This paper deals with the boundedness and compactness of the compositionintegral type operators T g, from F (p, q, s) spaces to(little) Bloch-type spaces in the unit ball of C n , where Tg,φf(z) =∫01fφ(tz)Rg(tz)(dt...This paper deals with the boundedness and compactness of the compositionintegral type operators T g, from F (p, q, s) spaces to(little) Bloch-type spaces in the unit ball of C n , where Tg,φf(z) =∫01fφ(tz)Rg(tz)(dt)/t , z ∈ B, g ∈ H(B) and φ∈H(B, B).展开更多
The Bloch-type space Bω consists of all functions f ∈ H(B) for which||f||Bω=sup/z∈Bω(z)|▽f(z)|< ∞.Let T be the extended Ces`aro operator with holomorphic symbol . The essential norm of T as an operator f...The Bloch-type space Bω consists of all functions f ∈ H(B) for which||f||Bω=sup/z∈Bω(z)|▽f(z)|< ∞.Let T be the extended Ces`aro operator with holomorphic symbol . The essential norm of T as an operator from Bω to Bμ is denoted by ||T||e,B ω→Bμ . The purpose of this paper is to prove that, for ω, μ normal and ∈H(B)||T||e,B ω→Bμ■ lim sup|z|→1 μ(z)|■ (z)|∫ |z| 0 dt ω(t) .展开更多
The boundedness and compactness of the weighted differentiation composition operators from mixed-norm spaces to Bloch-type spaces are discussed in this paper.
Let H(B) be the set of all harmonic functions f on the unit ball B of Rn. For 0 p, q ≤ ∞ and a normal weight φ, the mixed norm space Hp,q, φ(B) consists of all functions f in H(B) for which the mixed norm p,...Let H(B) be the set of all harmonic functions f on the unit ball B of Rn. For 0 p, q ≤ ∞ and a normal weight φ, the mixed norm space Hp,q, φ(B) consists of all functions f in H(B) for which the mixed norm p,q, φ ∞. In this article, we obtain some characterizations in terms of radial, tangential, and partial derivative norms in Hp,q, φ(B). The parallel results for the Bloch-type space are also obtained. As an application, the analogous problems for polyharmonic functions are discussed.展开更多
There is little work concerning the properties of quaternionic operators acting on slice regular function spaces defined on quaternions.In this paper,we present an equivalent characterization for the boundedness of th...There is little work concerning the properties of quaternionic operators acting on slice regular function spaces defined on quaternions.In this paper,we present an equivalent characterization for the boundedness of the product operator C_(φ)D^(m) acting on Bloch-type spaces of slice regular functions.After that,an equivalent estimation for its essential norm is established,which can imply several existing results on holomorphic spaces.展开更多
We characterize the symbol for which the induced extended Cesàro operator T: Bω→ Bμ(respectively, Bω,0 → Bμ,0) is bounded or compact, where is a given holomorphic function on the unit disc D, ω and...We characterize the symbol for which the induced extended Cesàro operator T: Bω→ Bμ(respectively, Bω,0 → Bμ,0) is bounded or compact, where is a given holomorphic function on the unit disc D, ω and μ both are normal functions on [0,1).展开更多
In order to investigate the boundedness or compactness of composition operator from the logarithmic Bloch-type space to the Bergman space on the unit polydisc, the classic Bergman norm is firstly changed into another ...In order to investigate the boundedness or compactness of composition operator from the logarithmic Bloch-type space to the Bergman space on the unit polydisc, the classic Bergman norm is firstly changed into another equivalent norm. Then according to some common inequalities, the properties of logarithmic Bloch-type space and the absolute continuity of the general integral, the conditions which the symbol map must meet when the composition operator is bounded or compact are obtained after a series of calculations, and the boundedness and compactness are proved to be equivalent.展开更多
