the damage evolution in the machining process of MgF_(2) single crystals.A stress field model induced by the scratch was developed by considering the anisotropy,which indicated that during the loading process,median cracks induced by the tensile stress initiated and propagated at the front of the indenter.Lateral cracks induced by tensile stress initiated and propagated on the subsurface during the unloading process.In addition,surface radial cracks induced by the tensile stress were easily generated during the unloading process.The stress change led to the deflection of the propagation direction of lateral cracks.Therefore,the lateral cracks propagated to the workpiece surface,resulting in brittle removal in the form of chunk chips.The plastic deformation parameter indicated that the more the slip systems were activated,the more easily the plastic deformation occurred.The cleavage fracture parameter indicated that the cracks propagated along the activated cleavage planes,and the brittle chunk removal was owing to the subsurface cleavage cracks propagating to the crystal surface.Under the same processing parameters,the scratch of the(001)crystal plane along the[100]crystal-orientation was found to be the most conducive to achieving plastic machining of MgF_(2) single crystals.The theoretical results agreed well with the experimental results,which will not only enhance the understanding of the anisotropy dependence of the damage evolution and removal process during the machining of MgF_(2) crystals,but also provide a theoretical foundation for achieving the high-efficiency and low-damage processing of anisotropic single crystals.展开更多
In this paper, we investigate the temperature and drain bias dependency of single event transient （SET） in 25-nm fin field-effect-transistor （FinFET） technology in a temperature range of 0-135 ℃ and supply voltag...In this paper, we investigate the temperature and drain bias dependency of single event transient （SET） in 25-nm fin field-effect-transistor （FinFET） technology in a temperature range of 0-135 ℃ and supply voltage range of 0.4 V- 1.6 V. Technology computer-aided design （TCAD） three-dimensional simulation results show that the drain current pulse duration increases from 0.6 ns to 3.4 ns when the temperature increases from 0 to 135 ℃. The charge collected increases from 45.5 ℃ to 436.9 fC and the voltage pulse width decreases from 0.54 ns to 0.18 ns when supply voltage increases from 0.4 V to 1.6 V. Furthermore, simulation results and the mechanism of temperature and bias dependency are discussed.展开更多
We sought to investigate the underlying mechanism of action of the long noncoding RNA （IncRNA） LOC283070 in the development of androgen independence in prostate cancer. The interactions between LOC283070 and target ...We sought to investigate the underlying mechanism of action of the long noncoding RNA （IncRNA） LOC283070 in the development of androgen independence in prostate cancer. The interactions between LOC283070 and target proteins were investigated by RNA pull-down and RNA-binding protein immunoprecipitation （RIP） assays. Subceilular fractionation and quantitative reverse transcription-polymerase chain reaction （qRT-PCR） were used to detect the subcellular localization of LOC283070. Western blotting was performed to detect the expression of prohibitin 2 （PHB2）. Luciferase activity assays were performed to evaluate the effects of LOC283070 and PHB2 on the androgen receptor （AR） signaling pathway. A methyl thiazolyl tetrazolium （MTT） assay and a growth curve assay were used to test cell viability. Flow cytometry was performed to analyze cell cycles. A transwell assay was employed to test cell migration. We identified PHB2 as an interaction partner of LOC283070 in the pull-down and RIP experiments. Furthermore, we confirmed that the enrichment of L0C283070 with PHB2 in androgen-independent LNCaP （LNCaP-AI） cells was much greater than that in LNCaP cells. Moreover, the expression of PHB2 was not significantly different between the two cell lines, and the expression of LOC283070 in the nuclei of the LNCaP-AI cells was significantly greater than that in the LNCaP cells. In vitro data revealed that PHB2 overexpression significantly inhibited AR activity and cell proliferation and migration and induced accumulation of prostate cancer cells in GO/G1 phase. Moreover, the overexpression of LOC283070 fully abrogated the effects of PHB2 overexpression. In conclusion, we found that LOC283070 can bind to PHB2 located in the nucleus and inhibit its effect, and this is one of the mechanisms by which LOC283070 is involved in the transition of LNCaP cells into androgen-independent cells.展开更多
Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green an...Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green and red emissions, respectively. In sharp contrast, two kinds of CPDs prepared via a hydrothermal process from citric acid(CA) and diethylenetriamine(DETA) exhibit obvious excitation-wavelength dependent emissions. Through the characterization and comparison of the two types of CPDs, it is concretely revealed that the polymer structure types during the formation of CPDs can effectively control the fluorescence excitation-wavelength independence/dependence. The homogeneous polymer structures contained in CPDs contribute to excitation-wavelength independence, whereas random copolymer structures contribute to excitation-wavelength dependence. These studies are of great significance for further understanding the polymer structures and designing unique optical properties of CPDs.展开更多
To construct pulsed high magnet, with rapid adjustments to large changes in the field strength, it is a mandatory acces-sory to development a special NMR probes to provide a precise real-time map of the magnetic field...To construct pulsed high magnet, with rapid adjustments to large changes in the field strength, it is a mandatory acces-sory to development a special NMR probes to provide a precise real-time map of the magnetic field. In order to do so, it is necessary to understand the variations of the spin transition and susceptibility of NMR samples in a time dependent longitudinal field. This work analyzes the effect on the spin transition by a time dependent longitudinal field. For a 1/2 spin system, we have derived a simple formula for the prediction of the probabilities of occupation of the 1/2 and ?1/2 states in a non-static field. We also calculate the magnetic susceptibility of the water and give an analysis of the effect on the magnetic susceptibility in a time dependent longitudinal field and RF frequency.展开更多
The world today is in a period of great development and integration of economy,information,and technology,especially the high-tech industries represented by big data,cloud computing,and artificial intelligence.It is p...The world today is in a period of great development and integration of economy,information,and technology,especially the high-tech industries represented by big data,cloud computing,and artificial intelligence.It is promoting the rapid increase of human productivity and leading the changes in various industries.Enterprises are facing more and more uncertain external environments.The previous organizational strategy,personnel structure,and operating strategies have been unable to adapt to the turbulent external environment,and innovation has become the norm.Therefore,how to find an innovative breakthrough point on the original strategic road on which to survive has become a matter of life and death.From the perspective of path dependence theory,this paper analyzes the characteristics of path dependence and transcendence path dependence during the adjustment of corporate strategy,and analyzes the internal causes and mechanisms of its generation with the help of the PEST model.Based on this,the negative impact of path dependence on the adjustment of the strategy was found.Furthermore,it was found above that the degree of transcendence path dependence in corporate strategic adjustment is determined by two factors:its ability to drive independent innovation in a dynamic environment and its ability to transform strategically.Finally,according to the research conclusions,it proposes countermeasures to overcome the path dependence of enterprises when adjusting their strategies,and provides suggestions for companies to find breakthrough points in disruptive innovation.展开更多
The world today is in a period of great development and integration of economy,information,and technology,especially the high-tech industries represented by big data,cloud computing,and artificial intelligence.It is p...The world today is in a period of great development and integration of economy,information,and technology,especially the high-tech industries represented by big data,cloud computing,and artificial intelligence.It is promoting the rapid increase of human productivity and leading the changes in various industries.Enterprises are facing more and more uncertain external environments.The previous organizational strategy,personnel structure,and operating strategies have been unable to adapt to the turbulent external environment,and innovation has become the norm.Therefore,how to find an innovative breakthrough point on the original strategic road on which to survive has become a matter of life and death.From the perspective of path dependence theory,this paper analyzes the characteristics of path dependence and transcendence path dependence during the adjustment of corporate strategy,and analyzes the internal causes and mechanisms of its generation with the help of the PEST model.Based on this,the negative impact of path dependence on the adjustment of the strategy was found.Furthermore,it was found above that the degree of transcendence path dependence in corporate strategic adjustment is determined by two factors:its ability to drive independent innovation in a dynamic environment and its ability to transform strategically.Finally,according to the research conclusions,it proposes countermeasures to overcome the path dependence of enterprises when adjusting their strategies,and provides suggestions for companies to find breakthrough points in disruptive innovation.展开更多
