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Statistic properties of Fermi gas in a strong magnetic field 被引量:2
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作者 门福殿 范召兰 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期108-111,共4页
Based on the thermodynamic potential function of Fermi gas in a strong magnetic field, using the thermodynamics method, the integrated analytical expressions of thermodynamic quantities of the system at low temperatur... Based on the thermodynamic potential function of Fermi gas in a strong magnetic field, using the thermodynamics method, the integrated analytical expressions of thermodynamic quantities of the system at low temperatures are derived, and the effects of the magnetic field on the statistic properties of the system are analysed. It is shown that, as long as the temperature is not zero, the effects of the magnetic field on the thermodynamic quantities of the system contain both oscillatory and non-oscillatory parts. For the non-oscillatory part, compared with the situation of Fermi gas in a weak magnetic field, the influence of the magnetic field on the thermodynamic quantities is not exactly the same. For the oscillatory part, the period and amplitude of the oscillation are all related to the magnetic field. Due to the oscillation, the chemical potential may be greater than Ferim energy of the system, but the oscillation does not affect the thermodynamic stability of the system. 展开更多
关键词 strong magnetic field Fermi gas statistic property
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STRONG LAW OF LARGE NUMBERS AND ASYMPTOTIC EQUIPARTITION PROPERTY FOR NONSYMMETRIC MARKOV CHAIN FIELDS ON CAYLEY TREES 被引量:2
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作者 包振华 叶中行 《Acta Mathematica Scientia》 SCIE CSCD 2007年第4期829-837,共9页
Some strong laws of large numbers for the frequencies of occurrence of states and ordered couples of states for nonsymmetric Markov chain fields (NSMC) on Cayley trees are studied. In the proof, a new technique for ... Some strong laws of large numbers for the frequencies of occurrence of states and ordered couples of states for nonsymmetric Markov chain fields (NSMC) on Cayley trees are studied. In the proof, a new technique for the study of strong limit theorems of Markov chains is extended to the case of Markov chain fields, The asymptotic equipartition properties with almost everywhere (a,e.) convergence for NSMC on Cayley trees are obtained, 展开更多
关键词 Cayley tree nonsymmetric Markov chain fields strong law of large numbers asymptotic equipartition property
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SOME METRIC AND TOPOLOGICAL PROPERTIES OF NEARLY STRONGLY AND NEARLY VERY CONVEX SPACES
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作者 Zihou ZHANG Vicente MONTESINOS Chunyan LIU 《Acta Mathematica Scientia》 SCIE CSCD 2020年第2期369-378,共10页
We obtain characterizations of nearly strong convexity and nearly very convexity by using the dual concept of S and WS points,related to the so-called Rolewicz’s property(α).We give a characterization of those point... We obtain characterizations of nearly strong convexity and nearly very convexity by using the dual concept of S and WS points,related to the so-called Rolewicz’s property(α).We give a characterization of those points in terms of continuity properties of the identity mapping.The connection between these two geometric properties is established,and finally an application to approximative compactness is given. 展开更多
