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Preliminary geological interpretation of long-wavelength magnetic anomalies over China and surrounding regions
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作者 Jie Wang YanYan Yang +4 位作者 ZhiMa Zeren Jian Wang Xin Wang YuXin Luo XuHui Shen 《Earth and Planetary Physics》 EI CAS CSCD 2024年第3期445-458,共14页
Long-wavelength(>500 km)magnetic anomalies originating in the lithosphere were first found in satellite magnetic surveys.Compared to the striking magnetic anomalies around the world,the long-wavelength magnetic ano... Long-wavelength(>500 km)magnetic anomalies originating in the lithosphere were first found in satellite magnetic surveys.Compared to the striking magnetic anomalies around the world,the long-wavelength magnetic anomalies in China and surrounding regions are relatively weak.Specialized research on each of these anomalies has been quite inadequate;their geological origins remain unclear,in particular their connection to tectonic activity in the Chinese and surrounding regions.We focus on six magnetic high anomalies over the(1)Tarim Basin,(2)Sichuan Basin(3)Great Xing’an Range,(4)Barmer Basin,(5)Central Myanmar Basin,and(6)Sunda and Banda Arcs,and a striking magnetic low anomaly along the southern part of the Himalayan-Tibetan Plateau.We have analyzed their geological origins by reviewing related research and by detailed comparison with geological results.The tectonic backgrounds for these anomalies belong to two cases:either ancient basin basement,or subduction-collision zone.However,the geological origins of large-scale regional magnetic anomalies are always subject to dispute,mainly because of limited surface exposure of sources,later tectonic destruction,and superposition of multi-phase events. 展开更多
关键词 long-wavelength magnetic anomaly lithospheric magnetic anomaly lithospheric magnetic field model satellite magnetic survey CSES
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Investigation of long-wavelength elastic wave propagation through wet bentonite-filled rock joints
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作者 Ji-Won Kim Song-Hun Chong +1 位作者 Jin-Seop Kim Geon-Young Kim 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2496-2507,共12页
The saturation of the compacted bentonite buffer in the deep geological repository can cause bentonite swelling,intrusion into rock fractures,and erosion.Inevitably,erosion and subsequent bentonite mass loss due to gr... The saturation of the compacted bentonite buffer in the deep geological repository can cause bentonite swelling,intrusion into rock fractures,and erosion.Inevitably,erosion and subsequent bentonite mass loss due to groundwater inflow can aggravate the overall integrity of the engineered barrier system.Therefore,the coupled hydro-mechanical interaction between the buffer and rock during groundwater inflow and bentonite intrusion should be evaluated to guarantee the long-term safety