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Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution
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作者 Chen-Gang Lu Xian-Ming Xiao +4 位作者 Zhen-Qian Xue Zhang-Xin Chen Yin-Tao Dong Yue Feng Gang Li 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2273-2286,共14页
Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marin... Methane adsorption is a critical assessment of the gas storage capacity(GSC)of shales with geological conditions.Although the related research of marine shales has been well-illustrated,the methane adsorption of marine-continental transitional(MCT)shales is still ambiguous.In this study,a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin,China.The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters.Subsequently,the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC)content of 1.71%,and the effects of reservoir pressure coefficient and water saturation on GSC were explored.In experimental results,compared to the composition of the MCT shale,the pore structure dominates the methane adsorption,and meanwhile,the maturity mainly governs the pore structure.Besides,maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth.The two parameters,micropore pore volume and non-micropore surface area,induce a good fit for the adsorption capacity data of the shale.In simulation results,the depth,pressure coefficient,and water saturation of the shale all affect the GSC.It demonstrates a promising shale gas potential of the MCT shale in a deeper block,especially with low water saturation.Specifically,the economic feasibility of shale gas could be a major consideration for the shale with a depth of<800 m and/or water saturation>60%in the Yushe-Wuxiang area.This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas. 展开更多
关键词 High-pressure methane adsorption Marine-continental transitional shale gas Ono-Kondo model Adsorption thermodynamics Gas storage capacity model
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A Well Productivity Model for Multi-Layered Marine and Continental Transitional Reservoirs with Complex Fracture Networks
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作者 Huiyan Zhao Xuezhong Chen +3 位作者 Zhijian Hu Man Chen Bo Xiong Jianying Yang 《Fluid Dynamics & Materials Processing》 EI 2024年第6期1313-1330,共18页
Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production rate.This model relies on the fractal theory... Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production rate.This model relies on the fractal theory of tortuous capillary bundles and can take into account multiple gas flow mechanisms at the micrometer and nanometer scales,as well as the flow characteristics in different types of thin layers(tight sandstone gas,shale gas,and coalbed gas).Moreover,a source-sink function concept and a pressure drop superposition principle are utilized to introduce a coupled flow model in the reservoir.A semi-analytical solution for the production rate is obtained using a matrix iteration method.A specific well is selected for fitting dynamic production data,and the calculation results show that the tight sandstone has the highest gas production per unit thickness compared with the other types of reservoirs.Moreover,desorption and diffusion of coalbed gas and shale gas can significantly contribute to gas production,and the daily production of these two gases decreases rapidly with decreasing reservoir pressure.Interestingly,the gas production from fractures exhibits an approximately U-shaped distribution,indicating the need to optimize the spacing between clusters during hydraulic fracturing to reduce the area of overlapping fracture control.The coal matrix water saturation significantly affects the coalbed gas production,with higher water saturation leading to lower production. 展开更多
关键词 Marine-continental transitional reservoir multi-layered reservoir seepage mechanisms apparent permeability hydraulic horizontal well productivity model
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A Modified Transitional Korteweg-De Vries Equation: Posed in the Quarter Plane
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作者 Charles Bu 《Journal of Applied Mathematics and Physics》 2024年第7期2691-2701,共11页
This paper is concerned with a modified transitional Korteweg-de Vries equation ut+f(t)u2ux+uxxx=0, (x,t)∈R+×R+with initial value u(x,0)=g(x)∈H4(R+)and inhomogeneous boundary value u(0,t)=Q(t)∈C2([ 0,∞ )). Un... This paper is concerned with a modified transitional Korteweg-de Vries equation ut+f(t)u2ux+uxxx=0, (x,t)∈R+×R+with initial value u(x,0)=g(x)∈H4(R+)and inhomogeneous boundary value u(0,t)=Q(t)∈C2([ 0,∞ )). Under the conditions either 1) f(t)≤0, f′(t)≥0or 2) f(t)≤−αwhere α>0, we prove the existence of a unique global classical solution. 展开更多
