Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation b...Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation but little study about the relation between serration and mode. Thus, taking axial single-turbine test bench NPU-Turb as object, the effect of Stator with Serrated Trailing-edge (Bionic S) and Rotor with Serrated Leading-edge (Bionic R) on duct acoustic modes of turbine turbulence interac-tion noise were studied in detail using DDES/AA hybrid model validated by acoustic experiment of NPU-Turb. Serval conclusions can be made here. First, for broadband noise, the effect of serrations on duct modes (increased or reduced of PWL<sub>mn</sub>) with the increasing frequency is more prominent. Second, the changing trend of ?PWL<sub>mn</sub> is something like Chinese character “人” with circumferential mode m and alternating with radial mode. Such distribution is more obvious at higher frequency. More theoretical and mechanistic research work needs to be carried out in depth in the future. .展开更多
Objective:To establish the quality standards for the preparation of Xiao’er Qingre enema in hospitals.Method:Thin-layer chromatography(TLC)was used to identify Radix Isatidis and Glycyrrhizae in the prescription.The ...Objective:To establish the quality standards for the preparation of Xiao’er Qingre enema in hospitals.Method:Thin-layer chromatography(TLC)was used to identify Radix Isatidis and Glycyrrhizae in the prescription.The content of(R,S)-Goitrin was determined by high-performance liquid chromatography(HPLC).Results:In TLC identification,there was no interference between the negative controls of Radix Isatidis and glycyrrhizae,and the spots were well-separated.The HPLC results of(R,S)-Goitrin showed a good linear relationship between the peak area and concentration within the range of 0.476-95.2μg·mL-1(r=0.9999).Conclusion:The TLC and HPLC methods established in this experiment are simple,reproducible,and specific,making them suitable for the quality control Xiao’er Qingre enema preparation in hospitals.展开更多
Introduction: Glomerular damage during Gougerot-Sjgren syndrome is much rarer than interstitial damage, and is essentially extra-membranous and membrano-proliferative glomerulonephritis. Observation: We report the cas...Introduction: Glomerular damage during Gougerot-Sjgren syndrome is much rarer than interstitial damage, and is essentially extra-membranous and membrano-proliferative glomerulonephritis. Observation: We report the case of a 44-year-old woman with primary Sjgrens syndrome, confirmed by clinical dryness syndrome, positive anti-SSA and anti-SSB antibodies, and a salivary gland biopsy revealing grade 4 lymphocytic sialadenitis according to CHISHOLMs classification. Later, the patient developed nephrotic syndrome, along with hypertension. Renal function remained normal with a creatinine level of 9.3 mg/l, and hematuria was absent. Only antinuclear antibodies tested positive, while anti-PLA2R antibodies were negative. A renal biopsy was performed, which was complicated on the same day by hemodynamic instability with hematuria. Renal CT scan with contrast injection revealed a posterior perirenal hematoma without contrast extravasation. Additionally, bilateral renal vein thrombosis was incidentally discovered, suggesting extramembranous glomerulonephritis. The patients hemodynamic status stabilized after fluid resuscitation with isotonic saline solution (0.9%), without the need for blood transfusion. Renal biopsy confirmed extramembranous glomerulonephritis with interstitial fibrosis and minimal tubular atrophy. The initial etiological assessment was negative. The patient was started on oral corticosteroids, angiotensin-converting enzyme inhibitors, and therapeutic anticoagulation for renal vein thrombosis. The patients condition improved, with the disappearance of the syndrome and spontaneous regression of the hematoma. Discussion: The association of nephrotic syndrome and renal vein thrombosis primarily suggests glomerulopathy, in particular extra-membranous glomerulonephritis. Sjgrens syndrome can be associated with extra-membranous glomerulonephritis without being its direct cause. Like, it is possible that it is a cause of glomerulonephritis, essentially extra membranous and membrano-proliferative. Conclusion: Sjgrens syndrome is generally underestimated cause of glomerulonephritis, which should be considered in cases of extra-membranous glomerulonephritis.展开更多
The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), ...The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), but few of them have considered the impact of the spatial configuration of ISA on UHI. Land surface temperature(LST) may be affected not only by urban land cover, but also by neighboring land cover. The aim of this research was to investigate the effects of the abundance and spatial association of ISAs on LST. Taking Harbin City, China as an example, the impact of ISA spatial association on LST measurements was examined. The abundance of ISAs and the LST measurements were derived from Landsat Thematic Mapper(TM) imagery of 2000 and 2010, and the spatial association patterns of ISAs were calculated using the local Moran’s I index. The impacts of ISA abundance and spatial association on LST were examined using correlation analysis. The results suggested that LST has significant positive associations with both ISA abundance and the Moran’s I index of ISAs, indicating that both the abundance and spatial clustering of ISAs contribute to elevated values of LST. It was also found that LST is positively associated with clustering of high-ISA-percentage areas(i.e.,>50%) and negatively associated with clustering of low-ISA-percentage areas(i.e.,<25%). The results suggest that, in addition to the abundance of ISAs,their spatial association has a significant effect on UHIs.展开更多