A model containing two two-level atoms and a single-mode cavity is considered, and the effect of the time-dependent atom-field couplings on entanglement between the two atoms is studied. The results indicate that both...A model containing two two-level atoms and a single-mode cavity is considered, and the effect of the time-dependent atom-field couplings on entanglement between the two atoms is studied. The results indicate that both for one-photon processes and for two-photon processes, the disappearance of the initial entanglement is delayed due to the linear modulation of the atom-field coupling coefficients as compared to the constant coupling model. The delayed time of the disappearance of the initial entanglement for the two-photon processes is much longer than that for the one-photon processes in the case of adiabatic variation.展开更多
Bacterial diversity in surface sediment from the Arctic Ocean was investigated by culture-dependent and-independent approaches. Conventional culture-dependent techniques revealed 11 strains based on their distinct mor...Bacterial diversity in surface sediment from the Arctic Ocean was investigated by culture-dependent and-independent approaches. Conventional culture-dependent techniques revealed 11 strains based on their distinct morphological characteristics on marine Zobell 2216E agar plates. Phylogenetic analysis showed that these isolates belonged to three major lineages of the Bacteria,γ-proteobacteria, Bacteroidetes and Actinobacteria, and that they included 10 genera. Most isolates were psychrotrophic, and NaCl was not necessary for their growth. Furthermore, they exhibited activity of at least one extracellular hydrolytic enzyme at 4＆#176;C and had various abilities to assimilate carbon sources. A total of 67 phylotypes were detected among 142 clones based on the 16S rRNA library of the total community DNA and grouped into nine major lineages of bacteria. Phylotypes afifliated withγ-,δ-andε-proteobacteria accounted for 36.7%, 21.8%and 16.9%of the total clones, respectively. The rest of the clones belonged to Bacteroidetes,α-proteobacteria, Actinobacteria, Fusobacteria, Nitrospirae and an unclassiifed group.展开更多
The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cro...The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cross section of this system is put forward. It is found that the photodetachment cross section of this system is nearly unaffected for the weak oscillating electric field strength, but oscillates complicatedly when the oscillating electric field strength turns strong. In addition, the frequency of the harmonic potential and the oscillating electric field （the frequency of the harmonic potential and the frequency of the oscillating electric field are the same in the paper, unless otherwise stated.） can also affect the photodetachment dynamics of this system. With the increase of the frequency in the harmonic potential and the oscillating electric field, the number of the closed orbits for the detached electrons increased, which makes the oscillatory structure in the photodetachment cross section much more complex. Our study presents an intuitive understanding of the photodetachment dynamics driven by a harmonic potential plus an oscillating electric field from a space and time dependent viewpoint. This study is very useful in guiding the future experimental research for the photodetachment dynamics in the electric field both changing with space and time.展开更多
GaSb p-channel metal-oxide-semiconductor field-effect transistors （MOSFETs） with an atomic layer deposited Al2O3 gate dielectric and a self-aligned Si-implanted source/drain are experimentally demonstrated. Temperat...GaSb p-channel metal-oxide-semiconductor field-effect transistors （MOSFETs） with an atomic layer deposited Al2O3 gate dielectric and a self-aligned Si-implanted source/drain are experimentally demonstrated. Temperature dependent electrical characteristics are investigated. Different electrical behaviors are observed in two temperature regions, and the un- derlying mechanisms are discussed. It is found that the reverse-bias pn junction leakage of the drain/substrate is the main component of the off-state drain leakage current, which is generation-current dominated in the low temperature regions and is diffusion-current dominated in the high temperature regions. Methods to further reduce the off-state drain leakage current are given.展开更多
文摘Field dependence/independence in Language Acquisition are discussed by many language learners.In this article,we will mainly focus on talking about the cognitive style,including the concept of Field-dependence/independence,their character istics and differences and functions in language acquisition.
