The construction and development of social public management's new normal depend on the scientific transformation of government functionalization orientation and highlighting the role of grassroots public's ex...The construction and development of social public management's new normal depend on the scientific transformation of government functionalization orientation and highlighting the role of grassroots public's extensive illustrations on social issues and social conditions.Based on this situation,in the process of public participation mechanism construction,it is necessary to emphasize that the construction of joint elements should be carried out systematically and comprehensively,and to dig deep into the relations and functions of all elements.When the stability of public participation mechanism construction is fully guaranteed,it will extensively supervise and evaluate the development of government's social public management cause,help achieve the final goal of coordinating social development environment and social development elements,ensure that the intrinsic value of public participation mechanism can be thoroughly displayed.展开更多
Reading is the main route to impart scientific and cultural knowledge.It is not only related to personal growth,but also closely related to the construction of our society and the prosperity of the nation.University l...Reading is the main route to impart scientific and cultural knowledge.It is not only related to personal growth,but also closely related to the construction of our society and the prosperity of the nation.University libraries must take on this important responsibility and strengthen the promotion of reading.In the"Internet+"era,university libraries need to focus on how to keep up with the development of the times and provide better digital reading services for teachers and students.The author studies and analyzes the main characteristics of digital reading in university libraries,and proposes the service strategy of digital reading for university libraries in the"Internet+"era,hoping to help with the university libraries playing their roles.展开更多
To capitalize on the primary role of major course teaching and to facilitate students’understanding of abstract concepts in the data structure course,it is essential to increase their interest in learning and develop...To capitalize on the primary role of major course teaching and to facilitate students’understanding of abstract concepts in the data structure course,it is essential to increase their interest in learning and develop case studies that highlight fine traditional culture.By incorporating these culture-rich case studies into classroom instruction,we employ a project-driven teaching approach.This not only allows students to master professional knowledge,but also enhances their abilities to solve specific engineering problems,ultimately fostering cultural confidence.Over the past few years,during which educational reforms have been conducted for trial runs,the feasibility and effectiveness of these reform schemes have been demonstrated.展开更多
Mobile Edge Computing(MEC)is proposed to solve the needs of Inter-net of Things(IoT)users for high resource utilization,high reliability and low latency of service requests.However,the backup virtual machine is idle w...Mobile Edge Computing(MEC)is proposed to solve the needs of Inter-net of Things(IoT)users for high resource utilization,high reliability and low latency of service requests.However,the backup virtual machine is idle when its primary virtual machine is running normally,which will waste resources.Overbooking the backup virtual machine under the above circumstances can effectively improve resource utilization.First,these virtual machines are deployed into slots randomly,and then some tasks with cooperative relationship are off-loaded to virtual machines for processing.Different deployment locations have different resource utilization and average service response time.We want tofind a balanced solution that minimizes the average service response time of the IoT application while maximizing resource utilization.In this paper,we propose a task scheduler and exploit a Task Deployment Algorithm(TDA)to obtain an optimal virtual machine deployment scheme.Finally,the simulation results show that the TDA can significantly increase the resource utilization of the system,while redu-cing the average service response time of the application by comparing TDA with the other two classical methods.The experimental results confirm that the perfor-mance of TDA is better than that of other two methods.展开更多
In recent years, more and more foreigners begin to learn Chinese characters, but they often make typos when using Chinese. The fundamental reason is that they mainly learn Chinese characters from the glyph and pronunc...In recent years, more and more foreigners begin to learn Chinese characters, but they often make typos when using Chinese. The fundamental reason is that they mainly learn Chinese characters from the glyph and pronunciation, but do not master the semantics of Chinese characters. If they can understand the meaning of Chinese characters and form knowledge groups of the characters with relevant meanings, it can effectively improve learning efficiency. We achieve this goal by building a Chinese character semantic knowledge graph (CCSKG). In the process of building the knowledge graph, the semantic computing capacity of HowNet was utilized, and 104,187 associated edges were finally established for 6752 Chinese characters. Thanks to the development of deep learning, OpenHowNet releases the core data of HowNet and provides useful APIs for calculating the similarity between two words based on sememes. Therefore our method combines the advantages of data-driven and knowledge-driven. The proposed method treats Chinese sentences as subgraphs of the CCSKG and uses graph algorithms to correct Chinese typos and achieve good results. The experimental results show that compared with keras-bert and pycorrector + ernie, our method reduces the false acceptance rate by 38.28% and improves the recall rate by 40.91% in the field of learning Chinese as a foreign language. The CCSKG can help to promote Chinese overseas communication and international education.