There is increasing evidence that the gut microbiota affects the incidence and progression of central nervous system diseases via the brain-gut axis.The spinal cord is a vital important part of the central nervous sys...There is increasing evidence that the gut microbiota affects the incidence and progression of central nervous system diseases via the brain-gut axis.The spinal cord is a vital important part of the central nervous system;however,the underlying association between spinal cord injury and gut interactions remains unknown.Recent studies suggest that patients with spinal cord injury frequently experience intestinal dysfunction and gut dysbiosis.Alterations in the gut microbiota can cause disruption in the intestinal barrier and trigger neurogenic inflammatory responses which may impede recovery after spinal cord injury.This review summarizes existing clinical and basic research on the relationship between the gut microbiota and spinal cord injury.Our research identified three key points.First,the gut microbiota in patients with spinal cord injury presents a key characteristic and gut dysbiosis may profoundly influence multiple organs and systems in patients with spinal cord injury.Second,following spinal cord injury,weakened intestinal peristalsis,prolonged intestinal transport time,and immune dysfunction of the intestine caused by abnormal autonomic nerve function,as well as frequent antibiotic treatment,may induce gut dysbiosis.Third,the gut microbiota and associated metabolites may act on central neurons and affect recovery after spinal cord injury;cytokines and the Toll-like receptor ligand pathways have been identified as crucial mechanisms in the communication between the gut microbiota and central nervous system.Fecal microbiota transplantation,probiotics,dietary interventions,and other therapies have been shown to serve a neuroprotective role in spinal cord injury by modulating the gut microbiota.Therapies targeting the gut microbiota or associated metabolites are a promising approach to promote functional recovery and improve the complications of spinal cord injury.展开更多
Dear Editor,This letter addresses the challenge of forecasting the motion of real-world vessels over an extended period with a limited amount of available data.By employing stochastic differential equation(SDE)modelin...Dear Editor,This letter addresses the challenge of forecasting the motion of real-world vessels over an extended period with a limited amount of available data.By employing stochastic differential equation(SDE)modeling,we integrate both deterministic and stochastic components of the available information.Subsequently,we establish a recursive prediction methodology based on Bayes’rule to update the model state when new measurements are received.Furthermore,we develop a stochastic model tailored specifically to vessel dynamics and introduce an approximation method to tackle computational complexities.Finally,we present an application example and conduct a comparative experiment to validate the effectiveness and superiority of the proposed method.展开更多
Probing the energy band gap of solid nitrogen at high pressures is of importance for understanding pressuredriven changes in electronic structures and insulator-to-metal transitions under high pressure.The λ-N_(2) fo...Probing the energy band gap of solid nitrogen at high pressures is of importance for understanding pressuredriven changes in electronic structures and insulator-to-metal transitions under high pressure.The λ-N_(2) formed by cold compression is known to be the most stable one in all solid nitrogen phases observed so far.By optimizing the optical system,we successfully measured the high-pressure absorption spectra of λ-N_(2) covering the polymericnitrogen synthetic pressures(124 GPa-165 GPa).The measured optical band gap decreases with increasing pressure,from 2.23 eV at 124 GPa to 1.55 eV at 165 GPa,with a negative pressure coefficient of-18.4 meV/GPa,which is consistent with the result from our ab initio total-energy calculations(-22.6 meV/GPa).The extrapolative metallization pressure for theλ-N_(2) is around 288(18)GPa,which is close to the metallization pressure(280 GPa)for the η-N_(2) expected by previous absorption edge and direct electrical measurements.Our results provide a direct spectroscopic evidence for the pressure-driven band gap narrowing of solid nitrogen.展开更多
