为了系统分析产品社会生命周期评价的研究进展和技术框架,采用CiteSpace对来源于中国知网、Web of Science数据库的文献进行计量分析。结果表明:产品社会生命周期评价研究热点演进分为框架搭建(2008—2013年)、方法探索(2013—2016年)...为了系统分析产品社会生命周期评价的研究进展和技术框架,采用CiteSpace对来源于中国知网、Web of Science数据库的文献进行计量分析。结果表明:产品社会生命周期评价研究热点演进分为框架搭建(2008—2013年)、方法探索(2013—2016年)和体系标准化(2017—2020年)3个阶段;产品社会生命周期评价技术框架包括确定目标与范围、清单分析、影响评价与结果解释4个部分,清单分析的指标选择过程涉及40个子指标,其中与健康、人权相关的为核心指标;社会影响特征化可以通过参考量表法与影响路径法进行量化,参考量表法包括子类别评价法与社会热点数据库法,其中子类别评价法体系较为完善。展开更多
Primary biliary cirrhosis(PBC),which is characterised by progressive destruction of intrahepatic bile ducts,is not a rare disease since both prevalence and incidence are increasing during the last years mainly due to ...Primary biliary cirrhosis(PBC),which is characterised by progressive destruction of intrahepatic bile ducts,is not a rare disease since both prevalence and incidence are increasing during the last years mainly due to the improvement of case finding strategies.The prognosis of the disease has improved due to both the recognition of earlier and indolent cases,and to the wide use of ursodeoxycholic acid(UDCA).New indicators of prog-nosis are available that will be useful especially for the growing number of patients with less severe disease.Most patients are asymptomatic at presentation.Pruri-tus may represent the most distressing symptom and,when UDCA is ineffective,cholestyramine represents the mainstay of treatment.Complications of long-standing cholestasis may be clinically relevant only in very ad-vanced stages.Available data on the effects of UDCA on clinically relevant end points clearly indicate that the drug is able to slow but not to halt the progression of the disease while,in advanced stages,the only thera-peutic option remains liver transplantation.展开更多
OBJECTIVE To discuss the pathologic characteristics and theprognosis of neuroendocrine carcinoma of the bladder(NECB)in order to assist in making a precise diagnosis and to effectivelytreat the disease.METHODS Clinico...OBJECTIVE To discuss the pathologic characteristics and theprognosis of neuroendocrine carcinoma of the bladder(NECB)in order to assist in making a precise diagnosis and to effectivelytreat the disease.METHODS Clinicopathologic features of the 6 cases with NECBwere analyzed retrospectively.The personal data of the patientsand the pathologic and immunohistochemical characteristics ofthe tumor were investigated.The follow-up of these patients wasconducted over a time period ranging from 3 months to 9 years.RESULTS Transurethral resection of the bladder tumorwas performed in all 6 patients.Based on the results of thepathologic examination,4 of the cases were diagnosed as smallcell neuroendocrine carcinoma and the other 2 were diagnosedas atypical carcinoid tumor.On immunohistochemical stainingall tumors expressed neuroendocrine markers includingneuronspecific enolase(CD56),synaptophysin(Syn)andchromogranin(CgA).In patients receiving partial cystectomyfollowed by postoperative chemotherapy,relapse was found in 4of the 6 cases on follow up.CONCLUSION NECB is a rare entity and a tumor with highmalignant potential and characteristic pathologic features.Hematuria is the cardinal symptom of NECB.Metastasis mayoccur at an early stage and the prognosis of the disease is poor.Final diagnosis of NECB depends on histopathologic examinationand immunohistochemical assays.Surgical excision combinedwith radiotherapy and chemotherapy is considered an effectivetreatment.展开更多
Salt-affected soils classification using remotely sensed images is one of the most common applications in remote sensing,and many algorithms have been developed and applied for this purpose in the literature.This stud...Salt-affected soils classification using remotely sensed images is one of the most common applications in remote sensing,and many algorithms have been developed and applied for this purpose in the literature.This study takes the Delta Oasis of Weigan and Kuqa Rivers as a study area and discusses the prediction of soil salinization from ETM +Landsat data.It reports the Support Vector Machine(SVM) classification method based on Independent Component Analysis(ICA) and Texture features.Meanwhile,the letter introduces the fundamental theory of SVM algorithm and ICA,and then incorporates ICA and texture features.The classification result is compared with ICA-SVM classification,single data source SVM classification,maximum likelihood classification(MLC) and neural network classification qualitatively and quantitatively.The result shows that this method can effectively solve the problem of low accuracy and fracture classification result in single data source classification.It has high spread ability toward higher array input.The overall accuracy is 98.64%,which increases by10.2% compared with maximum likelihood classification,even increases by 12.94% compared with neural net classification,and thus acquires good effectiveness.Therefore,the classification method based on SVM and incorporating the ICA and texture features can be adapted to RS image classification and monitoring of soil salinization.展开更多