展开更多
The bulk viscosity of interacting strange quark matter in a strong external magnetic field B m with a real equation of state is investigated.It is found that interquark interactions can significantly increase the bulk...The bulk viscosity of interacting strange quark matter in a strong external magnetic field B m with a real equation of state is investigated.It is found that interquark interactions can significantly increase the bulk viscosity,and the magnetic field B_(m) can cause irregular oscillations in both components of the bulk viscosity,ξ||(parallel to B_(m))and ξ⊥(perpendicular to B_(m)).A comparison with non-interacting strange quark matter reveals that when B_(m) is sufficiently large,ξ⊥is more affected by interactions than ξ||.Additionally,the quasi-oscillation of the bulk viscosity with changes in density may facilitate the for-mation of magnetic domains.Moreover,the resulting r-mode instability windows are in good agreement with observational data for compact stars in low-mass X-ray binaries.Specifically,the r-mode instability window for interacting strange quark matter in high magnetic fields has a minimum rotation frequency exceeding 1050 Hz,which may explain the observed very high spin frequency of a pulsar with V=1122 Hz.展开更多
A new complex, [Ni(acac)2(NITQ)2]-2CH2C12 1 (acac = acetylacetone, NITQ = 2-(2"-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide), was synthesized and charac- terized by elemental analysis, IR spec...A new complex, [Ni(acac)2(NITQ)2]-2CH2C12 1 (acac = acetylacetone, NITQ = 2-(2"-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide), was synthesized and charac- terized by elemental analysis, IR spectroscopy, UV-Vis absorption spectrum, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 9.6970(19), b = 20.410(4), c = 12.166(2) A, β = 93.89(3)°, Mr = 997.43, V= 2402.3(8) A3, Z = 2, Dc = 1.379 g/cm3, F(000) = 1040,μ = 0.684 mm-1, the final R = 0.0423 and wR = 0.1197 for 2884 observed reflections (1 〉 2σ(I)). Compound 1 is found to assume a mononuclear structure, which is further linked into a three-dimensional (3D) supramolecular network by hydrogen-bonding, C1...O weak contact and π...π stacking interactions. Moreover, the luminescent properties of the ligand and compound 1 were further investigated in detail.展开更多
Many researchers have studied the ocean carbon cycle model trying to regulate the level of CO2 in atmosphere from viewpoint of quantification. Unlike other researches, this paper analyzes the conversion process of car...Many researchers have studied the ocean carbon cycle model trying to regulate the level of CO2 in atmosphere from viewpoint of quantification. Unlike other researches, this paper analyzes the conversion process of carbon element in the ocean from the qualitative viewpoint. There are many complex roles in the ocean carbon cycle, and it is hard to represent the case that an entity plays different role in different environment. An ontology technology Hozo role theory developed by Osaka University Mizoguchi Laboratory is proposed as a solution. The basic concepts and representation mode of Hozo role theory is introduced. The conversion process of ocean carbon cycle is abstracted and an ontology model using Hozo role theory is proposed. Instead of comprehensive common ontology construction method, we propose our own ontology development steps. Then an ontology about ocean carbon cycle is built in order to describe and share the basic knowledge of ocean carbon cycle. A knowledge base of material circulation is proposed based on the ontology. Its construction framework is described and some knowledge base query examples are also illustrated. Conclusions show that the role theory can effectively solve the problem of multirole description in ocean carbon cycle, and knowledge reasoning based on ontology is also effective.展开更多
ZrO2 nanocrystallite-based charge trap flash memory capacitors incorporating a (ZrO2)0.6(SiO2)0.4 pseudobinary high-k oxide film as the charge trapping layer were prepared and investigated. The precipitation react...ZrO2 nanocrystallite-based charge trap flash memory capacitors incorporating a (ZrO2)0.6(SiO2)0.4 pseudobinary high-k oxide film as the charge trapping layer were prepared and investigated. The precipitation reaction in the charge trapping layer, forming ZrO2 nanocrystallites during rapid thermal annealing, was investigated by transmission electron microscopy and X-ray diffraction. It was observed that a ZrO2 nanocrystallite-based memory capacitor after post-annealing at 850 ℃ for 60 s exhibits a maximum memory window of about 6.8 V, good endurance and a low charge loss of -25% over a period of 10 years (determined by extrapolating the charge loss curve measured experimentally), even at 85 ℃. Such 850 ℃-annealed memory capacitors appear to be candidates for future nonvolatile flash memory device applications.展开更多