of deep geological disposal.This study investigated the effect of bentonite erosion and intrusion on the elastic wave propagation characteristics in jointed rocks using a quasi-static resonant column test.Jointed rock specimens with different joint conditions(i.e.joint surface saturation and bentonite filling)were prepared using granite rock discs sampled from the Korea Underground Research Tunnel(KURT)and Gyeongju bentonite.The long-wavelength longitudinal and shear wave velocities were measured under different normal stress levels.A Hertzian-type power model was used to fit the wave velocities,and the relationship between the two fitted parameters provided the trend of joint conditions.Numerical simulations using three-dimensional distinct element code(3DEC)were conducted to better understand how the long-wavelength wave propagates through wet bentonite-filled rock joints. 展开更多
关键词 Engineered barrier system Bentonite erosion and intrusion Jointed rock mass long-wavelength elastic wave velocity Quasi-static resonant column test Three-dimensional distinct element code(3DEC)
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Development of long-wavelength infrared detector and its space-based application requirements 被引量:1
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作者 Junku Liu Lin Xiao +2 位作者 Yang Liu Longfei Cao Zhengkun Shen 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第2期58-70,共13页
Infrared detection technology has greatly expanded the ability of mankind to study the earth and the universe. In recent years, the demand for long-wavelength infrared detectors is increasing for their advantages in e... Infrared detection technology has greatly expanded the ability of mankind to study the earth and the universe. In recent years, the demand for long-wavelength infrared detectors is increasing for their advantages in exploring the earth and the universe. A variety of long-wavelength infrared detectors have been made based on thermal resistive effect, photoelectric effect, etc., in the past few decades. Remarkable achievements have been made in infrared materials, device fabrication,readout circuit, and device package. However, high performance long-wavelength infrared detectors, especially those for large format long-wavelength infrared detector focus plane array, are still unsatisfactory. Low noise, high detectivity, and large format long-wavelength infrared detector is necessary to satisfy space-based application requirements. 展开更多
关键词 long-wavelength INFRARED DETECTOR THERMAL DETECTOR PHOTON DETECTOR SPACE-BASED application
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Growth of high material quality InAs/GaSb type-Ⅱ superlattice for long-wavelength infrared range by molecular beam epitaxy
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作者 Fang-Qi Lin Nong Li +10 位作者 Wen-Guang Zhou Jun-Kai Jiang Fa-Ran Chang Yong Li Su-Ning Cui Wei-Qiang Chen Dong-Wei Jiang Hong-Yue Hao Guo-Wei Wang Ying-Qiang Xu Zhi-Chuan Niu 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第9期624-627,共4页