Objective:The article aims to detect the expression of HER-2/neu gene in colon cancer tissues and adjacent tissues, to analyze the relationship between dif erent pathologic types and clinical features, also to invest...Objective:The article aims to detect the expression of HER-2/neu gene in colon cancer tissues and adjacent tissues, to analyze the relationship between dif erent pathologic types and clinical features, also to invest the distribution of patients with positive expression of HER-2 gene. Methods:The expression of HER-2 gene in the 223 samples with colon can-cer was detected by immunochemical approach. The expression of HER-2 gene in colon cancer tissues and adjacent tissues and dif erent pathologic types was analyzed byχ2 test. The correlation between the expression of HER-2 gene and clinical features was analyzed by Spearman. Results:The number of positive expression of HER-2 gene in colon cancer tissues and adjacent tissues were 74 and 0 respectively, the dif erence has statistical significance. The number of papil ary or tubular adenocarcinoma was 182, among them, 60 cases were positive expression. The number of mucinous adenocarcinoma was 41, among them, 14 cases were positive expression. The expression of HER-2/neu gene has no correlation with sex, age, the maximum diameter, general classification, degree of dif erentiation and depth of invasion, which has no statistical significance. However, the expression of HER-2/neu gene has correlation with metastasis of lymph node and Dukes stage, which has statistical significance. The expression of HER-2/neu gene was positive correlation with metastasis of lymph node and Dukes stage. The correlated coef icient index was 0.320 and 0.320 respectively. In the 74 patients with positive expression of HER-2 gene, 59.4%of them were 60-74 years old. And there was 97.3%of the patients without family history of adenocarcinoma. Conclusion:The expression of HER-2/neu gene in colon cancer tissues was higher than in adjacent tissues. The expression of HER-2/neu gene has no correlation with sex, age, the maximum diameter, general classification, degree of dif erentiation and depth of invasion, but has correlation with metastasis of lymph node and Dukes stage. The expression of HER-2/neu gene was positive correlation with metastasis of lymph node and Dukes stage. The expression of HER-2/neu gene with age of 60-74 years old and without family history of adenocarcinoma was higher than other groups.展开更多
This paper proposes an algorithm that extracts features of back side of the vehicle and detects the front vehicle in real-time by local feature tracking of vehicle in the continuous images.The features in back side of...This paper proposes an algorithm that extracts features of back side of the vehicle and detects the front vehicle in real-time by local feature tracking of vehicle in the continuous images.The features in back side of the vehicle are vertical and horizontal edges,shadow and symmetry.By comparing local features using the fixed window size,the features in the continuous images are tracked.A robust and fast Haarlike mask is used for detecting vertical and horizontal edges,and shadow is extracted by histogram equalization,and the sliding window method is used to compare both side templates of the detected candidates for extracting symmetry.The features for tracking are vertical edges,and histogram is used to compare location of the peak and magnitude of the edges.The method using local feature tracking in the continuous images is more robust for detecting vehicle than the method using single image,and the proposed algorithm is evaluated by continuous images obtained on the expressway and downtown.And it can be performed on real-time through applying it to the embedded system.展开更多
Based on the extraction and calculation of the short-term seismic precursory information magnitude from the 114 major precursory observations in the North China region, and together with consideration of factors such ...Based on the extraction and calculation of the short-term seismic precursory information magnitude from the 114 major precursory observations in the North China region, and together with consideration of factors such as geological structure, seismicity, crustal thickness, and in particular, the current geodynamics of the region, the authors studied the time-space evolution characteristics of the short-term earthquake precursory information magnitude and its relationship with earthquakes and proposed the index and method for the short-term synthetic prediction of earthquakes with M S≥5.0 in the North China region. The inspection through R-value shows that the method is effective to a certain extent for earthquake prediction.展开更多
