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Carbon Storage Dynamics in Lower Shimentan Formation of the Qiantang Sag, East China Sea Shelf Basin: Stratigraphy, Reservoir ‒ Cap Analysis, and Source ‒ Sink Compatibility
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作者 kailong Feng Weilin Zhu +6 位作者 kai zhong Qiang Fu Weizhen Chen Zengyuan Zhou Guanyu Zhang Ji Teng Zhe Yang 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第3期565-574,共10页
Excessive carbon emissions have resulted in the greenhouse effect, causing considerable global climate change. Marine carbon storage has emerged as a crucial approach to addressing climate change. The Qiantang Sag(QTS... Excessive carbon emissions have resulted in the greenhouse effect, causing considerable global climate change. Marine carbon storage has emerged as a crucial approach to addressing climate change. The Qiantang Sag(QTS) in the East China Sea Shelf Basin, characterized by its extensive area, thick sedimentary strata, and optimal depth, presents distinct geological advantages for carbon dioxide(CO_(2)) storage. Focusing on the lower section of the Shimentan Formation in the Upper Cretaceous of the QTS, this study integrates seismic interpretation and drilling data with core and thin-section analysis. We reveal the vertical variation characteristics of the strata by providing a detailed stratigraphic description. We use petrophysical data to reveal the development characteristics of high-quality carbon-storage layers and favorable reservoircaprock combinations, thereby evaluating the geological conditions for CO_(2) storage in various stratigraphic sections. We identify Layer B of the lower Shimentan Formation as the most advantageous stratum for marine CO_(2) storage. Furthermore, we analyze the carbon emission trends in the adjacent Yangtze River Delta region. Considering the characteristics of the source and sink areas, we suggest a strong correlation between the carbon emission sources of the Yangtze River Delta and the CO_(2) storage area of the QTS, making the latter a priority area for conducting experiments on marine CO_(2) storage. 展开更多
关键词 Carbon storage Qiantang Sag Reservoir-cap Source-sink dynamics East China Sea Shelf Basin
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Portal vein embolization combined with ex vivo liver resection and autotransplantation: A novel treatment strategy for end-stage and metastatic hepatic alveolar echinococcosis
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作者 Qiang Guo Mao-Lin Wang +5 位作者 kai zhong Jia-Long Li Tie-Min Jiang Hao Wen Tuerganaili Aji Ying-Mei Shao 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2024年第2期210-216,共7页
Alveolar echinococcosis(AE)is a lethal parasitic disease caused by Echinococcus multilocularis larvae,and more than 90%of pri-mary AE lesions occur in the liver.Most of the affected individ-uals remain asymptomatic an... Alveolar echinococcosis(AE)is a lethal parasitic disease caused by Echinococcus multilocularis larvae,and more than 90%of pri-mary AE lesions occur in the liver.Most of the affected individ-uals remain asymptomatic and the disease is often diagnosed at an advanced stage.The infection may spread to organs adjacent to the liver or distant locations,eventually causing end-stage multi-ple organ AE.Brain metastasis of AE is the most fatal with an inci-dence rate of 0.2%[1]. 展开更多
关键词 ORGANS ECHINOCOCCOSIS METASTASIS
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A holistic visualization for quality of Chinese materia medica: Structural and metabolic visualization by magnetic resonance imaging
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作者 Jing Wu kai zhong +7 位作者 Hongyi Yang Peiliang Zhang Nianjun Yu Weidong Chen Na Zhang Shuangying Gui Lan Han Daiyin Peng 《Journal of Pharmaceutical Analysis》 CSCD 2024年第11期1556-1566,共11页
The quality of Chinese materia medica(CMM)is a challenging and focused topic in the modernization of traditional Chinese medicine(TCM).A profound comprehension of the morphology,structure,active constituents,and dynam... The quality of Chinese materia medica(CMM)is a challenging and focused topic in the modernization of traditional Chinese medicine(TCM).A profound comprehension of the morphology,structure,active constituents,and dynamic changes during the whole process of CMM growth is essential,which needs highly precise contemporary techniques for in-depth elucidation.Magnetic resonance imaging(MRI)is a cutting-edge tool integrating the benefits of both nuclear magnetic resonance(NMR)spectroscopy and imaging technology.With real-time,non-destructive,and in situ detection capabilities,MRI has been previously used for monitoring internal and external structures of plants alongside compounds during physiological processes in vivo.Here,factors involved in the holistic quality evaluation of CMMs were investigated.Given the applications of MRI in various plants,several representative CMMs were used as examples to demonstrate a methodology of quality visualization by MRI,embodying holistically monitoring the real-time macroscopic morphology,mesoscopic structure,and microscopic metabolites nondestructively in situ.Taken together,the review not only presents a pioneering application mode for utilizing MRI for CMM quality visualization but also holds promise for advancing the quality control and evaluation of CMMs. 展开更多
