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Classification of Gastric Lesions Using Gabor Block Local Binary Patterns
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作者 Muhammad Tahir Farhan Riaz +1 位作者 Imran Usman Mohamed Ibrahim Habib 《Computer Systems Science & Engineering》 SCIE EI 2023年第9期4007-4022,共16页
The identification of cancer tissues in Gastroenterology imaging poses novel challenges to the computer vision community in designing generic decision support systems.This generic nature demands the image descriptors ... The identification of cancer tissues in Gastroenterology imaging poses novel challenges to the computer vision community in designing generic decision support systems.This generic nature demands the image descriptors to be invariant to illumination gradients,scaling,homogeneous illumination,and rotation.In this article,we devise a novel feature extraction methodology,which explores the effectiveness of Gabor filters coupled with Block Local Binary Patterns in designing such descriptors.We effectively exploit the illumination invariance properties of Block Local Binary Patterns and the inherent capability of convolutional neural networks to construct novel rotation,scale and illumination invariant features.The invariance characteristics of the proposed Gabor Block Local Binary Patterns(GBLBP)are demonstrated using a publicly available texture dataset.We use the proposed feature extraction methodology to extract texture features from Chromoendoscopy(CH)images for the classification of cancer lesions.The proposed feature set is later used in conjuncture with convolutional neural networks to classify the CH images.The proposed convolutional neural network is a shallow network comprising of fewer parameters in contrast to other state-of-the-art networks exhibiting millions of parameters required for effective training.The obtained results reveal that the proposed GBLBP performs favorably to several other state-of-the-art methods including both hand crafted and convolutional neural networks-based features. 展开更多
关键词 Texture analysis Gabor filters gastroenterology imaging convolutional neural networks block local binary patterns
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Braided river and distribution patterns of sand bodies of Jurassic Badaowan formation in Block T13 of Junggar basin 被引量:4
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作者 SUN Xiaofang JIN Zhenkui +2 位作者 WANG Zhaofeng HUANG Xiaoping GU Junfeng 《Mining Science and Technology》 EI CAS 2010年第3期446-452,共7页
In order to determine the planar and volume distribution of sand bodies of the Jurassic Badaowan formation in Block T13 of Junggar basin,we used analysis of field outcrop and 3D seismic data,which play an essential ro... In order to determine the planar and volume distribution of sand bodies of the Jurassic Badaowan formation in Block T13 of Junggar basin,we used analysis of field outcrop and 3D seismic data,which play an essential role in areas of sparse well coverage.We describe sedimentary facies characteristics,sand body planforms,width and connectivity patterns of sand bodies,and vertical associations and successions by acoustic impedance inversion technology and sedimentological theory.Results of our study show braided fluvial strata deposits in the Jurassic Badaowan formation.Each sand body is approximately lenticular in shape.The width of each sand body falls in the range 100~800 m,with most between 200 and 400 m.The sand bodies vary in thickness from 4 to 13 m,with most below 9 m.The width/thickness ratios lie in the range 20~55.The connectivity of braided fluvial channel sand bodies is controlled by changes of accommodation space.One fining-upward sedimentary cycle of base-level rise is recognized in Badaowan formation,representing an upward rise of base level.The connectivity of sand bodies was found to be greatest in the early stage of base-level rise,becoming progressively worse with increasing base-level rise. 展开更多
