《宇航学报》英文版(Advances in Astronautics)由中国宇航学会与哈尔滨工业大学联合主办,与中国宇航学会主办的中文旗舰学术期刊《宇航学报》实施一体化建设,定位于覆盖宇航领域主要技术方向的综合性英文学术期刊。本刊为英文季刊,与...《宇航学报》英文版(Advances in Astronautics)由中国宇航学会与哈尔滨工业大学联合主办,与中国宇航学会主办的中文旗舰学术期刊《宇航学报》实施一体化建设,定位于覆盖宇航领域主要技术方向的综合性英文学术期刊。本刊为英文季刊,与施普林格·自然集团合作出版,并已被Ei Compendex、Scopus等权威数据库收录,为全球科研人员提供高质量的成果发表平台。展开更多
Waxy crude oil exhibits complex shear-and-thermal-history-dependent non-Newtonian behaviors.In the past 10 years,driven by the petroleum industry,crude oil rheology has been an active field.Studies on crude oil rheolo...Waxy crude oil exhibits complex shear-and-thermal-history-dependent non-Newtonian behaviors.In the past 10 years,driven by the petroleum industry,crude oil rheology has been an active field.Studies on crude oil rheology have been passing a way from simply relying on rheological measurements,through quantitative experimental simulation of shear and thermal history effects in pipelining,to recent development of correlation between flow properties and shear and thermal history.Currently,the study is toward quantitative inquiry of relations between the rheological behaviors and micro-structures of wax crystals as well as oil compositions.Advances achieved by the author' team are summarized,including simulation of the thermal and shear history effects,correlations and computation of flow properties,fractal characterization of morphology and structure of wax crystals,relations of rheological behaviors to fractal dimension and oil compositions,and the most successful example of the application of rheology in crude oil pipelining.Future studies are prospected.展开更多
Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies ne...Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies necessary for realizing this possibility may be classified into those relevant to the four serial processes (a) the formation of a hydrate, (b) the processing (dewatering, pelletizing, etc. ) of the formed hydrate, (c) the storage and transportation of the processed hydrate, and (d) the regasification (dissociation) of the hydrate. The technological development of any of these processes is still at an early stage. For hydrate formation, for example, various rival operations have been proposed. However,many of them have never been subjected to actual tests for practical use. More efforts are required for examining the different hydrate-formation technologies and for rating them by comparison. The general design of the processing of the formed hydrate inevitably depends on both the hydrate-formation process and the storage/transportation process, hence it has a wide variability. The major uncertainty in the storage-process design lies in the as-yet unclarified utility of the "self-preservation" effect of the naturalgas hydrates. The process design as well as the relevant cost evaluation should strongly depend on whether the hydrates are well preserved at atmospheric pressure in large-scale storage facilities. The regasification process has been studied less extensively than the former processes. The state of the art of the technological development in each of the serial processes is reviewed, placing emphasis on the hydrate formation process.展开更多
Objective:Albumin-globulin ratio(AGR),prognostic nutritional index(PNI),and platelet to-lymphocyte ratio(PLR)have been validated as prognostic factors for gastric cancer(GC).However,significant gender differences exis...Objective:Albumin-globulin ratio(AGR),prognostic nutritional index(PNI),and platelet to-lymphocyte ratio(PLR)have been validated as prognostic factors for gastric cancer(GC).However,significant gender differences exist in albumin levels and inflammatory cell counts,and further research is required to understand how these differences influence GC prognosis.This study aims to investigate the prognostic impact of nutritional and inflammatory indicators on GC patients undergoing radical surgery,as well as the influence of gender on these indicators’prognostic value.Methods:The study included 596 patients with advanced GC hospitalized in the Department of Gastrointestinal Surgery,General Surgery,Xiangya Hospital of Central South University from January 2012 to December 2016.Receiver operating characteristic(ROC)analysis was performed to determine cutoff values for nutritional and inflammatory factors.Univariate analysis was used to identify factors significantly affecting survival in GC patients,while multivariate and Kaplan-Meier analyses determined independent prognostic factors for GC.Results:Multivariate analysis revealed that postsurgical tumor node metastasis(pTNM)stage[stage II:hazard ratio(HR)=3.284,P=0.012;stage III:HR:8.062,P<0.001],low preoperative AGR(HR=1.499,P=0.012),and postoperative PNI(HR=1.503,P=0.008)were risk factors for overall survival in male patients after radical GC surgery.For female patients,pN2-3(HR=3.185,P<0.001),total gastrectomy(HR=2.286,P=0.004),low preoperative PLR(HR=1.702,P=0.027),and postoperative PNI(HR=1.943,P=0.011)were identified as risk factors for overall survival.Conclusion:Postoperative PNI is an independent risk factor for all advanced GC patients.Preoperative PLR is an independent prognostic factor only for female patients,while preoperative AGR is an independent prognostic factor only for male patients.Further research is warranted to investigate the gender-specific differences in GC prognosis.展开更多