关键词 Chinese materia medica QUALITY Structure and metabolites VISUALIZATION Magnetic resonance imaging
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Data-Driven Based Fault Prognosis for Industrial Systems:A Concise Overview 被引量:21
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作者 kai zhong Min Han Bing Han 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2020年第2期330-345,共16页
Fault prognosis is mainly referred to the estimation of the operating time before a failure occurs,which is vital for ensuring the stability,safety and long lifetime of degrading industrial systems.According to the re... Fault prognosis is mainly referred to the estimation of the operating time before a failure occurs,which is vital for ensuring the stability,safety and long lifetime of degrading industrial systems.According to the results of fault prognosis,the maintenance strategy for underlying industrial systems can realize the conversion from passive maintenance to active maintenance.With the increased complexity and the improved automation level of industrial systems,fault prognosis techniques have become more and more indispensable.Particularly,the datadriven based prognosis approaches,which tend to find the hidden fault factors and determine the specific fault occurrence time of the system by analysing historical or real-time measurement data,gain great attention from different industrial sectors.In this context,the major task of this paper is to present a systematic overview of data-driven fault prognosis for industrial systems.Firstly,the characteristics of different prognosis methods are revealed with the data-based ones being highlighted.Moreover,based on the different data characteristics that exist in industrial systems,the corresponding fault prognosis methodologies are illustrated,with emphasis on analyses and comparisons of different prognosis methods.Finally,we reveal the current research trends and look forward to the future challenges in this field.This review is expected to serve as a tutorial and source of references for fault prognosis researchers. 展开更多
关键词 DATA-DRIVEN fault prognosis feature extraction industrial systems
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Structural characteristics of central depression belt in deep-water area of the Qiongdongnan Basin and the hydrocarbon discovery of Songnan low bulge 被引量:4
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作者 Mo Ji Qingbo Zeng +2 位作者 Haizhang Yang Shuai Guo kai zhong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第2期42-53,共12页
The Qiongdongnan Basin has the first proprietary high-yield gas field in deep-water areas of China and makes the significant breakthroughs in oil and gas exploration.The central depression belt of deep-water area in t... The Qiongdongnan Basin has the first proprietary high-yield gas field in deep-water areas of China and makes the significant breakthroughs in oil and gas exploration.The central depression belt of deep-water area in the Qiongdongnan Basin is constituted by five sags,i.e.Ledong Sag,Lingshui Sag,Songnan Sag,Baodao Sag and Changchang Sag.It is a Cenozoic extensional basin with the basement of pre-Paleogene as a whole.The structural research in central depression belt of deep-water area in the Qiongdongnan Basin has the important meaning in solving the basic geological problems,and improving the exploration of oil and gas of this basin.The seismic interpretation and structural analysis in this article was operated with the 3D seismic of about 1.5×104 km2 and the 2D seismic of about 1×104 km.Eighteen sampling points were selected to calculate the fault activity rates of the No.2 Fault.The deposition rate was calculated by the ratio of residual formation thickness to deposition time scale.The paleo-geomorphic restoration was obtained by residual thickness method and impression method.The faults in the central depression belt of deep-water area of this basin were mainly developed during Paleogene,and chiefly trend in NE–SW,E–W and NW–SE directions.The architectures of these sags change regularly from east to west:the asymmetric grabens are developed in the Ledong Sag,western Lingshui Sag,eastern Baodao Sag,and western Changchang Sag;half-grabens are developed in the Songnan Sag,eastern Lingshui Sag,and eastern Changchang Sag.The tectonic evolution history in deep-water area of