关键词 Modified transitional KdV Equation Initial-Boundary Value Problem Semi-Group Local and Global Existence
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Sediment source-to-sink process variations of sandy-muddy transitional beaches and their morphological indications
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作者 Shaohua Zhao Feng Cai +4 位作者 Hongshuai Qi Jianhui Liu Chao Cao Gen Liu Gang Lei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第7期10-24,共15页
The clay mineralogy of 28 sandy-muddy transitional beach(SMT-Beach)sediments and surrounding mountain river sediments along the coasts of southeastern China was systematically investigated to reveal the sediment sourc... The clay mineralogy of 28 sandy-muddy transitional beach(SMT-Beach)sediments and surrounding mountain river sediments along the coasts of southeastern China was systematically investigated to reveal the sediment source-to-sink process variations of such beaches and their morphological indications.The results show that the clay mineral assemblages of these SMT-Beaches mainly comprise of almost equal illite(~30%),kaolinite(~28%),chlorite(~22%),and smectite(~20%)contents.From the surrounding mountain rivers to the SMT-Beaches,clay mineral assemblages show distinct spatial changes characterized by a large decrease(~40%)in kaolinite,whereas the other three clay minerals present relative increases,especially clear for smectite.The muddy sediment sources of SMT-Beaches inferred from the clay mineralogy are mainly derived from nearby mountain rivers coupled with long-distance transport and penetration of the Changjiang River.The sandy sediments of these beaches are predominantly sourced from nearby mountain rivers,the weathering products of surrounding rocks in both mainland and island environments,and erosion of the“Old Red Sand”and“Red Soil Platform”.However,the sandy sediment sources of the SMT-Beaches are largely reduced because of the remarkable decrease in the river fluvial supply associated with intensive human activities such as dam construction and coastal reclamation.Subsequently,the sandy sections of SMT-Beaches present clear erosion and have revealed by both time series remote sensing images and a compilation of published literature.In contrast,the muddy sediment supply of SMT-Beaches is temporarily stable and relatively constant,resulting in the landward migration of the mudflats with relative transgression or accumulation.These findings highlight that the natural evolution processes of SMT-Beaches have been greatly reshaped by intensive human activities. 展开更多
关键词 sandy-muddy transitional beach clay mineral sediment source human activity fluvial discharge morphological evolution
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Artificial neural network-based one-equation model for simulation of laminar-turbulent transitional flow 被引量:2
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作者 Lei Wu Bing Cui Zuoli Xiao 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2023年第1期50-57,共8页
A mapping function between the Reynolds-averaged Navier-Stokes mean flow variables and transition intermittency factor is constructed by fully connected artificial neural network(ANN),which replaces the governing equa... A mapping function between the Reynolds-averaged Navier-Stokes mean flow variables and transition intermittency factor is constructed by fully connected artificial neural network(ANN),which replaces the governing equation of the intermittency factor in transition-predictive Spalart-Allmaras(SA)-γmodel.By taking SA-γmodel as the benchmark,the present ANN model is trained at two airfoils with various angles of attack,Mach numbers and Reynolds numbers,and tested with unseen airfoils in different flow states.The a posteriori tests manifest that the mean pressure coefficient,skin friction coefficient,size of laminar separation bubble,mean streamwise velocity,Reynolds shear stress and lift/drag/moment coefficient from the present two-way coupling ANN model almost coincide with those from the benchmark SA-γmodel.Furthermore,the ANN model proves to exhibit a higher calculation efficiency and better convergence quality than traditional SA-γmodel. 展开更多
关键词 TRANSITION TURBULENCE Eddy-viscosity model Artificial neural network Intermittency factor
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Clinical Significance of Cytokeratin 19 and Cytokeratin 20 in Predicting Recurrence of Bladder Transitional Cell Carcinoma 被引量:1
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作者 章慧平 杨为民 +2 位作者 叶章群 陈春莲 余虓 《The Chinese-German Journal of Clinical Oncology》 CAS 2006年第2期132-134,共3页