基金Supported by the Natural Science Foundation of Henan University（05ZDZR001）
文摘In this paper, we give the algebraic independence measures for the values ofMahler type functions in complex number field and p-adic number field, respectively.
文摘Ralph Waldo Emerson 's essay Self-reliance is one of the major writings that helped carve the ethnic American individualism and form the intellectual basis of today's writers.Self-reliant individuals are so closely associated with the society that people involved in it must learn how to deal with the relationship with it.Total independence is an illusion,an illusion which blinds us to the realities and the deficiencies of our dependencies and the dependencies of others upon us.
文摘The phase field method for fracture integrates the Griffith theory and damage mechanics approach to predict crack initiation and propagation within one framework.It replaced the discrete representation of crack by diffusive damage and solved it based on a minimization of the global energy storage functional.As a result,no crack tracking topology is needed,and complex crack shapes can be captures without user intervention.However,it is also reported to have an inconsistency between the predicted fracture toughness and the material strength.Recently,a novel energetic degradation function was proposed in literature to handle this issue.This research does some further modifications to the global energy storage functional so that Newton's method can be directly used to solve the energy minimization.With the new energy form,direct implementation of the length-scale independent phase field method into finite element packages like LS-DYNA becomes possible.This paper presents the framework and details of implementing the length-scale independent phase field method into LS-DYNA through a user-defined element and material subroutine.Several numerical examples are presented to compare with the experiment crack shape.Most importantly,this paper is one of the first ones to quantitatively predict accurate force response compared to experiments.These examples verify the accuracy of the new energy form and implementation.
文摘Taking into account the interaction of an electron with both bulk longitudinaloptical (LO) and interfaceoptical(IO) phonons, we investigate the magnetic field and temperature dependence of the properties of a magnetopolaron at the interface of polarpolar crystals in an external magnetic field by using the generalized Haga perturbation method. The results reveal that as the magnetic field B is lower than critical strengths BCL and BCI, the selftrapping of the interface magnetopolaron weakens with increasing temperature, but it strengthens with the rising temperature when B is higher than BCL and BCI. The effect of temperature becomes striking while B is close to BCL or BCI. The results also show that the farther from the interface the electron, the more markedly the electronLO phonon interction changes with the variation of temperature. On the other hand, the nearer from the interface the electron, the more distinctly the electronIO phonon interaction changes with varying temperature.
基金Project supported by the State Key Development Program for Basic Research of China （Grant No 2002CB613401）, the National Natural Science Foundation of China （Grant Nos 20474023 and 50673035）, the Program for Changjiang Scholars and Innovative Research Team in University （Grant No IRT0422）, the 111 Project （Grant No B06009） and the Research Project of Jilin Province, China （Grant Nos 20050504 and 20060702）.
文摘This paper reports that the blend films of poly （2-methoxy-5-（2＇-ethyl-hexyloxy）-p-phenylene vinylene） （MEH-PPV） and N,N＇-bis（1-ethylpropyl）-3,4： 9,10-perylene bis （tetracarboxyl diimide） （EP-PDI） with the weight ratio of 1：2.5 have been prepared by spin-coating from chloroform （CF） and chlorobenzene （CB） solutions respectively. The absorption spectra and the morphology of the blend films show that large crystal-like EP-PDI aggregates are formed in film prepared from CB solution, which corresponds to a new absorption shoulder near 590 nm, while there is no shoulder around 590 nm in the UV-Vis absorption spectra of the blend film from CF solution. The electric-field dependence spectra of the photocurrent generation quantum yield of the film from CB solution shows that at weak electric field the EP-PDI aggregates act as more efficient sensitizers, but at strong electric field the quantum yields become almost invariable over the entire spectral range no matter what the state of EP-PDI, monomer or aggregate. At strong electric field, the photocurrent generation yields of both films from CF and CB solution saturate and their yield spectra become spectrally similar, mentioning that at strong electric field the photoexcitons dissociate efficiently and the free charges are collected by the electrodes almost completely.