目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,...目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。展开更多
We characterize those holomorphic mappings ψ from the polydisc Dn in Cn to itself for which the induced composition operators Cψ are bounded (or compact) from the Bloch-type space Bω to βμ (respectively, from the...We characterize those holomorphic mappings ψ from the polydisc Dn in Cn to itself for which the induced composition operators Cψ are bounded (or compact) from the Bloch-type space Bω to βμ (respectively, from the little Bloch-type space Bω,0 to Bμ,0),where ω is a normal function on [0, 1) andμ is a nonnegative function on [0, 1) withμ(tn) > 0for some sequence {tn}n∞n=1(∪) [0, 1) satisfying limn→∞ tn = 1.展开更多
Let B be the unit ball of a complex Banach space X. In this paper, we generalize the Bloch-type spaces and the little Bloch-type spaces to the open unit ball B by using the radial derivative. Next, we de?ne an extende...Let B be the unit ball of a complex Banach space X. In this paper, we generalize the Bloch-type spaces and the little Bloch-type spaces to the open unit ball B by using the radial derivative. Next, we de?ne an extended Ces`aro operator T_φ with the holomorphic symbol φ and characterize those φ for which T_φ is bounded between the Bloch-type spaces and the little Bloch-type spaces. We also characterize those φ for which T_φ is compact between the Bloch-type spaces and the little Bloch-type spaces under some additional assumption on the symbol φ. When B is the open unit ball of a ?nite dimensional complex Banach space X, this additional assumption is automatically satis?ed.展开更多
目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作...目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作者、关键词进行分析。结果最终纳入多发伤急救研究文献2519篇,整体发文数量较平稳,以2016年为小高峰;发文量最高的机构是华中科技大学附属同济医院。多发伤急救研究热点包括院前急救、并发症护理、风险因素分析和预后效果评估,研究前沿包括不同多发伤人群的诊断、治疗、手术和护理体会等方面。结论本文通过可视化分析国内多发伤急救研究的热点及趋势,指明了多发伤目前研究存在的问题和未来研究发展的方向,为进一步完善多发伤急救卫生服务和管理体系提供指导。展开更多
高质量教师是高质量教育发展的中坚力量。教师信念作为教师专业素养构成的关键要素,对促进教师专业发展、提升教师质量具有重要作用与影响。为借鉴国际体育教师信念研究的成果与经验,促进国内对体育教师信念的研究,研究利用CiteSpace软...高质量教师是高质量教育发展的中坚力量。教师信念作为教师专业素养构成的关键要素,对促进教师专业发展、提升教师质量具有重要作用与影响。为借鉴国际体育教师信念研究的成果与经验,促进国内对体育教师信念的研究,研究利用CiteSpace软件,对Web of Science核心合集数据库中1960—2022年的英文文献进行可视化研究。发现:体育教师信念研究高潮出现于2021年,载文数量最多的期刊是Journal of Teaching in Physical Education;研究中心度最高的国家是美国,核心圈层的代表学者是Richards KAR、Kulinna PH和Curtner-smith MD等人;研究热点趋势集中于体力活动促进、职业社会化、批判性教学法、职前体育教师、专业发展等方面。启示:国内未来研究应重点关注体育教师信念对课程改革的影响以及促进职前、职后阶段体育教师信念的发展。展开更多
近年来,我国生物产业快速发展,且发酵对身体和胃肠道健康具有很多益处,有关微生物发酵的研究逐渐增多。为探讨发酵领域近5年的研究现状与发展前景,对中国知网和Web of Science数据库中2019—2023年发表的文献进行检索并筛选,使用Cite Sp...近年来,我国生物产业快速发展,且发酵对身体和胃肠道健康具有很多益处,有关微生物发酵的研究逐渐增多。为探讨发酵领域近5年的研究现状与发展前景,对中国知网和Web of Science数据库中2019—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队、研究热点进行图谱分析。结果表明,近5年国内发酵领域发文量偏少,年发文量平稳上升;国外发文量较多,年发文量超过100篇,2023年发文量达到200篇;国内外研究群体主要是中医药高校和研究机构;国内外研究热点集中在抗氧化和肠道菌群,国内研究重点为发酵技术,而国外研究范围较广,重点为益生菌的研究;国内外学者间合作较为密切,但研究机构间尚未形成紧密的合作关系。高校和研究机构应突破地区间的限制,促进发酵研究领域的融合。肠道菌群是近5年发酵的研究热点,也是未来发酵研究深入的对象。展开更多
为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示...为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示,从发文量看,国内外学者对护理不良事件的关注度整体较高,可视化分析结果并未发现作者之间、机构之间的联系。未来减少护理不良事件的方法一定会越来越紧贴科学技术,越来越多的新型信息化平台、App等会用于医疗行业,降低护理不良事件预防的难度,但护理人员仍要重视护理安全。展开更多