Objective: To investigate the expressions of cytokeratin 19 (CK19) and cytokeratin 20 (CK20) in bladder transitional cell carcinoma (TCC) and their clinical significance. Methods: The expression of CK19 and CK... Objective: To investigate the expressions of cytokeratin 19 (CK19) and cytokeratin 20 (CK20) in bladder transitional cell carcinoma (TCC) and their clinical significance. Methods: The expression of CK19 and CK20 was detected in 54 cases of TCC by immunohistochemical methods and image processing techniques. Results: The expression of CK19 and CK20 was significantly stronger in the recurrent group than in the non-recurrent group (P〈0.01, P〈0.001, respectively). Conclusion: The expression of CK19 and CK20 was obviously related with biological behaviors of TCC, suggesting that CK19 and CK20 could be used to predict the recurrence of TCC. 展开更多
关键词 cytokeratin 19 cytokeratin 20 bladder transitional cell carcinoma tumor marker
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Expression and Significance of PTEN in Bladder Transitional Cell Carcinoma 被引量:1
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作者 张建华 杨为民 周四维 《The Chinese-German Journal of Clinical Oncology》 CAS 2005年第4期218-220,共3页
Objective: To explore the expression of anti-oncogene PTEN in bladder transitional cell carcinoma and its clinical significance. Methods: Using immunohistochemical S-P methods, the expression of PTEN gene was detect... Objective: To explore the expression of anti-oncogene PTEN in bladder transitional cell carcinoma and its clinical significance. Methods: Using immunohistochemical S-P methods, the expression of PTEN gene was detected in 62 specimens of bladder cancer and 18 specimens of normal bladder tissue. Results: In the 62 bladder cancers, the positive rate of PTEN was 53.2% (33/62). All 18 normal bladder tissues were positive for the PTEN expression. The expression of PTEN was negatively correlated to tumor grades (P〈0.05). Conclusion: The reduced expression of PETN might play an important role in carcinogenesis and progression of bladder cancer. Detection of PTEN might be useful for judgement of tumor development and prognosis. 展开更多
关键词 transitional cell carcinoma PTEN gene IMMUNOHISTOCHEMISTRY
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Tumor formation of prostate cancer cells influenced by stromal cells from the transitional or peripheral zones of the normal prostate 被引量:19
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作者 Fu-Jun Zhao Bang-Min Han +1 位作者 Sheng-Qiang Yu Shu-Jie Xia 《Asian Journal of Andrology》 SCIE CAS CSCD 2009年第2期176-182,共7页
This study was designed to investigate the different involvements of prostatic stromal cells from the normal transitional zone(TZ)or peripheral zone(PZ)in the carcinogenesis of prostate cancer(PCa)epithelial cells(PC-... This study was designed to investigate the different involvements of prostatic stromal cells from the normal transitional zone(TZ)or peripheral zone(PZ)in the carcinogenesis of prostate cancer(PCa)epithelial cells(PC-3)in vitro and in vivo co-culture models.Ultra-structures and gene expression profiles of primary cultures of human prostatic stromal cells from the normal TZ or PZ were analyzed by electron microscopy and microarray analysis.In vitro and in vivo co-culture models composed of normal TZ or PZ stromal cells and human PCa PC-3 cells were established.We assessed tumor growth and weight in the in vivo nude mice model.There are morphological and ultra-structural differences in stromal cells from TZ and PZ of the normal prostate.In all,514 differentially expressed genes were selected by microarray analysis;483 genes were more highly expressed in stromal cells from TZ and 31 were more highly expressed in those from PZ.Co-culture with PZ stromal cells and transforming growth factor-β1(TGF-β1)increased the tumor growth of PC-3 cells in vitro and in vivo,as well as Bcl-2 expression.On the other hand,stromal cells of TZ suppressed PC-3 cell tumor growth in the mouse model.We conclude that ultra-structures and gene expression differ between the stromal cells from TZ or PZ of the normal prostate,and stroma-epithelium interactions from TZ or PZ might be responsible for the distinct zonal localization of prostate tumor formation. 展开更多
关键词 CO-CULTURE epithelial cells stromal cells transitional zone peripheral zone prostate cancer
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Full-Sized Pore Structure and Fractal Characteristics of Marine-Continental Transitional Shale: A Case Study in Qinshui Basin, North China 被引量:6
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作者 YIN Liangliang GUO Shaobin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第3期675-691,共17页