Anti-Stokes/Stokes Raman peak intensity ratio was used to infer sample temperatures,but the influence factors of system correction factors were not clear.Non-contact in-situ anti-Stokes/Stokes temperature calibration ...Anti-Stokes/Stokes Raman peak intensity ratio was used to infer sample temperatures,but the influence factors of system correction factors were not clear.Non-contact in-situ anti-Stokes/Stokes temperature calibration was carried out for up to 1500 K based on six different samples under two excitation light sources(±50 K within 1000 K,±100 K above1000 K),and the system correction factorγwas systematically investigated.The results show that the correction factorγof anti-Stokes/Stokes thermometry is affected by the wavelength of the excitation light source,Raman mode peak position,temperature measurement region and other factors.The anti-Stokes/Stokes thermometry was applied to the laser-heating diamond anvil cell(LHDAC)experiment to investigate the anharmonic effect of h BN under high temperature and high pressure.It is concluded that the strong anharmonic effect caused by phonon scattering at low pressure gradually changes into the predominance of localized molecular lattice thermal expansion at high pressure.展开更多
In this paper we study a periodic two-component Camassa-Holm equation with generalized weakly dissipation. The local well-posedness of Cauchy problem is investigated by utilizing Kato’s theorem. The blow-up criteria ...In this paper we study a periodic two-component Camassa-Holm equation with generalized weakly dissipation. The local well-posedness of Cauchy problem is investigated by utilizing Kato’s theorem. The blow-up criteria and the blow-up rate are established by applying monotonicity. Finally, the global existence results for solutions to the Cauchy problem of equation are proved by structuring functions.展开更多
Recently, 3D bioprinting is developed as an emerging approach, increasingly applied to materials for healthcare;while, the precise placement of cells and materials, and the shape fidelity of forming constructs is of g...Recently, 3D bioprinting is developed as an emerging approach, increasingly applied to materials for healthcare;while, the precise placement of cells and materials, and the shape fidelity of forming constructs is of great importance for successful application of 3D bioprinting. Research efforts have been made to develop new bioinks as "raw materials" with better biocompatibility and biofunctionality, but the printability of bioinks is largely ignored and still needs to be carefully examined to enable robotic bioprinting. This article aims to introduce a recent published review (Appl. Phys. Rev. 2018, 5, 041304) on the evaluation of bioink printability by Huang's research group from University of Florida. Huang et al. comprehensively reviewed the bioink printability based on the physical point of view during inkjet printing, laser printing, and microextrusion, and a series of self-consistent time scales and dimensi on less quantities were utilized to physically understand and evaluate bioink printability. This article would be helpful to know the trends on physical understanding of bioink printability.展开更多
The high-frequency edge of the first-order Raman mode of diamond reflects the stress state at the culet of anvil, and is often used for the pressure calibration in diamond anvil cell(DAC) experiments. Here we point ou...The high-frequency edge of the first-order Raman mode of diamond reflects the stress state at the culet of anvil, and is often used for the pressure calibration in diamond anvil cell(DAC) experiments. Here we point out that the high-frequency edge of the diamond Raman phonon corresponds to the Brillouin zone(BZ) center Γ point as a function of pressure. The diamond Raman pressure gauge relies on the stability of crystal lattice of diamond under high stress. Upon the diamond anvil occurs failure under the uniaxial stress(197 GPa), the loss of intensity of the first-order Raman phonon and a stressdependent broad Raman band centered at 600 cm^(-1) are observed, which is associated with a strain-induced local mode corresponding to the BZ edge phonon of the L1 transverse acoustic phonon branch.展开更多
Mechanized transplanting of rapeseed(Brassica napus L.)blanket seedling is an innovative cultivation technology.Cultivating high quality blanket seedling to ensure high survival rate of seedling after transplanting is...Mechanized transplanting of rapeseed(Brassica napus L.)blanket seedling is an innovative cultivation technology.Cultivating high quality blanket seedling to ensure high survival rate of seedling after transplanting is the key of the technology.The effects of different uniconazole rates of 0,0.5,1.0,1.5 and 2.0 mg/tray,spraying at one leaf and one heart stage,on selected agronomic traits,physiological indexes and survival rate of two rapeseed cultivars(‘Qinyou 100 and’Yangyou 90)were investigated in 2018 and 2019.Our results showed that the plant height decreased significantly with the increase of uniconazole rate.However,the collar diameter increased significantly with the increase of uniconazole rate up to 1.5 mg/tray,and the leaf area,dry weights of root and shoot increased with increased uniconazole rate up to 1.0 mg/tray.The root to shoot ratios,N concentrations of root and shoot with the uniconazole rates of 1.0 and 1.5 mg/tray were higher than those with other treatments.As uniconazole rate