this basin can be divided into three stages,i.e.faulted-depression stage,thermal subsidence stage,and neotectonic stage.The Ledong-Lingshui sags,near the Red River Fault,developed large-scale sedimentary and subsidence by the uplift of Qinghai-Tibet Plateau during neotectonic stage.The Baodao-Changchang sags,near the northwest oceanic sub-basin,developed the large-scale magmatic activities and the transition of stress direction by the expansion of the South China Sea.The east sag belt and west sag belt of the deep-water area in the Qiongdongnan Basin,separated by the ancient Songnan bulge,present prominent differences in deposition filling,diaper genesis,and sag connectivity.The west sag belt has the advantages in high maturity,well-developed fluid diapirs and channel sand bodies,thus it has superior conditions for oil and gas migration and accumulation.The east sag belt is qualified by the abundant resources of oil and gas.The Paleogene of Songnan low bulge,located between the west sag belt and the east sag belt,is the exploration potential.The YL 8 area,located in the southwestern high part of the Songnan low bulge,is a favorable target for the future gas exploration.The Well 8-1-1 was drilled in August 2018 and obtained potential business discovery,and the Well YL8-3-1 was drilled in July 2019 and obtained the business discovery. 展开更多
关键词 Qiongdongnan Basin deep-water area structural differentiation
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Geochemistry and zircon U-Pb ages of the Oligocene sediments in the Baiyun Sag, Zhujiang River Mouth Basin 被引量:2
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作者 Rui Sun Ming Ma +5 位作者 kai zhong Xiayang Wang Zhao Zhao Shuai Guo Xingzong Yao Gongcheng Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第2期123-135,共13页
In this study,element geochemistry and zircon chronology are used to analyze the Oligocene sediments in the Baiyun Sag,Zhujiang River Mouth Basin.The experimental results are discussed with respect to weathering condi... In this study,element geochemistry and zircon chronology are used to analyze the Oligocene sediments in the Baiyun Sag,Zhujiang River Mouth Basin.The experimental results are discussed with respect to weathering conditions,parent rock lithologies,and provenances.The chemical index of alteration and the chemical index of weathering values of mudstone samples from the lower Oligocene Enping Formation indicate that clastic particles in the study area underwent moderate weathering.Mudstone samples exhibit relatively enriched light rare earth elements and depleted heavy rare earth elements,"V"-shaped negative Eu anomalies,and negligible Ce anomalies.The rare earth element distribution curves are obviously right-inclined,with shapes and contents similar to those of post-Archean Australian shale and upper continental crust,indicating that the samples originated from acid rocks in the upper crust.The Hf-La/Th and La/Sc-Co/Th diagrams show this same origin for the sediments in the study area.For the samples from the upper Enping deltas,the overall age spectrum shows four major age peaks ca.59–68 Ma,98–136 Ma,153–168 Ma and 239–260 Ma.For the Zhuhai Formation samples,the overall age spectrum shows three major age peaks ca.149 Ma,252 Ma and 380 Ma.The detrital zircon shapes and U-Pb ages reveal that during Oligocene sedimentation,the sediments on the northwestern margin of the Baiyun Sag were supplied jointly from two provenances:Precambrian-Paleozoic metamorphic rocks in the extrabasinal South China fold zone and Mesozoic volcanic rocks in the intrabasinal Panyu Low Uplift,and the former supply became stronger through time.Thus,the provenance of the Oligocene deltas experienced a transition from an early proximal intrabasinal source to a late distal extrabasinal source. 展开更多
关键词 weathering degree lithology of parent rock PROVENANCE element geochemistry zircon U-Pb ages Baiyun Sag
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Overview and progress of X-nuclei magnetic resonance imaging in biomedical studies 被引量:2
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作者 Gengxin Wang Hongyi Yang +3 位作者 Juan Li Jie Wen kai zhong Changlin Tian 《Magnetic Resonance Letters》 2023年第4期327-343,共17页
Proton nuclear(^(1)H)is the observed nucleus on which most magnetic resonance imaging(MRI)applications depend.Most traditional^(1)H MRI can provide structural and functional information about organisms,while various n... Proton nuclear(^(1)H)is the observed nucleus on which most magnetic resonance imaging(MRI)applications depend.Most traditional^(1)H MRI can provide structural and functional information about organisms,while various non-proton nuclei(X-nuclei)MRI can provide more metabolic information.However,due to the relatively poor signal-to-noise ratio(SNR)of X-nuclei MRI,their applications are quite rare compared to^(1)H.Benefit from the rapid developments of MRI hardware and software technologies,X-nuclei MRI has recently attracted increasing interests in biomedical research.This review firstly introduces some current methods to improve the SNR of X-nuclei MRI.Secondly,this review describes biomedical applications of X-nuclei MRI,especially focusing on the current use of X-nuclei(^(13)C,^(17)O,^(19)F,^(23)Na and^(31)P)MRI to study related diseases in different organs,including the brain,liver,kidney,heart and bone.Finally,perspectives studies on X-nuclei imaging and its potential applications are described in biomedical research. 展开更多