关键词 Banach spaces nearly strongly convex spaces nearly very convex spaces Kadec property Radon-Riesz property approximative compactness
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基于腐熟稻壳的育苗混配基质及其应用效果
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作者 张春梅 汪亚娟 +5 位作者 翟亚南 吕硕 吴晓蕾 高洪波 郜英豪 宫彬彬 《中国蔬菜》 北大核心 2024年第3期111-117,共7页
为研发以腐熟稻壳为主要成分的育苗基质,在测定腐熟稻壳等单一基质理化性质的基础上,根据基质理化性质模型,初步确定了以腐熟稻壳为主的11种育苗配方,并以番茄和叶用莴苣幼苗为试材,对配方进一步筛选确定适宜蔬菜幼苗生长的基质配方。... 为研发以腐熟稻壳为主要成分的育苗基质,在测定腐熟稻壳等单一基质理化性质的基础上,根据基质理化性质模型,初步确定了以腐熟稻壳为主的11种育苗配方,并以番茄和叶用莴苣幼苗为试材,对配方进一步筛选确定适宜蔬菜幼苗生长的基质配方。结果表明:腐熟稻壳EC值与容重适宜,但持水孔隙度偏小,不适宜单独作为育苗基质材料;通过模型预测的11种基质配方复合合意值为0.91~0.98,均在育苗基质适宜指标范围内,且11种基质配方的理化性质实测值与模型预估值相对误差较小,为3.23%~9.63%;混配后的腐熟稻壳基质可以满足蔬菜苗期的生长需要,其中腐熟稻壳∶蛭石∶珍珠岩以6∶2∶2的混配基质栽培的番茄和叶用莴苣生长效果最好,壮苗指数分别比对照提高82.76%和184.80%,植株生长健壮。基质理化性质预测模型用于基质的研发方法可行。 展开更多
关键词 腐熟稻壳 复合合意值 理化性质 番茄 叶用莴苣 壮苗指数
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施氮量对两个强筋小麦品种品质的影响
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作者 张一智 郭雷 +6 位作者 晏帅 王鲁振 赵一悦 陈怡菲 李红霞 王中华 高欣 《西北农业学报》 CAS CSCD 北大核心 2024年第4期595-605,共11页
为了探究施氮量对强筋小麦品质特性的影响,以强筋小麦品种‘郑麦366’和‘郑农46’为试验材料,分别设置0、120、240和360 kg/hm^(2)的施氮量,研究不同氮水平对小麦面筋蛋白组成及二级结构、淀粉的粒度分布和粘度特性、面团流变学特性的... 为了探究施氮量对强筋小麦品质特性的影响,以强筋小麦品种‘郑麦366’和‘郑农46’为试验材料,分别设置0、120、240和360 kg/hm^(2)的施氮量,研究不同氮水平对小麦面筋蛋白组成及二级结构、淀粉的粒度分布和粘度特性、面团流变学特性的影响。结果表明,‘郑麦366’和‘郑农46’分别在N_(1)(120 kg/hm^(2))和N_(2)(240 kg/hm^(2))水平下流变学特性达到最佳,这可能是因为两个小麦品种分别在N_(1)和N_(2)下蛋白质含量较高、总淀粉含量较低、B型淀粉相对含量较高;相比于N_(0)(0 kg/hm^(2)),N_(3)(360 kg/hm^(2))条件下的面团流变学特性显著降低,可能是由于过量施氮分别影响了‘郑麦366’的蛋白含量和‘郑农46’的B型淀粉含量。综上,相比于其他品质性状,蛋白含量对‘郑麦366’品质的影响更大,而B型淀粉含量的变化在‘郑农46’品质形成中起主导作用。本研究为强筋小麦‘郑麦366’和‘郑农46’的氮素施用提供理论依据。 展开更多
关键词 施氮量 强筋小麦 面筋蛋白 淀粉 二级结构 流变学特性
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限水条件下灌水量对强筋小麦旗叶衰老特性和籽粒产量的影响 被引量:1
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作者 毕经鑫 李清瑶 +4 位作者 蔡瑞国 王文政 杨敏 郭振清 张敏 《麦类作物学报》 CAS CSCD 北大核心 2024年第4期453-461,共9页
为探究灌水量对强筋小麦花后旗叶衰老和籽粒产量的调控效应,以2个强筋小麦品种(中麦998和中麦1062)为供试材料,设置0 m^(3)·hm^(-2)(W_(0))、450 m^(3)·hm^(-2)(W_(1))和900 m^(3)·hm^(-2)(W_(2))3个灌水量(拔节期和开... 为探究灌水量对强筋小麦花后旗叶衰老和籽粒产量的调控效应,以2个强筋小麦品种(中麦998和中麦1062)为供试材料,设置0 m^(3)·hm^(-2)(W_(0))、450 m^(3)·hm^(-2)(W_(1))和900 m^(3)·hm^(-2)(W_(2))3个灌水量(拔节期和开花期各灌水50%),分析了不同处理下小麦旗叶叶绿素含量、同化物含量、丙二醛含量、抗氧化酶活性、抗衰老激素含量、蛋白质含量和籽粒产量的差异。结果表明,增加灌水量可延缓强筋小麦花后旗叶衰老。灌浆前中期旗叶叶绿素含量在不同处理间无显著差异,灌浆后期叶绿素含量在W_(2)处理下最高。W_(2)处理下小麦旗叶可溶性糖含量显著高于其他处理;旗叶可溶性蛋白含量在花后0~21 d保持较高水平,在花后21~35 d含量逐渐下降,且W_(1)处理下花后21~35 d旗叶可溶性蛋白含量较W_(0)处理显著提高。灌水量对花后0~21 d强筋小麦旗叶中游离氨基酸含量无显著影响,而在灌浆后期以W_(2)处理最高;与W_(0)处理相比,增加灌水量可显著提高旗叶过氧化氢酶活性、过氧化物酶活性和生长素含量,显著降低丙二醛和脱落酸含量,并且显著延长测定酶活性和激素含量峰值出现时间。随灌水量的增加,籽粒蛋白质含量下降,但产量显著升高。总体来看,在本试验条件下,W_(2)处理(拔节水450 m^(3)·hm^(-2)+开花水450 m^(3)·hm^(-2))能够显著延缓强筋小麦旗叶衰老,在维持较高蛋白质含量同时,获得最高籽粒产量。 展开更多
关键词 强筋小麦 旗叶 衰老特性 籽粒产量
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邛崃产区中高温大曲性能及微生物动态变化研究
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作者 林涵瑞 刘林培 +7 位作者 黄蜀生 王峰 唐文博 陈勇 王轩 吴波 谢鸿观 何明雄 《食品与发酵工业》 CAS CSCD 北大核心 2024年第19期117-126,共10页