文摘We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of local density approximation complemented by self-interaction correction. It is found that photoelectron emission in one photon regime could be considered as a probing tool for the main character of different types of molecular orbitals （σ or π）. The pattern of emitted photoelectrons strongly depends on the polarized angle of the laser, for σ orbital, the number of photoelectron decreases with increasing the polarized angle, while for π orbital, it has the inverse relation to the polarized angle, which reveals the multi-electron effect in molecules. On the other hand, concerning the total photoelectron emission, one should take into account a few occupied orbitals instead of only the outmost one.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10774013 and 10804006)the National High Technology Research and Development Program of China (Grant No. 2006AA03Z412)+3 种基金the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070004024)the Research Fund for the Youth Scholars of the Doctoral Program of Higher Education, China (Grant No. 20070004031)the New Star Plan of Science and Technology of Beijing, China(Grant No. 2007A024)the research grants from the Academy of Sciences for the Developing World (Grant No. B08002)
文摘With the aim of understanding the relationships between organic small molecule field-effect transistors （FETs） and organic conjugated polymer FETs, we investigate the thickness dependence of surface morphology and charge carrier mobility in pentacene and regioregular poly （3-hexylthiophene） （RR-P3HT） field-effect transistors. On the basis of the results of surface morphologies and electrical properties, we presume that the charge carrier mobility is largely related to the morphology of the organic active layer. We observe that the change trends of the surface morphologies （average size and average roughness） of pentacene and RR-P3HT thin films are mutually opposite, as the thickness of the organic layer increases. Further, we demonstrate that the change trends of the field-effect mobilities of pentacene and RR-P3HT FETs are also opposite to each other, as the thickness of the organic layer increases within its limit.
基金supported by the Ministry of Science and Technology of Chinathe National Natural Science Foundation of China
文摘In some organic materials, varying the finite distance between adjacent carrier traps modifies the Coulomb potential around each trap, resulting in a more complex field-dependence of mobility, differing from （but not incompatible with） the usually considered relationship of ln μ∝√E ,a relationship which has been successfully explained by the Poole-Frenkel effect. To investigate the influence of the adjacency of traps, a model system is proposed, which consists of two traps separated by distance α. Our numerical calculation shows that with increasing α, the dependence of mobility on the electric field changes from linear to exponential. Moreover, beyond a certain large α, i.e., as the distance to the nearest trap approaches infinity, the proposed model is essentially the same as the Poole-Frenkel effect. The proposed model accounts for the effect of the energy barrier shape, especially the effect of the location of the potential-energy maximum, a phenomenon which is not accommodated in the Poole-Frenkel model. Because the model assumes the Coulomb interaction between the adjacent traps, it applies to those charged traps which may exist in organic materials for various reasons.