关键词 block T13 Badaowan formation braided river sand body distribution patterns
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Simple Metrics for Representing East Asian Winter Monsoon Variability:Urals Blocking and Western Pacific Teleconnection Patterns 被引量:1
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作者 Hoffman H.N.CHEUNG Wen ZHOU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第6期695-705,共11页
Instead of conventional East Asian winter monsoon indices (EAWMIs), we simply use two large-scale teleconnection patterns to represent long-term variations in the EAWM. First, the Urals blocking pattern index (UBI... Instead of conventional East Asian winter monsoon indices (EAWMIs), we simply use two large-scale teleconnection patterns to represent long-term variations in the EAWM. First, the Urals blocking pattern index (UBI) is closely related to cold air advection from the high latitudes towards western Siberia, such that it shows an implicit linkage with the Siberian high intensity and the surface air temperature (SAT) variations north of 40°N in the EAWM region. Second, the well-known western Pacific teleconnection index (WPI) is connected with the meridional displacement of the East Asian jet stream and the East Asian trough. This is strongly related to the SAT variations in the coastal area south of 40°N in the EAWM region. The temperature variation in the EAWM region is also represented by the two dominant temperature modes, which are called the northern temperature mode (NTM) and the southern temperature mode (STM). Compared to 19 existing EAWMIs and other well-known teleconnection patterns, the UBI shows the strongest correlation with the NTM, while the WPI shows an equally strong correlation with the STM as four EAWMIs. The UBI-NTM and WPI-STM relationships are robust when the correlation analysis is repeated by (1) the 31-year running correlation and (2) the 8-year high-pass and low-pass filter. Hence, these results are useful for analyzing the large-scale teleconnections of the EAWM and for evaluating this issue in climate models. Int particular, more studies should focus on the teleconnection patterns over extratropical Eurasia. 展开更多
关键词 East Asian winter monsoon Urals blocking high western Pacific teleconnection pattern TELECONNECTION
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Application of non-small cell lung cancer pleural effusion cell blocks in molecular pathological detection 被引量:1
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作者 Ying Zhang Nan Jiang +4 位作者 Dongdong Qian Xiangzhou Li Yu Zhou Jia Mei Xiaohui Cao 《The Chinese-German Journal of Clinical Oncology》 CAS 2014年第4期157-161,共5页
Objective: The tumor tissues used in molecular pathological detection were usually obtained by surgery, which would cause trauma and may not be suitable for the terminal cancer patients. This paper evaluated the value... Objective: The tumor tissues used in molecular pathological detection were usually obtained by surgery, which would cause trauma and may not be suitable for the terminal cancer patients. This paper evaluated the value of the non-small cell lung cancer(NSCLC) pleural effusion cell blocks as tumor tissues replacement materials in the application of molecular pathological detection. Methods: Tumor cells were made into cell blocks through stratified centrifugal from 30 NSCLC patients with the pleural effusion. The immunohistochemistry, fluorescence in situ hybridization(FISH) and gene sequencing methods were employed in our experiments. Results: The tumor cells of cell block section were rich and could keep part of histological structure. Immunohistochemistry staining could assist diagnosis and tumor parting. Epidermal growth factor receptor(EGFR) FISH-positive was found in 33.33% of the group, high polysomy in 6 cases, amplification in 4 cases. EGFR gene mutations were found in 8 cases of 30 samples, with an incidence of 26.67%, 6 cases were detected in the exon 19, and 2 cases were detected in the exon 21. Conclusion: The NSCLC pleural effusion cell blocks are useful for the diagnosis and determining the primary source of tumor, instructed targeted therapy. 展开更多