大曲被誉为“酒之骨”,其品质对于白酒发酵至关重要。通过Illumina高通量测序分析邛崃产区中高温大曲微生物结构的组成以及变化规律;利用顶空固相微萃取-气相色谱-质谱联用技术研究了挥发性风味物质成分;使用冗余分析与热图分析,将微生... 大曲被誉为“酒之骨”,其品质对于白酒发酵至关重要。通过Illumina高通量测序分析邛崃产区中高温大曲微生物结构的组成以及变化规律;利用顶空固相微萃取-气相色谱-质谱联用技术研究了挥发性风味物质成分;使用冗余分析与热图分析,将微生物群落结合大曲理化性质与挥发性物质综合分析其相关性。结果表明,大曲在制备过程中,性能与储存时间基本呈负相关。入库后风味物质含量与储存时间基本呈正相关。酯类与醇类是挥发性物质的主要成分,酯类以十六烷酸甲酯、9-十八碳烯酸甲酯、9,12-十八碳二烯酸甲酯为主,醇类物质基本以苯乙醇为主。优势细菌属为Staphylococcus、Escherichia-Shigella和Pediococcus。真菌分别以Thermoascus、Aspergillus和Pichia为优势真菌属。相关性分析显示,细菌优势菌属Pseudomonas与酯化力呈正相关,与十五烷酸甲酯的含量具有显著性正相关(P<0.05),真菌优势菌属Archaeorhizomyces与酯化力呈负相关,与苯乙醇的含量极显著性负相关(P<0.01)。结果显示,大曲的性能及挥发性物质与微生物结构的动态变化显著相关。文章研究了邛崃产区中高温大曲制备过程中的性能及微生物动态变化,为邛崃产区中高温大曲的品控提供一定的理论依据。 展开更多
关键词 邛崃产区 中高温大曲 性能品质 微生物群落 挥发性物质
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The Path-Positive Property on the Products of Graphs
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作者 连广昌 《Journal of Southeast University(English Edition)》 EI CAS 1998年第2期130-134,共5页
The products of graphs discussed in this paper are the following four kinds: the Cartesian product of graphs, the tensor product of graphs, the lexicographic product of graphs and the strong direct product of graphs. ... The products of graphs discussed in this paper are the following four kinds: the Cartesian product of graphs, the tensor product of graphs, the lexicographic product of graphs and the strong direct product of graphs. It is proved that:① If the graphs G 1 and G 2 are the connected graphs, then the Cartesian product, the lexicographic product and the strong direct product in the products of graphs, are the path positive graphs. ② If the tensor product is a path positive graph if and only if the graph G 1 and G 2 are the connected graphs, and the graph G 1 or G 2 has an odd cycle and max{ λ 1μ 1,λ nμ m}≥2 in which λ 1 and λ n [ or μ 1 and μ m] are maximum and minimum characteristic values of graph G 1 [ or G 2 ], respectively. 展开更多
关键词 product of graphs path positive property Cartesian product of graphs tensor product of graphs lexicographic product of graphs strong direct product of graphs
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堆石料宏细观力学特性离散元分析
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作者 杨舒涵 漆天奇 刘嘉英 《人民长江》 北大核心 2024年第2期203-210,共8页
堆石料的力学特性直接影响堆石坝工程的设计、施工和运行,对坝体变形及安全有重要影响。基于大石峡混凝土面板堆石坝工程,采用离散单元法(DEM)建立了接近于3BA区堆石料真实颗粒形状的椭球颗粒试样,开展了一系列常规三轴数值试验,研究了... 堆石料的力学特性直接影响堆石坝工程的设计、施工和运行,对坝体变形及安全有重要影响。基于大石峡混凝土面板堆石坝工程,采用离散单元法(DEM)建立了接近于3BA区堆石料真实颗粒形状的椭球颗粒试样,开展了一系列常规三轴数值试验,研究了3BA区堆石料的宏、细观力学特性。通过不同围压下的宏观应力应变演化曲线,获得堆石料的宏观应力、变形指标。采用平均接触力将接触网络划分为强、弱2个子网络,分析强、弱接触网络的配位数分布与拓扑演化规律。结果表明:割线模量、泊松比、峰值内摩擦角与围压呈线性变化,剪胀角与围压呈非线性变化;颗粒体系内接触的拓扑演化主要发生在弱接触网络,进而影响堆石料的宏观体积变化,强接触网络内的接触保持不变,为堆石料提供稳定的传力通道。研究结果可用于指导实际工程中不同围压下宏观力学指标的选取。 展开更多
关键词 离散元 椭球颗粒试样 宏观力学指标 强弱接触网络 拓扑 宏细观特性
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Lensless ghost imaging through the strongly scattering medium 被引量:4
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作者 杨哲 赵连洁 +2 位作者 赵学亮 秦伟 李俊林 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期170-174,共5页
Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system ... Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided. 展开更多
关键词 lensless ghost imaging second-order correlation strongly scattering medium robust property