increasing,gibberellin(GA)and auxin(IAA)concentrations of root and shoot decreased,while abscisic acid(ABA)concentrations increased,and cytokinin(CTK)concentrations topped at uniconazole rate of 1.0 mg/tray and decreased thereafter.The seedling survival rates with 1.0 and 1.5 mg/tray were greatly higher than those in other treatments.Regression analysis suggested plant survival rate was positively related to CTK concentrations and negatively to GA concentrations of root and shoot.To achieve high survival rate after mechanized transplanting,our study revealed that the uniconazole applied at a rate of 1.0 mg/tray was recommended as the best,followed by 1.5 mg/tray.The findings would help to enhance qualities of rapeseed blanket seedling and to promote popularization of mechanized transplanting of rapeseed production.展开更多
High-pressure Raman scattering from hexagonal close-packed(HCP) metals Os and Re have been extended up to 200 GPa, and the pressure-dependent shear modulus C_(44)has been deduced from the Raman-active mode E_(28), whi...High-pressure Raman scattering from hexagonal close-packed(HCP) metals Os and Re have been extended up to 200 GPa, and the pressure-dependent shear modulus C_(44)has been deduced from the Raman-active mode E_(28), which is generated from the adjacent vibration of atoms in hexagonal planes, providing the valuable information about the elastic properties for HCP metals under high pressure. Combined with the available data of HCP metals from previous works,a further study indicates that the C_(44)/C_(44)ratio would be close to a constant value, 0.01, with increasing atomic number of metals. The results obtained from high-pressure Raman scattering will allow us to probe the elastic anisotropy of the HCP metals at very high pressure.展开更多
The sensitive area of targeted observations for short-term(7 d)prediction of vertical thermal structure(VTS)in summer in the Yellow Sea was investigated.We applied the Conditional Nonlinear Optimal Perturbation(CNOP)m...The sensitive area of targeted observations for short-term(7 d)prediction of vertical thermal structure(VTS)in summer in the Yellow Sea was investigated.We applied the Conditional Nonlinear Optimal Perturbation(CNOP)method and an adjoint-free algorithm with the Regional Ocean Modeling System(ROMS).We used vertical integration of CNOP-type temperature errors to locate the sensitive areas,where reduction of initial errors is expected to yield the greatest improvement in VTS prediction for the selected verification area.The identified sensitive areas were northeast−southwest orientated northeast to the verification area,which were possibly related to the southwestward background currents.Then,we performed a series of sensitivity experiments to evaluate the effectiveness of the identified sensitive areas.Results show that initial errors in the identified sensitive areas had the greatest negative effect on VTS prediction in the verification area compared to errors in other areas(e.g.,the verification area and areas to its east and northeast).Moreover,removal of initial errors through deploying simulated observations in the identified sensitive areas led to more refined prediction than correction of initial conditions in the verification area itself.Our results suggest that implementation of targeted observation in the CNOP-based sensitive areas is an effective method to improve short-term prediction of VTS in summer in the Yellow Sea.展开更多
We observed an isostructural phase transition in the solid nitrogen λ-N_(2) at approximately 50 GPa accompanied by anomalies in lattice parameters,atomic volume and Raman vibron modes.The anomalies are ascribed to a ...We observed an isostructural phase transition in the solid nitrogen λ-N_(2) at approximately 50 GPa accompanied by anomalies in lattice parameters,atomic volume and Raman vibron modes.The anomalies are ascribed to a slight reorientation of the nitrogen molecules,which does not seem to affect the monoclinic symmetry(space group P2_(1)/c).Our ab initio calculations further confirm the phenomena,and suggest an optimized structure for the λ-N_(2) phase.In addition,a new high-pressure amorphous phase of η′-N_(2) was also discovered by a detailed investigation of the pressure-temperature phase diagram of nitrogen with the aim of probing the phase stability of λ-N_(2).Our result may provide helpful information about the crystallographic nature of dissociation transitions in diatomic molecular crystals(H_(2),O_(2),N_(2),etc).展开更多
Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to...Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to scrambling blocks in this paper. At first, the original image is scrambled by using logistic mapping to obtain the encrypted image, and then the encrypted image is divided into many blocks. Finally, the position of the blocked image is scrambled by using the improved Josephus ring to get the encrypted image. According to the experiments, the information entropy of the encrypted image reaches 7.99 and the adjacent correlations in three directions are within ±0.1. The experimental results show that the proposed algorithm has advantages of large key space, high key sensitivity and can effectively resist the attacks of statistical analysis and gray value analysis. It has good encryption effect on digital image encryption.展开更多