关键词 CARCINOMA non-small cell lung (NSCLC) pleural effusion cell block IMMUNOHISTOCHEMISTRY fluorescence insitu hybridization (FISH) MUTATION
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On the Blocking Flow Patterns in the Euro–Atlantic Sector:A Simple Model Study
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作者 LUO Dehai YAO Yao 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第5期1181-1196,共16页
The flow patterns of Euro-Atlantic blocking events in winter are investigated by dividing the sector into three sub- regions: 60°-30°W (Greenland region); 20°W-30°E [eastern Atlantic-Europe (EA... The flow patterns of Euro-Atlantic blocking events in winter are investigated by dividing the sector into three sub- regions: 60°-30°W (Greenland region); 20°W-30°E [eastern Atlantic-Europe (EAE) region]; and 50°-90°E (Ural region). It is shown that blocking events in winter are extremely frequent in the three sub-regions. Composite 500-mb geopotential height fields for intense and long-lived blocking events demonstrate that the blocking fields over Greenland and Ural regions exhibit southwest-northeast (SW-NE) and southeast-northwest (SE-NW) oriented dipole-type patterns, respectively, while the composite field over the EAE region exhibits an Ω-type pattern. The type of composite blocking pattern seems to be related to the position of the blocking region relative to the positive center of the climatological stationary wave (CSW) anomaly existing near 10°W. The physical cause of why there are different composite blocking types in the three sub-regions is identified using a nonlinear multiscale interaction model. It is found that when the blocking event is in almost the same position as the positive CSW anomaly, the planetary-scale field can exhibit an Ω-type pattern due to the enhanced positive CSW anomaly. Neverthe- less, a SW-NE (SE-NW) oriented dipole-type block can occur due to the reduced positive CSW anomaly as it is farther in the west (east) of the positive CSW anomaly. The total fields of blocking in the three regions may exhibit a meandering flow comprised of several isolated anticyclonic and cyclonic vortices, which resembles the Berggren-Bolin-Rossby meandering jet type. 展开更多
关键词 blocking flow pattern synoptic eddies nonlinear multiscale interaction climatological stationary wave anomaly
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GIS-based analysis of fault patterns in urban areas: A case study of Irkutsk city, Russia 被引量:2
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作者 R.M. Lobatskaya I.P. Strelchenko 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第2期287-294,共8页
The capabilities of GIS in modeling fault patterns are explored for Irkutsk city in East Siberia with implications for ground stability. The neotectonic structure of the area is visualized in three dimension (3D) ta... The capabilities of GIS in modeling fault patterns are explored for Irkutsk city in East Siberia with implications for ground stability. The neotectonic structure of the area is visualized in three dimension (3D) taking into account fault dips, using the ArcGIS, GlobalMapper and Paradigm Geophysical packages. The study area is divided into blocks of different size classes according to the length-based ranks of the bounding faults, which are of five classes distinguished with the equal interval method. The blocks show different deformation patterns, with different densities and strikes