关键词 Magnetic resonance imaging X-nuclei BIOMEDICAL ^(13)C ^(17)O ^(19)F ^(23)Na ^(31)P
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Preliminary study on fine structures of subcortical nuclei in rhesus monkeys by ex vivo 9.4 T MRI 被引量:1
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作者 Huan-Zhi Chen Hong-Yi Yang +1 位作者 kai zhong Jia-Li Li 《Zoological Research》 SCIE CAS CSCD 2020年第2期199-202,共4页
DEAR EDITOR,Changes in fine structures of the brain over a life span can have robust effects on neural activity and brain function,which both play crucial roles in neurodegenerative diseases.Clinically,however,low-res... DEAR EDITOR,Changes in fine structures of the brain over a life span can have robust effects on neural activity and brain function,which both play crucial roles in neurodegenerative diseases.Clinically,however,low-resolution MRI only provides limited information about fine brain structures.Here,using highresolution 9.4 T MRI,we established a set of structural images and explored the fine structures of the claustrum,hippocampus,amygdala complex,and subregions of the amygdala complex(BLA,including lateral,basal,and accessory basal subnuclei)in rhesus macaque(Macaca mulatta)brains.Based on these high-resolution images,we were able to discriminate the subregional boundaries accurately and,at the same time,obtain the volume of each brain nuclei.Thus,advanced high-resolution 9.4 T MRI not only provides a new strategy for early diagnosis of neurodegenerative diseases,but also provides the ability to observe fine structural changes in the brain across a life span. 展开更多
关键词 DIAGNOSIS CLINICAL DISEASES
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Meta-analysis of efficacy and safety of Qianliexin capsule combined with western medicine in benign prostatic hyperplasia treatment 被引量:1
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作者 Sheng-Nan Wang Yi-Hua Fan +4 位作者 Shan Lin Jin-Rui Wei Sheng-Xuan Zhao Qiao Liu kai zhong 《TMR Integrative Medicine》 2021年第20期1-13,共13页
Objective:To systematically evaluate the efficacy and safety of Qianliexin capsule combined with western medicine in benign prostatic hyperplasia treatment.Methods:Randomized controlled trials of Qianliexin capsule co... Objective:To systematically evaluate the efficacy and safety of Qianliexin capsule combined with western medicine in benign prostatic hyperplasia treatment.Methods:Randomized controlled trials of Qianliexin capsule combined with western medicine in the treatment of benign prostatic hyperplasia were searched from PubMed,the Cochrane Library,EMBASE,Web of Science,China National Knowledge Infrastructure,VIP,Wanfang and China Biomedical Literature Databases from establishment of the database to February 2021.Meta-analysis was performed using RevMan5.4 software after two researchers independently screened the literatures,extracted the data and evaluated the bias risks in the included studies according to the Cochrane Collaboration System Evaluator Manual.Results:6 randomized controlled trials involving 1060 patients were included.Meta-analysis results showed that the treatment group was better than the control group in total effective rate(Relative Risk=1.19,95%Confidence Interval(1.10,1.28),P<0.00001),International Prostate Symptom Score(Mean Difference=-2.99,95%confidence interval(-4.00,-1.99),P<0.00001),prostate volume(Mean Difference=-3.77,95%Confidence Interval(-4.67,-2.86),P<0.00001),postvoid residual urine volume(Mean Difference=-5.96,95%Confidence Interval(-8.15,-3.77),P<0.00001)and maximum urine flow rate(Mean Difference=3.45,95%Confidence Interval(2.53,4.37),P<0.00001).While there was no significant difference in the adverse effects rate(Relative Risk=0.71,95%Confidence Interval(0.33,1.56),P=0.40)between the treatment group and the control group.Conclusion:Qianliexin capsule combined with western medicine in the treatment of benign prostatic hyperplasia showed good efficacy and high safety.However,more high-quality and large-sample studies are needed to confirm the above conclusions. 展开更多
关键词 Qianliexin capsule Benign prostatic hyperplasia META-ANALYSIS Randomized controlled trial
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Early Cenozoic paleontological assemblages and provenance evolution of the Lishui Sag,East China Sea