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A study on physical property of crustal material and seismogenic environment in northeastern Pamir 被引量:2
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作者 刘志 张先康 +3 位作者 周雪松 赵金仁 张成科 潘纪顺 《Acta Seismologica Sinica(English Edition)》 CSCD 2003年第3期251-259,共9页
2-D crustal structure and velocity ratio are obtained by processing S-wave data from two wide-angle reflec-tion/refraction profiles in and around Jiashi in northeastern Pamir, with the result of P-wave data taken into... 2-D crustal structure and velocity ratio are obtained by processing S-wave data from two wide-angle reflec-tion/refraction profiles in and around Jiashi in northeastern Pamir, with the result of P-wave data taken into con-sideration. The result shows that: 1) Average crustal velocity ratio is obviously higher in Tarim block than in West Kunlun Mts. and Tianshan fold zone, which reflects its crustal physical property of 'hardness' and stability. The relatively low but normai velocity ratio (Poisson's ratio) of the lower crust indicates that the 'downward thrusting' of Tarim basin is the main feature of crustal movement in this area. 2) The rock layer in the upper crust of Tianshan fold zone is relatively 'soft', which makes it prone to rupture and stress energy release. This is the primary tectonic factor for the concentration of small earthquakes in this area. 3) Jiashi is located right over the apex or the inflection point of the updoming lower crustal interface C and the crust-mantle boundary, which is the deep struc-tural background for the occurrence of strong earthquakes. The alternate variation of vp/vs near the block bounda-ries and the complicated configuration of the interfaces in the upper and middie part of the upper crust form a par-ticular structural environment for the Jiashi strong earthquake swarm. vp/vs is comparatively high and shear modulus is low at the focal region, which may be the main reason for the low stress drop of the Jiashi strong earthquake swarm. 展开更多
关键词 northeastern Pamirs crustal structure in terms of physical property Jiashi strong earthquake swarm velocity ratio
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AN ANALOGUE OF KüNNETH THEOREM INSTRONG HOMOLOGY 被引量:1
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作者 Dae- Woong Lee 《Acta Mathematica Scientia》 SCIE CSCD 2002年第1期32-40,共9页
After defining the strong tensor product of strong (sub)chain complenes, it is shown that an analogue of the Kunneth theorem holds in strong homology by proving that the kernel (cokernel) of connecting homomorphisms i... After defining the strong tensor product of strong (sub)chain complenes, it is shown that an analogue of the Kunneth theorem holds in strong homology by proving that the kernel (cokernel) of connecting homomorphisms is isomorphic to the direct sum of torsion (tensor) products of strong homology groups. An isomorphism between strong (r-stage) homology groups of inverse systems is also constructed. 展开更多
关键词 Derived limit strong (r-stage) homology strong tensor product Mittag-Leffler property
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First-principles calculations of electronic and magnetic properties of CeN:The LDA +U method