A GaN/Si nanoheterojunction is prepared through growing Ga N nanocrystallites(nc-GaN) on a silicon nanoporous pillar array(Si-NPA) by a chemical vapor deposition(CVD) technique at a relatively low temperature. T...A GaN/Si nanoheterojunction is prepared through growing Ga N nanocrystallites(nc-GaN) on a silicon nanoporous pillar array(Si-NPA) by a chemical vapor deposition(CVD) technique at a relatively low temperature. The average size of nc-Ga N is determined to be ~10 nm. The spectral measurements disclose that the photoluminescence(PL) from GaN/SiNPA is composed of an ultraviolet(UV) band and a broad band spanned from UV to red region, with the feature that the latter band is similar to that of electroluminescence(EL). The electron transition from the energy levels of conduction band and, or, shallow donors to that of deep acceptors of Ga N is indicated to be responsible for both the broad-band PL and the EL luminescence. A study of the I-V characteristic shows that at a low forward bias, the current across the heterojunction is contact-limited while at a high forward bias it is bulk-limited, which follows the thermionic emission model and space-charge-limited current(SCLC) model, respectively. The bandgap offset analysis indicates that the carrier transport is dominated by electron injection from n-GaN into the p-Si-NPA, and the EL starts to appear only when holes begin to be injected from Si-NPA into GaN with biases higher than a threshold voltage.展开更多
A GaN/Si nanoheterostructure is prepared by growing wurtzite GaN on a silicon nanoporous pillar array (Si-NPA) with a chemical vapor deposition method. The temperature evolution of the photoluminescence (PL) of Ga...A GaN/Si nanoheterostructure is prepared by growing wurtzite GaN on a silicon nanoporous pillar array (Si-NPA) with a chemical vapor deposition method. The temperature evolution of the photoluminescence (PL) of GaN/Si- NPA is measured and the PL mechanism is analyzed. It is found that the PL spectrum is basically composed of two narrow ultraviolet peaks and a broad blue peak, corresponding to the near band-edge emission of GaN and its phonon replicas, and the emission from Si-NPA. No GaN defect-related PL is observed in the as-prepared GaN/Si-NPA. Our experiments prove that Si-NPA might be an ideal substrate for preparing high-quality Si-based GaN nanomaterials or nanodeviees.展开更多
A two-dimensional(2D) 44 topological ZnⅡ coordination polymer {[Zn2Cl2(L)(4bpy)2]}∞(H2L = anthracene-9,10-dicarboxylic acid, 4bpy = 4,4ˊ-bipyridine) based on binuclear [Zn2Cl2] nodes has been synthesized an...A two-dimensional(2D) 44 topological ZnⅡ coordination polymer {[Zn2Cl2(L)(4bpy)2]}∞(H2L = anthracene-9,10-dicarboxylic acid, 4bpy = 4,4ˊ-bipyridine) based on binuclear [Zn2Cl2] nodes has been synthesized and characterized by IR, elemental analysis, X-ray powder diffraction and single-crystal X-ray diffraction analysis. Moreover, the luminescent properties of the correspon- ding compound have been briefly investigated.展开更多
Research performed during the past decade revealed an important role of symmetry energy in the equation of state(EOS)of strange quark matter(SQM).By introducing an isospin-dependent term into the quark mass scaling,th...Research performed during the past decade revealed an important role of symmetry energy in the equation of state(EOS)of strange quark matter(SQM).By introducing an isospin-dependent term into the quark mass scaling,the SQM stability window in the equivparticle model was studied.The results show that a sufficiently strong isospin dependence C_(I)can significantly widen the SQM region of absolute stability,yielding results that simultaneously satisfy the constraints of the astrophysical observations of PSR J1614-2230 with 1.928±0.017 Mand tidal deformability 70≤Λ_(1:4)≤580 measured in the event GW170817.With increasing C_(I),the difference between the u,d,and s quark fractions for the SQM inβ-equilibrium becomes inconspicuous for C>0,leading to small isospin asymmetryδ,and further resulting in similar EOS and structures of strange quark stars(SQSs).Moreover,unlike the behavior of the maximum mass of ud QSs,which varies with C_(I)depending on the sign of the parameter C,the maximum mass of the SQSs decreases monotonously with increasing CI.展开更多
A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurall...A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurally as well as magnetically in detail. The crystal belongs to the monoclinic system, space group P2_1/c with a = 9.6896(1), b = 20.539(4), c = 12.147(2) ?, β = 93.84(3)°, M_r = 997.65, V = 2412.1(8) ?~3, Z = 2, Dc = 1.374 g/cm, F(000) = 1038, m = 0.635 mm^(-1), the final R = 0.0539 and w R = 0.1289 for 5998 observed reflections(I 〉 2σ(I)). The Co(Ⅱ) ion is coordinated by two nitrogen atoms of quinoxaline rings from two NITQs and four oxygen atoms from two acac ions to complete a distorted octahedral coordination environment. Compound 1 is further linked into a three-dimensional(3D) supramolecular network by hydrogen-bonding, Cl×××O weak contact and π···π stacking interactions. The magnetic measurements show compound 1 exhibits weak ferromagnetic interactions.展开更多