In this study,seed yield,quality and N-fertilizer use efficiency in rape(Brassica napus L.) were researched in normal oil content cultivar(Yangyou 6) and two high oil content cultivars(Zhongshuang 11 and Zheyou 50). R...In this study,seed yield,quality and N-fertilizer use efficiency in rape(Brassica napus L.) were researched in normal oil content cultivar(Yangyou 6) and two high oil content cultivars(Zhongshuang 11 and Zheyou 50). Results showed that the average oil content of all treatments in Yangyou 6,Zhongshuang 11 and Zheyou 50 was 42. 87%,47. 37% and 48. 28%,respectively. The average protein content of all treatments in Yangyou 6,Zhongshuang 11 and Zheyou 50 was 24. 15%,22. 71% and 21. 84%,respectively. The increased ratio of total nitrogen accumulation amount in Yangyou 6 was higher than that in Zhongshuang 11 and Zheyou 50. Among three cultivars,the total protein accumulation amount in Yangyou 6 was highest,and the total oil accumulation amount was highest in Zheyou 50. With increasing nitrogen fertilization,the value of different parameters of N-fertilizer use efficiency decreased. The average N use efficiency in Yangyou 6 was 68. 70%,which was higher than that in Zhongshuang 11 and Zheyou 50(65. 06% and 60. 30%,respectively). The average N-fertilizer agronomic use efficiency in Yangyou 6 was also highest among three cultivars,which was 8. 97 kg seed / kg N. On the contrary,the average N-fertilizer physiological use efficiency in Zhongshuang 11 and Zheyou 50 was 13. 03 kg seed / kg N and 13. 84 kg seed / kg N,respectively,which was higher than that in Yangyou 6(12. 91 kg seed / kg N). Differences in partial factor productivity of N-fertilizer were slight among three cultivars.展开更多
Since 2006, the public corporations in China are required to include its social responsibilities in its annual report by company law. Corporations’ business activities should not only focus on maximizing its economic...Since 2006, the public corporations in China are required to include its social responsibilities in its annual report by company law. Corporations’ business activities should not only focus on maximizing its economic profit but also serve the society. With the awareness of the importance of social responsibility, there are an increasing number of public corporations in China to undertake more charitable activities or employee training activities. There have been a lot of academic researches investigating the relationship between corporate social responsibilities and corporate financial performance. However, the results are inconsistent and vary according to different industries. This study chose Chinese culture, sports and entertainment industry as a sample to test the relationship between CSR and corporate financial performance. Four financial ratios were used to test whether the caproate’s reasonability to government, employee, investors and society has significant impact on its financial performance. The empirical results show that apart from the responsibility to employees which is negatively influence the corporate financial performance the other three factors are found not significantly influence corporate financial performance.展开更多
The QSH edge channels can be used to connect dissipationless nanoelectronic devices, when the topological edge states and the bulk states have the perfectly spaced. But the monolayer 1T’-WTe<sub>2</sub> b...The QSH edge channels can be used to connect dissipationless nanoelectronic devices, when the topological edge states and the bulk states have the perfectly spaced. But the monolayer 1T’-WTe<sub>2</sub> bulk state is metallic nature, with edge channel lengths around 100 nm, which hinders its further study. By simulating the different terminational edge states, using the GGA-1/2 method to calculate, we found a stable terminational edge state. And under strain engineering, fixed the a-axis, the band gap gradually increases with the b-axis tensile. When the tensile to 2.9%, the band gap increases to 245 meV. It greatly improves the application of 1T’-WTe<sub>2</sub>. During the phase transition of the material from half-metal to insulator, the topology of edge states remains unchanged, showing strong robustness. Thus introducing strain can make 1T’-WTe<sub>2</sub> a suitable material for fundamental research or topological electronic devices.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82105019(to YC),82271218(to CZ)Natural Science Foundation of Tianjin Municipality Foundation,No.20JCZDJC00540(to CZ).