The safety of offshore pipeline has drawn a great deal of attention during deepwater installation due to the combined actions of high external pressure, axial tension, and bending moment. Meanwhile, the pipeline confi...The safety of offshore pipeline has drawn a great deal of attention during deepwater installation due to the combined actions of high external pressure, axial tension, and bending moment. Meanwhile, the pipeline configuration has a remarkable effect on the structural behaviour of the tube. The special studies focus on the deepwater S-lay technique in the present paper. The stiffened catenary theory is applied to establish the static equilibrium governing differential equation of a pipe element, and the solution equations of the total pipeline configuration from a lay-barge over a stinger to the seabed are derived, The numerical iteration method for solving pipeline configuration is described in detail, and the corresponding program is developed to conduct the analysis of effects of various parameters such as laying water depth, pipe diameter, thickness of concrete weighted coating layer, stinger length, control strain, and axial tension on pipeline configuration. The results show that the laying water depth, the submerged weight of the pipe, and the axial tension are the critical factors influencing pipeline configuration. In addition, geometrical parameters of the stinger such as length, radius, and shape have an important effect on the pipe-laying capacity of the vessel. The validity of the program is further verified by means of a comparison with results obtained from the commercial finite element software OFFPIPE.展开更多
The mechanism of three⁃order Rubiks Cube(RC)has the characteristics of recombination and variable degree of freedom,and it is difficult to accurately describe the degree of its freedom.This paper takes RC as...The mechanism of three⁃order Rubiks Cube(RC)has the characteristics of recombination and variable degree of freedom,and it is difficult to accurately describe the degree of its freedom.This paper takes RC as the research object,and the adjacency matrix is constructed based on topology and graph theory in order to describe the variation rule of topological configuration in the single layer rotation of RC.In this paper,the degree of freedom of the RC in any shape can be described by defining the concept of entanglement degree of freedom,establishing a set of adjacency matrix,and determining the degree of freedom of the RC which is attributed to the number of non⁃zero elements in the set of adjacent matrix.The prime number is proposed to describe the rotation of the RC combined with the rotation recognition of RC,which is simple and convenient for computer processing.The research contents in this paper are beneficial to the study of RC from the perspective of mechanism science.Meanwhile,it is of great significance to the study of other complex mechanisms with variable degrees of freedom.展开更多
Due to the defects of current aircraft product configuration technology, such as the gap between product design and cus- tomers' requirements, the low configuration efficiency and etc. a customer-oriented product con...Due to the defects of current aircraft product configuration technology, such as the gap between product design and cus- tomers' requirements, the low configuration efficiency and etc. a customer-oriented product configuration solution of aircraft was proposed in this paper. Basing on a deep investigation into the market and the structure of the aircraft, this paper proposed a method of dividing and creating the aircraft options, in which we set up optional constraints to meet the demand of configuration and then optimized the constraint algorithm. This work can help to realize the optimum association between the aircraft options and modules. Basing on a research on customer demand, The paper established a customer demand model and a mapping relationship which exists between customer demand and aircraft options, It can also help to make a great contribution to build customer personalized demand of the aircraft configuration orocess and the aircraft confimiration library.展开更多
文摘Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation but little study about the relation between serration and mode. Thus, taking axial single-turbine test bench NPU-Turb as object, the effect of Stator with Serrated Trailing-edge (Bionic S) and Rotor with Serrated Leading-edge (Bionic R) on duct acoustic modes of turbine turbulence interac-tion noise were studied in detail using DDES/AA hybrid model validated by acoustic experiment of NPU-Turb. Serval conclusions can be made here. First, for broadband noise, the effect of serrations on duct modes (increased or reduced of PWL<sub>mn</sub>) with the increasing frequency is more prominent. Second, the changing trend of ?PWL<sub>mn</sub> is something like Chinese character “人” with circumferential mode m and alternating with radial mode. Such distribution is more obvious at higher frequency. More theoretical and mechanistic research work needs to be carried out in depth in the future. .