Silicon nanoporous pillar array (Si-NPA) is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photolumin...Silicon nanoporous pillar array (Si-NPA) is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photolumines- cence (PL) from Si-NPA important. We measure the PL of Si-NPA in the range of 11-300K. By analyzing the evolution of the peak energy and intensity with temperature, the ultraviolet, blue, orange and red PL bands from Si-NPA are attributed to the radiative recombination through the deep-levels in silicon oxide, oxygen-related defect states in silicon nanocrystallites (nc-Si), band-to-band transition within nc-Si, and surface/interface states of nc-Si or between nc-Si and SiOx, respectively. At least two non-radiative recombination processes, which are activated at different temperature ranges, are proposed for the PL intensity variation with temperature. These results might provide strong foundations for designing and constructing optoelectronic devices based on silicon nanostruetures.展开更多
Designed ZrxSi1-xO2 films with combining bent and flat energy bands are employed as a charge trapping layer for memory capacitors.Compared to a single bent energy band,the bandgap structure with combining bent and fla...Designed ZrxSi1-xO2 films with combining bent and flat energy bands are employed as a charge trapping layer for memory capacitors.Compared to a single bent energy band,the bandgap structure with combining bent and flat energy bands exhibits larger memory window,faster program/erase speed,lower charge loss even at 200℃ for 104s,and wider temperature insensitive regions.The tunneling thickness together with electron recaptured efficiency in the trapping layer,and the balance of two competing electron loss mechanisms in the bent and flat energy band regions collectively contribute to the improved memory characteristics.Therefore,the proposed ZrxSi1-xO2 with combining bent and flat energy bands should be a promising candidate for future nonvolatile memory applications,taking into consideration of the trade-off between the operation speed and retention characteristics.展开更多
This paper is concerned with the Cauchy problem of a seventh order dispersive equation. We prove local well-posedness with initial data in Sobolev spaces Hs(R) for negative indices of s〉-114 .
A composition-modulated (HfO2)x(Al2O3)1-x charge trapping layer is proposed for charge trap flash memory by controlling the A1 atom content to form a peak and valley shaped band gap. It is found that the memory de...A composition-modulated (HfO2)x(Al2O3)1-x charge trapping layer is proposed for charge trap flash memory by controlling the A1 atom content to form a peak and valley shaped band gap. It is found that the memory device using the composition-modulated (HfO2)x(Al2O3)l-x as the charge trapping layer exhibits a larger memory window of 11.5 V, improves data retention even at high temperature, and enhances the program/erase speed. Improvements of the memory characteristics are attributed to the special band-gap structure resulting from the composition-modulated trapping layer. Therefore, the composition-modulated charge trapping layer may be useful in future nonvolatile flash memory device application.展开更多
A thin-flexible multiband terahertz metamaterial absorber (MA) has been investigated. Each unit cell of the MA consists of a simple metal structure, which includes the top metal resonator ring and the bottom metalli...A thin-flexible multiband terahertz metamaterial absorber (MA) has been investigated. Each unit cell of the MA consists of a simple metal structure, which includes the top metal resonator ring and the bottom metallic ground plane, separated by a thin-flexible dielectric spacer. Finite-difference time domain simulation indicates that this MA can achieve over 99% absorption at frequencies of 1.50 THz, 3.33 THz, and 5.40 THz by properly assembling the sandwiched structure. However, because of its asymmetric structure, the MA is polarization-sensitive and can tune the absorptivity of the second absorption peak by changing the incident polarization angle. The effect of the error of the structural parameters on the absorption efficiency is also carefully analyzed in detail to guide the fabrication. Moreover, the proposed MA exhibits high refractive-index sensing sensitivity, which has potential applications in multi-wavelength sensing in the terahertz region.展开更多
基金supported by the Research Program of Henan Federation of Humanities and Social Sciences entitled“The Research of Chinese Higher Education Model”(SKL-2011-2135)
文摘The construction and development of social public management's new normal depend on the scientific transformation of government functionalization orientation and highlighting the role of grassroots public's extensive illustrations on social issues and social conditions.Based on this situation,in the process of public participation mechanism construction,it is necessary to emphasize that the construction of joint elements should be carried out systematically and comprehensively,and to dig deep into the relations and functions of all elements.When the stability of public participation mechanism construction is fully guaranteed,it will extensively supervise and evaluate the development of government's social public management cause,help achieve the final goal of coordinating social development environment and social development elements,ensure that the intrinsic value of public participation mechanism can be thoroughly displayed.