基金supported by the National Natural Science Foundation of China (52005134&51975154)China Postdoctoral Science Foundation (2022T150163, 2020M670901)+4 种基金Self-Planned Task (No. SKLRS202214B) of State Key Laboratory of Robotics and System (HIT)Heilongjiang Postdoctoral Fund (LBH-Z20016)Shenzhen Science and Technology Program (GJHZ20210705142804012)Fundamental Research Funds for the Central Universities(FRFCU5710051122)Open Fund of ZJUT Xinchang Research Institute
文摘To understand the anisotropy dependence of the damage evolution and material removal during the machining process of MgF_(2) single crystals,nanoscratch tests of MgF_(2) single crystals with different crystal planes and directions were systematically performed,and surface morphologies of the scratched grooves under different conditions were analyzed.The experimental results indicated that anisotropy considerably affected the damage evolution in the machining process of MgF_(2) single crystals.A stress field model induced by the scratch was developed by considering the anisotropy,which indicated that during the loading process,median cracks induced by the tensile stress initiated and propagated at the front of the indenter.Lateral cracks induced by tensile stress initiated and propagated on the subsurface during the unloading process.In addition,surface radial cracks induced by the tensile stress were easily generated during the unloading process.The stress change led to the deflection of the propagation direction of lateral cracks.Therefore,the lateral cracks propagated to the workpiece surface,resulting in brittle removal in the form of chunk chips.The plastic deformation parameter indicated that the more the slip systems were activated,the more easily the plastic deformation occurred.The cleavage fracture parameter indicated that the cracks propagated along the activated cleavage planes,and the brittle chunk removal was owing to the subsurface cleavage cracks propagating to the crystal surface.Under the same processing parameters,the scratch of the(001)crystal plane along the[100]crystal-orientation was found to be the most conducive to achieving plastic machining of MgF_(2) single crystals.The theoretical results agreed well with the experimental results,which will not only enhance the understanding of the anisotropy dependence of the damage evolution and removal process during the machining of MgF_(2) crystals,but also provide a theoretical foundation for achieving the high-efficiency and low-damage processing of anisotropic single crystals.
基金Project supported by the State Key Program of the National Natural Science of China (Grant No. 60836004)the National Natural Science Foundation of China (Grant Nos. 61076025 and 60906014)
文摘In this paper, we investigate the temperature and drain bias dependency of single event transient （SET） in 25-nm fin field-effect-transistor （FinFET） technology in a temperature range of 0-135 ℃ and supply voltage range of 0.4 V- 1.6 V. Technology computer-aided design （TCAD） three-dimensional simulation results show that the drain current pulse duration increases from 0.6 ns to 3.4 ns when the temperature increases from 0 to 135 ℃. The charge collected increases from 45.5 ℃ to 436.9 fC and the voltage pulse width decreases from 0.54 ns to 0.18 ns when supply voltage increases from 0.4 V to 1.6 V. Furthermore, simulation results and the mechanism of temperature and bias dependency are discussed.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 81702538, 81372764, and 81528015） and the Natural Science Foundation of Shandong Province （No. ZR201702160271, ZR2018MH030, and ZR2018MH025）.
文摘We sought to investigate the underlying mechanism of action of the long noncoding RNA （IncRNA） LOC283070 in the development of androgen independence in prostate cancer. The interactions between LOC283070 and target proteins were investigated by RNA pull-down and RNA-binding protein immunoprecipitation （RIP） assays. Subceilular fractionation and quantitative reverse transcription-polymerase chain reaction （qRT-PCR） were used to detect the subcellular localization of LOC283070. Western blotting was performed to detect the expression of prohibitin 2 （PHB2）. Luciferase activity assays were performed to evaluate the effects of LOC283070 and PHB2 on the androgen receptor （AR） signaling pathway. A methyl thiazolyl tetrazolium （MTT） assay and a growth curve assay were used to test cell viability. Flow cytometry was performed to analyze cell cycles. A transwell assay was employed to test cell migration. We identified PHB2 as an interaction partner of LOC283070 in the pull-down and RIP experiments. Furthermore, we confirmed that the enrichment of L0C283070 with PHB2 in androgen-independent LNCaP （LNCaP-AI） cells was much greater than that in LNCaP cells. Moreover, the expression of PHB2 was not significantly different between the two cell lines, and the expression of LOC283070 in the nuclei of the LNCaP-AI cells was significantly greater than that in the LNCaP cells. In vitro data revealed that PHB2 overexpression significantly inhibited AR activity and cell proliferation and migration and induced accumulation of prostate cancer cells in GO/G1 phase. Moreover, the overexpression of LOC283070 fully abrogated the effects of PHB2 overexpression. In conclusion, we found that LOC283070 can bind to PHB2 located in the nucleus and inhibit its effect, and this is one of the mechanisms by which LOC283070 is involved in the transition of LNCaP cells into androgen-independent cells.