of crossing and bounding faults. The data are statistically processed using GIS to estimate the deformation degrees of blocks in arbitrary units per square kilometer using the attributes of rank and crossing/bounding position of faults and the size of blocks. The deformation degrees are then compared with available estimates of ground stability measured as a score of points corresponding to destabilizing factors. Although the comparison generally confirms some linkage between the deformation degree of blocks and their ground stability, the correlation is intricate and ambiguous. In order to enhance the advantages of GIS in building and analyzing 3D models of fault patterns for estimating ground stability and mitigating geological hazards, it is expected in the future to proceed from the reported initial step of visualization to more advanced analysis. 展开更多
关键词 GIS 3D modeling Fault pattern FAULTS blockS Ground stability
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Does the Luangwa Hippo Population Size and Density Distribution Vary between Upper and Lower Study Blocks? What Are the Management Implications of Such Distribution Pattern? 被引量:2
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作者 Chansa Chomba Twakundine Simpamba +1 位作者 George Kampamba Vincent Nyirenda 《Open Journal of Ecology》 2014年第5期262-280,共19页
The pattern of population distribution of the common hippopotamus was examined along the 165 km stretch of the Luangwa River in eastern Zambia. The study area was divided between the upper (A-D) and lower (E-H) study ... The pattern of population distribution of the common hippopotamus was examined along the 165 km stretch of the Luangwa River in eastern Zambia. The study area was divided between the upper (A-D) and lower (E-H) study blocks. Population data are collected between 1976-2008 and this study 2009-2012 showed a significant difference in the pattern of density distribution between upper and lower study blocks. Upper blocks had higher density of 41/km than lower blocks 29/km. Length of study blocks was discounted as density was used to determine distribution pattern. Results obtained suggest that primary production in each study block as influenced by river geomorphologic features such as river bends and confluences characterized higher hippopotamus density in the upper blocks. Further research is required to investigate other factors that may have interplayed with food (above ground grass biomass) and river meander features to separate upper and lower blocks. 展开更多
关键词 Common HIPPOPOTAMUS pattern Density UPPER blockS LOWER blockS
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Simulation of Landscape Pattern of Old Growth Forests of Korean Pine By Block Kriging 被引量:1
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作者 王政权 张颜东 +1 位作者 王庆成 HarbinLi 《Journal of Forestry Research》 SCIE CAS CSCD 1997年第3期131-136,共6页
The study area was located in Liangshui Natural Reserve. Xaoxing'an Mountains. Northeastern China. Korean pine forests are the typical forest ecosystems and landscapcs in this region. It is a high degrees of spati... The study area was located in Liangshui Natural Reserve. Xaoxing'an Mountains. Northeastern China. Korean pine forests are the typical forest ecosystems and landscapcs in this region. It is a high degrees of spatial and temporal hetcrogeneity at different scales, which effected on landscape pattern and processes. In this paper we used the data of 144 plots and semivariogram to analyze spatial heterogeneity of old growth forests of Korean pine in landscape level. Model for forest variations by isotropic semivariogram is linear with sill. The spatial heterogeneity is dependent on scales and dircctions in Korean pine forests. Patterns of forest types in space were resulted from complex interactions between physical and biological forces. We uscd 20 metres for interpolation interval to cstimate the values of unsampled area. Comparing the results with field data, block kriging and mapping are an cffective techniques to simulate landscape pattern. 展开更多