文摘Reading is the main route to impart scientific and cultural knowledge.It is not only related to personal growth,but also closely related to the construction of our society and the prosperity of the nation.University libraries must take on this important responsibility and strengthen the promotion of reading.In the"Internet+"era,university libraries need to focus on how to keep up with the development of the times and provide better digital reading services for teachers and students.The author studies and analyzes the main characteristics of digital reading in university libraries,and proposes the service strategy of digital reading for university libraries in the"Internet+"era,hoping to help with the university libraries playing their roles.
基金the research outcomes of a blended top-tier undergraduate course in Henan ProvinceData Structures and Algorithms(Jiao Gao[2022]324)a research-based teaching demonstration course in Henan Province-Data Structures and Algorithms(Jiao Gao[2023]36)a model course of ideological and political education of Anyang Normal University-Data Structures and Algorithms(No.YBKC20210012)。
文摘To capitalize on the primary role of major course teaching and to facilitate students’understanding of abstract concepts in the data structure course,it is essential to increase their interest in learning and develop case studies that highlight fine traditional culture.By incorporating these culture-rich case studies into classroom instruction,we employ a project-driven teaching approach.This not only allows students to master professional knowledge,but also enhances their abilities to solve specific engineering problems,ultimately fostering cultural confidence.Over the past few years,during which educational reforms have been conducted for trial runs,the feasibility and effectiveness of these reform schemes have been demonstrated.
基金supported by the National Natural Science Foundation of China under Grant No.62173126the National Natural Science Joint Fund project under Grant No.U1804162+2 种基金the Key Science and Technology Research Project of Henan Province under Grant No.222102210047,222102210200 and 222102320349the Key Scientific Research Project Plan of Henan Province Colleges and Universities under Grant No.22A520011 and 23A510018the Key Science and Technology Research Project of Anyang City under Grant No.2021C01GX017.
文摘Mobile Edge Computing(MEC)is proposed to solve the needs of Inter-net of Things(IoT)users for high resource utilization,high reliability and low latency of service requests.However,the backup virtual machine is idle when its primary virtual machine is running normally,which will waste resources.Overbooking the backup virtual machine under the above circumstances can effectively improve resource utilization.First,these virtual machines are deployed into slots randomly,and then some tasks with cooperative relationship are off-loaded to virtual machines for processing.Different deployment locations have different resource utilization and average service response time.We want tofind a balanced solution that minimizes the average service response time of the IoT application while maximizing resource utilization.In this paper,we propose a task scheduler and exploit a Task Deployment Algorithm(TDA)to obtain an optimal virtual machine deployment scheme.Finally,the simulation results show that the TDA can significantly increase the resource utilization of the system,while redu-cing the average service response time of the application by comparing TDA with the other two classical methods.The experimental results confirm that the perfor-mance of TDA is better than that of other two methods.
文摘In recent years, more and more foreigners begin to learn Chinese characters, but they often make typos when using Chinese. The fundamental reason is that they mainly learn Chinese characters from the glyph and pronunciation, but do not master the semantics of Chinese characters. If they can understand the meaning of Chinese characters and form knowledge groups of the characters with relevant meanings, it can effectively improve learning efficiency. We achieve this goal by building a Chinese character semantic knowledge graph (CCSKG). In the process of building the knowledge graph, the semantic computing capacity of HowNet was utilized, and 104,187 associated edges were finally established for 6752 Chinese characters. Thanks to the development of deep learning, OpenHowNet releases the core data of HowNet and provides useful APIs for calculating the similarity between two words based on sememes. Therefore our method combines the advantages of data-driven and knowledge-driven. The proposed method treats Chinese sentences as subgraphs of the CCSKG and uses graph algorithms to correct Chinese typos and achieve good results. The experimental results show that compared with keras-bert and pycorrector + ernie, our method reduces the false acceptance rate by 38.28% and improves the recall rate by 40.91% in the field of learning Chinese as a foreign language. The CCSKG can help to promote Chinese overseas communication and international education.