基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (No. 1107047002)the Key Research and Development Plan (Modern Agriculture) of Jiangsu Province (No. BE2018385)Innovation Platform Project supported by Jiangsu Province (No. 6907041203)。
文摘Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green and red emissions, respectively. In sharp contrast, two kinds of CPDs prepared via a hydrothermal process from citric acid(CA) and diethylenetriamine(DETA) exhibit obvious excitation-wavelength dependent emissions. Through the characterization and comparison of the two types of CPDs, it is concretely revealed that the polymer structure types during the formation of CPDs can effectively control the fluorescence excitation-wavelength independence/dependence. The homogeneous polymer structures contained in CPDs contribute to excitation-wavelength independence, whereas random copolymer structures contribute to excitation-wavelength dependence. These studies are of great significance for further understanding the polymer structures and designing unique optical properties of CPDs.
文摘To construct pulsed high magnet, with rapid adjustments to large changes in the field strength, it is a mandatory acces-sory to development a special NMR probes to provide a precise real-time map of the magnetic field. In order to do so, it is necessary to understand the variations of the spin transition and susceptibility of NMR samples in a time dependent longitudinal field. This work analyzes the effect on the spin transition by a time dependent longitudinal field. For a 1/2 spin system, we have derived a simple formula for the prediction of the probabilities of occupation of the 1/2 and ?1/2 states in a non-static field. We also calculate the magnetic susceptibility of the water and give an analysis of the effect on the magnetic susceptibility in a time dependent longitudinal field and RF frequency.
文摘The world today is in a period of great development and integration of economy,information,and technology,especially the high-tech industries represented by big data,cloud computing,and artificial intelligence.It is promoting the rapid increase of human productivity and leading the changes in various industries.Enterprises are facing more and more uncertain external environments.The previous organizational strategy,personnel structure,and operating strategies have been unable to adapt to the turbulent external environment,and innovation has become the norm.Therefore,how to find an innovative breakthrough point on the original strategic road on which to survive has become a matter of life and death.From the perspective of path dependence theory,this paper analyzes the characteristics of path dependence and transcendence path dependence during the adjustment of corporate strategy,and analyzes the internal causes and mechanisms of its generation with the help of the PEST model.Based on this,the negative impact of path dependence on the adjustment of the strategy was found.Furthermore,it was found above that the degree of transcendence path dependence in corporate strategic adjustment is determined by two factors:its ability to drive independent innovation in a dynamic environment and its ability to transform strategically.Finally,according to the research conclusions,it proposes countermeasures to overcome the path dependence of enterprises when adjusting their strategies,and provides suggestions for companies to find breakthrough points in disruptive innovation.
文摘The world today is in a period of great development and integration of economy,information,and technology,especially the high-tech industries represented by big data,cloud computing,and artificial intelligence.It is promoting the rapid increase of human productivity and leading the changes in various industries.Enterprises are facing more and more uncertain external environments.The previous organizational strategy,personnel structure,and operating strategies have been unable to adapt to the turbulent external environment,and innovation has become the norm.Therefore,how to find an innovative breakthrough point on the original strategic road on which to survive has become a matter of life and death.From the perspective of path dependence theory,this paper analyzes the characteristics of path dependence and transcendence path dependence during the adjustment of corporate strategy,and analyzes the internal causes and mechanisms of its generation with the help of the PEST model.Based on this,the negative impact of path dependence on the adjustment of the strategy was found.Furthermore,it was found above that the degree of transcendence path dependence in corporate strategic adjustment is determined by two factors:its ability to drive independent innovation in a dynamic environment and its ability to transform strategically.Finally,according to the research conclusions,it proposes countermeasures to overcome the path dependence of enterprises when adjusting their strategies,and provides suggestions for companies to find breakthrough points in disruptive innovation.