By optimizing theⅤ/Ⅲbeam-equivalent pressure ratio,a high-quality InAs/GaSb type-Ⅱsuperlattice material for the long-wavelength infrared(LWIR)range is achieved by molecular beam epitaxy(MBE).High-resolution x-ray d... By optimizing theⅤ/Ⅲbeam-equivalent pressure ratio,a high-quality InAs/GaSb type-Ⅱsuperlattice material for the long-wavelength infrared(LWIR)range is achieved by molecular beam epitaxy(MBE).High-resolution x-ray diffraction(HRXRD),atomic force microscopy(AFM),and Fourier transform infrared(FTIR)spectrometer are used to characterize the material growth quality.The results show that the full width at half maximum(FWHM)of the superlattice zero-order diffraction peak,the mismatching of the superlattice zero-order diffraction peak between the substrate diffraction peaks,and the surface roughness get the best results when the beam-equivalent pressure(BEP)ratio reaches the optimal value,which are 28 arcsec,13 arcsec,and 1.63?,respectively.The intensity of the zero-order diffraction peak is strongest at the optimal value.The relative spectral response of the LWIR detector shows that it exhibits a 100%cut-off wavelength of 12.6μm at 77 K.High-quality epitaxial materials have laid a good foundation for preparing high-performance LWIR detector. 展开更多
关键词 type-Ⅱsuperlattice INAS/GASB long-wavelength strain-balanced
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The Long-Wavelength Mantle Structure, and the supercontinent Evolution since the Paleozoic
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作者 ZHANG Nan LI Zheng-Xiang ZHONG Shijie 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期49-,共1页
The Earth’s lower mantle structure,as revealed by seismic tomography studies,is best characterized by two large low seismic velocity provinces(i.e.,LLSVP)beneath Africa and Pacific and their surrounding,circum-
关键词 The long-wavelength Mantle Structure and the supercontinent Evolution since the Paleozoic
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A non-peptide-based chymotrypsin-targeted long-wavelength emission fluorescent probe with large Stokes shift and its application in bioimaging
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作者 Chuanfeng Fan Jian Gao +10 位作者 Yingkai Gao Xintong Yang Gaoning Li Xiaochun Wang Fei Li Jin Zhou Haifeng Yu Yi Huang Jin Chen Yingying Shan Li Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第10期430-436,共7页
As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an inno... As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an innovative long-wavelength emission fluorescent probe TCF-CHT was designed and synthesized for the high specificity detection of CHT,which utilized TCF-OH and a mimetic peptide substrate 4-bromobutyryl as chromogenic group and recognition group,respectively.TCF-CHT exhibited excellent selectivity and eye-catching sensitivity(8.91 ng/m L)towards CHT,“off-on”long-wavelength emission at 670 nm and large Stokes shift(140 nm).Furthermore,the successful fulfillment and perfect performance in imaging endogenous CHT in complex organisms(P815 cells,HepG2 cells,zebrafish and tumor-bearing mice)verified its potential as a powerful tool for the recognition of CHT in complicated biological environments. 展开更多