基金This work was supported by the National Natural Science Foundation of China(Nos.12005005,11947098)Key Research Projects of Universities in Henan Province(No.20A140003)。
文摘The bulk viscosity of interacting strange quark matter in a strong external magnetic field B m with a real equation of state is investigated.It is found that interquark interactions can significantly increase the bulk viscosity,and the magnetic field B_(m) can cause irregular oscillations in both components of the bulk viscosity,ξ||(parallel to B_(m))and ξ⊥(perpendicular to B_(m)).A comparison with non-interacting strange quark matter reveals that when B_(m) is sufficiently large,ξ⊥is more affected by interactions than ξ||.Additionally,the quasi-oscillation of the bulk viscosity with changes in density may facilitate the for-mation of magnetic domains.Moreover,the resulting r-mode instability windows are in good agreement with observational data for compact stars in low-mass X-ray binaries.Specifically,the r-mode instability window for interacting strange quark matter in high magnetic fields has a minimum rotation frequency exceeding 1050 Hz,which may explain the observed very high spin frequency of a pulsar with V=1122 Hz.
基金Supported by the National Natural Science Foundation of China(No.21071006)the Natural Science Foundation of Henan Province(No.102102210457)the Natural Science Foundation of the Henan Higher Education Institutions of China(No.2010B150001)
文摘A new complex, [Ni(acac)2(NITQ)2]-2CH2C12 1 (acac = acetylacetone, NITQ = 2-(2"-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide), was synthesized and charac- terized by elemental analysis, IR spectroscopy, UV-Vis absorption spectrum, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 9.6970(19), b = 20.410(4), c = 12.166(2) A, β = 93.89(3)°, Mr = 997.43, V= 2402.3(8) A3, Z = 2, Dc = 1.379 g/cm3, F(000) = 1040,μ = 0.684 mm-1, the final R = 0.0423 and wR = 0.1197 for 2884 observed reflections (1 〉 2σ(I)). Compound 1 is found to assume a mononuclear structure, which is further linked into a three-dimensional (3D) supramolecular network by hydrogen-bonding, C1...O weak contact and π...π stacking interactions. Moreover, the luminescent properties of the ligand and compound 1 were further investigated in detail.
基金supported by the New Century Excellent Talents in University (NCET-07-0784)the Foundation of Henan Educational Committee (12A520003)
文摘Many researchers have studied the ocean carbon cycle model trying to regulate the level of CO2 in atmosphere from viewpoint of quantification. Unlike other researches, this paper analyzes the conversion process of carbon element in the ocean from the qualitative viewpoint. There are many complex roles in the ocean carbon cycle, and it is hard to represent the case that an entity plays different role in different environment. An ontology technology Hozo role theory developed by Osaka University Mizoguchi Laboratory is proposed as a solution. The basic concepts and representation mode of Hozo role theory is introduced. The conversion process of ocean carbon cycle is abstracted and an ontology model using Hozo role theory is proposed. Instead of comprehensive common ontology construction method, we propose our own ontology development steps. Then an ontology about ocean carbon cycle is built in order to describe and share the basic knowledge of ocean carbon cycle. A knowledge base of material circulation is proposed based on the ontology. Its construction framework is described and some knowledge base query examples are also illustrated. Conclusions show that the role theory can effectively solve the problem of multirole description in ocean carbon cycle, and knowledge reasoning based on ontology is also effective.