A simple and facile gas chromatography-mass spectrometer (GC-MS) fingerprint of Su-He-Xiang-Wan (SHXW) was developed, the similarity analysis was conducted, and attribution of the major characteristic peaks was id...A simple and facile gas chromatography-mass spectrometer (GC-MS) fingerprint of Su-He-Xiang-Wan (SHXW) was developed, the similarity analysis was conducted, and attribution of the major characteristic peaks was identified for SHXW quality control. GC-MS analysis was performed on a QP2010 instrument (Shimadzu, Japan) equipped with a capillary column of RTX-5MS. The column temperature was initiated at 50℃, held for 5 min, increased at the rate of 3 ℃/min to 120 ℃, held for 2 min, and then increased at the rate of 4 ℃/min to 220℃, held for 10 min. Helium carrier gas was used at a constant flow rate of 1.3 mL/min. Mass conditions were ionization voltage, 70 eV; injector temperature, 250℃; ion source temperature, 250 ℃; splitting ratio, 30:1; full scan mode in the 40-500 Da mass ranges with rate of 0.2 s per scan. Attribution of the major characteristic peaks was identified for SHXW by comparing the chemical standards, references of Chinese herbal medicines and the negative controls of prescription samples (NC) of SHXW. With the help of the temperature-programmed retention indices (PTRIs) used together with mass spectra and chemical standards, 25 major characteristic peaks have been identified. Nine volatile medicinal materials were identified in the prescription of SHXW by attributing to the 27 major characteristic peaks. The results demonstrate that the proposed method is a powerful approach to quality control of complex herbal medicines.展开更多
Highly efficient synthesis methods have been developed and characteristics of nanometallocarbosilanes molecular structure were studied by the research team of GNIIChTEOS (State Research Institute for Chemistry and Te...Highly efficient synthesis methods have been developed and characteristics of nanometallocarbosilanes molecular structure were studied by the research team of GNIIChTEOS (State Research Institute for Chemistry and Technology of Organoelement Compounds). Nanometallocarbosilanes were synthesized by thermal co-condensation of oligocarbosilanes and alkyl amides of refractory metals. Initial, intermediate and final products of side reactions were characterized by 1H, 13C, 29Si NMR (nuclear magnetic resonance), IR (infra-red) spectroscopy, GPC (gel-penetrating chromatography), TGA (thermal gravimetric analysis), TEM (transmission electron microscopy), SEM (scanning electron microscopy), RES (X-ray phase analysis) and elemental analysis. The proposed synthesis method of nanometallocarbosilanes was lbund to produce fusable soluble organosilicon oligomers with homogeneous distribution of nanoscale (10-20 nm) metal particles in the oligomer matrix. A computational model of the group and elemental composition of nanometallocarbosilanes was developed; it was shown that they are molecular globules of near-spherical shape and rigid polycyclic structure. Thermochemical treatment of nanometallocarbosilanes leads to SiC-nanoceramics (a high yield of up to 75-80 mass%) modified by metal nanoparticles (20-30 nm) contributing to its stabilization. The application of preceramic oxygen-free nanometallocarbosilanes will make it possible to advance in solving the problem of ceramic composite materials with long-term resistance at temperatures above 1,500 ℃ in oxidizing environments.展开更多
Objective: To investigate the correlations among the expressions of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial cell growth factor (VEGF) and microvessel density (MVD), and their relationships ...Objective: To investigate the correlations among the expressions of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial cell growth factor (VEGF) and microvessel density (MVD), and their relationships to the clinicopathologic characteristics of esophageal squamous cell carcinomas (ESCC). Methods: The expressions of HIF-1α, VEGF and MVD were detected by immunohistochemical method in 45 cases of ESCC, 30 intraepithelial neoplasia and 35 normal esophageal mucosal epithelia tissues. The correlations among the expressions of HIF-1α, VEGF and MVD, and their relationships to the clinicopathologic features of ESCC were analyzed. Results: The rate of positive expression of HIF-1α and VEGF which were 80% and 84% in ESCC were significantly higher than those in intraepithelial neoplasia and normal esophageal mucosal epithelium tissues (P 〈 0.01) and so did the MVD value which was71.10 ±15.02 in ESCC (P 〈 0.01). The expression of HIF-1α and VEGF were positively correlated with the depth of tumor invasion, lymph node metastasis and TNM staging of ESCC. The expressions of HIF-1α were positively correlated with the expressions of VEGF and the value of MVD. Conclusion: Overexpression of HIF-1α is found in ESCC. HIF-1α may induce the angiogenesis in ESCC by upregulating the transcription of VEGF gene. It may play an important role in the carcinogenesis and aggression in ESCC, HIF-1α, VEGF and MVD may be a useful marker for evaluating the biological behaviors of ESCC.展开更多