关键词 CHYMOTRYPSIN Fluorescent probe long-wavelength emission Large Stokes shift BIOIMAGING
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A review on the developments and space applications of mid- and long-wavelength infrared detection technologies
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作者 Yuying WANG Jindong LI +1 位作者 Hezhi SUN Xiang LI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2024年第8期1031-1056,共26页
Mid-wavelength infrared(MWIR)detection and long-wavelength infrared(LWIR)detection constitute the key technologies for space-based Earth observation and astronomical detection.The advanced ability of infrared(IR)detec... Mid-wavelength infrared(MWIR)detection and long-wavelength infrared(LWIR)detection constitute the key technologies for space-based Earth observation and astronomical detection.The advanced ability of infrared(IR)detection technology to penetrate the atmosphere and identify the camouflaged targets makes it excellent for space-based remote sensing.Thus,such detectors play an essential role in detecting and tracking low-temperature and far-distance moving targets.However,due to the diverse scenarios in which space-based IR detection systems are built,the key parameters of IR technologies are subject to unique demands.We review the developments and features of MWIR and LWIR detectors with a particular focus on their applications in space-based detection.We conduct a comprehensive analysis of key performance indicators for IR detection systems,including the ground sampling distance(GSD),operation range,and noise equivalent temperature difference(NETD)among others,and their interconnections with IR detector parameters.Additionally,the influences of pixel distance,focal plane array size,and operation temperature of space-based IR remote sensing are evaluated.The development requirements and technical challenges of MWIR and LWIR detection systems are also identified to achieve high-quality space-based observation platforms. 展开更多
关键词 Infrared detection Space application Mid-and long-wavelength infrared detection Space-based Earth observation Remote sensing
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乙纶分子结构及热变性三级长波近红外-中红外光谱研究 被引量:7
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作者 柴嘉欣 吉一帆 +5 位作者 李雨情 宗鹤宸 宗雪晴 王静伟 常美玲 于宏伟 《纺织科学与工程学报》 CAS 2024年第1期58-67,共10页
