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Structural Interpretation and Restoration of Rocky Mountain Brazeau Zone
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作者 Juhee Kang Heejung Kim 《Journal of Earth Science》 SCIE CAS CSCD 2017年第5期867-873,共7页
The Rocky Mountain Foothills lie along the eastern margin of the Rocky Mountain fold-thrust belt. The area has been the focus of extensive research aimed at locating oil and gas fields with the potential to be used as... The Rocky Mountain Foothills lie along the eastern margin of the Rocky Mountain fold-thrust belt. The area has been the focus of extensive research aimed at locating oil and gas fields with the potential to be used as CO2 storage traps. In this study, we use a seismic line from the Ca- nadian Rockies to interpret the geologic structures along a cross-section parallel to the tectonic transport direction. We then compare our results with those of previous studies. The section was restored using the MOVE software (manufactured by Midland Valley Exploration Ltd.). The pri- mary objectives of this work are: (1) to conduct a stratigraphic and structural interpretation of a 2D seismic profile; and (2) to conduct a cross-sectional restoration of the structures in order to validate the seismic interpretation in terms of CO2 storage candidates. Additional data sources include maps of the surface geology, which show that the age of horizons decrease from west to east, and strati- graphic and structural profiles derived from well logs. The results of our structural restoration indi- cate a detachment fault between the foreland and hinterland. This fault is responsible for the cutting and subsequent upwards and eastwards movement of a stratum located between the basement and the Late Devonian formation. Large thrust faults are responsible for the deformation of strata (through both folding and faulting) in the foreland basin. As a result of continuous eastward tectonic stress, the strata from Jurassic have deformed, forming a duplex system in the middle of the section and resulting in the uplift of the upper part of the section. Following surface erosion, this uplifted area became exposed during the Tertiary Period. The high shortening rate (53%) detected through structural restoration is consistent with the thin-skinned tectonic model. 展开更多
关键词 Rocky Mountain Foothills fold-thrust belt stratigraphic and structural interpreta- tion structural restoration.
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Floristic diversity, regeneration status, and vegetation structure of woodlands in Metema Area, Amhara National Regional State, North-western Ethiopia 被引量:4
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作者 Haile Adamu Wale Tamrat Bekele Gemedo Dalle 《Journal of Forestry Research》 CAS CSCD 2012年第3期391-398,共8页
We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia Our objective was to describe plant species composition, diversity, re- generation status, a... We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia Our objective was to describe plant species composition, diversity, re- generation status, and population structure by a selective approach with a systematic sampling design. A total of 74 quadrats (each for 25 m x 25 m, spaced at intervals of 150--200 m) were sampled along established tran- sect lines following the homogeneity of the vegetation. Vegetation data including cover-abundance, height, diameter at breast height (DBH), and numbers of seedlings and saplings of woody species were analyzed using Excel spreadsheet, Shannon Weiner diversity index, and PAST version 1.62. A total of 87 vascular plant species of 74 genera and 36 families were recorded. The dominant family was Fabaceae represented by 16 (18.39 %) species of 13 genera. Shannon Weiner diversity and evenness were 3.67 and 0.82, respectively, which showed that