基金supported by the Science Fund of Educational Department of Henan Province of China (Grant No. 13A140021)the National Natural Science Foundation of China (Grant Nos. 50972054 and 61176124)+1 种基金the State Key Program for Basic Research of China (Grant No. 2010CB934201)the State Key Program for Science and Technology of China (Grant No. 2009ZX02039-004)
文摘ZrO2 nanocrystallite-based charge trap flash memory capacitors incorporating a (ZrO2)0.6(SiO2)0.4 pseudobinary high-k oxide film as the charge trapping layer were prepared and investigated. The precipitation reaction in the charge trapping layer, forming ZrO2 nanocrystallites during rapid thermal annealing, was investigated by transmission electron microscopy and X-ray diffraction. It was observed that a ZrO2 nanocrystallite-based memory capacitor after post-annealing at 850 ℃ for 60 s exhibits a maximum memory window of about 6.8 V, good endurance and a low charge loss of -25% over a period of 10 years (determined by extrapolating the charge loss curve measured experimentally), even at 85 ℃. Such 850 ℃-annealed memory capacitors appear to be candidates for future nonvolatile flash memory device applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.61176044)
文摘A GaN/Si nanoheterojunction is prepared through growing Ga N nanocrystallites(nc-GaN) on a silicon nanoporous pillar array(Si-NPA) by a chemical vapor deposition(CVD) technique at a relatively low temperature. The average size of nc-Ga N is determined to be ~10 nm. The spectral measurements disclose that the photoluminescence(PL) from GaN/SiNPA is composed of an ultraviolet(UV) band and a broad band spanned from UV to red region, with the feature that the latter band is similar to that of electroluminescence(EL). The electron transition from the energy levels of conduction band and, or, shallow donors to that of deep acceptors of Ga N is indicated to be responsible for both the broad-band PL and the EL luminescence. A study of the I-V characteristic shows that at a low forward bias, the current across the heterojunction is contact-limited while at a high forward bias it is bulk-limited, which follows the thermionic emission model and space-charge-limited current(SCLC) model, respectively. The bandgap offset analysis indicates that the carrier transport is dominated by electron injection from n-GaN into the p-Si-NPA, and the EL starts to appear only when holes begin to be injected from Si-NPA into GaN with biases higher than a threshold voltage.
文摘A GaN/Si nanoheterostructure is prepared by growing wurtzite GaN on a silicon nanoporous pillar array (Si-NPA) with a chemical vapor deposition method. The temperature evolution of the photoluminescence (PL) of GaN/Si- NPA is measured and the PL mechanism is analyzed. It is found that the PL spectrum is basically composed of two narrow ultraviolet peaks and a broad blue peak, corresponding to the near band-edge emission of GaN and its phonon replicas, and the emission from Si-NPA. No GaN defect-related PL is observed in the as-prepared GaN/Si-NPA. Our experiments prove that Si-NPA might be an ideal substrate for preparing high-quality Si-based GaN nanomaterials or nanodeviees.
基金Supported by the key project of Science,the Technology Department of Henan province(No.112102210371)the science and technology research projects of Education Department of Henan province(No.12B150003)
文摘A two-dimensional(2D) 44 topological ZnⅡ coordination polymer {[Zn2Cl2(L)(4bpy)2]}∞(H2L = anthracene-9,10-dicarboxylic acid, 4bpy = 4,4ˊ-bipyridine) based on binuclear [Zn2Cl2] nodes has been synthesized and characterized by IR, elemental analysis, X-ray powder diffraction and single-crystal X-ray diffraction analysis. Moreover, the luminescent properties of the correspon- ding compound have been briefly investigated.
基金supported by the National Natural Science Foundation of China(Nos.12005005 and 11875052)the National SKA Program of China(No.2020SKA0120300)+1 种基金the Hunan Provincial Nature Science Foundation of China(No.2021JJ40188)the Scientific Research Start-up Fund of Talent Introduction of Suqian University(No.Xiao2022XRC061).
文摘Research performed during the past decade revealed an important role of symmetry energy in the equation of state(EOS)of strange quark matter(SQM).By introducing an isospin-dependent term into the quark mass scaling,the SQM stability window in the equivparticle model was studied.The results show that a sufficiently strong isospin dependence C_(I)can significantly widen the SQM region of absolute stability,yielding results that simultaneously satisfy the constraints of the astrophysical observations of PSR J1614-2230 with 1.928±0.017 Mand tidal deformability 70≤Λ_(1:4)≤580 measured in the event GW170817.With increasing C_(I),the difference between the u,d,and s quark fractions for the SQM inβ-equilibrium becomes inconspicuous for C>0,leading to small isospin asymmetryδ,and further resulting in similar EOS and structures of strange quark stars(SQSs).Moreover,unlike the behavior of the maximum mass of ud QSs,which varies with C_(I)depending on the sign of the parameter C,the maximum mass of the SQSs decreases monotonously with increasing CI.