基金Supported by the NSFC-Henan Talent Development Joint Fund under Grant No.U1204616the National Natural Science Foundation of China under Grant No.61378011the Fundamental Research of The Education Department of Henan Province of China under Grant Nos.13A140798,2010A140010
文摘A model containing two two-level atoms and a single-mode cavity is considered, and the effect of the time-dependent atom-field couplings on entanglement between the two atoms is studied. The results indicate that both for one-photon processes and for two-photon processes, the disappearance of the initial entanglement is delayed due to the linear modulation of the atom-field coupling coefficients as compared to the constant coupling model. The delayed time of the disappearance of the initial entanglement for the two-photon processes is much longer than that for the one-photon processes in the case of adiabatic variation.
基金financially supported by the Public Science and Technology Funds for Ocean Projects(Grant nos.201005032-2 and 201205020-5)by the Special Funds for Basic Scientific Research by Central Non-profit Institutes(Grant no.GY02-2012G14)
文摘Bacterial diversity in surface sediment from the Arctic Ocean was investigated by culture-dependent and-independent approaches. Conventional culture-dependent techniques revealed 11 strains based on their distinct morphological characteristics on marine Zobell 2216E agar plates. Phylogenetic analysis showed that these isolates belonged to three major lineages of the Bacteria,γ-proteobacteria, Bacteroidetes and Actinobacteria, and that they included 10 genera. Most isolates were psychrotrophic, and NaCl was not necessary for their growth. Furthermore, they exhibited activity of at least one extracellular hydrolytic enzyme at 4＆#176;C and had various abilities to assimilate carbon sources. A total of 67 phylotypes were detected among 142 clones based on the 16S rRNA library of the total community DNA and grouped into nine major lineages of bacteria. Phylotypes afifliated withγ-,δ-andε-proteobacteria accounted for 36.7%, 21.8%and 16.9%of the total clones, respectively. The rest of the clones belonged to Bacteroidetes,α-proteobacteria, Actinobacteria, Fusobacteria, Nitrospirae and an unclassiifed group.
基金supported by the National Natural Science Foundation of China(Grant No.11374133)the Taishan Scholars Project of Shandong Province,China(Grant No.ts2015110055)
文摘The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cross section of this system is put forward. It is found that the photodetachment cross section of this system is nearly unaffected for the weak oscillating electric field strength, but oscillates complicatedly when the oscillating electric field strength turns strong. In addition, the frequency of the harmonic potential and the oscillating electric field （the frequency of the harmonic potential and the frequency of the oscillating electric field are the same in the paper, unless otherwise stated.） can also affect the photodetachment dynamics of this system. With the increase of the frequency in the harmonic potential and the oscillating electric field, the number of the closed orbits for the detached electrons increased, which makes the oscillatory structure in the photodetachment cross section much more complex. Our study presents an intuitive understanding of the photodetachment dynamics driven by a harmonic potential plus an oscillating electric field from a space and time dependent viewpoint. This study is very useful in guiding the future experimental research for the photodetachment dynamics in the electric field both changing with space and time.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00602)the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2011ZX02708-002)
文摘GaSb p-channel metal-oxide-semiconductor field-effect transistors （MOSFETs） with an atomic layer deposited Al2O3 gate dielectric and a self-aligned Si-implanted source/drain are experimentally demonstrated. Temperature dependent electrical characteristics are investigated. Different electrical behaviors are observed in two temperature regions, and the un- derlying mechanisms are discussed. It is found that the reverse-bias pn junction leakage of the drain/substrate is the main component of the off-state drain leakage current, which is generation-current dominated in the low temperature regions and is diffusion-current dominated in the high temperature regions. Methods to further reduce the off-state drain leakage current are given.