Based on 10 shale samples collected from 4 wells in Qinshui Basin,we investigate the full-sized pore structure and fractal characteristics of Marine-Continental transitional shale by performing organic geochemistry,mi... Based on 10 shale samples collected from 4 wells in Qinshui Basin,we investigate the full-sized pore structure and fractal characteristics of Marine-Continental transitional shale by performing organic geochemistry,mineralogical composition,Nitrogen gas adsorption(N2 adsorption)and Nuclear Magnetic Resonance(NMR)measurements and fractal analysis.Results show that the TOC content of the shale samples is relatively high,with an average value of 2.44wt%,and the thermal evolution is during the mature-over mature stage.The NMR T2 spectrum can be used to characterize the fullsized pore structure characteristics of shale.By combining N2 adsorption pore structure parameters and NMR T2 spectrums,the surface relaxivity of samples are calculated to be between 1.7877 um/s and 5.2272 um/s.On this basis,the T2 spectrums are converted to full-sized pore volume and surface area distribution curves.The statistics show that the pore volume is mainly provided by mesopore,followed by micropore,and the average percentages are 65.04%and 30.83%respectively;the surface area is mainly provided by micropore,followed by mesopore,and the average percentages are 60.8004%and 39.137%respectively;macropore contributes little to pore volume and surface area.The pore structure characteristics of shale have no relationship with TOC,but strong relationships with clay minerals content.NMR fractal dimensions Dmicro and Dmeso have strong positive relationships with the N2 adsorption fractal dimensions D1 and D2 respectively,indicating that Dmicro can be used to characterize the fractal characteristics of pore surface,and Dmeso can be used to characterize the fractal characteristics of pore structure.The shale surface relaxivity is controlled by multiple factors.The increasing of clay mineral content,pore surface area,pore surface fractal dimension and the decreasing of average pore size,will all lead to the decreasing of shale surface relaxivity. 展开更多
关键词 Marine-Continental transitional SHALE nuclear magnetic resonance nitrogen adsorption full-sized PORE structure FRACTAL dimensions
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Development of the Transitional Care Model for nursing care in China's Mainland:A literature review 被引量:11
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作者 Zeng-Jie Ye Mei-Ling Liu +4 位作者 Rui-Qing Cai Mei-Xia Zhong Hui Huang Mu-Zhi Liang Xiao-Ming Quan 《International Journal of Nursing Sciences》 2016年第1期113-130,共18页
Background:The Transitional Care Model(TCM)for nursing care has yet to be implemented in China despite its success in Western countries.However,rapid social changes have demanded an upgrade in the quality of nursing c... Background:The Transitional Care Model(TCM)for nursing care has yet to be implemented in China despite its success in Western countries.However,rapid social changes have demanded an upgrade in the quality of nursing care;in 2010,the Chinese government has acknowledged the need to implement the TCM in China.Objective:This study has the following objectives:(1)perform a thorough review of the literature regarding the development and implementation of the TCM in China's Mainland within the past 5 years;(2)provide a comprehensive discussion of the current status,problems,and strategies related to the implementation of the TCM in China's Mainland;and(3)suggest strategies pertaining to the future of the TCM in China.Design:The current pertinent literature is systematically reviewed.Data sources:Systematic and manual searches in computerized databases for relevant studies regarding the TCM led to the inclusion of 26 papers in this review.Review methods:Abstracts that satisfied the inclusion criteria were reviewed independently by the two authors of this manuscript,and discrepancies were resolved through discussion.The same reviewers independently assessed the paper in its entirety for selected abstracts.Results:The present English literature reviewrevealed a paucity of updated information about the development and implementation of the TCM in China's Mainland.Nevertheless,the dramatic growth of the TCM in the past 5 years has had a vital impact within the society and in nursing development.This review also revealed numerous issues regarding the focus of the TCM.Overall implications for practiceandrecommendations for future researchare discussed.Conclusion:Despite the potential of this nursing model to have a successful and beneficial impact in China's Mainland,it remains an under-researched topic.Further research on education and training as well as premium policies for nurses under the TCM are needed. 展开更多