文摘There is increasing evidence that the gut microbiota affects the incidence and progression of central nervous system diseases via the brain-gut axis.The spinal cord is a vital important part of the central nervous system;however,the underlying association between spinal cord injury and gut interactions remains unknown.Recent studies suggest that patients with spinal cord injury frequently experience intestinal dysfunction and gut dysbiosis.Alterations in the gut microbiota can cause disruption in the intestinal barrier and trigger neurogenic inflammatory responses which may impede recovery after spinal cord injury.This review summarizes existing clinical and basic research on the relationship between the gut microbiota and spinal cord injury.Our research identified three key points.First,the gut microbiota in patients with spinal cord injury presents a key characteristic and gut dysbiosis may profoundly influence multiple organs and systems in patients with spinal cord injury.Second,following spinal cord injury,weakened intestinal peristalsis,prolonged intestinal transport time,and immune dysfunction of the intestine caused by abnormal autonomic nerve function,as well as frequent antibiotic treatment,may induce gut dysbiosis.Third,the gut microbiota and associated metabolites may act on central neurons and affect recovery after spinal cord injury;cytokines and the Toll-like receptor ligand pathways have been identified as crucial mechanisms in the communication between the gut microbiota and central nervous system.Fecal microbiota transplantation,probiotics,dietary interventions,and other therapies have been shown to serve a neuroprotective role in spinal cord injury by modulating the gut microbiota.Therapies targeting the gut microbiota or associated metabolites are a promising approach to promote functional recovery and improve the complications of spinal cord injury.
基金supported by the National Natural Science Foundation of China(62073019)the Key R&D Program of Hebei Province(22340301D)+1 种基金China Postdoctoral Science Foundation(2021M703021)Hebei Postdoctoral Science Foundation(B2021003031)。
文摘Dear Editor,This letter addresses the challenge of forecasting the motion of real-world vessels over an extended period with a limited amount of available data.By employing stochastic differential equation(SDE)modeling,we integrate both deterministic and stochastic components of the available information.Subsequently,we establish a recursive prediction methodology based on Bayes’rule to update the model state when new measurements are received.Furthermore,we develop a stochastic model tailored specifically to vessel dynamics and introduce an approximation method to tackle computational complexities.Finally,we present an application example and conduct a comparative experiment to validate the effectiveness and superiority of the proposed method.
基金supported by the National Natural Science Foundation of China(Grant Nos.12374013,U2030107,and 11974154)the Fundamental Research Funds for the Central Universities(Grant No.2020SCUNL107)the Taishan Scholars Special Funding for Construction Projects。
文摘Probing the energy band gap of solid nitrogen at high pressures is of importance for understanding pressuredriven changes in electronic structures and insulator-to-metal transitions under high pressure.The λ-N_(2) formed by cold compression is known to be the most stable one in all solid nitrogen phases observed so far.By optimizing the optical system,we successfully measured the high-pressure absorption spectra of λ-N_(2) covering the polymericnitrogen synthetic pressures(124 GPa-165 GPa).The measured optical band gap decreases with increasing pressure,from 2.23 eV at 124 GPa to 1.55 eV at 165 GPa,with a negative pressure coefficient of-18.4 meV/GPa,which is consistent with the result from our ab initio total-energy calculations(-22.6 meV/GPa).The extrapolative metallization pressure for theλ-N_(2) is around 288(18)GPa,which is close to the metallization pressure(280 GPa)for the η-N_(2) expected by previous absorption edge and direct electrical measurements.Our results provide a direct spectroscopic evidence for the pressure-driven band gap narrowing of solid nitrogen.