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作者 Yingzhao Zhang Yiming Jiang +7 位作者 Zhenghua Liu Shuai Li Ning Li Jinshui Liu Peijun Qiao kai zhong Shuhui Chen Thian Lai Goh 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第3期113-122,共10页
The East China Sea Shelf Basin generated a series of back-arc basins with thick successions of marine-and terrestrial-facies sediments during Cenozoic.It is enriched with abundant oil and gas resources and is of great... The East China Sea Shelf Basin generated a series of back-arc basins with thick successions of marine-and terrestrial-facies sediments during Cenozoic.It is enriched with abundant oil and gas resources and is of great significance to the petroleum exploration undertakings.Therein,the Lishui Sag formed fan delta,fluvial delta and littoral-to-neritic facies sediments during Paleocene–Eocene,and the research on its sedimentary environment and sediment source was controversial.This study analyzed the paleontological combination characteristics,and conducted a source-to-sink comparative analysis to restore the sedimentary environment and provenance evolution of the Lishui Sag during Paleocene–Eocene based on the integration of detrital zircon U-Pb age spectra patterns with paleontological assemblages.The results indicated that Lishui Sag was dominated by littoral and neritic-facies environment during time corroborated by large abundance of foraminifera,calcareous nannofossils and dinoflagellates.Chronological analysis of detrital zircon U-Pb revealed that there were significant differences in sediment sources between the east and west area of the Lishui Sag.The western area was featured by deeper water depths in the Paleocene–Eocene,and the sediment was characterized by a single Yanshanian peak of zircon U-Pb age spectra,and mainly influenced from Yanshanian magmatic rocks of South China Coast and the surrounding paleo-uplifts.However,its eastern area partly showed Indosinian populations.In particular,the upper Eocene Wenzhou sediments were featured by increasingly plentiful Precambrian zircons in addition to the large Indosinian-Yanshanian peaks,indicating a possible impact from the Yushan Low Uplift to the east.Therefore,it is likely that the eastern Lishui Sag generated large river systems as well as deltas during time.Due to the Yuquan Movement,the Lishui Sag experienced uplifting and exhumation in the late stage of the late Eocene and was not deposited with sediments until Miocene.Featured by transitional-facies depositions of Paleocene–Eocene,the Lishui Sag thus beared significant potential for source rock and oil-gas reservoir accumulation. 展开更多
关键词 East China Sea Lishui Sag paleontological assemblages SEDIMENTARY PROVENANCE hydrocarbon exploration
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In-situ 3D contour measurement for laser powder bed fusion based on phase guidance
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作者 Yuze Zhang Pan Zhang +3 位作者 Xin Jiang Siyuan Zhang kai zhong zhongwei Li 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2023年第2期113-119,共7页
In-situ layerwise imaging measurement of laser powder bed fusion(LPBF)provides a wealth of forming and defect data which enables monitoring of components quality and powder bed homogeneity.Using high-resolution camera... In-situ layerwise imaging measurement of laser powder bed fusion(LPBF)provides a wealth of forming and defect data which enables monitoring of components quality and powder bed homogeneity.Using high-resolution camera layerwise imaging and image processing algorithms to monitor fusion area and powder bed geometric defects has been studied by many researchers,which successfully monitored the contours of components and evaluated their accuracy.However,research for the methods of in-situ 3D contour measurement or component edge warping identification is rare.In this study,a 3D contour mea-surement method combining gray intensity and phase difference is proposed,and its accuracy is verified by designed experiments.The results show that the high-precision of the 3D contours can be achieved by the constructed energy minimization function.This method can detect the deviations of common ge-ometric features as well as warpage at LPBF component edges,and provides fundamental data for in-situ quality monitoring tools. 展开更多
关键词 Laser powder bed fusion In-situ measurement Active contours 3D contour Measurement accuracy
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Neuroprotective effects of saffron on chronic focal cerebral ischemia through inhibiting glial scar formation in rats
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作者 Yi-lu YE Rou-xin WANG +4 位作者 Si-qi YAO Ze-kang FANG kai zhong Qi ZHANG Yue-ping YU 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2018年第4期326-326,共1页