关键词 transitional Care Model Continued nursing Continuity of care Health care needs DEVELOPMENT Mainland China
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Expression of KAI1/CD82 and MRP-1/CD9 in Transitional Cell Carcinoma of Bladder 被引量:7
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作者 艾星 张旭 +4 位作者 吴准 马鑫 居正华 王保军 史涛坪 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2007年第1期79-82,共4页
The expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder (TCCB) and its clinical significance were investigated. Immunohistochemistry was used to detect KAI1/CD82 and MRP-1/CD9 protein exp... The expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder (TCCB) and its clinical significance were investigated. Immunohistochemistry was used to detect KAI1/CD82 and MRP-1/CD9 protein expression in 52 TCCB specimens. Correlation between the expression of KAI1/CD82 and MRP-1/CD9 to clinicopathologic factors was statistically analyzed. The results showed that the positive rate of KAI1/CD82 and MRP-1/CD9 in TCCB was 50% and 61.5%, respectively. The MRP-1/CD9 and KAI1/CD82 expression was significantly associated with grade of TCCB (P〈0.05), but no correlation was found between MRP-1/CD9 or KAI1/CD82 expression and clinical stage of TCCB (P〉0.05). The expression level of MRP-1/CD9 and KAI1/CD82 in recurrent TCCB samples was lower than that in non-recurrent samples (P〈0.05). Meanwhile, the correlation between the KAI1/CD82 expression and MRP-1/CD9 expression was statistically significant (r=0.316, P〈0.05). It was concluded that KAI1/CD82 and MRP-1/CD9 expression may be important prognostic indicators and potentially useful for assessing the biological behavior of TCCB. 展开更多
关键词 bladder carcinoma transitional cell KAI1/CD82 MRP-1/CD9 IMMUNOHISTOCHEMISTRY
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Porosity model and pore evolution of transitional shales:an example from the Southern North China Basin 被引量:5
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作者 Xiao-Guang Yang Shao-Bin Guo 《Petroleum Science》 SCIE CAS CSCD 2020年第6期1512-1526,共15页
The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect.Thermal simulation experiments were conducted... The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect.Thermal simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale,and X-ray diffraction(XRD),CO2 adsorption,N2 adsorption and high-pressure mercury injection(MIP)were then used to characterize shale diagenesis and porosity.Moreover,simulations of mechanical compaction adhering to mathematical models were performed,and a shale compaction model was proposed considering clay content and kaolinite proportions.The advantage of this model is that the change in shale compressibility,which is caused by the transformation of clay minerals during thermal evolution,may be considered.The combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical compaction.Such interactions may then express the pore evolution of shale in actual conditions of formation.Accordingly,the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content,proving that other clay minerals such as illite-smectite mixed layers(I/S)and illite are conducive to the development of pores.Shales possessing a high clay mineral content have a higher porosity in shallow layers(<3500 m)and a lower porosity in deep layers(>3500 m).Both the amount and location of the increase in porosity differ at different geothermal gradients.High geothermal gradients favor the preservation of high porosity in shale at an appropriate Ro.The pore evolution of the marine-continental transitional shale is divided into five stages.Stage 2 possesses an Ro of 1.0%-1.6%and has high porosity along with a high specific surface area.Stage 3 has an Ro of 1.6%-2.0%and contains a higher porosity with a low specific surface area.Finally,Stage 4 has an Ro of 2.0%-2.9%with a low porosity and high specific surface area. 展开更多
关键词 Thermal simulation Porosity model Pore evolution transitional shale Southern North China Basin Shanxi formation
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Favorable lithofacies types and genesis of marine- continental transitional black shale: A case study of Permian Shanxi Formation in the eastern margin of Ordos Basin, NW China 被引量:5
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作者 WU Jin WANG Hongyan +7 位作者 SHI Zhensheng WANG Qi ZHAO Qun DONG Dazhong LI Shuxin LIU Dexun SUN Shasha QIU Zhen 《Petroleum Exploration and Development》 CSCD 2021年第6期1315-1328,共14页