the area was en- dowed with rich floral diversity evenly distributed. The vegetation structure, as quantified by cumulative diameter class frequency distribution, plotted as an interrupted inverted-J- shape pattern with a sharp decrease in the 2nd diameter class. This indicated poor vegetation structure. The diameter classes frequency distributions of selected species plotted in four general patterns i.e., interrupted Inverted-J-shape, J-shape, Bell-shape and Irregular-shape. In conclusion, although the area showed high floral diversity and evenness, woody species including Sterculea setigera, Boswellia papyrifera, and Pterocarpus lucens showed lowest recruitment of seedlings and saplings. 展开更多
关键词 EQUITABILITY diversity DRYLAND Metema Woodland popula- tion structure REGENERAtion
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A novel variable structure multi-model approach based on error-ambiguity decomposition 被引量:1
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作者 Han SHEN-TU Yingjiao RONG +2 位作者 Dongliang PENG Mengfan XUE Yunfei GUO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第6期1731-1746,共16页
Model Set Adaptation(MSA)plays a key role in the Variable Structure Multi-Model tracking approach(VSMM).In this paper,the Error-Ambiguity Decomposition(EAD)principle is adopted to derive the EAD-MSA criterion that is ... Model Set Adaptation(MSA)plays a key role in the Variable Structure Multi-Model tracking approach(VSMM).In this paper,the Error-Ambiguity Decomposition(EAD)principle is adopted to derive the EAD-MSA criterion that is optimal in the sense of minimizing the square error between the estimate and the truth.Consequently,the EAD Variable Structure first-order General Pseudo Bayesian(EAD-VSGPB1)algorithm and the EAD Variable Structure Interacting Multiple Model(EAD-VSIMM)algorithm are constructed.The proposed algorithms are tested in two groups of maneuvering target tracking scenarios under different modes and observation error conditions.The simulation results demonstrate the effectiveness of the EAD-VSMM approach and show that,compared to some existing multi-model algorithms,the proposed EAD-VSMM algorithms achieve more robust and accurate tracking results. 展开更多
关键词 Error-ambiguity decomposi­tion Maneuvering target tracking Model sequence set adapta­tion Multi-model estimation Variable structure
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Improvement of Impeller Blade Structure for Gas Injection Refining under Mechanical Stirring 被引量:5
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作者 Yan LIU Zi-mu ZHANG +3 位作者 Sano MASAMICHI Jun ZHANG Pin SHAO Ting-an ZHANG 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2014年第2期135-143,共9页
Abstract: The impeller blade structure for gas injection refining under mechanical stirring has been explored by water model experiments. A sloped swept-back blade impeller is'proposed for the purpose. The central p... Abstract: The impeller blade structure for gas injection refining under mechanical stirring has been explored by water model experiments. A sloped swept-back blade impeller is'proposed for the purpose. The central part of the impeller is disk- or plate-shaped, and the blades are fitted to the side of the disk or plate. In addition, a disk is put on the top side of the impeller blades. The impeller can strengthen the radial and downward flow between the blades and weaken the swirl flow in the zone above the impeller. These effects on flow phenomena are favorable for disintegration and wide dispersion of bubbles which are injected from a nozzle attached to the center of the underside of the impeller. In addition, the sloped swept-back impeller requires less power consumption. The impeller shaft should be placed away from the vessel center so as to disperse the injected bubbles widely in the bath under mechanical stirring even with unidi- rectional impeller rotation and without installing baffles. The number of gas holes in the nozzle and the direction of gas injection have a little effect on the bubble disintegration and dispersion in the bath. Highly efficient gas injection refining can be established under the conditions of proper impeller size, larger nozzle immersion depth, larger eccen- tricity and rotation speed of the impeller. The sloped swept back blade impeller can decrease the power consumption and vet improve the bubble disintegration and wide dist^ersion in the bath. 展开更多