OBJECTIVE To explore the neuro-protective effects of saffron(Crocus satius L.) on chronic focal cerebral ischemia in rats.METHODS SD rats were randomly divided into 6 groups:sham control group,MCAO group,edaravone gro... OBJECTIVE To explore the neuro-protective effects of saffron(Crocus satius L.) on chronic focal cerebral ischemia in rats.METHODS SD rats were randomly divided into 6 groups:sham control group,MCAO group,edaravone group and saffron 30,100,300 mg·kg^(-1) groups.Focal cerebral ischemia was induced by middle cerebral artery occlusion(MCAO).Saffron was administered orally by once daily from 2 h to 42 d after ischemia.At 42 d after cerebral ischemia,neurological deficit score,spontaneous activity test,elevated plus maze test,marble burying test and novel objective recognition test were used to evaluate the effects of saffron on the behevioural change.Infarct volume,survival neuron density,activated astrocyte number,and the thickness of glial scar were also detected.GFAP expression and inflammatory cytokine contents in ischemic peripheral region were detected by Western blot and ELISA,separately.RESULTS Saffron(100,300 mg·kg^(-1)) improved the body weight decrease,neurological deficit and spontaneous activity.Saffron(30-300 mg · kg^(-1)) increased the traveled distance ratio and total time in open arm,decreased the buried marble number,which indicated that saffron could ameliorate anxiety-and depression-like behaviors.Saffron(100,300 mg·kg^(-1)) improved the learning and memory function,which manifested by increased discrimination ratio(DR) and discrim.ination index(DI) in T2 test.The results of toluidine blue found saffron treatment(100,300 mg · kg^(-1))decreased the infarct volume and increased the neuron density in cortex and hippocampal.The activated astrocyte number,the thickness of glial scar and GFAP expression in ischemic peripheral region decreased after saffron.Saffron(100,300 mg · kg^(-1)) decreased the contents of IL-6 and IL-1β,increased the content of IL-10 in ischemic peripheral region.CONCLUSION Saffron exerted neuro-protective effects on chronic focal cerebral ischemia,which could be related with inhibiting the activation of astrocyte and glial scar,following with the decrease of inflammatory reaction. 展开更多
关键词 藏红花 脑缺血 治疗方法 临床分析
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Theoretical and experimental study on broadband terahertz atmospheric transmission characteristics
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作者 Shi-Bei Guo kai zhong +5 位作者 Mao-Rong Wang Chu Liu Yong Xiao Wen-Peng Wang De-Gang Xu Jian-Quan Yao 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第1期597-602,共6页
Broadband terahertz(THz) atmospheric transmission characteristics from 0 to 8 THz are theoretically simulated based on a standard Van Vleck–Weisskopf line shape, considering 1696 water absorption lines and 298 oxyg... Broadband terahertz(THz) atmospheric transmission characteristics from 0 to 8 THz are theoretically simulated based on a standard Van Vleck–Weisskopf line shape, considering 1696 water absorption lines and 298 oxygen absorption lines.The influences of humidity, temperature, and pressure on the THz atmospheric absorption are analyzed and experimentally verified with a Fourier transform infrared spectrometer(FTIR) system, showing good consistency. The investigation and evaluation on high-frequency atmospheric windows are good supplements to existing data in the low-frequency range and lay the foundation for aircraft-based high-altitude applications of THz communication and radar. 展开更多
关键词 terahertz atmospheric propagation line absorption continuum absorption
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Tunable Terahertz Source Based on Optics Pumped Nonlinear Crystals
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作者 De-Gang Xu Peng-Xiang Liu +3 位作者 Yu-Ye Wang kai zhong Wei Shi Jian-Quan Yao 《Journal of Electronic Science and Technology》 CAS 2014年第4期377-382,共6页
Recent progresses about optical pumped tunable terahertz (THz) sources are interviewed, including THz parametric oscillation (TPO) and difference frequency generation (DFG). We develop high efficiency and high p... Recent progresses about optical pumped tunable terahertz (THz) sources are interviewed, including THz parametric oscillation (TPO) and difference frequency generation (DFG). We develop high efficiency and high power surface-emitted TPO, as well as DFG with nonlinear crystals. A novel scheme for the high efficiency DFG source based on the Cherenkov phase-matching technology is comprehensively investigated in both bulk crystals. The widely tunable optical THz radiation is also researched based on the organic nonlinear 4-N,N-dimethylamino-4'-N'- methylstilbazolium 2,4,6-trimethylbenzenesulfonate (DSTMS) crystal. 展开更多
关键词 Cherenkov phase-matching differencefrequency generation nonlinear optics parametricoscillation.