In this article,we investigate the(big) Hankel operator H_(f) on the Hardy spaces of bounded strongly pseudoconvex domains Ω in C^(n).We observe that H_(f )is bounded on H~p(Ω)(1 <p <∞) if f belongs to BMO an...In this article,we investigate the(big) Hankel operator H_(f) on the Hardy spaces of bounded strongly pseudoconvex domains Ω in C^(n).We observe that H_(f )is bounded on H~p(Ω)(1 <p <∞) if f belongs to BMO and we obtain some characterizations for Hf on H~2(Ω) of other pseudoconvex domains.In these arguments,Amar's L~p-estimations and Berndtsson's L^(2)-estimations for solutions of the ■_(b)-equation play a crucial role.In addition,we solve Gleason's problem for Hardy spaces H~p(Ω)(1 ≤p≤∞) of bounded strongly pseudoconvex domains.展开更多
Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in sit...Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.展开更多
Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying som...Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying some mild assumptions.Let HX,L(ℝ^(n))be the Hardy space associated with both X and L,which is defined by the Lusin area function related to the semigroup generated by L.In this article,the authors establish various maximal function characterizations of the Hardy space HX,L(ℝ^(n))and then apply these characterizations to obtain the solvability of the related Cauchy problem.These results have a wide range of generality and,in particular,the specific spaces X to which these results can be applied include the weighted space,the variable space,the mixed-norm space,the Orlicz space,the Orlicz-slice space,and the Morrey space.Moreover,the obtained maximal function characterizations of the mixed-norm Hardy space,the Orlicz-slice Hardy space,and the Morrey-Hardy space associated with L are completely new.展开更多
基金Supported by the NNSF of China(10771064, 11101139)Supported by the NSF of Zhejiang Province(Y7080197, Y6090036, Y6100219)Supported by the Foundation of Creative Group in Colleges and Universities of Zhejiang Province(T200924)
文摘This paper deals with the boundedness and compactness of the compositionintegral type operators T g, from F (p, q, s) spaces to(little) Bloch-type spaces in the unit ball of C n , where Tg,φf(z) =∫01fφ(tz)Rg(tz)(dt)/t , z ∈ B, g ∈ H(B) and φ∈H(B, B).
基金Supported by the NNSF of China(10771064) Supported by the Natural Science Foundation of Zhejiang Province(YT080197, Y6090036, Y6100219) Supported by the Foundation of Creative Group in Colleges and Universities of Zhejiang Province(T200924)
Acknowledgement The author would like to express her thanks to her supervisor, Prof HU Zhang-jian, for his guidance.
文摘The Bloch-type space Bω consists of all functions f ∈ H(B) for which||f||Bω=sup/z∈Bω(z)|▽f(z)|< ∞.Let T be the extended Ces`aro operator with holomorphic symbol . The essential norm of T as an operator from Bω to Bμ is denoted by ||T||e,B ω→Bμ . The purpose of this paper is to prove that, for ω, μ normal and ∈H(B)||T||e,B ω→Bμ■ lim sup|z|→1 μ(z)|■ (z)|∫ |z| 0 dt ω(t) .
基金item: Supported by the National Natural Science Foundation of China(60573040)
文摘The boundedness and compactness of the weighted differentiation composition operators from mixed-norm spaces to Bloch-type spaces are discussed in this paper.
基金Supported by the NNSF of China (10771064,10971063)the NSF of Zhejiang Province (Y6100219, Y7080197, Y6090036, D7080080)the Innovation Team Foundation of the Department of Education of Zhejiang Province (T200924)
文摘Let H(B) be the set of all harmonic functions f on the unit ball B of Rn. For 0 p, q ≤ ∞ and a normal weight φ, the mixed norm space Hp,q, φ(B) consists of all functions f in H(B) for which the mixed norm p,q, φ ∞. In this article, we obtain some characterizations in terms of radial, tangential, and partial derivative norms in Hp,q, φ(B). The parallel results for the Bloch-type space are also obtained. As an application, the analogous problems for polyharmonic functions are discussed.