Introduction Most of our knowledge of knee kinematics during gait is based on studies measuring knee motion using external skin markers. While these studies have dramatically improved our knowledge of human gait it re...Introduction Most of our knowledge of knee kinematics during gait is based on studies measuring knee motion using external skin markers. While these studies have dramatically improved our knowledge of human gait it remains a challenge to展开更多
文摘《宇航学报》英文版(Advances in Astronautics)由中国宇航学会与哈尔滨工业大学联合主办,与中国宇航学会主办的中文旗舰学术期刊《宇航学报》实施一体化建设,定位于覆盖宇航领域主要技术方向的综合性英文学术期刊。本刊为英文季刊,与施普林格·自然集团合作出版,并已被Ei Compendex、Scopus等权威数据库收录,为全球科研人员提供高质量的成果发表平台。
文摘Waxy crude oil exhibits complex shear-and-thermal-history-dependent non-Newtonian behaviors.In the past 10 years,driven by the petroleum industry,crude oil rheology has been an active field.Studies on crude oil rheology have been passing a way from simply relying on rheological measurements,through quantitative experimental simulation of shear and thermal history effects in pipelining,to recent development of correlation between flow properties and shear and thermal history.Currently,the study is toward quantitative inquiry of relations between the rheological behaviors and micro-structures of wax crystals as well as oil compositions.Advances achieved by the author' team are summarized,including simulation of the thermal and shear history effects,correlations and computation of flow properties,fractal characterization of morphology and structure of wax crystals,relations of rheological behaviors to fractal dimension and oil compositions,and the most successful example of the application of rheology in crude oil pipelining.Future studies are prospected.
文摘Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies necessary for realizing this possibility may be classified into those relevant to the four serial processes (a) the formation of a hydrate, (b) the processing (dewatering, pelletizing, etc. ) of the formed hydrate, (c) the storage and transportation of the processed hydrate, and (d) the regasification (dissociation) of the hydrate. The technological development of any of these processes is still at an early stage. For hydrate formation, for example, various rival operations have been proposed. However,many of them have never been subjected to actual tests for practical use. More efforts are required for examining the different hydrate-formation technologies and for rating them by comparison. The general design of the processing of the formed hydrate inevitably depends on both the hydrate-formation process and the storage/transportation process, hence it has a wide variability. The major uncertainty in the storage-process design lies in the as-yet unclarified utility of the "self-preservation" effect of the naturalgas hydrates. The process design as well as the relevant cost evaluation should strongly depend on whether the hydrates are well preserved at atmospheric pressure in large-scale storage facilities. The regasification process has been studied less extensively than the former processes. The state of the art of the technological development in each of the serial processes is reviewed, placing emphasis on the hydrate formation process.
基金supported by the National Natural Science Foundation of China(8197103463).
文摘Objective:Albumin-globulin ratio(AGR),prognostic nutritional index(PNI),and platelet to-lymphocyte ratio(PLR)have been validated as prognostic factors for gastric cancer(GC).However,significant gender differences exist in albumin levels and inflammatory cell counts,and further research is required to understand how these differences influence GC prognosis.This study aims to investigate the prognostic impact of nutritional and inflammatory indicators on GC patients undergoing radical surgery,as well as the influence of gender on these indicators’prognostic value.Methods:The study included 596 patients with advanced GC hospitalized in the Department of Gastrointestinal Surgery,General Surgery,Xiangya Hospital of Central South University from January 2012 to December 2016.Receiver operating characteristic(ROC)analysis was performed to determine cutoff values for nutritional and inflammatory factors.Univariate analysis was used to identify factors significantly affecting survival in GC patients,while multivariate and Kaplan-Meier analyses determined independent prognostic factors for GC.Results:Multivariate analysis revealed that postsurgical tumor node metastasis(pTNM)stage[stage II:hazard ratio(HR)=3.284,P=0.012;stage III:HR:8.062,P<0.001],low preoperative AGR(HR=1.499,P=0.012),and postoperative PNI(HR=1.503,P=0.008)were risk factors for overall survival in male patients after radical GC surgery.For female patients,pN2-3(HR=3.185,P<0.001),total gastrectomy(HR=2.286,P=0.004),low preoperative PLR(HR=1.702,P=0.027),and postoperative PNI(HR=1.943,P=0.011)were identified as risk factors for overall survival.Conclusion:Postoperative PNI is an independent risk factor for all advanced GC patients.Preoperative PLR is an independent prognostic factor only for female patients,while preoperative AGR is an independent prognostic factor only for male patients.Further research is warranted to investigate the gender-specific differences in GC prognosis.
文摘Introduction Most of our knowledge of knee kinematics during gait is based on studies measuring knee motion using external skin markers. While these studies have dramatically improved our knowledge of human gait it remains a challenge to