基金financially supported by the National Natural Science Foundation of China(Grant No.U2030107)the Fundamental Research Funds for the Central Universities(Grant No.2020SCUNL107)。
文摘Anti-Stokes/Stokes Raman peak intensity ratio was used to infer sample temperatures,but the influence factors of system correction factors were not clear.Non-contact in-situ anti-Stokes/Stokes temperature calibration was carried out for up to 1500 K based on six different samples under two excitation light sources(±50 K within 1000 K,±100 K above1000 K),and the system correction factorγwas systematically investigated.The results show that the correction factorγof anti-Stokes/Stokes thermometry is affected by the wavelength of the excitation light source,Raman mode peak position,temperature measurement region and other factors.The anti-Stokes/Stokes thermometry was applied to the laser-heating diamond anvil cell(LHDAC)experiment to investigate the anharmonic effect of h BN under high temperature and high pressure.It is concluded that the strong anharmonic effect caused by phonon scattering at low pressure gradually changes into the predominance of localized molecular lattice thermal expansion at high pressure.
基金supported by the National Natural Science Foundation of China[grant number 41922038]the Fundamental Research Funds for the Central Universities[grant number 14380187].
文摘In this paper we study a periodic two-component Camassa-Holm equation with generalized weakly dissipation. The local well-posedness of Cauchy problem is investigated by utilizing Kato’s theorem. The blow-up criteria and the blow-up rate are established by applying monotonicity. Finally, the global existence results for solutions to the Cauchy problem of equation are proved by structuring functions.
文摘Recently, 3D bioprinting is developed as an emerging approach, increasingly applied to materials for healthcare;while, the precise placement of cells and materials, and the shape fidelity of forming constructs is of great importance for successful application of 3D bioprinting. Research efforts have been made to develop new bioinks as "raw materials" with better biocompatibility and biofunctionality, but the printability of bioinks is largely ignored and still needs to be carefully examined to enable robotic bioprinting. This article aims to introduce a recent published review (Appl. Phys. Rev. 2018, 5, 041304) on the evaluation of bioink printability by Huang's research group from University of Florida. Huang et al. comprehensively reviewed the bioink printability based on the physical point of view during inkjet printing, laser printing, and microextrusion, and a series of self-consistent time scales and dimensi on less quantities were utilized to physically understand and evaluate bioink printability. This article would be helpful to know the trends on physical understanding of bioink printability.
基金Project support by the National Natural Science Foundation of China(Grant No.11774247)。
文摘The high-frequency edge of the first-order Raman mode of diamond reflects the stress state at the culet of anvil, and is often used for the pressure calibration in diamond anvil cell(DAC) experiments. Here we point out that the high-frequency edge of the diamond Raman phonon corresponds to the Brillouin zone(BZ) center Γ point as a function of pressure. The diamond Raman pressure gauge relies on the stability of crystal lattice of diamond under high stress. Upon the diamond anvil occurs failure under the uniaxial stress(197 GPa), the loss of intensity of the first-order Raman phonon and a stressdependent broad Raman band centered at 600 cm^(-1) are observed, which is associated with a strain-induced local mode corresponding to the BZ edge phonon of the L1 transverse acoustic phonon branch.