Based on core description,thin section identification,X-ray diffraction analysis,scanning electron microscopy,low-temperature gas adsorption and high-pressure mercury intrusion porosimetry,the shale lithofacies of Sha... Based on core description,thin section identification,X-ray diffraction analysis,scanning electron microscopy,low-temperature gas adsorption and high-pressure mercury intrusion porosimetry,the shale lithofacies of Shan23 sub-member of Permian Shanxi Formation in the east margin of Ordos Basin was systematically analyzed in this study.The Shan23 sub-member has six lithofacies,namely,low TOC clay shale(C-L),low TOC siliceous shale(S-L),medium TOC siliceous shale(S-M),medium TOC hybrid shale(M-M),high TOC siliceous shale(S-H),and high TOC clay shale(C-H).Among them,S-H is the best lithofacies,S-M and M-M are the second best.The C-L and C-H lithofacies,mainly found in the upper part of Shan23 sub-member,generally developed in tide-dominated delta facies;the S-L,S-M,S-H and M-M shales occurring in the lower part of Shan23 sub-member developed in tide-dominated estuarine bay facies.The S-H,S-M and M-M shales have good pore struc-ture and largely organic matter pores and mineral interparticle pores,including interlayer pore in clay minerals,pyrite inter-crystalline pore,and mineral dissolution pore.C-L and S-L shales have mainly mineral interparticle pores and clay mineral in-terlayer pores,and a small amount of organic matter pores,showing poorer pore structure.The C-H shale has organic mi-cro-pores and a small number of interlayer fissures of clay minerals,showing good micro-pore structure,and poor meso-pore and macro-pore structure.The formation of favorable lithofacies is jointly controlled by depositional environment and diagen-esis.Shallow bay-lagoon depositional environment is conducive to the formation of type II2 kerogen which can produce a large number of organic cellular pores.Besides,the rich biogenic silica is conducive to the preservation of primary pores and en-hances the fracability of the shale reservoir. 展开更多
关键词 marine-continental transitional facies shale gas favorable lithofacies reservoir characteristics Permian Shanxi Formation Ordos Basin
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Transitional care for patients with chronic obstructive pulmonary disease 被引量:5
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作者 Jia-Mei Li Shou-Zhen Cheng +4 位作者 Wei Cai Zhao-Hui Zhang Qiong-Hui Liu Bi-Zhen Xie Mu-Dan Wang 《International Journal of Nursing Sciences》 2014年第2期157-164,共8页
Objectives:To observe the effects of transitional care on the quality of life of chronic obstructive pulmonary disease(COPD)patients.Methods:A total of 114 COPD patients were recruited from the First Affiliated Hospit... Objectives:To observe the effects of transitional care on the quality of life of chronic obstructive pulmonary disease(COPD)patients.Methods:A total of 114 COPD patients were recruited from the First Affiliated Hospital,Sun Yat-sen University,Guangzhou,China and divided equally into an intervention group and control group.Following discharge,patients from the intervention group recieved threemonths intervention in addition to regular nursing care,while control group patients received regular nursing care only.Patients’quality of life was measured using the St.George’s respiratory questionnaire(SGRQ),the 12-item General Health Questionnaire(GHQ-12)and body mass index(BMI).Results:The symptoms section score,the activity section score,the impacts section score,the total score and the rate of mental disorders were significantly changed after the intervention while there was no statistical difference in BMI between groups.Conclusions:Transitional care can improve health-related quality of life in COPD patients who have recently suffered an exacerbation. 展开更多
关键词 Chronic obstructive Pulmonary disease Quality of life transitional care
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Prediction of transitional lumbosacral anatomy on magnetic resonance imaging of the lumbar spine 被引量:5
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作者 Majid Chalian Theodoros Soldatos +3 位作者 John A Carrino Alan J Belzberg Jay Khanna Avneesh Chhabra 《World Journal of Radiology》 CAS 2012年第3期97-101,共5页
AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects wit... AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated. In each study, the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table (A-angle), as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum (B-angle). RESULTS: The total study population consisted of 100 subjects (46 males, 54 females, 51 ± 16 years old). There were no differences in age and sex between the two groups. Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls (P < 0.05). The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8° (sensitivity = 80%, specificity = 80%, accuracy = 83%; 95% confidence interval = 74%-89%, P = 0.0001) and 35.9° (sensitivity = 80%, specificity = 54%, accuracy = 69%; 95% confidence interval = 59%-78%, P = 0.0005), respectively. CONCLUSION: On sagittal MR images of the lumbar spine, an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV. 展开更多