关键词 Korean pine SEMIVARIOGRAM block kriging SIMULATION Landscape pattern
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An efficient BTC image compression algorithm with visual patterns
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作者 陆哲明 潘正祥 孙圣和 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第3期62-65,共4页
Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and it... Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and its main drawback of high bit rate of 2 bits/pixel for a 256 gray image for the purpose of reducing the bit rate, and introduces a simple look up table method for coding the higher mean and the lower mean of a block, and a set of 24 visual patterns used to encode 4×4 bit plane of the high detail block and proposes a new algorithm, when needs only 19 bits to encode 4×4 high detail block and 12 bits to encode the 4×4 low detail block. 展开更多
关键词 block TRUNCATION CODING VISUAL patterns image compression
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A Perspective on the Evolution of Atmospheric Blocking Theories:From Eddy-Mean flow Interaction to Nonlinear Multiscale Interaction 被引量:1
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作者 Dehai LUO Binhe LUO Wenqi ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第4期553-569,共17页
In this paper,we first review the research advancements in blocking dynamics and highlight the merits and drawbacks of the previous theories of atmospheric blocking.Then,the dynamical mechanisms of atmospheric blockin... In this paper,we first review the research advancements in blocking dynamics and highlight the merits and drawbacks of the previous theories of atmospheric blocking.Then,the dynamical mechanisms of atmospheric blocking are presented based on a nonlinear multi-scale interaction(NMI)model.Previous studies suggested that the eddy deformation(e.g.,eddy straining,wave breaking,and eddy merging)might lead to the formation and maintenance of atmospheric blocking.However,the results were speculative and problematic because the previous studies,based on the time-mean eddy-mean flow interaction model,cannot identify the causal relationship between the evolution of atmospheric blocking and the eddy deformation.Based on the NMI model,we indicate that the onset,growth,maintenance,and decay of atmospheric blocking is mainly produced by the spatiotemporal evolution of pre-existing upstream synoptic-scale eddies,whereas the eddy deformation is a concomitant phenomenon of the blocking formation.The lifetime of blocking is mainly determined by the meridional background potential vorticity gradient(PVy)because a small PVyfavors weak energy dispersion and strong nonlinearity to sustain the blocking.But the zonal movement of atmospheric blocking is associated with the background westerly wind,PVy,and the blocking amplitude.Using this NMI model,a bridge from the climate change to sub-seasonal atmospheric blocking and weather extremes might be established via examining the effect of climate change on PVy.Thus,it is expected that using the NMI model to explore the dynamics of atmospheric blocking and its change is a new direction in the future. 展开更多
关键词 atmospheric blocking teleconnection patterns eddy deformation potential vorticity gradient climate change nonlinear multiscale interaction
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Beam Pattern Scanning (BPS) versus Space-Time Block Coding (STBC) and Space-Time Trellis Coding (STTC)
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作者 Peh Keong TEH Seyed ZEKAVAT 《International Journal of Communications, Network and System Sciences》 2009年第6期469-479,共11页