基金This research was funded by the National Key Research and Development Program of China(2018YFD1000900)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Mechanized transplanting of rapeseed(Brassica napus L.)blanket seedling is an innovative cultivation technology.Cultivating high quality blanket seedling to ensure high survival rate of seedling after transplanting is the key of the technology.The effects of different uniconazole rates of 0,0.5,1.0,1.5 and 2.0 mg/tray,spraying at one leaf and one heart stage,on selected agronomic traits,physiological indexes and survival rate of two rapeseed cultivars(‘Qinyou 100 and’Yangyou 90)were investigated in 2018 and 2019.Our results showed that the plant height decreased significantly with the increase of uniconazole rate.However,the collar diameter increased significantly with the increase of uniconazole rate up to 1.5 mg/tray,and the leaf area,dry weights of root and shoot increased with increased uniconazole rate up to 1.0 mg/tray.The root to shoot ratios,N concentrations of root and shoot with the uniconazole rates of 1.0 and 1.5 mg/tray were higher than those with other treatments.As uniconazole rate increasing,gibberellin(GA)and auxin(IAA)concentrations of root and shoot decreased,while abscisic acid(ABA)concentrations increased,and cytokinin(CTK)concentrations topped at uniconazole rate of 1.0 mg/tray and decreased thereafter.The seedling survival rates with 1.0 and 1.5 mg/tray were greatly higher than those in other treatments.Regression analysis suggested plant survival rate was positively related to CTK concentrations and negatively to GA concentrations of root and shoot.To achieve high survival rate after mechanized transplanting,our study revealed that the uniconazole applied at a rate of 1.0 mg/tray was recommended as the best,followed by 1.5 mg/tray.The findings would help to enhance qualities of rapeseed blanket seedling and to promote popularization of mechanized transplanting of rapeseed production.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 11774247 and U2030107)Sichuan University Innovation Research Program of China (Grant No. 2020SCUNL107)。
文摘High-pressure Raman scattering from hexagonal close-packed(HCP) metals Os and Re have been extended up to 200 GPa, and the pressure-dependent shear modulus C_(44)has been deduced from the Raman-active mode E_(28), which is generated from the adjacent vibration of atoms in hexagonal planes, providing the valuable information about the elastic properties for HCP metals under high pressure. Combined with the available data of HCP metals from previous works,a further study indicates that the C_(44)/C_(44)ratio would be close to a constant value, 0.01, with increasing atomic number of metals. The results obtained from high-pressure Raman scattering will allow us to probe the elastic anisotropy of the HCP metals at very high pressure.
基金The National Natural Science Foundation of China under contract Nos 41705081 and 41906005the Innovation Special Zone Project under contract No.18-H863-05-ZT-001-012-06the Open Project Fund of the Laboratory for Regional Oceanography and Numerical Modeling,Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2019A05.
文摘The sensitive area of targeted observations for short-term(7 d)prediction of vertical thermal structure(VTS)in summer in the Yellow Sea was investigated.We applied the Conditional Nonlinear Optimal Perturbation(CNOP)method and an adjoint-free algorithm with the Regional Ocean Modeling System(ROMS).We used vertical integration of CNOP-type temperature errors to locate the sensitive areas,where reduction of initial errors is expected to yield the greatest improvement in VTS prediction for the selected verification area.The identified sensitive areas were northeast−southwest orientated northeast to the verification area,which were possibly related to the southwestward background currents.Then,we performed a series of sensitivity experiments to evaluate the effectiveness of the identified sensitive areas.Results show that initial errors in the identified sensitive areas had the greatest negative effect on VTS prediction in the verification area compared to errors in other areas(e.g.,the verification area and areas to its east and northeast).Moreover,removal of initial errors through deploying simulated observations in the identified sensitive areas led to more refined prediction than correction of initial conditions in the verification area itself.Our results suggest that implementation of targeted observation in the CNOP-based sensitive areas is an effective method to improve short-term prediction of VTS in summer in the Yellow Sea.
基金supported by the Sichuan University Innovation Research Program of China(Grant No.2020SCUNL107)the National Natural Science Foundation of China(Grant No.U2030107,11774247,and 11974154)+1 种基金Chinese Academy of Sciences(Grant Nos.2019-BEPC-PT003237 and 2020-SSRF-PT-012109)the Natural Science Foundation of Shandong Province(Grant Nos.2019GGX103023 and Z2018S008)。
文摘We observed an isostructural phase transition in the solid nitrogen λ-N_(2) at approximately 50 GPa accompanied by anomalies in lattice parameters,atomic volume and Raman vibron modes.The anomalies are ascribed to a slight reorientation of the nitrogen molecules,which does not seem to affect the monoclinic symmetry(space group P2_(1)/c).Our ab initio calculations further confirm the phenomena,and suggest an optimized structure for the λ-N_(2) phase.In addition,a new high-pressure amorphous phase of η′-N_(2) was also discovered by a detailed investigation of the pressure-temperature phase diagram of nitrogen with the aim of probing the phase stability of λ-N_(2).Our result may provide helpful information about the crystallographic nature of dissociation transitions in diatomic molecular crystals(H_(2),O_(2),N_(2),etc).