To realize the stabilization and the tracking of flight control for an air-breathing hypersonic cruise vehicle, the linearization of the longitudinal model under trimmed cruise condition is processed firstly. Furtherm...To realize the stabilization and the tracking of flight control for an air-breathing hypersonic cruise vehicle, the linearization of the longitudinal model under trimmed cruise condition is processed firstly. Furthermore, the flight control problem is formulated as a robust model tracking control problem. And then, based on the robust parametric approach, eigenstructure assignment and reference model tracking theory, a parametric optimization method for robust controller design is presented. The simulation results show the effectiveness of the proposed approach.展开更多
This paper describes a non-linear information dynamics model for integrated risk assessment of complex disaster system from an evolution perspective. According to the occurrence and evolution of natural disaster syste...This paper describes a non-linear information dynamics model for integrated risk assessment of complex disaster system from an evolution perspective. According to the occurrence and evolution of natural disaster system with complicated and nonlinear characteristics, a non-linear information dynamics mode is introduced based on the maximum flux principle during modeling process to study the integrated risk assessment of complex disaster system. Based on the non-equilibrium statistical mechanics method, a stochastic evolution equation of this system is established. The integrated risk assessment of complex disaster system can be achieved by giving reasonable weights of each evaluation index to stabilize the system. The new model reveals the formation pattern of risk grade and the dynamics law of evolution. Meanwhile, a method is developed to solve the dynamics evolution equations of complex system through the self-organization feature map algorithm. The proposed method has been used in complex disaster integrated risk assessment for 31 provinces, cities and autonomous regions in China mainland. The results have indicated that the model is objective and effective.展开更多
文摘为了系统分析产品社会生命周期评价的研究进展和技术框架,采用CiteSpace对来源于中国知网、Web of Science数据库的文献进行计量分析。结果表明:产品社会生命周期评价研究热点演进分为框架搭建(2008—2013年)、方法探索(2013—2016年)和体系标准化(2017—2020年)3个阶段;产品社会生命周期评价技术框架包括确定目标与范围、清单分析、影响评价与结果解释4个部分,清单分析的指标选择过程涉及40个子指标,其中与健康、人权相关的为核心指标;社会影响特征化可以通过参考量表法与影响路径法进行量化,参考量表法包括子类别评价法与社会热点数据库法,其中子类别评价法体系较为完善。
文摘Primary biliary cirrhosis(PBC),which is characterised by progressive destruction of intrahepatic bile ducts,is not a rare disease since both prevalence and incidence are increasing during the last years mainly due to the improvement of case finding strategies.The prognosis of the disease has improved due to both the recognition of earlier and indolent cases,and to the wide use of ursodeoxycholic acid(UDCA).New indicators of prog-nosis are available that will be useful especially for the growing number of patients with less severe disease.Most patients are asymptomatic at presentation.Pruri-tus may represent the most distressing symptom and,when UDCA is ineffective,cholestyramine represents the mainstay of treatment.Complications of long-standing cholestasis may be clinically relevant only in very ad-vanced stages.Available data on the effects of UDCA on clinically relevant end points clearly indicate that the drug is able to slow but not to halt the progression of the disease while,in advanced stages,the only thera-peutic option remains liver transplantation.
文摘OBJECTIVE To discuss the pathologic characteristics and theprognosis of neuroendocrine carcinoma of the bladder(NECB)in order to assist in making a precise diagnosis and to effectivelytreat the disease.METHODS Clinicopathologic features of the 6 cases with NECBwere analyzed retrospectively.The personal data of the patientsand the pathologic and immunohistochemical characteristics ofthe tumor were investigated.The follow-up of these patients wasconducted over a time period ranging from 3 months to 9 years.RESULTS Transurethral resection of the bladder tumorwas performed in all 6 patients.Based on the results of thepathologic examination,4 of the cases were diagnosed as smallcell neuroendocrine carcinoma and the other 2 were diagnosedas atypical carcinoid tumor.On immunohistochemical stainingall tumors expressed neuroendocrine markers includingneuronspecific enolase(CD56),synaptophysin(Syn)andchromogranin(CgA).In patients receiving partial cystectomyfollowed by postoperative chemotherapy,relapse was found in 4of the 6 cases on follow up.CONCLUSION NECB is a rare entity and a tumor with highmalignant potential and characteristic pathologic features.Hematuria is the cardinal symptom of NECB.Metastasis mayoccur at an early stage and the prognosis of the disease is poor.Final diagnosis of NECB depends on histopathologic examinationand immunohistochemical assays.Surgical excision combinedwith radiotherapy and chemotherapy is considered an effectivetreatment.