In this paper, Beam Pattern Scanning (BPS), a transmit diversity technique, is compared with two well known transmit diversity techniques, space-time block coding (STBC) and space-time trellis coding (STTC). In BPS (a... In this paper, Beam Pattern Scanning (BPS), a transmit diversity technique, is compared with two well known transmit diversity techniques, space-time block coding (STBC) and space-time trellis coding (STTC). In BPS (also called beam pattern oscillation), controlled time varying weight vectors are applied to the antenna array elements mounted at the base station (BS). This creates a small movement in the antenna array pattern directed toward the desired user. In rich scattering environments, this small beam pattern movement creates an artificial fast fading channel. The receiver is designed to exploit time diversity benefits of the fast fading channel. Via the application of simple combining techniques, BPS improves the probability-of-error performance and network capacity with minimal cost and complexity. In this work, to highlight the potential of the BPS, we compare BPS and Space-Time Coding (i.e., STBC and STTC) schemes. The comparisons are in terms of their complexity, system physical dimension, network capacity, probability-of-error performance, and spectrum efficiency. It is shown that BPS leads to higher network capacity and performance with a smaller antenna dimension and complexity with minimal loss in spectrum efficiency. This identifies BPS as a promising scheme for future wireless communications with smart antennas. 展开更多
关键词 Antenna Array Beam pattern SWEEPING Transmit Diversity SPACE-TIME block CODES and SPACE-TIME TRELLIS Coding
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Body Fuzzy Pattern Recognition in Woman Basic Block Design
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作者 谢红 张渭源 《Journal of Donghua University(English Edition)》 EI CAS 2003年第2期59-62,共4页
Basic block is the foundation of clothing construction design because it is the media between body and clothes and the fitness of clothes should be based on the accuracy of basic block. That needs us to recognize body... Basic block is the foundation of clothing construction design because it is the media between body and clothes and the fitness of clothes should be based on the accuracy of basic block. That needs us to recognize body not to record it. This paper reports the Algorithm of woman body fuzzy pattern recognition. It is organized in three sections:(i) extracting woman body feature; (ii) establishing membership functions of feature indexes;(iii) presenting an Algorithm for woman body fuzzy pattern recognition by example. 展开更多
关键词 Basic block FUZZY pattern Recognition
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Role of imaging biomarkers in mutation-driven non-small cell lung cancer
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作者 Dexter P Mendoza Zofia Piotrowska +1 位作者 Jochen K Lennerz Subba R Digumarthy 《World Journal of Clinical Oncology》 CAS 2020年第7期412-427,共16页
Lung cancer remains the leading cause of cancer-related deaths worldwide.The treatment of non-small cell lung cancer(NSCLC),which accounts for a vast majority of lung cancers,has shifted to personalized,targeted thera... Lung cancer remains the leading cause of cancer-related deaths worldwide.The treatment of non-small cell lung cancer(NSCLC),which accounts for a vast majority of lung cancers,has shifted to personalized,targeted therapy following discoveries of several targetable oncogenic mutations.Targeting of specific mutations has improved outcomes in many patients.This success has led to several target-specific agents replacing chemotherapy as first-line treatment in certain mutated NSCLC.Several researchers have reported that there may be imaging biomarkers that may be predictive of the presence of these mutations.These features,when present,have the potential in triaging patients into the most appropriate diagnostic and treatment algorithms.Distinct imaging features and patterns of metastases that have been associated with NSCLC with various targetable oncogenic mutations are presented in this review. 展开更多