关键词 gas injection refining cold model eccentric mechanical stirring impeller structure power consump-tion bubble disintegration bubble dispersion
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Structure formation of entanglement entropy in a system of two superconducting qubits coupled with an LC-resonator 被引量:1
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作者 葛国勤 覃翠 +1 位作者 尹淼 黄勇华 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第8期39-46,共8页
This paper investigates theoretically the evolutions of the entanglement entropy of a system of two coupled-charge- qubits interacting with an LC-resonator. It is found that when the initial states of the two qubits a... This paper investigates theoretically the evolutions of the entanglement entropy of a system of two coupled-charge- qubits interacting with an LC-resonator. It is found that when the initial states of the two qubits are prepared in a given superposition excited state, the evolution of the von Neumann entropy of the system depends significantly on the coupling strength between the two Josephson charge qubits. With the variation of the coupling strength, the evolution of the entanglement entropy of the system forms some structures, especially the periodically bistable properties, which are the first discovered for such a system to our knowledge. It is found that the relative entropy entanglement of the system is also sensitive to the variation of the coupling strength between the two charge qubits, some novel 'collective oscillations' of the relative entropy are found for the system. 展开更多
关键词 superconducting quantum circuits evolutions of entanglement entropy structure forma-tion
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Information in the Structure of Reality:the Scientific Worldview and the Fundamental Question of Philosophy
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作者 Konstantin Kolin 《学术界》 CSSCI 北大核心 2015年第1期257-260,共4页
We offer a new understanding of the scientific world and the contents of the basic question of philosophy,which is based on an analysis of the phenomenon of the specific information in the various components of the st... We offer a new understanding of the scientific world and the contents of the basic question of philosophy,which is based on an analysis of the phenomenon of the specific information in the various components of the structure of reality.It is shown that,in addition to material objects,processes,and events,in the real world are also intangible objects,processes and conditions that are in its information content.So the basic question of philosophy is proposed to treat the relationship as a tangible and intangible component of reality.More succinctly it can be formulated as the ratio of matter and information.This allows you to point to some new challenges studying the phenomenon of information in various components of the structure of reality. 展开更多
关键词 结构信息 科学世界观 哲学 组成部分 现实世界 信息内容 事件
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Filtering algorithm of line structured light for long-distance obstacle detection
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作者 邵海燕 张振海 李科杰 《Journal of Beijing Institute of Technology》 EI CAS 2016年第4期521-525,共5页