长波近红外-中红外(LW-NIR-MIR)光谱开展乙纶分子结构研究。红外模式主要包括:2ν_(asCH3-去卷积-乙纶)、2ν_(asCH2-去卷积-乙纶)、2ν_(sCH3-去卷积-乙纶)、2ν_(sCH2-去卷积-乙纶)、(ν_(asCH2-去卷积-乙纶)+ν_(CH-去卷积-乙纶))、(... 长波近红外-中红外(LW-NIR-MIR)光谱开展乙纶分子结构研究。红外模式主要包括:2ν_(asCH3-去卷积-乙纶)、2ν_(asCH2-去卷积-乙纶)、2ν_(sCH3-去卷积-乙纶)、2ν_(sCH2-去卷积-乙纶)、(ν_(asCH2-去卷积-乙纶)+ν_(CH-去卷积-乙纶))、(ν_(asCH2-去卷积-乙纶)+ν_(sCH2-去卷积-乙纶))、ν_(asCH3-去卷积-乙纶)、ν_(sCH3-去卷积-乙纶)、ν_(asCH2-去卷积-乙纶)、ν_(sCH2-去卷积-乙纶)、δ_(CH2-去卷积-乙纶)和ρ_(CH2-去卷积-乙纶)。进一步开展了变温LW-NIR-MIR光谱研究。在303 K~393 K的温度范围内,结构官能团(2ν_(sCH2-去卷积-乙纶),ν_(asCH2-去卷积-乙纶)和ρ_(CH2-去卷积-乙纶))对应频率及强度都有明显改变。最后开展二维LW-NIR-MIR光谱研究。LW-NIR区间,5835 cm^(-1)(2ν_(asCH2-2-二维-乙纶))>5700 cm^(-1)(2ν_(sCH2-二维-乙纶))>5867 cm^(-1)(2ν_(asCH2-1-二维-乙纶))>5800 cm^(-1)(ν_(asCH2-二维-乙纶)+ν_(CH-二维-乙纶))>5762 cm^(-1)(ν_(asCH2-二维-乙纶)+ν_(sCH2-二维-乙纶))>5894 cm^(-1)(2ν_(asCH3-二维-乙纶))。MIR区间,2915 cm^(-1)(ν_(asCH2-二维))>2845 cm^(-1)(ν_(sCH2-二维-乙纶))>2945 cm^(-1)(ν_(asCH3-二维-乙纶))>2885 cm^(-1)(ν_(sCH3-二维-乙纶))。1452 cm^(-1)(δ_(CH2-2-二维-乙纶))>1475 cm^(-1)(δ_(CH2-1-二维-乙纶))。LW-NIR-MIR区间,5835 cm^(-1)(2ν_(asCH2-2-二维-乙纶))>2915 cm^(-1)(ν_(asCH2-二维-乙纶))>2845 cm^(-1)(ν_(sCH2-二维-乙纶))>5894 cm^(-1)(2ν_(asCH3-二维-乙纶))。乙纶分子结构主要官能团对热的敏感程度及变化快慢顺序都存在着较大的差异性。研究拓展了三级LW-NIR-MIR谱在乙纶分子结构及热变性的研究范围。 展开更多
关键词 乙纶 长波近红外-中红外光谱 结构 热变性
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长波长发射碳点合成、调控及应用研究进展
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作者 陈劲良 曲丹 +2 位作者 赵雯辛 安丽 孙再成 《发光学报》 EI CAS CSCD 北大核心 2024年第4期534-556,共23页
近年来,随着碳点在合成路线、反应机理、光学性质等方面的发展,大量的工作聚焦于红光或近红外光等长波长发射的碳点。长波长是指发射范围在600~1800 nm的红色或近红外光谱区,相比短波长碳点,其具有深组织穿透、较小自荧光、长荧光寿命... 近年来,随着碳点在合成路线、反应机理、光学性质等方面的发展,大量的工作聚焦于红光或近红外光等长波长发射的碳点。长波长是指发射范围在600~1800 nm的红色或近红外光谱区,相比短波长碳点,其具有深组织穿透、较小自荧光、长荧光寿命以及光损伤小等特点,能够进一步应用在生物医学治疗、光电子以及光学器件制备等领域。因此,深入探究长波长发射碳点的设计和合成对于其发展和广泛应用具有重要意义。本文综述了近年来长波长发射碳点的研究进展,从碳源选择和光学性质调控两个方面介绍了长波长发射碳点的设计与制备。选择氨基较多的脂肪族化合物和具有共轭结构的芳香化合物,以及通过调控有效共轭长度、表面修饰和杂原子掺杂等方法来调控其光学性质。最后,阐述了长波长碳点在生物医学、LED光学器件和加密防伪等一些领域的最新研究和未来的挑战。 展开更多
关键词 长波长发射 碳点 光学性质 应用
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太赫兹光热电探测器读出方法
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作者 张金铎 陈猛 +1 位作者 刘睿丰 王迎新 《太赫兹科学与电子信息学报》 2024年第10期1063-1072,1103,共11页
太赫兹光热电探测器基于热生载流子在温度梯度驱使下迁移的原理实现太赫兹波探测,具有快响应、超宽带、自供电、室温工作及结构简单等优势,受到广泛关注。目前,探测器读出主要采用调制-解调方法,通过电流放大器与锁相放大器级联实现测量... 太赫兹光热电探测器基于热生载流子在温度梯度驱使下迁移的原理实现太赫兹波探测,具有快响应、超宽带、自供电、室温工作及结构简单等优势,受到广泛关注。目前,探测器读出主要采用调制-解调方法,通过电流放大器与锁相放大器级联实现测量,集成度低,成本高,难以实现阵列读出。为满足光谱测量、成像感知等应用需求,本文对光热电阵列探测器单元读出方法进行研究。从探测器机理出发,对输出信号进行建模分析;在此基础上设计板级专用读出电路,实现前置放大与锁相放大功能。测试表明,该方法可以在强噪声背景环境下对太赫兹光热电探测器进行高精确度读出,增益达到140.7 dB,信噪比改善了38.3 dB。 展开更多
关键词 读出电路 光热电效应 太赫兹波 锁相放大 长波光子学
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锗基长波红外圆锥形微结构减反射性能
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作者 汤克彬 李珊 +3 位作者 李初晨 毛科 张顺关 曾绍禹 《红外技术》 CSCD 北大核心 2024年第1期36-42,共7页
锗是重要的红外光学材料,为减小锗表面的菲涅耳反射损耗,提高光利用率,研究了锗基底圆锥形微结构的减反射性能。基于时域有限差分法(Finite Difference Time Domain),并采用单因素法研究了微结构的占空比、周期、高度等结构参数与入射角... 锗是重要的红外光学材料,为减小锗表面的菲涅耳反射损耗,提高光利用率,研究了锗基底圆锥形微结构的减反射性能。基于时域有限差分法(Finite Difference Time Domain),并采用单因素法研究了微结构的占空比、周期、高度等结构参数与入射角在8~12μm长波红外波段对反射率的影响,确定了微结构在低反射情况下较优的结构参数组合,其在整个波段范围内的平均反射率低于1%,远低于平板锗结构的35.47%,在9~11μm的波段范围内反射率低于0.5%,且光波在40°范围内入射时,圆锥形微结构的平均反射率仍然较低。将优化的圆锥形微结构与平板结构进行了对比,从等效折射率、反射场分布和能量吸收分布3方面进一步证实了圆锥形微结构在整个波段范围内优异的减反射性能。 展开更多
关键词 亚波长结构 时域有限差分法 锗基微结构 减反射 长波红外