关键词 Lumbosacral transitional vertebra Magnetic resonance imaging Lumbar spine ANGLE PREDICTION
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Analyzing Land-use Change in Farming-pastoral Transitional Region Using Autologistic Model and Household Survey Approach 被引量:3
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作者 ZHU Likai MENG Jijun MAO Xiyan 《Chinese Geographical Science》 SCIE CSCD 2013年第6期716-728,共13页
Land change science (LCS) strives to understand and model land-use change, which will further advance the understanding of multiple issues in the socio-ecological systems. Based on GIS/RS techniques, autologistic mo... Land change science (LCS) strives to understand and model land-use change, which will further advance the understanding of multiple issues in the socio-ecological systems. Based on GIS/RS techniques, autologistic model, and household survey method, this study investigated major land use changes and their causes from 1978 to 2008 in Uxin Banner (county-level), Inner Mongolia in China and then developed an understanding of the relationships between household livelihood and land-use pattern. Results showed that cultivated land increased from 1988 to 2000, and leveled offafter 2000. Built-up land increased stably for the period 1978 2008. The change of grassland and bare land differed among the three periods. From 1978 to 1988, grassland increased by 23.3%, and bare land decreased by 20.48%. From 1988 to 2000, bare land expanded by 1.7%, but grassland declined by 1.3%. From 2000 to 2008, an increase in grassland area by 1.8% was observed, but a decrease in bare land area by 9.0% was witnessed. The autologistic models performed better than logistic models as indicated by lower Akaike Information Criterion (AIC) values. Factors associated with human activities significantly correlated with the change of cultivated land, forest land, grassland, and built-up land. The produce prices and extensive cultivated land use are major issues in the farming area. This study suggests that completing land circulation systems and maintaining the stability of price are effective solutions. By contrast, reclamation and overgrazing are major concerns in the pastoral areas. Implementing environmental policies effectively, transferring population out of rural pastoral areas, and developing modem animal husbandry are effective ways to address these issues. 展开更多
关键词 farming-pastoral transitional region land use change driving force LIVELIHOOD autologistic model Uxin Banner(county-level) Inner Mongolia
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MICROSTRUCTURE AND INFRARED EMISSIVITY AT NORMAL TEMPERATURE IN TRANSITIONAL METAL OXIDES SYSTEM CERAMICS 被引量:3
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作者 徐庆 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2000年第2期15-20,共6页
The fabrication of Fe2O3-MnO2-Co2O3-CuO system ceramics, and the composite system ceramics of transitional metal oxides-cordierite and transitional metal oxides-kaolinit are presented in this work. The research was ca... The fabrication of Fe2O3-MnO2-Co2O3-CuO system ceramics, and the composite system ceramics of transitional metal oxides-cordierite and transitional metal oxides-kaolinit are presented in this work. The research was carried out with the main attention to the infrared emissivity in the band of 8 similar to 14 mu m at room temperature, the microstructure of the ceramics and the relation between them. High infrared emissivities exceeding 0.9 in the band of 8 similar to 14 mu m at room temperature were gained in the transitional metal oxide ceramics and the composite system ceramics. It is suggested that the formation of inverse spinels and partially inverse spinels, such as Fe3O4, CoFe2O4, CuFe2O4 and CuMn2O4, is beneficial to the enhancement of the infrared emissivity of the transitional metal oxide ceramics. The transitional metal oxides play an important role in determining the infrared emissivity of the composite system ceramics. 展开更多
关键词 transitional metal oxide CORDIERITE KAOLINITE infrared radiation ceramics room temperature
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Modified Rayleigh Distribution of Wave Heights in Transitional Water Depths 被引量:3
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作者 王迎光 《China Ocean Engineering》 SCIE EI CSCD 2016年第3期447-458,共12页