关键词 non-small cell lung cancer Imaging biomarker Targeted therapy Oncogenic mutations Radiomics Metastatic pattern
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The Warm Arctic-Cold Eurasia Pattern and Its Key Region in Winter in CMIP6 Model Simulations
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作者 Liang ZHAO Yunwen LIU +6 位作者 Yihui DING Qingquan LI Wei DONG Xinyong SHEN Wei CHENG Haoxin YAO Ziniu XIAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第12期2138-2153,I0002-I0006,共21页
An enhanced Warm Arctic-Cold Eurasia(WACE)pattern has been a notable feature in recent winters of the Northern Hemisphere.However,divergent results between model and observational studies of the WACE still remain.This... An enhanced Warm Arctic-Cold Eurasia(WACE)pattern has been a notable feature in recent winters of the Northern Hemisphere.However,divergent results between model and observational studies of the WACE still remain.This study evaluates the performance of 39 climate models participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)in simulating the WACE pattern in winter of 1980-2014 and explores the key factors causing the differences in the simulation capability among the models.The results show that the multimodel ensemble(MME)can better simulate the spatial distribution of the WACE pattern than most single models.Models that can/cannot simulate both the climatology and the standard deviation of the Eurasian winter surface air temperature well,especially the latter,usually can/cannot simulate the WACE pattern well.This mainly results from the different abilities of the models to simulate the range and intensity of the warm anomaly in the Barents Sea-Kara seas(BKS)region.Further analysis shows that a good performance of the models in the BKS area is usually related to their ability to simulate location and persistence of Ural blocking(UB),which can transport heat to the BKS region,causing the warm Arctic,and strengthen the westerly trough downstream,cooling central Eurasia.Therefore,simulation of UB is key and significantly affects the model’s performance in simulating the WACE. 展开更多
关键词 warm Arctic-cold Eurasia pattern Arctic amplification CMIP6 simulation evaluation extreme climate blocking highs
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城市街区单元绿地空间格局与植物群落碳汇效益优化研究
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作者 王晶懋 王一凡 +2 位作者 张涛 范李一璇 孙婷 《风景园林》 北大核心 2024年第6期37-45,共9页
【目的】目前城市绿地已经进入存量发展阶段,如何在城市有限绿地空间条件下实现“碳中和”目标,合理布局低碳绿地空间格局,科学配置植物群落以增加生物多样性,成为目前城市绿地碳汇效益研究的重点和难点。【方法】以西安市碑林区和沣西... 【目的】目前城市绿地已经进入存量发展阶段,如何在城市有限绿地空间条件下实现“碳中和”目标,合理布局低碳绿地空间格局,科学配置植物群落以增加生物多样性,成为目前城市绿地碳汇效益研究的重点和难点。【方法】以西安市碑林区和沣西新城的城市绿地空间格局为研究对象,对研究区域内街区单元的绿地空间格局进行分析并分类,探索街区单元绿地空间格局与碳汇量化关系,并从平面布局和垂直结构两方面提出城市街区单元绿地碳汇效益的优化方法,并选取碳储量最低的单核心辐射型街区单元的3个绿地样方进行碳汇效益优化设计。【结果】总结出4种西安市典型城市街区单元绿地空间格局模式,明晰了碳储量分布特征以及绿地空间格局对碳储量的影响机制,提出了城市街区单元绿地空间格局碳汇效益优化方法,发现碳储量与斑块类型面积(CA)、景观形状指数(LSI)呈极显著正相关关系,与聚集度(AI)呈极显著负相关关系。各类绿地空间格局碳储量大小为多核心辐射型>散点分布型或廊道穿越型>单核心辐射型,建议在单核心辐射型街区单元优化中增加植物群落层次结构,并增加高固碳植物种类及数量,提升样方内年固碳量。【结论】从中观尺度讨论街区单元绿地空间格局与植物群落碳汇效益之间的关系,使城市中小尺度绿地发挥应有的生态系统服务功能,探索街区单元绿地空间格局的构成要素与设计方法,为低碳绿地设计提供参考,提升城市街区单元内社区生活圈的人居环境质量。 展开更多
关键词 城市街区单元 绿地空间格局 景观格局指数 碳储量 碳汇效益 植物群落设计 陕西西安
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深部煤层孔隙结构与流体差异赋存特征研究
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作者 吴见 孙强 +1 位作者 石雪峰 高丽军 《煤田地质与勘探》 EI CAS CSCD 北大核心 2024年第8期89-100,共12页