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THz wave generation by repeated and continuous frequency conversions from pump wave to high-order Stokes waves
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作者 zhongyang Li Qianze Yan +7 位作者 Pengxiang Liu Binzhe Jiao Gege Zhang Zhiliang Chen Pibin Bing Sheng Yuan kai zhong Jianquan Yao 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第7期343-348,共6页
We propose a novel scheme for THz wave generation by repeated and continuous frequency conversions from pump wave to high-order Stokes waves(HSWs).The repeated frequency conversions are accomplished by oscillations of... We propose a novel scheme for THz wave generation by repeated and continuous frequency conversions from pump wave to high-order Stokes waves(HSWs).The repeated frequency conversions are accomplished by oscillations of Stoke waves in resonant cavity(RC)where low-order Stokes waves(LSWs)are converted to high-order Stokes waves again and again.The continuous frequency conversions are accomplished by optimized cascaded difference frequency generation(OCDFG)where the poling periods of the optical crystal are aperiodic leading to the frequency conversions from low-order Stokes waves to high-order Stokes waves uninterruptedly and unidirectionally.Combined with the repeated and continuous frequency conversions,the optical-to-THz energy conversion efficiency(OTECE)exceeds 26%at 300 K and 43%at 100 K with pump intensities of 300 MW/cm^(2). 展开更多
关键词 THz wave generation optimized cascaded difference frequency generation aperiodic periodically poled lithium niobate
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Monochromatic and Tunable Terahertz Source Based on Nonlinear Optics
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作者 De-Gang Xu Peng-Xiang Liu +3 位作者 Yu-Ye Wang kai zhong Wei Shi Jian-Quan Yao 《Journal of Electronic Science and Technology》 CAS 2013年第4期339-348,共10页
Recent progresses made by authors on monochromatic and tunable terahertz (THz) generation based on nonlinear optics are reviewed, including THz parametric oscillation (TPO) and difference frequency generation (DF... Recent progresses made by authors on monochromatic and tunable terahertz (THz) generation based on nonlinear optics are reviewed, including THz parametric oscillation (TPO) and difference frequency generation (DFG). From the technical point of view, we develop extra- and intra-cavity surface-emitted TPO, as well as DFG with QPM-GaAs crystal. From the point of view of mechanism, Cherenkov phase-matching is comprehensively investigated in both bulk crystal and planar waveguide. A novel scheme for cascading enhanced Cherenkov DFG in waveguide is proposed. From the point of view of material, organic crystal 4-N,N-dimethylamino-4'-N'-methyl-stibazolium tosylate (DAST) is utilized as the nonlinear medium. 展开更多
关键词 Differencenonlinear optics parametricsource.frequency generation oscillation terahertz
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The law of oral traditional Chinese medicine for insomnia based on Chinese medical code
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作者 Yuyan Li Yihua Fan +3 位作者 Jinxiang Mao Naijin Zhang Aikedai·Abulimiti kai zhong 《Medical Data Mining》 2019年第4期160-168,共9页
Objective:This study aimed to collect,sort out and excavate the literature on the diagnosis and treatment of insomnia in Chinese Medical Code,and to explore the law of internal administration of traditional Chinese me... Objective:This study aimed to collect,sort out and excavate the literature on the diagnosis and treatment of insomnia in Chinese Medical Code,and to explore the law of internal administration of traditional Chinese medicine in the treatment of insomnia.Methods:We used"Chinese Medical Code"as the source of data retrieval,"insomnia","not sleepy","no sleeping"and"eye not sleeping"as the key words,and excluded temporary insomnia,physiological insomnia,insomnia caused by other diseases,and excluded other methods such as acupuncture and massage,the medical cases.Prescriptions of insomnia treated with traditional Chinese medicine were screened out.The database was established by using Microsoft excel 2010.Descriptive statistics were used to analyze the frequency,menstruation of nature,taste and efficacy of