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Long-wavelength(red to near-infrared) emissive carbon dots: Key factors for synthesis, fluorescence mechanism, and applications in biosensing and cancer theranostics 被引量:3
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作者 Aman Lv Qiao Chen +5 位作者 Chen Zhao Si Li Shan Sun Junping Dong Zhongjun Li Hengwei Lin 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第12期3653-3664,共12页
Carbon dots(CDs), as a new member of carbon nanostructures, have been widely applied in extensive fields due to their exceptional physicochemical properties. While, the emissions of most reported CDs are located in th... Carbon dots(CDs), as a new member of carbon nanostructures, have been widely applied in extensive fields due to their exceptional physicochemical properties. While, the emissions of most reported CDs are located in the blue to green range under the excitation of ultraviolet or blue light, which severely limits their practical applications, especially in photovoltaic and biological fields. Studies that focused on synthesizing CDs with long-wavelength(red to near-infrared) emission/excitation features(simply named L-w CDs) and exploring their potential applications have been frequently reported in recent years. In this review, we analyzed the key influence factors for the synthesis of CDs with long wavelength and multicolor(containing long wavelength) emissive properties, discussed possible fluorescence mechanism,and summarized their applications in sensing and cancer theranostics. Finally, the existing challenges and potential opportunities of L-w CDs are presented. 展开更多
关键词 long-wavelength emission Carbon dots Fluorescence mechanism Sensing Cancer theranostics
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2080 nm long-wavelength, high-power dissipative soliton resonance in a dumbbell-shaped thulium-doped fiber laser 被引量:1
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作者 Hua Wang Tuanjie Du +7 位作者 Yanhong Li Jinhai Zou Kaijie Wang Fuyong Zheng Junfeng Fu Jihai Yang Hongyan Fu Zhengqian Luo 《Chinese Optics Letters》 SCIE EI CAS CSCD 2019年第3期18-21,共4页
We demonstrate a 2080 nm long-wavelength mode-locked thulium(Tm)-doped fiber laser operating in the dissipative soliton resonance(DSR) regime. The compact all-fiber dumbbell-shaped laser is simply constructed by a 50/... We demonstrate a 2080 nm long-wavelength mode-locked thulium(Tm)-doped fiber laser operating in the dissipative soliton resonance(DSR) regime. The compact all-fiber dumbbell-shaped laser is simply constructed by a 50/50 fiber loop mirror(FLM), a 10/90 FLM, and a piece of large-gain Tm-doped double-clad fiber pumped by a 793 nm laser diode. The 10/90 FLM is not only used as an output mirror, but also acts as a periodical saturable absorber for initiating DSR mode locking. The stable DSR pulses are generated at the center wavelength as long as 2080.4 nm, and the pulse duration can be tunable from 780 to 3240 ps as the pump power is increased. The maximum average output power is 1.27 W, corresponding to a pulse energy of 290 nJ and a nearly constant peak power of 93 W. This is, to the best of our knowledge, the longest wavelength for DSR operation in a mode-locked fiber laser. 展开更多