基金Supported by the National Key Basic Research Development Pro-gram (2009CB421302 )National Natural Science Foundation ofChina (40861020,40961025,40901163)+1 种基金Natural Science Foun-dation of Xinjiang (200821128 )Open Foundation of State KeyLaboratory of Resources and Environment Information ystems(2010KF0003SA)
文摘Salt-affected soils classification using remotely sensed images is one of the most common applications in remote sensing,and many algorithms have been developed and applied for this purpose in the literature.This study takes the Delta Oasis of Weigan and Kuqa Rivers as a study area and discusses the prediction of soil salinization from ETM +Landsat data.It reports the Support Vector Machine(SVM) classification method based on Independent Component Analysis(ICA) and Texture features.Meanwhile,the letter introduces the fundamental theory of SVM algorithm and ICA,and then incorporates ICA and texture features.The classification result is compared with ICA-SVM classification,single data source SVM classification,maximum likelihood classification(MLC) and neural network classification qualitatively and quantitatively.The result shows that this method can effectively solve the problem of low accuracy and fracture classification result in single data source classification.It has high spread ability toward higher array input.The overall accuracy is 98.64%,which increases by10.2% compared with maximum likelihood classification,even increases by 12.94% compared with neural net classification,and thus acquires good effectiveness.Therefore,the classification method based on SVM and incorporating the ICA and texture features can be adapted to RS image classification and monitoring of soil salinization.
文摘Objective:The article aims to detect the expression of HER-2/neu gene in colon cancer tissues and adjacent tissues, to analyze the relationship between dif erent pathologic types and clinical features, also to invest the distribution of patients with positive expression of HER-2 gene. Methods:The expression of HER-2 gene in the 223 samples with colon can-cer was detected by immunochemical approach. The expression of HER-2 gene in colon cancer tissues and adjacent tissues and dif erent pathologic types was analyzed byχ2 test. The correlation between the expression of HER-2 gene and clinical features was analyzed by Spearman. Results:The number of positive expression of HER-2 gene in colon cancer tissues and adjacent tissues were 74 and 0 respectively, the dif erence has statistical significance. The number of papil ary or tubular adenocarcinoma was 182, among them, 60 cases were positive expression. The number of mucinous adenocarcinoma was 41, among them, 14 cases were positive expression. The expression of HER-2/neu gene has no correlation with sex, age, the maximum diameter, general classification, degree of dif erentiation and depth of invasion, which has no statistical significance. However, the expression of HER-2/neu gene has correlation with metastasis of lymph node and Dukes stage, which has statistical significance. The expression of HER-2/neu gene was positive correlation with metastasis of lymph node and Dukes stage. The correlated coef icient index was 0.320 and 0.320 respectively. In the 74 patients with positive expression of HER-2 gene, 59.4%of them were 60-74 years old. And there was 97.3%of the patients without family history of adenocarcinoma. Conclusion:The expression of HER-2/neu gene in colon cancer tissues was higher than in adjacent tissues. The expression of HER-2/neu gene has no correlation with sex, age, the maximum diameter, general classification, degree of dif erentiation and depth of invasion, but has correlation with metastasis of lymph node and Dukes stage. The expression of HER-2/neu gene was positive correlation with metastasis of lymph node and Dukes stage. The expression of HER-2/neu gene with age of 60-74 years old and without family history of adenocarcinoma was higher than other groups.
基金supported by the Brain Korea 21 Project in 2011 and MKE(The Ministry of Knowledge Economy),Korea,under the ITRC(Infor mation Technology Research Center)support program supervised by the NIPA(National IT Industry Promotion Agency)(NIPA-2011-C1090-1121-0010)
文摘This paper proposes an algorithm that extracts features of back side of the vehicle and detects the front vehicle in real-time by local feature tracking of vehicle in the continuous images.The features in back side of the vehicle are vertical and horizontal edges,shadow and symmetry.By comparing local features using the fixed window size,the features in the continuous images are tracked.A robust and fast Haarlike mask is used for detecting vertical and horizontal edges,and shadow is extracted by histogram equalization,and the sliding window method is used to compare both side templates of the detected candidates for extracting symmetry.The features for tracking are vertical edges,and histogram is used to compare location of the peak and magnitude of the edges.The method using local feature tracking in the continuous images is more robust for detecting vehicle than the method using single image,and the proposed algorithm is evaluated by continuous images obtained on the expressway and downtown.And it can be performed on real-time through applying it to the embedded system.