文摘Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to scrambling blocks in this paper. At first, the original image is scrambled by using logistic mapping to obtain the encrypted image, and then the encrypted image is divided into many blocks. Finally, the position of the blocked image is scrambled by using the improved Josephus ring to get the encrypted image. According to the experiments, the information entropy of the encrypted image reaches 7.99 and the adjacent correlations in three directions are within ±0.1. The experimental results show that the proposed algorithm has advantages of large key space, high key sensitivity and can effectively resist the attacks of statistical analysis and gray value analysis. It has good encryption effect on digital image encryption.
基金Supported by National Science and Technology Support Program(2014-BAD11B03)Yangzhou Agricultural Science and Technology Research Project(YZ2014172)Yangzhou Modern Agricultural Project(YZ2015026)
文摘In this study,seed yield,quality and N-fertilizer use efficiency in rape(Brassica napus L.) were researched in normal oil content cultivar(Yangyou 6) and two high oil content cultivars(Zhongshuang 11 and Zheyou 50). Results showed that the average oil content of all treatments in Yangyou 6,Zhongshuang 11 and Zheyou 50 was 42. 87%,47. 37% and 48. 28%,respectively. The average protein content of all treatments in Yangyou 6,Zhongshuang 11 and Zheyou 50 was 24. 15%,22. 71% and 21. 84%,respectively. The increased ratio of total nitrogen accumulation amount in Yangyou 6 was higher than that in Zhongshuang 11 and Zheyou 50. Among three cultivars,the total protein accumulation amount in Yangyou 6 was highest,and the total oil accumulation amount was highest in Zheyou 50. With increasing nitrogen fertilization,the value of different parameters of N-fertilizer use efficiency decreased. The average N use efficiency in Yangyou 6 was 68. 70%,which was higher than that in Zhongshuang 11 and Zheyou 50(65. 06% and 60. 30%,respectively). The average N-fertilizer agronomic use efficiency in Yangyou 6 was also highest among three cultivars,which was 8. 97 kg seed / kg N. On the contrary,the average N-fertilizer physiological use efficiency in Zhongshuang 11 and Zheyou 50 was 13. 03 kg seed / kg N and 13. 84 kg seed / kg N,respectively,which was higher than that in Yangyou 6(12. 91 kg seed / kg N). Differences in partial factor productivity of N-fertilizer were slight among three cultivars.
文摘Since 2006, the public corporations in China are required to include its social responsibilities in its annual report by company law. Corporations’ business activities should not only focus on maximizing its economic profit but also serve the society. With the awareness of the importance of social responsibility, there are an increasing number of public corporations in China to undertake more charitable activities or employee training activities. There have been a lot of academic researches investigating the relationship between corporate social responsibilities and corporate financial performance. However, the results are inconsistent and vary according to different industries. This study chose Chinese culture, sports and entertainment industry as a sample to test the relationship between CSR and corporate financial performance. Four financial ratios were used to test whether the caproate’s reasonability to government, employee, investors and society has significant impact on its financial performance. The empirical results show that apart from the responsibility to employees which is negatively influence the corporate financial performance the other three factors are found not significantly influence corporate financial performance.
文摘The QSH edge channels can be used to connect dissipationless nanoelectronic devices, when the topological edge states and the bulk states have the perfectly spaced. But the monolayer 1T’-WTe<sub>2</sub> bulk state is metallic nature, with edge channel lengths around 100 nm, which hinders its further study. By simulating the different terminational edge states, using the GGA-1/2 method to calculate, we found a stable terminational edge state. And under strain engineering, fixed the a-axis, the band gap gradually increases with the b-axis tensile. When the tensile to 2.9%, the band gap increases to 245 meV. It greatly improves the application of 1T’-WTe<sub>2</sub>. During the phase transition of the material from half-metal to insulator, the topology of edge states remains unchanged, showing strong robustness. Thus introducing strain can make 1T’-WTe<sub>2</sub> a suitable material for fundamental research or topological electronic devices.