【目的】鄂尔多斯盆地东缘已打破深部煤层气勘探禁区,多个区块呈现“单点突破、区域差异开发”特征,深部煤储层孔裂隙结构作为流体赋存与产出的物质空间,对于深部煤层气区块差异开发至关重要。【方法】系统采集鄂尔多斯盆地东缘神府区... 【目的】鄂尔多斯盆地东缘已打破深部煤层气勘探禁区,多个区块呈现“单点突破、区域差异开发”特征,深部煤储层孔裂隙结构作为流体赋存与产出的物质空间,对于深部煤层气区块差异开发至关重要。【方法】系统采集鄂尔多斯盆地东缘神府区块深部煤样品,基于常规孔渗物性测试、CO_(2)吸附、低温N2吸附、压汞和核磁共振等测试,以神府区块8+9号煤为例,系统总结深煤层孔隙结构及流体赋存模式。【结果和结论】结果表明:(1)深部煤孔隙结构差异较大,神府煤介孔−宏孔均发育,多为墨水瓶型和开放型孔。综合认为中阶煤孔隙结构的跨尺度效应稍有减弱,相对有利扩散、渗流。(2)中阶煤吸附能力降低,等温吸附曲线高压段曲线平缓,初期解吸效率低;含水饱和度增高,其介孔−宏孔的束缚水含量较高导致可动水孔隙率减小,降低了游离气的储集空间。(3)研究区存在“宏孔−微裂缝主控的游离气−自由水赋存”型、“微孔−介孔−宏孔主控的吸附气−束缚水赋存”型两类气水赋存模式,导致煤层气排采差异明显,其中“宏孔−微裂缝主控的游离气−自由水赋存”型是深部煤层气快速高产模式,该模式具有“见气时间短、中高产气、低产水”的生产特征,且由于应力对中大孔−微裂缝的伤害较强,建议该模式下的气井排采需适当控制排采速度以减小储层伤害,防止产量陡降;“微孔−介孔−宏孔主控的吸附气束缚水赋存”型模式具有“短期排水、缓慢见气”生产特征,排采仍需遵循“缓慢、连续”原则保证气井稳产;此外,由于孔隙以微孔、介孔为主,束缚水含量高,气井短期难获高产,需进一步探索加大压裂改造规模提高该类气藏产量。 展开更多
关键词 神府区块 深部煤层气 多尺度 孔隙结构 气水赋存模式 生产特征
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场所精神理论下传统街区文化空间呈现与感知
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作者 赵寰熹 《北京社会科学》 CSSCI 北大核心 2024年第5期97-109,共13页
随着城市的快速发展,传统街区面临着文化空间的传承问题。地方文脉的传承,与地区空间格局的演变、空间特性的延续、人们对区域氛围的感知变化等问题密切相关。选择场所精神理论作为切入点,以北京天桥地区为例,使用质性研究中扎根理论三... 随着城市的快速发展,传统街区面临着文化空间的传承问题。地方文脉的传承,与地区空间格局的演变、空间特性的延续、人们对区域氛围的感知变化等问题密切相关。选择场所精神理论作为切入点,以北京天桥地区为例,使用质性研究中扎根理论三级编码和地理空间展示与分析方法,从空间格局演变、场所精神分析、文化空间的呈现与场所精神的传承三个方面,对城市传统街区文化空间呈现与感知问题进行研究。结果显示:人们对天桥地区的整体认知体现在“古今具有高知名度的艺术表演区域”这一内涵上。人们通过观看展览演出等活动,体验区域的整体空间氛围,进而感受地方文化。这样的游览模式,适合此类新旧文化空间同时呈现的传统街区。 展开更多
关键词 场所精神理论 文化空间 传统街区 空间格局 北京天桥地区
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鄂尔多斯盆地东缘深部煤层气开发先导试验效果与启示 被引量:7
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作者 聂志宏 徐凤银 +10 位作者 时小松 熊先钺 宋伟 张雷 刘莹 孙伟 冯延青 刘世瑞 闫霞 孙潇逸 吴满生 《煤田地质与勘探》 EI CAS CSCD 北大核心 2024年第2期1-12,共12页
鄂尔多斯盆地东缘大宁-吉县区块深部煤层气勘探开发取得突破对煤层气产业带来重大影响,引起业内广泛关注和跟进。前期一些学者对深部煤层气勘探开发理论技术难点与对策开展了研究,但缺乏对典型气田开发先导试验系统总结。通过深入剖析... 鄂尔多斯盆地东缘大宁-吉县区块深部煤层气勘探开发取得突破对煤层气产业带来重大影响,引起业内广泛关注和跟进。前期一些学者对深部煤层气勘探开发理论技术难点与对策开展了研究,但缺乏对典型气田开发先导试验系统总结。通过深入剖析深部煤层气地质特征与效益开发难点,总结大宁-吉县区块开发先导试验项目取得的进展和成效,明确开发规律并提出效益开发对策。结果表明:(1)深部煤层具有广覆式发育、含气性好、游离气含量高、保存条件好、煤体结构好、脆性指数高、顶底板封盖性强等地质特征,但微构造发育、渗透性极差、矿化度高等因素制约了深部煤层气效益开发;(2)不同地质条件下气井生产特征差异较大,通过先导试验落实气井产能和适应性开发技术对策,采用滚动开发模式可有效降低煤层强非均质性带来的开发风险;(3)开展地质-工程一体化井网优化设计,构建井网与缝网高度弥合的人造气藏,可实现资源动用和采收率最大化;(4)“长水平段+多段多簇+大砂量”的大规模、大排量极限体积压裂技术可增大有效改造体积和井控储量,大幅提高单井产量;(5)深部煤层气井具有“见气时间短、上产速度快、初期产量高、递减快”的生产特征,可实现短期快速规模上产,但气田长期稳产需持续新井投入;(6)前期开发成本偏高,实现效益开发需不断提高工程作业效率、降低开发成本。综合认为,深部煤层气资源品质好,可动用性强,具备快速推广复制条件,大宁-吉县区块深部煤层气开发实践可为国内其他区块深部煤层气规模动用提供技术借鉴,对加快深部煤层气规模勘探开发具有重要意义。 展开更多
关键词 鄂尔多斯盆地东缘 大宁-吉县区块 深部煤层气 先导试验 开发规律 极限体积压裂技术
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鄂尔多斯盆地东缘韩城区块煤层气高产井地质主控因素 被引量:1
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作者 熊先钺 季亮 +5 位作者 张正朝 闫霞 伊伟 杨宏涛 邢雪杰 刘清 《天然气工业》 EI CAS CSCD 北大核心 2024年第3期64-71,共8页
鄂尔多斯盆地东缘韩城区块煤层气资源丰富,受构造地质条件影响,不同构造分区的煤层气单井产能差异较大。为明确该区块煤层气高产井地质主控因素,基于构造、煤储层特征及煤层气富集控制因素,结合气田生产数据,对煤层气高产井的地质主控... 鄂尔多斯盆地东缘韩城区块煤层气资源丰富,受构造地质条件影响,不同构造分区的煤层气单井产能差异较大。为明确该区块煤层气高产井地质主控因素,基于构造、煤储层特征及煤层气富集控制因素,结合气田生产数据,对煤层气高产井的地质主控因素进行了剖析。研究结果表明:(1)煤层气井产能受“构造条件、水动力条件、煤体结构”三大因素控制,其中构造条件控制煤层气富集成藏,水动力条件影响煤层气保存,煤体结构影响煤储层渗透率;(2)区块内的煤层气高产井主要分布于次级构造发育区,地层水矿化度介于(2~11)×10^(3)mg/L,原生—碎裂煤平均厚度为4.4m,单井日产气量大于1000m^(3);(3)小断层或者微构造改善了煤储层的渗透性,尤其是次级构造高部位产生的裂隙,有利于煤层气解吸渗流,有利于煤层气高产;(4)在构造活动较剧烈的条件下,大断层附近易于形成煤层气逸散通道,不利于煤层气的保存。结论认为,鄂尔多斯盆地东缘韩城区块构造运动不但造就了各种构造形态,而且使煤体结构发生了变化,不同构造形态下的水动力条件也不同,因此构造运动对韩城区块煤层气井高产起到了极为重要的控制作用;该研究成果对韩城区块的煤层气开发调整具有一定的指导意义,对地质条件类似的煤层气区块具有借鉴意义。 展开更多
关键词 鄂尔多斯盆地 韩城区块 煤层气 高产井 构造条件 富集规律 地质主控因素
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EPS-棉秆纤维灌孔轻质复合砌块砌体的基本力学性能研究
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作者 陈驰 夏多田 +2 位作者 朱清峰 武海洋 梁轩 《石河子大学学报(自然科学版)》 CAS 北大核心 2024年第2期165-173,共9页
为推广利用基于地方煤基固废资源和棉杆纤维资源的三低型复合砌块墙体结构在新疆地区村镇低层建筑中的工程应用,以砂浆强度和芯柱材料强度为变量,对57件(27件受压、30件受剪)复合砌体试件进行抗压和抗剪力学性能试验,并对试件的破坏过... 为推广利用基于地方煤基固废资源和棉杆纤维资源的三低型复合砌块墙体结构在新疆地区村镇低层建筑中的工程应用,以砂浆强度和芯柱材料强度为变量,对57件(27件受压、30件受剪)复合砌体试件进行抗压和抗剪力学性能试验,并对试件的破坏过程、破坏形态特征、抗压及抗剪强度进行了分析。结果表明:当砂浆与砌块的强度比低于1.6时,砂浆强度的提升对三低型复合砌体的抗压强度影响较大;芯材部分对复合砌体抗压和抗剪强度贡献最大,且随着芯柱材料强度的提升,贡献持续增大。基于砌体实际强度测定方法,建立并拟合得出了适用于三低型砌块砌体的抗压强度、抗剪强度的平均值计算公式。这对了解EPS-棉秆纤维灌孔复合混凝土砌块砌体基本力学性能具有一定的参考价值,为其在实际工程中的应用提供科学的理论依据。 展开更多
关键词 煤基固废 三低型砌体 破坏形态 抗压强度 抗剪强度
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