Since unmanned ground vehicles often encounter concave and convex obstacles in wild ground, a filtering algorithm using line structured light to detect these long distance obstacles is proposed. For the line structure... Since unmanned ground vehicles often encounter concave and convex obstacles in wild ground, a filtering algorithm using line structured light to detect these long distance obstacles is proposed. For the line structured light image, a ranked-order based adaptively extremum median (RAEM) filter algorithm on salt and pepper noise is presented. In the algorithm, firstly effective points and noise points in a filtering window are differentiated; then the gray values of noise points are replaced by the medium of gray values of the effective pixels, with the efficient points' gray values unchanged; in the end this algorithm is proved to be efficient by experiments. Experimental resuits demonstrate that the image blur, resulting into proposed algorithm can remove noise points effectively and minimize the protecting the edge information as much as possible. 展开更多
关键词 unmanned ground vehicles line structured light concave and convex obstacles detec-tion ranked-order based adaptively extremum median (RAEM) filter filter algorithm
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五波束Janus结构ADCP超声换能器安装偏差分析及校准
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作者 王红亮 柴哲凡 何常德 《测试技术学报》 2026年第1期88-95,共8页
声学多普勒流速剖面仪(Acoustic Doppler Current Profiler,ADCP)是目前海洋、江河流速测量的最主要仪器之一。已有对于ADCP的安装偏差分析大多是针对其安装在船上后,基阵发生偏移的安装偏差。针对5个超声换能器集成为五波束Janus结构A... 声学多普勒流速剖面仪(Acoustic Doppler Current Profiler,ADCP)是目前海洋、江河流速测量的最主要仪器之一。已有对于ADCP的安装偏差分析大多是针对其安装在船上后,基阵发生偏移的安装偏差。针对5个超声换能器集成为五波束Janus结构ADCP后,由于机械加工、安装工艺造成的安装偏差,提出将安装偏差分为安装位置偏差和安装角度偏差两部分进行研究。证明了在100 m探测距离内,毫米级安装位置偏差等效于10^(-3)~10^(-2)度级安装角度偏差,得出了安装角度偏差是安装偏差中最主要部分的结论。设计了基于回波延时测距搭配高精度姿态仪的安装偏差校准方法,并通过仿真分析了校准过程中不同因素对校准精度的影响,以针对不同校准精度需求选取不同的校准环境。结果表明该校准方法有一定实用价值,可以用来对超声换能器集成为五波束Janus结构后的安装偏差进行校准。 展开更多
关键词 五波束Janus结构 声学多普勒流速剖面仪 超声换能器 安装偏差
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Identification and Cu Enrichment Capacity of TLSB_2-K, a Cu-tolerant Strain 被引量:1
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作者 康薇 郑进 《Agricultural Science & Technology》 CAS 2014年第12期2081-2084,2144,共5页
[Objective] The Cu-tolerance and Cu enrichment capacity of TLSB2-K were investigated. [Method] The previously isolated TLSB2-K strain was identified though morphological observation, gram staining and 16S rDNA sequenc... [Objective] The Cu-tolerance and Cu enrichment capacity of TLSB2-K were investigated. [Method] The previously isolated TLSB2-K strain was identified though morphological observation, gram staining and 16S rDNA sequence alignment. In ad- dition, the effects of temperature, pH and osmotic pressure on the growth of strain were also investigated by using shaking culture. The Cu-tolerance and Cu enrich- ment capacity of TLSB2-K strain under Cu stress were also studied. [Result] The results showed TLSB2-K belongs to Bacillus spp., and its optimum growth conditions were as follows: temperature, 27 ~C; pH, 7.0; osmotic pressure, 1.1% NaCI. When the Cu concentration ranged from 100 mg/L to 500 mg/L, the strain grew well; when the Cu concentration ranged from 100 mg/L to 400 mg/L, the Cu content in bacteria was increased with the increase of Cu concentration; when the Cu con- centration was 400 mg/L and the incubation time was 30 h, the Cu content in bac- teria reached the peak (2 250 mg/kg); the highest tolerant concentration was 700 mg/L. [Conclusion] TLSB2-K strain had relatively high Cu tolerance and Cu enrich- ment capacity. They had important theoretical research and engineering application values. 展开更多
关键词 Soil contamination Cu tolerance Bacillus cereus Molecular identifica- tion Enrichment capacity
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Research Progress and Identification Method of Apple Stress Resistance