基金Xi’an Science and Technology Plan Project(Project number:23YXYJ0163)Education and Teaching Reform Research Project of Xi,an Medical University in(2023)(Project number:S202311840061)First Affiliated Hospital of Xi’an Medical University of China(Fund number:XYYFY-2023-01).
文摘Objective:To establish the quality standards for the preparation of Xiao’er Qingre enema in hospitals.Method:Thin-layer chromatography(TLC)was used to identify Radix Isatidis and Glycyrrhizae in the prescription.The content of(R,S)-Goitrin was determined by high-performance liquid chromatography(HPLC).Results:In TLC identification,there was no interference between the negative controls of Radix Isatidis and glycyrrhizae,and the spots were well-separated.The HPLC results of(R,S)-Goitrin showed a good linear relationship between the peak area and concentration within the range of 0.476-95.2μg·mL-1(r=0.9999).Conclusion:The TLC and HPLC methods established in this experiment are simple,reproducible,and specific,making them suitable for the quality control Xiao’er Qingre enema preparation in hospitals.
文摘Introduction: Glomerular damage during Gougerot-Sjgren syndrome is much rarer than interstitial damage, and is essentially extra-membranous and membrano-proliferative glomerulonephritis. Observation: We report the case of a 44-year-old woman with primary Sjgrens syndrome, confirmed by clinical dryness syndrome, positive anti-SSA and anti-SSB antibodies, and a salivary gland biopsy revealing grade 4 lymphocytic sialadenitis according to CHISHOLMs classification. Later, the patient developed nephrotic syndrome, along with hypertension. Renal function remained normal with a creatinine level of 9.3 mg/l, and hematuria was absent. Only antinuclear antibodies tested positive, while anti-PLA2R antibodies were negative. A renal biopsy was performed, which was complicated on the same day by hemodynamic instability with hematuria. Renal CT scan with contrast injection revealed a posterior perirenal hematoma without contrast extravasation. Additionally, bilateral renal vein thrombosis was incidentally discovered, suggesting extramembranous glomerulonephritis. The patients hemodynamic status stabilized after fluid resuscitation with isotonic saline solution (0.9%), without the need for blood transfusion. Renal biopsy confirmed extramembranous glomerulonephritis with interstitial fibrosis and minimal tubular atrophy. The initial etiological assessment was negative. The patient was started on oral corticosteroids, angiotensin-converting enzyme inhibitors, and therapeutic anticoagulation for renal vein thrombosis. The patients condition improved, with the disappearance of the syndrome and spontaneous regression of the hematoma. Discussion: The association of nephrotic syndrome and renal vein thrombosis primarily suggests glomerulopathy, in particular extra-membranous glomerulonephritis. Sjgrens syndrome can be associated with extra-membranous glomerulonephritis without being its direct cause. Like, it is possible that it is a cause of glomerulonephritis, essentially extra membranous and membrano-proliferative. Conclusion: Sjgrens syndrome is generally underestimated cause of glomerulonephritis, which should be considered in cases of extra-membranous glomerulonephritis.