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作者 郝爱民 白静 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期460-462,共3页
Electronic and magnetic properties of CeN are investigated using first-principles calculations based on density func- tional theory (DFT) with the LDA + U method. Our results show that CeN is a half-metal. The majo... Electronic and magnetic properties of CeN are investigated using first-principles calculations based on density func- tional theory (DFT) with the LDA + U method. Our results show that CeN is a half-metal. The majority-spin electron band structure has metallic intersections, whereas the minority-spin electron band structure has a semiconducting gap straddling the Fermi level. A small indirect energy gap occurs between X and W. The calculated magnetic moment is 0.99 μb per unit cell. 展开更多
关键词 first-principles calculations strongly correlated system electronic structure magnetic properties
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Research on strong earthquake type division and forecast method for subsequent strong earthquakes
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作者 陈海通 孙次昌 +1 位作者 黎向东 梁静 《Acta Seismologica Sinica(English Edition)》 CSCD 2000年第2期216-223,共8页
The relationships between energy, amplitude and frequency of eanhquake are correlative with the property of the seismic source. And the grade of the correlativity can be used as an index to distinguish the types of st... The relationships between energy, amplitude and frequency of eanhquake are correlative with the property of the seismic source. And the grade of the correlativity can be used as an index to distinguish the types of strong earth quakes. Primarily the strong earthquake can be divided into three types of main-after earthquakes, double-main earthquakes and swarm of strong earthquake. There are similarity and a certain repeatability at the quantificational indexes of hypocenter property between the same type of strong earthquakes, which supply basis for the forecast of subsequent strong shocks. The reference indexes of after strong shock forecast which are valuable for the applica tions of the method of type-divided forecast come from the analysis about more than fifty strong shock wide-band (BPZ wave) recording data of CDSN from 1988 to 1997. 展开更多
关键词 property of hypocenter type of strong earthquake quantificational index type-divided forecast
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强磁场下的格点QCD研究进展 被引量:6
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作者 丁亨通 李胜泰 刘俊宏 《核技术》 CAS CSCD 北大核心 2023年第4期96-107,共12页
本文综述了近期利用格点量子色动力学对强磁场下量子色动力学(Quantum Chromodynamics,QCD)性质的研究进展。首先介绍了在格点上如何引入磁场,重点阐述零温下QCD的手征性质、QCD相转变温度及反磁催化,以及强磁场下QCD相结构,最后给出总结。
关键词 强磁场 格点量子色动力学 相结构 手征性质
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数字经济时代知识产权司法鉴定制度的发展与完善 被引量:2
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作者 马治国 赵世桥 《西北大学学报(哲学社会科学版)》 CSSCI 北大核心 2023年第5期66-77,共12页
知识产权司法鉴定是知识产权保护不可缺少的专业技术支撑。改革开放40多年来,我国知识产权司法鉴定制度历经了基础奠定、初步设立、快速发展、清理退出和探索重建四个发展阶段。数字经济时代,知识产权保护工作中专业技术支撑的需求与日... 知识产权司法鉴定是知识产权保护不可缺少的专业技术支撑。改革开放40多年来,我国知识产权司法鉴定制度历经了基础奠定、初步设立、快速发展、清理退出和探索重建四个发展阶段。数字经济时代,知识产权保护工作中专业技术支撑的需求与日俱增,知识产权司法鉴定制度具有显著的制度优势和结构功能,并受国家高度重视,因而具备正当性。然而,法制保障、管理体制等方面的不足制约了知识产权司法鉴定制度的发展。为提升数字经济时代知识产权保护质效,加快知识产权强国建设,建议加强政策保障,开展知识产权司法鉴定制度创新试点工作,并围绕立法推进、机制配套、信用监管等方面对知识产权司法鉴定制度进行完善。 展开更多