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作者 王贵平 王金政 +2 位作者 薛晓敏 路超 聂佩显 《Agricultural Science & Technology》 CAS 2013年第10期1413-1416,共4页
In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving ... In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well. 展开更多
关键词 APPLE Adverse stress Stress resistance Research progress identifica- tion method
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螺栓连接接触区域对导波传播特性影响分析
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作者 董晗 李佳鑫 +3 位作者 史维佳 赵勃 杨彬 谭久彬 《测试技术学报》 2026年第1期10-16,共7页
螺栓连接广泛应用于航空航天、机械和土木工程中,其失效会严重影响系统可靠性与安全性。因此,螺栓预紧力的在线监测至关重要。超声导波因穿透性强、传播距离远、检测灵敏度高,被广泛用于螺栓监测,但导波与螺栓连接界面相互作用机制尚不... 螺栓连接广泛应用于航空航天、机械和土木工程中,其失效会严重影响系统可靠性与安全性。因此,螺栓预紧力的在线监测至关重要。超声导波因穿透性强、传播距离远、检测灵敏度高,被广泛用于螺栓监测,但导波与螺栓连接界面相互作用机制尚不清晰。为此,建立二维频域有限元模型,通过扫频分析验证模型准确性,并研究不同激励频率下A0和S0模态的最优激发频率。仿真结果表明,导波与连接界面作用时发生模态转换,各模态能量传输系数随接触长度呈周期性变化。当激励频率为255 kHz时,A0模态对接触长度变化更敏感,适用于早期松动检测;当频率为345 kHz时,S0模态周期更长,适合螺栓从紧固到完全松动的全过程监测。 展开更多
关键词 超声导波 传输系数 螺栓连接 有限元仿真 结构健康监测
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Self-assembly as a route to one-dimensional lanthanum(Ⅲ) salicylaldimine coordination polymer 被引量:1
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作者 Wanda Radecka-Paryzek Izabela Pospieszna-Markiewicz Maciej Kubicki 《Journal of Rare Earths》 SCIE EI CAS CSCD 2010年第S1期51-55,共5页
The self-assembled formation of a one-dimensional lanthanum salicylald imine coordination polymer was proved by the X-ray diffraction analysis of new l anthanum(Ⅲ) nitrate complex containing N,N’-bis(salicylidene)-1... The self-assembled formation of a one-dimensional lanthanum salicylald imine coordination polymer was proved by the X-ray diffraction analysis of new l anthanum(Ⅲ) nitrate complex containing N,N’-bis(salicylidene)-1,5-pentanediami ne ligand(H2L) . It was obtained in situ in a one-step,metal-templated condensa tion of salicylaldehyde with 1,5-pentanediamine(cadaverine,biogenic polyamine) and characterized by microanalysis and spectroscopic(IR,ESI-MS,UV-Vis,and 1 H NMR) data. The [La(NO3) 3(μ-H2L) 2]∞ complex displayed 10-coordinate distorted bicapped dodecahedron geometry with unusual coordination pattern of undeprotonat ed salicylaldimines which acted as μ-bridging ditopic ligands using exclusivel y the oxygens as donor atoms with the nitrogen atoms not being involved in the c oordination environment. 展开更多
关键词 self assembly LANTHANUM SALICYLALDIMINE crystal structure coordina tion polymer rare earths
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Crystal Structure and Electronic Structure of a Luminescent Compound 2-(2-Pyridyl) Benzimidazole 被引量:1
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作者 岳淑美 苏忠民 +3 位作者 马建方 廖奕 阚玉和 张恒君 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2003年第2期174-178,共5页
The crystal structure of 2-(2-pyridyl) benzimidazole was determined by single- crystal X-ray diffraction at 193(2) K. It crystallizes in orthorhombic system, space group Pbca with unit cell constants a = 10.6204(7), b... The crystal structure of 2-(2-pyridyl) benzimidazole was determined by single- crystal X-ray diffraction at 193(2) K. It crystallizes in orthorhombic system, space group Pbca with unit cell constants a = 10.6204(7), b = 10.1407(4), c = 18.6327(8) , Z = 8, V = 2006.7(2) 3, Dc = 1.292 g/cm3, F(000) = 816 and m(MoK) = 0.081 mm-1. The structure was refined to R = 0.0317 and wR = 0.0454 for 795 observed reflections with I > 2s(I). In the solid state, it has an emission maximum at 369 nm, while in solution (DMSO), the maximum excitation is at 372 nm. Quantum chemistry calculation was performed by the method of density functional theory. Theoretical results show that atom N is the reactive site when coordinating with a metal, and the electronic structure of the title compound presents excellent carrier transport properties. 展开更多
关键词 pyridyl) benzimidazole LUMINESCENT synthesis quantum chemistry calcula- tion crystal structure