基金Under the auspices of the National Social Science Foundation of China(No.16BJY039)
文摘The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), but few of them have considered the impact of the spatial configuration of ISA on UHI. Land surface temperature(LST) may be affected not only by urban land cover, but also by neighboring land cover. The aim of this research was to investigate the effects of the abundance and spatial association of ISAs on LST. Taking Harbin City, China as an example, the impact of ISA spatial association on LST measurements was examined. The abundance of ISAs and the LST measurements were derived from Landsat Thematic Mapper(TM) imagery of 2000 and 2010, and the spatial association patterns of ISAs were calculated using the local Moran’s I index. The impacts of ISA abundance and spatial association on LST were examined using correlation analysis. The results suggested that LST has significant positive associations with both ISA abundance and the Moran’s I index of ISAs, indicating that both the abundance and spatial clustering of ISAs contribute to elevated values of LST. It was also found that LST is positively associated with clustering of high-ISA-percentage areas(i.e.,>50%) and negatively associated with clustering of low-ISA-percentage areas(i.e.,<25%). The results suggest that, in addition to the abundance of ISAs,their spatial association has a significant effect on UHIs.
基金supported by the National Natural Science Foundation of China (Grant No. 51009122)the Fundamental Research Funds for the Central Universities (Grant No. 2010QNA4030)the National High Technology Research and Development Program of China (863 Program, Grant No. 2006AA09A105)
文摘The safety of offshore pipeline has drawn a great deal of attention during deepwater installation due to the combined actions of high external pressure, axial tension, and bending moment. Meanwhile, the pipeline configuration has a remarkable effect on the structural behaviour of the tube. The special studies focus on the deepwater S-lay technique in the present paper. The stiffened catenary theory is applied to establish the static equilibrium governing differential equation of a pipe element, and the solution equations of the total pipeline configuration from a lay-barge over a stinger to the seabed are derived, The numerical iteration method for solving pipeline configuration is described in detail, and the corresponding program is developed to conduct the analysis of effects of various parameters such as laying water depth, pipe diameter, thickness of concrete weighted coating layer, stinger length, control strain, and axial tension on pipeline configuration. The results show that the laying water depth, the submerged weight of the pipe, and the axial tension are the critical factors influencing pipeline configuration. In addition, geometrical parameters of the stinger such as length, radius, and shape have an important effect on the pipe-laying capacity of the vessel. The validity of the program is further verified by means of a comparison with results obtained from the commercial finite element software OFFPIPE.
基金the National Natural Science Foundation of China(Grant No.51775473)the Natural Science Foundation of Hebei Province(Grant No.E2018203140).
文摘The mechanism of three⁃order Rubiks Cube(RC)has the characteristics of recombination and variable degree of freedom,and it is difficult to accurately describe the degree of its freedom.This paper takes RC as the research object,and the adjacency matrix is constructed based on topology and graph theory in order to describe the variation rule of topological configuration in the single layer rotation of RC.In this paper,the degree of freedom of the RC in any shape can be described by defining the concept of entanglement degree of freedom,establishing a set of adjacency matrix,and determining the degree of freedom of the RC which is attributed to the number of non⁃zero elements in the set of adjacent matrix.The prime number is proposed to describe the rotation of the RC combined with the rotation recognition of RC,which is simple and convenient for computer processing.The research contents in this paper are beneficial to the study of RC from the perspective of mechanism science.Meanwhile,it is of great significance to the study of other complex mechanisms with variable degrees of freedom.
基金Supported by China's 863 Programs-"Key Technologies of i-Plane for Large Aircraft Development"(No.2009AA043306)Fundamental Research Funds for the Central Universities
文摘Due to the defects of current aircraft product configuration technology, such as the gap between product design and cus- tomers' requirements, the low configuration efficiency and etc. a customer-oriented product configuration solution of aircraft was proposed in this paper. Basing on a deep investigation into the market and the structure of the aircraft, this paper proposed a method of dividing and creating the aircraft options, in which we set up optional constraints to meet the demand of configuration and then optimized the constraint algorithm. This work can help to realize the optimum association between the aircraft options and modules. Basing on a research on customer demand, The paper established a customer demand model and a mapping relationship which exists between customer demand and aircraft options, It can also help to make a great contribution to build customer personalized demand of the aircraft configuration orocess and the aircraft confimiration library.