基金supported by the National Natural Science Foundation of China(No.21071006)the Natural Science Foundation of Henan Province(No.102102210457)the Natural Science Foundation of the Henan Higher Education Institutions of China(No.2010B150001)
文摘A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurally as well as magnetically in detail. The crystal belongs to the monoclinic system, space group P2_1/c with a = 9.6896(1), b = 20.539(4), c = 12.147(2) ?, β = 93.84(3)°, M_r = 997.65, V = 2412.1(8) ?~3, Z = 2, Dc = 1.374 g/cm, F(000) = 1038, m = 0.635 mm^(-1), the final R = 0.0539 and w R = 0.1289 for 5998 observed reflections(I 〉 2σ(I)). The Co(Ⅱ) ion is coordinated by two nitrogen atoms of quinoxaline rings from two NITQs and four oxygen atoms from two acac ions to complete a distorted octahedral coordination environment. Compound 1 is further linked into a three-dimensional(3D) supramolecular network by hydrogen-bonding, Cl×××O weak contact and π···π stacking interactions. The magnetic measurements show compound 1 exhibits weak ferromagnetic interactions.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61176044 and 11074224.
文摘Silicon nanoporous pillar array (Si-NPA) is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photolumines- cence (PL) from Si-NPA important. We measure the PL of Si-NPA in the range of 11-300K. By analyzing the evolution of the peak energy and intensity with temperature, the ultraviolet, blue, orange and red PL bands from Si-NPA are attributed to the radiative recombination through the deep-levels in silicon oxide, oxygen-related defect states in silicon nanocrystallites (nc-Si), band-to-band transition within nc-Si, and surface/interface states of nc-Si or between nc-Si and SiOx, respectively. At least two non-radiative recombination processes, which are activated at different temperature ranges, are proposed for the PL intensity variation with temperature. These results might provide strong foundations for designing and constructing optoelectronic devices based on silicon nanostruetures.
基金Project supported by the National Natural Science Foundation of China(Grant No.51402004)the Science and Technology Research Key Project of Education Department of Henan Province of China(Grant No.19A140001)。
文摘Designed ZrxSi1-xO2 films with combining bent and flat energy bands are employed as a charge trapping layer for memory capacitors.Compared to a single bent energy band,the bandgap structure with combining bent and flat energy bands exhibits larger memory window,faster program/erase speed,lower charge loss even at 200℃ for 104s,and wider temperature insensitive regions.The tunneling thickness together with electron recaptured efficiency in the trapping layer,and the balance of two competing electron loss mechanisms in the bent and flat energy band regions collectively contribute to the improved memory characteristics.Therefore,the proposed ZrxSi1-xO2 with combining bent and flat energy bands should be a promising candidate for future nonvolatile memory applications,taking into consideration of the trade-off between the operation speed and retention characteristics.
基金supported by the National Natural Science Foundation of China(11171266)
文摘This paper is concerned with the Cauchy problem of a seventh order dispersive equation. We prove local well-posedness with initial data in Sobolev spaces Hs(R) for negative indices of s〉-114 .
基金supported by the Science and Technology Research Key Project of Education Department of Henan, China (Grant No. 13A140021)the National Natural Science Foundation of China (Grant Nos. 50972054 and 61176124)+1 种基金the National Basic Research Program of China (Grant No. 2010CB934201)the State Key Program for Science and Technology of China (Grant No. 2009ZX02039-004)
文摘A composition-modulated (HfO2)x(Al2O3)1-x charge trapping layer is proposed for charge trap flash memory by controlling the A1 atom content to form a peak and valley shaped band gap. It is found that the memory device using the composition-modulated (HfO2)x(Al2O3)l-x as the charge trapping layer exhibits a larger memory window of 11.5 V, improves data retention even at high temperature, and enhances the program/erase speed. Improvements of the memory characteristics are attributed to the special band-gap structure resulting from the composition-modulated trapping layer. Therefore, the composition-modulated charge trapping layer may be useful in future nonvolatile flash memory device application.
基金Project supported by the National Natural Science Foundation of China(Grant No.11504006)the Key Scientific Research Project of Higher Education of Henan Province,China(Grant No.15A140002)the Science and Technology Planning Project of Henan Province,China(Grant No.142300410366)
文摘A thin-flexible multiband terahertz metamaterial absorber (MA) has been investigated. Each unit cell of the MA consists of a simple metal structure, which includes the top metal resonator ring and the bottom metallic ground plane, separated by a thin-flexible dielectric spacer. Finite-difference time domain simulation indicates that this MA can achieve over 99% absorption at frequencies of 1.50 THz, 3.33 THz, and 5.40 THz by properly assembling the sandwiched structure. However, because of its asymmetric structure, the MA is polarization-sensitive and can tune the absorptivity of the second absorption peak by changing the incident polarization angle. The effect of the error of the structural parameters on the absorption efficiency is also carefully analyzed in detail to guide the fabrication. Moreover, the proposed MA exhibits high refractive-index sensing sensitivity, which has potential applications in multi-wavelength sensing in the terahertz region.