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Regeneration dynamics of dominant tree species along an altitudinal gradient in moist temperate valley slopes of the Garhwal Himalaya 被引量:2
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作者 Sumeet Gairola C.M.Sharma +1 位作者 S.K.Ghildiyal Sarvesh Suyal 《Journal of Forestry Research》 CAS CSCD 2012年第1期53-63,共11页
The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to understand the regeneration dynamics of the dominant tr... The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to understand the regeneration dynamics of the dominant tree species along an altitudinal gradient in naturally regen- erating, restricted access forest. The overall regeneration status was fairly high in the study area. Most of the native canopy and undercanopy domi- nants had frequent reproduction and expanding populations, which sug- gests the stability of forest structure/composition and further expansion of dominant species. The overall regeneration of trees in the forest had a greater contribution of middle and understurey species. Because of infre- quent rep'roduction and declining populations of some of the dominant native species viz., Abies pindrow, Alnus nepalensis and Betula alnoides, structural/compositional changes in the future are expected in respective forests dominated by them..4bies pindrow and Taxus baccata need im- mediate attention by forest managers for their survival in the area. Seed- lings were found to be more prone to competition from herb and shrubs than saplings. 展开更多
关键词 Garhwal environmental gradient forest structure regenera-tion curves species diversity
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A Novel Verification Approach of Workflow Schema
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作者 WANG Guangqi WANG Juying +2 位作者 WANG Yan SONG Baoyan YU Ge 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1292-1296,共5页
A workflow schema is an abstract description of the business processed by workflow model, and plays a critical role in analyzing, executing and reorganizing business processes. The verification issue on the correctnes... A workflow schema is an abstract description of the business processed by workflow model, and plays a critical role in analyzing, executing and reorganizing business processes. The verification issue on the correctness of complicated workflow schemas is difficult in the field of workflow. We make an intensive study of it in this paper. We present here local errors and schema logic errors (global errors) in workflow schemas in detail, and offer some constraint rules trying to avoid schema errors during modeling. In addition, we propose a verification approach based on graph reduction and graph spread, and give the algorithm. The algorithm is implemented in a workflow prototype system e-ScopeWork. 展开更多
关键词 WORKFLOW workflow model schema verifica tion transition structure
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DEEP-UV CONFOCAL FLUORESCENCE IMAGING AND SUPER-RESOLUTION OPTICAL MICROSCOPY OF BIOLOGICAL SAMPLES
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作者 TREVOR A.SMITH LIISA M.HIRVONEN +1 位作者 CRAIG N.LINCOLN XIAOTAO HAO 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2012年第4期24-32,共9页
A wide range of techniques has been developed to image biological samples at high spatial and temporal resolution.In this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent ... A wide range of techniques has been developed to image biological samples at high spatial and temporal resolution.In this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent emission from fuorophores such as tryptophan,and structured ilumination microscopy(SIM)of biological materials.One motivation for developing deep-UV fhuorescence imaging and SIM is to provide methods to complement our measurements in the emerging field of X-ray coherent diffractive imaging. 展开更多