基金supported by the National Natural Science Foundation of China(11701422).
文摘There is little work concerning the properties of quaternionic operators acting on slice regular function spaces defined on quaternions.In this paper,we present an equivalent characterization for the boundedness of the product operator C_(φ)D^(m) acting on Bloch-type spaces of slice regular functions.After that,an equivalent estimation for its essential norm is established,which can imply several existing results on holomorphic spaces.
基金Supported by the National Natural Science Foundation of China(10471039)Supported by the Natural Science Foundation of Zhejiang Province(Y606197)Supported by the Foundation of Education of Zhejiang Province(20070482)
文摘We characterize the symbol for which the induced extended Cesàro operator T: Bω→ Bμ(respectively, Bω,0 → Bμ,0) is bounded or compact, where is a given holomorphic function on the unit disc D, ω and μ both are normal functions on [0,1).
基金Supported by National Natural Science Foundation of China (No.10971153)
文摘In order to investigate the boundedness or compactness of composition operator from the logarithmic Bloch-type space to the Bergman space on the unit polydisc, the classic Bergman norm is firstly changed into another equivalent norm. Then according to some common inequalities, the properties of logarithmic Bloch-type space and the absolute continuity of the general integral, the conditions which the symbol map must meet when the composition operator is bounded or compact are obtained after a series of calculations, and the boundedness and compactness are proved to be equivalent.
文摘目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。
基金supported by the National Natural Science Foundation of China(Grant No.10471039)the Natural Science Foundation of Zhejiang Ptovince(Grant No.M103104).
文摘We characterize those holomorphic mappings ψ from the polydisc Dn in Cn to itself for which the induced composition operators Cψ are bounded (or compact) from the Bloch-type space Bω to βμ (respectively, from the little Bloch-type space Bω,0 to Bμ,0),where ω is a normal function on [0, 1) andμ is a nonnegative function on [0, 1) withμ(tn) > 0for some sequence {tn}n∞n=1(∪) [0, 1) satisfying limn→∞ tn = 1.
基金supported by Japan Society for the Promotion of Science KAKENHI (Grant No. JP16K05217)
文摘Let B be the unit ball of a complex Banach space X. In this paper, we generalize the Bloch-type spaces and the little Bloch-type spaces to the open unit ball B by using the radial derivative. Next, we de?ne an extended Ces`aro operator T_φ with the holomorphic symbol φ and characterize those φ for which T_φ is bounded between the Bloch-type spaces and the little Bloch-type spaces. We also characterize those φ for which T_φ is compact between the Bloch-type spaces and the little Bloch-type spaces under some additional assumption on the symbol φ. When B is the open unit ball of a ?nite dimensional complex Banach space X, this additional assumption is automatically satis?ed.