关键词 数字经济 知识产权强国 知识产权司法鉴定 正当性
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A study of the strong pulses detected from PSR B0656+14 using the Urumqi 25-m radio telescope at 1540 MHz 被引量:2
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作者 Guo-Cun Tao Ali Esamdin +3 位作者 Hui-Dong Hu Mao-Fei Qian Jing Li Na Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第12期1649-1654,共6页
We report on the properties of strong pulses from PSR B0656+14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total... We report on the properties of strong pulses from PSR B0656+14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656+14 have different characteristics from both typical giant pulses and its regular pulses. 展开更多
关键词 stars:neutron-pulsars-pulsars:individual(B0656+14)Options: Encrypt Page Allow Cookies Remove Scripts Remove Objects 收藏本站首页期刊全文库学位论文库会议论文库学术百科吾喜杂志工具书优先出版注册|登录|我的账户基础科学|工程科技I辑|工程科技II辑|医药卫生科技|信息科技|农业科技|哲学与人文科学|社会科学I辑|社会科学II辑|经济管理高级搜索: 用" stars neutron-pulsars—pulsars "到知网平台检索 点击这里搜索更多...《Research in Astronomy and Astrophysics》 2012年12期 加入收藏 获取最新 A study of the strong pulses detected from PSR B0656+14 using the Urumqi 25-m radio telescope at 1540 MHzAli Esamdin 【摘要】: We report on the properties of strong pulses from PSR B0656+14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile they are relatively narrow with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656+14 have different characteristics from both typical giant pulses and its regular pulses.【作者单位】 Xinjiang
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代数不等式的概率证明方法
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作者 刘杰 胡太忠 庄玮玮 《高等数学研究》 2023年第1期21-24,27,共5页
本文讨论了三种概率性质在代数不等式证明中的应用,阐述了如何针对不等式的特点构造随机事件和随机变量,运用概率强可加性、方差非负性、期望线性性质进行不等式证明,同时结合实例展示了证明过程和技巧.
关键词 概率强可加性 方差非负性 期望线性性质 不等式
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花岗岩的动态力学性能、本构模型与状态方程研究 被引量:2
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作者 李干 李杰 +2 位作者 宋春明 李孝臣 王明洋 《力学与实践》 北大核心 2023年第5期952-959,共8页
为研究强动载荷条件下花岗岩的动态力学性能、本构模型与状态方程,分别采用分离式霍普金森压杆和轻气炮系统进行了压杆试验和飞片撞击试验,以获得不同条件下花岗岩的动态力学参数。压杆试验结果表明,花岗岩在应变率为80~320 s-1范围内... 为研究强动载荷条件下花岗岩的动态力学性能、本构模型与状态方程,分别采用分离式霍普金森压杆和轻气炮系统进行了压杆试验和飞片撞击试验,以获得不同条件下花岗岩的动态力学参数。压杆试验结果表明,花岗岩在应变率为80~320 s-1范围内呈现明显的应变率效应,其强度和应变率近似呈指数关系。飞片撞击试验表明,随着飞片速度的增大,冲击波传播速度呈现明显的三折线变化趋势,而试样的可压缩性则随着加载速度的提高先逐渐增强然后再次降低。最后,根据试验数据,给出了强动载荷条件下花岗岩的HJC(Holmquist-Johnson-Cook)本构模型、Gruneisen状态方程以及动态屈服强度参数。 展开更多
关键词 强动载荷 花岗岩 动态力学性能 本构模型 状态方程
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对称分子H_(2)^(+)在强短波激光场中高次谐波椭偏率性质的研究 被引量:1
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作者 于术娟 刘竹琴 李雁鹏 《物理学报》 SCIE EI CAS CSCD 北大核心 2023年第4期18-26,共9页
通过数值计算,研究了强短波(400—600 nm)激光场中H_(2)^(+)分子高次谐波辐射的椭偏率性质.研究表明,H_(2)^(+)分子在不同激光强度、不同激光波长、不同核间距及不同取向角下高次谐波的椭偏率性质是不同的;特别是在两中心干涉区,激发态... 通过数值计算,研究了强短波(400—600 nm)激光场中H_(2)^(+)分子高次谐波辐射的椭偏率性质.研究表明,H_(2)^(+)分子在不同激光强度、不同激光波长、不同核间距及不同取向角下高次谐波的椭偏率性质是不同的;特别是在两中心干涉区,激发态在高次谐波产生中起着重要作用,但在不同取向角下,激发态对谐波椭偏率的影响不同;分析表明,这些不同的影响源于沿平行和垂直于激光偏振方向辐射的高次谐波的相对产量,以及激发态对平行和垂直谐波产量的影响;此外,椭偏率的测量检验了强场近似和平面波近似在强短波激光场中是成立的,并对强短波激光场中分子动力学做了更充分的研究. 展开更多
关键词 高次谐波 高频激光场 谐波椭偏率 偶极子
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