关键词 Time resolved fuorescence imaging structured ilumnina tion microscopy
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GEOTECTONIC BACKGROUND OF PYROPHYLLITE MINERALIZATION AND ORE-BEARING VOLCANIC FORMATION IN SOUTHEASTERN COASTAL AREAS,CHINA
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作者 Wang Ling(Changsha Institute of Geotectonics, Academia Sinica, Changsha, 410013, Hunan, China)Liu Dongshen (Geologic Institute, National Construction Material Industry Bureau, 100010, Beijing, China) 《Geotectonica et Metallogenia》 1996年第Z1期46-50,共5页
The volcanic gas-liguid type of pyrophyllite deposits in the SoutheasternCoastal areas, China are the product of tectono-magama-volcanism in Diwa regions. The pyro-phyllite ore-bearing volcanic formation were formed ... The volcanic gas-liguid type of pyrophyllite deposits in the SoutheasternCoastal areas, China are the product of tectono-magama-volcanism in Diwa regions. The pyro-phyllite ore-bearing volcanic formation were formed in the maximum-mobility period of Diwa, which are mainly the Late Jurassic strata and are secondly the Early Cretaceous volcanic-sedi-mentary rock series strata. The lithology of the host rock is mainly rhyolitic crystal-vitric tuff, and the chemical composition is characterized by high silicon rich alumium and low iron, be-longing to the acid-intermediate-acid rock and the kalicalc-calc-alkalic series and the rhyo-lite-rhyodacite assemblage. They play an important role in the pyrophyllite mineralization. 展开更多
关键词 PYROPHYLLITE DIWA structure nonmetallic metailogeny ore-bearing forma-tion the Sountheastern Coastal Areas China
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跨域飞行器结构与变构型设计技术进展与挑战
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作者 朱继宏 韩嘉诚 +4 位作者 谷小军 张亚辉 王骏 侯杰 张卫红 《航空学报》 北大核心 2025年第18期270-301,共32页
跨域飞行器凭借“一机多能”和大空域、宽速域高效重复飞行的设计定位,在航空航天领域具有划时代意义,正在成为各国科技竞争的焦点之一。由于这一领域高度的前沿性和综合性,目前尚未形成实现大包线跨域飞行的明确技术路线,但是普遍认同... 跨域飞行器凭借“一机多能”和大空域、宽速域高效重复飞行的设计定位,在航空航天领域具有划时代意义,正在成为各国科技竞争的焦点之一。由于这一领域高度的前沿性和综合性,目前尚未形成实现大包线跨域飞行的明确技术路线,但是普遍认同变构型是其中的关键技术与必要手段。以变构型为主线,从与之相关的飞行器基础构型、变体方式、变体结构优化与热防护4个方面论述了实现跨域飞行的概念性路线,分析了现有研究对跨域飞行器设计提供的技术铺垫和参考价值,并综述了各自的技术进展与挑战。首先,介绍了几种有应用潜力的基础构型,对比了其气动性能、容积率等方面的差异;其次,按照机翼和头锥部位变体分类,分析了不同方案的结构设计和气动影响;接着,从提高变体结构变形、承载与防热性能的角度,介绍了系统布局优化、构件拓扑优化与材料-结构多尺度优化和被动、主动热防护结构设计;最后,总结了目前跨域飞行器结构与变构型设计工作仍面临的挑战与难题,展望了相关研究在未来的发展方向。 展开更多
关键词 跨域飞行器 变构型 结构优化 轻量化 热防护技术
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液体火箭发动机涡轮泵振动问题研究现状及展望
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作者 王珏 窦唯 +1 位作者 杜家磊 金志磊 《推进技术》 北大核心 2025年第4期14-29,共16页
涡轮泵作为液体火箭发动机的核心高速旋转增压组件,其振动特性研究涉及多学科交叉领域,涵盖流体力学、结构力学、转子动力学及热力学等。本文系统梳理了涡轮泵振动问题的研究进展,从结构激振、流体激振和耦合振动三个维度展开论述:在结... 涡轮泵作为液体火箭发动机的核心高速旋转增压组件,其振动特性研究涉及多学科交叉领域,涵盖流体力学、结构力学、转子动力学及热力学等。本文系统梳理了涡轮泵振动问题的研究进展,从结构激振、流体激振和耦合振动三个维度展开论述:在结构激振方面,重点探讨了转子不平衡、动静碰摩、轴系松动及内摩擦等典型问题,在流体激振方面,深入分析了动静干涉流体激振、喘振、空化等;在耦合振动方面,主要讨论了密封-转子耦合、涡轮颤振等多物理场耦合问题。针对大推力可重复使用发动机的研制,指出需要在振动引起的涡轮泵关键构件动应力与疲劳寿命关系,涡轮泵大幅偏离设计工况引起的流体激振问题,多因素耦合建模分析和振动的主动控制三方面加强涡轮泵振动问题研究,以适应发动机大范围变工况、高可靠和长寿命工作要求。 展开更多
关键词 液体火箭发动机 涡轮泵 结构激振 流体激振 耦合振动 综述
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不同干旱条件下区域抗旱水源优化配置研究
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作者 郭溪 梁鹏辉 +2 位作者 吴泽宁 何晨涛 曹欠欠 《水利学报》 北大核心 2025年第9期1228-1239,共12页
干旱是全球最常见和最严重的自然灾害之一,高温极端干旱事件对国家水安全保障构成了严重威胁。针对不同干旱条件下的抗旱水源配置原则、约束条件、目标函数及模型构建等问题,基于不同干旱条件对抗旱水源配置系统的结构破坏和功能损失机... 干旱是全球最常见和最严重的自然灾害之一,高温极端干旱事件对国家水安全保障构成了严重威胁。针对不同干旱条件下的抗旱水源配置原则、约束条件、目标函数及模型构建等问题,基于不同干旱条件对抗旱水源配置系统的结构破坏和功能损失机理,分别构建一般干旱与特大干旱条件下的区域抗旱水源优化配置准则、目标函数、约束条件和方案生成方法,建立了不同干旱条件下区域抗旱水源优化配置模型,并以楚雄州为例进行应用验证。结果表明:经抗旱水源优化配置后,一般干旱条件下,楚雄州社会总缺水量降至1883.01万m3,经济损失减少4.4亿元;特大干旱条件下,楚雄州缺水损伤程度下降至14.54%,水源工程总体破坏程度降至11.26%。综上,区域抗旱水源优化配置模型可有效降低旱灾损失及供需水系统破坏程度,提高各用水户的供水保证率,可为区域整体干旱应对能力提升提供技术支撑。 展开更多
关键词 干旱 特大干旱 供用水系统结构-功能损伤 优化配置模型 抗旱水源
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