traditional Chinese medicine.We analyzed the association rules between drugs and mined the rules of prescriptions by the Apriori algorithm in SPSS Modeler 14.1.Results:A total of 147 prescriptions,138 traditional Chinese medicines,20 pairs of core drugs,57 common drug combinations and 3 core pharmaceuticals were included.The basic prescription is:Suan Zao Ren,Bai Zi Ren,Fu Shen,Fu Ling,Yuan Zhi,Dang Gui,Gan Cao(Zhi).Conclusion:In summary,according to the drug analysis above,the main disease of insomnia is in the heart,involving the liver,spleen and kidney.Because it involves different viscera and syndrome,the methods of treatment are also different.However,there is a basic pathogenesis,that’s the loss of mental nourishment.By excavating the law of the use of traditional Chinese medicine in the treatment of insomnia on the Chinese Medical Code,we expect that it can guide the treatment of insomnia. 展开更多
关键词 INSOMNIA literature mining medicine law Chinese Medical Code
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家族控制权会加剧企业资金期限结构错配吗?——来自中国非国有上市公司的经验证据 被引量:21
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作者 钟凯 刘金钊 王化成 《会计与经济研究》 CSSCI 北大核心 2018年第2期3-20,共18页
家族控制权体现为"监督效应"还是"侵占效应",一直以来是学术研究的焦点。家族控制权对企业资金期限结构错配的影响机理如何?研究发现,家族控制权越强,企业资金期限结构错配越严重,且主要是家族控制权存在的较高利... 家族控制权体现为"监督效应"还是"侵占效应",一直以来是学术研究的焦点。家族控制权对企业资金期限结构错配的影响机理如何?研究发现,家族控制权越强,企业资金期限结构错配越严重,且主要是家族控制权存在的较高利益侵占动机所致。深入研究发现,对于融资约束企业,家族控制权对企业资金期限结构错配的影响更强,而且家族控制权会导致债务期限结构缩短,表明银行等债权人通过短期借款的方式加强治理效应,进一步支持了家族控制权的"侵占效应"。此外,家族控制权越强,资金期限结构错配造成的企业风险越大。研究表明,家族控制权存在的侵占动机很可能通过资金期限结构错配的途径加剧企业风险,研究发现对于加强中国家族企业公司治理、维护实体经济发展具有一定借鉴意义。 展开更多
关键词 家族企业 控制权 期限结构 资金错配 风险
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多晶材料随机准相位匹配研究进展 被引量:1
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作者 刘科飞 钟凯 姚建铨 《激光与光电子学进展》 CSCD 北大核心 2020年第21期1-12,共12页
由非线性晶体颗粒烧结成的多晶材料在宏观上是各向同性的,但由于各晶粒取向的随机分布,激光与其发生作用时产生的非线性极化存在相干增强的可能,且非线性转换效率统计均值与互作用长度存在线性关系,这被称作随机准相位匹配(RQPM)。与双... 由非线性晶体颗粒烧结成的多晶材料在宏观上是各向同性的,但由于各晶粒取向的随机分布,激光与其发生作用时产生的非线性极化存在相干增强的可能,且非线性转换效率统计均值与互作用长度存在线性关系,这被称作随机准相位匹配(RQPM)。与双折射相位匹配(BPM)及准相位匹配(QPM)相比,多晶材料的RQPM在带宽方面具有明显优势,因此多晶材料在宽带飞秒激光的频率变换中具有重要意义。近年来,基于多晶材料RQPM的差频(DFG)、倍频(SHG)及高效率光参量振荡器(OPO)等相继诞生,为实现超连续谱及宽带光频梳提供了一种低成本的新选择。对RQPM技术与理论的发展过程及研究现状进行了综述,对超宽带RQPM频率变换的最新重要成果进行了讨论,介绍了多晶陶瓷处理及建模的基本方法,并展望了RQPM发展前景,以期能够为国内超快激光及非线性光学频率变换等领域的研究提供参考。 展开更多
关键词 非线性光学 随机准相位匹配 多晶材料 宽带频率变换 超连续谱 光频梳
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High-average-power, high-repetition-rate tunable terahertz difference frequency generation with GaSe crystal pumped by 2 μm dual-wavelength intracavity KTP optical parametric oscillator 被引量:6
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作者 DEXIAN YAN YUYE WANG +12 位作者 DEGANG XU PENGXIANG LIU CHAO YAN JIA SHI HONGXIANG LIU YIXIN HE LONGHUANG TANG JIANCHEN FENG JIANQIN GUO WEI SHI kai zhong YUEN H.TSANG JIANQUAN YAO 《Photonics Research》 SCIE EI 2017年第2期82-87,共6页
We have demonstrated a high-average-power,high-repetition-rate optical terahertz(THz)source based on difference frequency generation(DFG)in the GaSe crystal by using a near-degenerate 2μm intracavity KTP optical para... We have demonstrated a high-average-power,high-repetition-rate optical terahertz(THz)source based on difference frequency generation(DFG)in the GaSe crystal by using a near-degenerate 2μm intracavity KTP optical parametric oscillator as the pump source.The power of the 2μm dual-wavelength laser was up to 12.33 W with continuous tuning ranges of 1988.0–2196.2 nm/2278.4–2065.6 nm for two waves.Different GaSe cystal lengths have been experimentally investigated for the DFG THz source in order to optimize the THz output power,which was in good agreement with the theoretical analysis.Based on an 8 mm long GaSe crystal,the THz wave was continuously tuned from 0.21 to 3 THz.The maximum THz average power of 1.66μW was obtained at repetition rate of 10 kHz under 1.48 THz.The single pulse energy amounted to 166 pJ and the conversion efficiency from 2 μm laser to THz output was 1.68×10^(-6).The signal-to-noise ratio of the detected THz voltage was 23 dB.The acceptance angle of DFG in the GaSe crystal was measured to be 0.16°. 展开更多
关键词 GASE THz KTP High-average-power m dual-wavelength intracavity KTP optical parametric oscillator rate
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