关键词 2080 NM long-wavelength HIGH-POWER DISSIPATIVE thulium-doped fiber LASER
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大跨度铁路桥梁整体变形波长特征分析
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作者 赵健业 胡所亭 +3 位作者 郭辉 张楠 苏朋飞 廖晓璇 《铁道建筑》 北大核心 2024年第2期6-12,共7页
针对三座大跨度桥(A桥和C桥为悬索桥、B桥为斜拉桥)分别建立有限元模型,分析在温度、沉降、风、列车等作用下的桥面整体变形波长特征,并采用HHT(Hilbert‐Huang Transform)法、中点弦测法和曲率半径法定量分析桥面变形波长。结果表明:A... 针对三座大跨度桥(A桥和C桥为悬索桥、B桥为斜拉桥)分别建立有限元模型,分析在温度、沉降、风、列车等作用下的桥面整体变形波长特征,并采用HHT(Hilbert‐Huang Transform)法、中点弦测法和曲率半径法定量分析桥面变形波长。结果表明:A桥在整体升降温作用下,产生的变形曲线为波长82~140 m、波幅不超过5.5 mm的曲线段;在静风荷载作用下,产生的变形曲线为波长97~140 m、波幅不超过5.4 mm的曲线段;桥塔沉降作用下A桥不产生显著变形曲线。上述三种荷载作用下B桥均不产生显著变形曲线。C桥在整体升降温作用下,产生的变形曲线为波长70~84 m、波幅不超过2.2 mm的曲线段;桥塔沉降和静风力作用下C桥均不产生显著变形曲线。列车全局荷载对三座桥的桥面变形产生影响,若关注幅值3 mm及以上的曲线段,A桥、B桥、C桥最短波长依次为66、93、53 m。就此三座桥梁而言,荷载引起的桥面垂向变形对行车性能影响的显著程度均依次为列车全局荷载、整体升温、桥塔沉降。 展开更多
关键词 大跨度铁路桥 波长特征 垂向变形 横向变形 温度 沉降 风荷载
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Sensitivity analysis of an HgCdTe based photovoltaic receiver for long-wavelength free space optical communication systems 被引量:1
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作者 A.D.D.Dwivedi P.Chakrabarti 《Optoelectronics Letters》 EI 2009年第1期21-25,共5页
We examine theoretically the performance of an Hg0.77Cd0.23Te based p-n photodetector/HFET optical receiver due to its possible application at 10.6 μm free space optical communication system at high bit rate.A rigoro... We examine theoretically the performance of an Hg0.77Cd0.23Te based p-n photodetector/HFET optical receiver due to its possible application at 10.6 μm free space optical communication system at high bit rate.A rigorous noise model of the receiver has been developed for this purpose.We calculate the total noise and sensitivity of the receiver.The front-end of the receiver exhibits a sensitivity of -45 dBm at a bit rate of 1 Gb/s and -30 dBm at a bit rate of 10 Gb/s,and the total mean-square noise curren t〈i2n〉=5×10-15 A2 at a bit rate of 1 Gb/s an d〈i2n〉 =10-12 A2 at a bit rate of 10 Gb/s,and a 3-dB bandwidth of 10 GHz. 展开更多
关键词 Hg HFET Sensitivity analysis of an HgCdTe based photovoltaic receiver for long-wavelength free space optical communication systems free
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岩石圈长波长磁异常及其地质意义
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作者 王婕 杨艳艳 +4 位作者 纪飞 罗钰馨 泽仁志玛 黄建平 申旭辉 《地球与行星物理论评(中英文)》 2024年第6期668-680,共13页
在低轨卫星几百千米的高度上,大部分近地表观测到的岩石圈磁异常细节衰减殆尽,只留下衰减较慢的长波长磁异常.长波长磁异常可以揭示出岩石圈居里面以上显著的物性差异,对于研究地壳深部的物质组成、结构和演化具有重要意义.为了使读者... 在低轨卫星几百千米的高度上,大部分近地表观测到的岩石圈磁异常细节衰减殆尽,只留下衰减较慢的长波长磁异常.长波长磁异常可以揭示出岩石圈居里面以上显著的物性差异,对于研究地壳深部的物质组成、结构和演化具有重要意义.为了使读者能从全球尺度上对长波长磁异常的起源形成具体的认识,本文首先回顾了不同时期的卫星磁异常图及主要的岩石圈磁场模型,然后基于CHAOS-7模型计算结果,对500 km高度除极区外幅值大于4 nT的长波长磁异常进行了识别编号,共计29个磁异常.其中,陆地上磁异常20个,海洋中磁异常9个.通过对已有研究成果的综述及地质资料的对比分析,逐一介绍了磁异常的起源.陆地区域的长波长磁异常大多位于前寒武基底,相关的地质单元有太古代地核、元古代地体、富铁建造等,少数位于造山带背景.海洋区域的长波长磁异常全部都位于洋底高原,普遍与白垩纪时期冈瓦纳大陆裂解相关,具有加厚地壳特征.因此,针对长波长磁异常的持续深入研究对于地壳生长和演化具有重要意义.随着我国卫星磁测的蓬勃发展,相信会有越来越多的国内科研人员关注并研究这类大规模磁异常. 展开更多