文摘目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作者、关键词进行分析。结果最终纳入多发伤急救研究文献2519篇,整体发文数量较平稳,以2016年为小高峰;发文量最高的机构是华中科技大学附属同济医院。多发伤急救研究热点包括院前急救、并发症护理、风险因素分析和预后效果评估,研究前沿包括不同多发伤人群的诊断、治疗、手术和护理体会等方面。结论本文通过可视化分析国内多发伤急救研究的热点及趋势,指明了多发伤目前研究存在的问题和未来研究发展的方向,为进一步完善多发伤急救卫生服务和管理体系提供指导。
文摘高质量教师是高质量教育发展的中坚力量。教师信念作为教师专业素养构成的关键要素,对促进教师专业发展、提升教师质量具有重要作用与影响。为借鉴国际体育教师信念研究的成果与经验,促进国内对体育教师信念的研究,研究利用CiteSpace软件,对Web of Science核心合集数据库中1960—2022年的英文文献进行可视化研究。发现:体育教师信念研究高潮出现于2021年,载文数量最多的期刊是Journal of Teaching in Physical Education;研究中心度最高的国家是美国,核心圈层的代表学者是Richards KAR、Kulinna PH和Curtner-smith MD等人;研究热点趋势集中于体力活动促进、职业社会化、批判性教学法、职前体育教师、专业发展等方面。启示:国内未来研究应重点关注体育教师信念对课程改革的影响以及促进职前、职后阶段体育教师信念的发展。
文摘近年来,我国生物产业快速发展,且发酵对身体和胃肠道健康具有很多益处,有关微生物发酵的研究逐渐增多。为探讨发酵领域近5年的研究现状与发展前景,对中国知网和Web of Science数据库中2019—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队、研究热点进行图谱分析。结果表明,近5年国内发酵领域发文量偏少,年发文量平稳上升;国外发文量较多,年发文量超过100篇,2023年发文量达到200篇;国内外研究群体主要是中医药高校和研究机构;国内外研究热点集中在抗氧化和肠道菌群,国内研究重点为发酵技术,而国外研究范围较广,重点为益生菌的研究;国内外学者间合作较为密切,但研究机构间尚未形成紧密的合作关系。高校和研究机构应突破地区间的限制,促进发酵研究领域的融合。肠道菌群是近5年发酵的研究热点,也是未来发酵研究深入的对象。
文摘为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示,从发文量看,国内外学者对护理不良事件的关注度整体较高,可视化分析结果并未发现作者之间、机构之间的联系。未来减少护理不良事件的方法一定会越来越紧贴科学技术,越来越多的新型信息化平台、App等会用于医疗行业,降低护理不良事件预防的难度,但护理人员仍要重视护理安全。
基金supported by the National Natural Science Foundation of China(12271101)。
文摘In this article,we investigate the(big) Hankel operator H_(f) on the Hardy spaces of bounded strongly pseudoconvex domains Ω in C^(n).We observe that H_(f )is bounded on H~p(Ω)(1 <p <∞) if f belongs to BMO and we obtain some characterizations for Hf on H~2(Ω) of other pseudoconvex domains.In these arguments,Amar's L~p-estimations and Berndtsson's L^(2)-estimations for solutions of the ■_(b)-equation play a crucial role.In addition,we solve Gleason's problem for Hardy spaces H~p(Ω)(1 ≤p≤∞) of bounded strongly pseudoconvex domains.
基金CNSA for providing access to the lunar sample CE5C0200YJFM00302funding support from the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB 41000000)+5 种基金the National Natural Science Foundation of China (Nos. 42273042 and 41931077)the Youth Innovation Promotion Association Chinese Academy of Sciences (No. 2020395)Key Research Program of Frontier Sciences, Chinese Academy of Sciences (Nos. ZDBS-SSW-JSC00710 and QYZDY-SSW-DQC028)the Young and Middleaged Academic Technology Leader Reserve Talent Project of Yunnan Province (No. 2018HB009)the Science Fund for Outstanding Youth of Yunnan Province (No. 202101 AV070007)the "From 0 to 1" Original Exploration Cultivation Project, Institute of Geochemistry, Chinese Academy of Sciences (No. DHSZZ2023-3)
文摘Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.
基金supported by the National Key Research and Development Program of China(2020YFA0712900)the National Natural Science Foundation of China(12371093,12071197,12122102 and 12071431)+2 种基金the Key Project of Gansu Provincial National Science Foundation(23JRRA1022)the Fundamental Research Funds for the Central Universities(2233300008 and lzujbky-2021-ey18)the Innovative Groups of Basic Research in Gansu Province(22JR5RA391).
文摘Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying some mild assumptions.Let HX,L(ℝ^(n))be the Hardy space associated with both X and L,which is defined by the Lusin area function related to the semigroup generated by L.In this article,the authors establish various maximal function characterizations of the Hardy space HX,L(ℝ^(n))and then apply these characterizations to obtain the solvability of the related Cauchy problem.These results have a wide range of generality and,in particular,the specific spaces X to which these results can be applied include the weighted space,the variable space,the mixed-norm space,the Orlicz space,the Orlicz-slice space,and the Morrey space.Moreover,the obtained maximal function characterizations of the mixed-norm Hardy space,the Orlicz-slice Hardy space,and the Morrey-Hardy space associated with L are completely new.