This paper concerns the calculation of wave height exceedance probabilities for nonlinear irregular waves in transitional water depths, and a Transformed Rayleigh method is first proposed for carrying out the calculat... This paper concerns the calculation of wave height exceedance probabilities for nonlinear irregular waves in transitional water depths, and a Transformed Rayleigh method is first proposed for carrying out the calculation. In the proposed Transformed Rayleigh method, the transformation model is chosen to be a monotonic exponential function, calibrated such that the first three moments of the transformed model match the moments of the true process. The proposed new method has been applied for calculating the wave height exceedance probabilities of a sea state with the surface elevation data measured at the Poseidon platform. It is demonstrated in this case that the proposed new method can offer better predictions than those by using the conventional Rayleigh wave height distribution model. The proposed new method has been further applied for calculating the total horizontal loads on a generic jacket, and its accuracy has once again been substantiated. The research findings gained from this study demonstrate that the proposed Transformed Rayleigh model can be utilized as a promising alternative to the well-established nonlinear wave height distribution models. 展开更多
关键词 wave height transitional water depth nonlinear irregular waves transformed Rayleigh method
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Boundary Shift of Potential Suitable Agricultural Area in Farming-grazing Transitional Zone in Northeastern China under Background of Climate Change During 20th Century 被引量:3
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作者 YE Yu FANG Xiuqi 《Chinese Geographical Science》 SCIE CSCD 2013年第6期655-665,共11页
Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential su... Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded: 1) The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2) The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3) The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area. 展开更多
关键词 land cover changes farming-grazing transitional zone climate change agricultural production
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Spatio-temporal characteristics of population and economy in transitional geographic space at the southern end of"Hu Huan-yong Line" 被引量:3
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作者 DENG Wei CHENG Yu-fang +3 位作者 YU Huan PENG Li KONG Bo HOU Yu-ting 《Journal of Mountain Science》 SCIE CSCD 2022年第2期350-364,共15页
"Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human be... "Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human beings’adaptation to the natural environment.With the development of the times and the progress of modern science and technology,especially the rapid urbanization and construction of transportation network system in China,the connection between economic and geographical space has been continuously strengthened.The geographical transition zones from mountain areas to plains,i.e.,transitional geographical space,have promoted the changes in human-land relationships through population migration and agglomeration.Taking Sichuan-Yunnan provinces at the southern end of Hu Line as study area,this study analyzed the spatial correlation between population distribution and economy in this region,explored the pattern of geographical agglomeration and deagglomeration,and explained the changing characteristics of humanland relationship in transitional geographic space using global Moran’s I index,global regression model(GRM)and geographically weighted regression(GWR).The results show that population and Gross Domestic Product(GDP)have significant spatial dependence to this region,with obvious aggregation in geographical distribution and positive autocorrelation;comparing with the general least square model,the GWR model incorporating spatial effect was more suitable for revealing the distribution characteristics of geographical elements,with fine results and better fitting;the spatial model of population and GDP as well as the spatio-temporal evolution model of their changes,all of them strongly indicated that Normalized Difference Vegetation Index(NDVI)and road density were important factors governing the spatial differentiation of population and economy;under the rapid development of regional economy and continuous evolution of urban-rural relations,rural transformation and spatial reconstruction promoted the change of population migration and agglomeration. 展开更多
关键词 Hu Huan-yong Line Spatial correlation Geographically weighted regression Population distribution transitional geographic space
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