关键词 长波长磁异常 卫星磁测 岩石圈磁异常 前寒武基底 洋底高原
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基于行车平稳性的大跨度铁路桥梁成桥线形评价方法研究
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作者 陆粤 王铭 +2 位作者 陈嵘 李小珍 王平 《铁道标准设计》 北大核心 2024年第6期44-51,共8页
超大跨度铁路桥梁成桥线形较设计线形易出现较大偏差,导致原轨面设计线形无法实现,通常需基于成桥线形变更轨面线形设计。为保障铺出的轨面线形满足行车性能的要求,在铺轨前合理评价大跨度铁路桥梁成桥线形尤为重要。基于实测成桥线形... 超大跨度铁路桥梁成桥线形较设计线形易出现较大偏差,导致原轨面设计线形无法实现,通常需基于成桥线形变更轨面线形设计。为保障铺出的轨面线形满足行车性能的要求,在铺轨前合理评价大跨度铁路桥梁成桥线形尤为重要。基于实测成桥线形的特征分析,结合桥上有砟道床的可调整能力,提出一种基于行车平稳性的大跨度铁路桥梁成桥线形评价方法,并将车体敏感波长范围的成桥线形幅值作为评价指标。以线路随机不平顺、桥梁受载附加变形及轨面线形引起的车体垂向加速度不超Ⅰ级管理标准为评价原则,确定车体敏感波长范围轨面线形的加速度容许值;研究车体加速度与弦测幅值、弦测幅值与线形幅值的相关性,确定车体敏感波长范围轨面线形的幅值限值;通过推导车体敏感波长范围轨面线形和成桥线形的幅值对应关系,最终制定评价指标限值。结合国内某千米级悬索桥的工程实例,确定评价指标限值为58 mm,该桥车体敏感波长范围实测成桥线形幅值最大值为36 mm,未超限值,表明成桥线形控制效果良好,在满足桥上道床厚度要求的前提下,基于成桥线形能够铺出满足行车平稳性的轨面线形。 展开更多
关键词 铁路桥 大跨度桥 成桥线形 行车平稳性 敏感波长
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长波长量约束剩余静校正技术研究与应用
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作者 王豆豆 《石化技术》 CAS 2024年第10期92-94,共3页
由于近地表条件的变化,在地震勘探中会带来静校正问题,静校正问题的存在严重影响成像质量还会引起假构造,因此解决静校正问题对地震勘探至关重要。在实际生产中通常采用层析静校正解决中长波长静校正问题,利用地表一致性剩余静校正解决... 由于近地表条件的变化,在地震勘探中会带来静校正问题,静校正问题的存在严重影响成像质量还会引起假构造,因此解决静校正问题对地震勘探至关重要。在实际生产中通常采用层析静校正解决中长波长静校正问题,利用地表一致性剩余静校正解决中短波长静校正问题。但常规地表一致性剩余静校正处理技术在信噪比低、不满覆盖区域,会引入不可靠的长波长量,在成像剖面中引起假构造。长波长量约束剩余静校正技术是地表一致性的,能够在求解剩余静校正量时对长波长量进行约束,避免不合理的长波长量剩余静校正量被带入到炮点、检波点的剩余静校正量中,从而改善成像质量,避免出现假构造,在沙漠工区实际资料应用中取得比较好的效果。 展开更多
关键词 地震勘探 地表一致性 长波长量约束 剩余静校正
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NIR-Ⅱ发射增强的双配体稳定金纳米簇的合成和性能研究
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作者 易书晓 胡晴 +1 位作者 屈慧娇 肖艳 《安徽化工》 CAS 2024年第2期101-105,共5页
针对目前金纳米簇存在发光不强且在大于1 100 nm区域发光微弱的问题,通过巯基己酸和巯基己醇掺杂的方式合成了长波发射增强的双配体稳定金纳米簇MHA/MEHE-Au NCs。合成的近红外二区(NIR-Ⅱ)金纳米簇荧光发射强度明显增强,在1 000~1 400... 针对目前金纳米簇存在发光不强且在大于1 100 nm区域发光微弱的问题,通过巯基己酸和巯基己醇掺杂的方式合成了长波发射增强的双配体稳定金纳米簇MHA/MEHE-Au NCs。合成的近红外二区(NIR-Ⅱ)金纳米簇荧光发射强度明显增强,在1 000~1 400 nm区域是未掺杂金纳米簇MHA-Au NCs的1.74倍,在1 200~1 400 nm区域是MHA-Au NCs的3.29倍;表征发现该材料是水中分散性良好且粒径为2.45 nm的球形纳米颗粒;其在模拟组织中的穿透深度较MHA-Au NCs明显增加,因此拥有应用于活体获得深层组织高分辨率成像的潜力。 展开更多
关键词 金纳米簇 长波发射 穿透深度
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基于基因荧光检测的长波通滤光片研制
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作者 林亦心 董新康 +4 位作者 杨宁 辛亚武 祝晗 彭永超 熊仕富 《光电技术应用》 2024年第3期36-41,共6页
光学滤光片是滤去杂质光干扰的重要光学器件,不同波段的滤光片在基因检测得到广泛应用。基于膜系设计理论与薄膜制备工艺,利用电子束蒸发离子辅助沉积技术,以Ta_(2)O_(5)和SiO_(2)为镀膜材料,在JGS1基底玻璃上设计并制备了一种截止中心... 光学滤光片是滤去杂质光干扰的重要光学器件,不同波段的滤光片在基因检测得到广泛应用。基于膜系设计理论与薄膜制备工艺,利用电子束蒸发离子辅助沉积技术,以Ta_(2)O_(5)和SiO_(2)为镀膜材料,在JGS1基底玻璃上设计并制备了一种截止中心λ_(0)=520 nm的高反射,透射带λ为530~750 nm的高透射长波通滤光片。通过分析膜层敏感度和电场分布,设置合理的晶控方案,调整工艺参数,避免监控高敏感膜层时石英晶控灵敏度下降,解决光谱透过率降低的问题。研制的滤光片在520 nm处反射率为99.77%,在530~750 nm波段平均透过率为98.58%,可满足应用需求。 展开更多
关键词 光学薄膜 长波通滤光片 膜堆周期 离子辅助沉积
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