文摘Based on the extraction and calculation of the short-term seismic precursory information magnitude from the 114 major precursory observations in the North China region, and together with consideration of factors such as geological structure, seismicity, crustal thickness, and in particular, the current geodynamics of the region, the authors studied the time-space evolution characteristics of the short-term earthquake precursory information magnitude and its relationship with earthquakes and proposed the index and method for the short-term synthetic prediction of earthquakes with M S≥5.0 in the North China region. The inspection through R-value shows that the method is effective to a certain extent for earthquake prediction.
基金Foundation item: Projects(21275164, 21075138) supported by the National Natural Science Foundation of China
文摘A simple and facile gas chromatography-mass spectrometer (GC-MS) fingerprint of Su-He-Xiang-Wan (SHXW) was developed, the similarity analysis was conducted, and attribution of the major characteristic peaks was identified for SHXW quality control. GC-MS analysis was performed on a QP2010 instrument (Shimadzu, Japan) equipped with a capillary column of RTX-5MS. The column temperature was initiated at 50℃, held for 5 min, increased at the rate of 3 ℃/min to 120 ℃, held for 2 min, and then increased at the rate of 4 ℃/min to 220℃, held for 10 min. Helium carrier gas was used at a constant flow rate of 1.3 mL/min. Mass conditions were ionization voltage, 70 eV; injector temperature, 250℃; ion source temperature, 250 ℃; splitting ratio, 30:1; full scan mode in the 40-500 Da mass ranges with rate of 0.2 s per scan. Attribution of the major characteristic peaks was identified for SHXW by comparing the chemical standards, references of Chinese herbal medicines and the negative controls of prescription samples (NC) of SHXW. With the help of the temperature-programmed retention indices (PTRIs) used together with mass spectra and chemical standards, 25 major characteristic peaks have been identified. Nine volatile medicinal materials were identified in the prescription of SHXW by attributing to the 27 major characteristic peaks. The results demonstrate that the proposed method is a powerful approach to quality control of complex herbal medicines.
文摘Highly efficient synthesis methods have been developed and characteristics of nanometallocarbosilanes molecular structure were studied by the research team of GNIIChTEOS (State Research Institute for Chemistry and Technology of Organoelement Compounds). Nanometallocarbosilanes were synthesized by thermal co-condensation of oligocarbosilanes and alkyl amides of refractory metals. Initial, intermediate and final products of side reactions were characterized by 1H, 13C, 29Si NMR (nuclear magnetic resonance), IR (infra-red) spectroscopy, GPC (gel-penetrating chromatography), TGA (thermal gravimetric analysis), TEM (transmission electron microscopy), SEM (scanning electron microscopy), RES (X-ray phase analysis) and elemental analysis. The proposed synthesis method of nanometallocarbosilanes was lbund to produce fusable soluble organosilicon oligomers with homogeneous distribution of nanoscale (10-20 nm) metal particles in the oligomer matrix. A computational model of the group and elemental composition of nanometallocarbosilanes was developed; it was shown that they are molecular globules of near-spherical shape and rigid polycyclic structure. Thermochemical treatment of nanometallocarbosilanes leads to SiC-nanoceramics (a high yield of up to 75-80 mass%) modified by metal nanoparticles (20-30 nm) contributing to its stabilization. The application of preceramic oxygen-free nanometallocarbosilanes will make it possible to advance in solving the problem of ceramic composite materials with long-term resistance at temperatures above 1,500 ℃ in oxidizing environments.
基金Supported by a grant from the Natural Sciences Foundation of Anhui Province (No.2006KJ134C)
文摘Objective: To investigate the correlations among the expressions of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial cell growth factor (VEGF) and microvessel density (MVD), and their relationships to the clinicopathologic characteristics of esophageal squamous cell carcinomas (ESCC). Methods: The expressions of HIF-1α, VEGF and MVD were detected by immunohistochemical method in 45 cases of ESCC, 30 intraepithelial neoplasia and 35 normal esophageal mucosal epithelia tissues. The correlations among the expressions of HIF-1α, VEGF and MVD, and their relationships to the clinicopathologic features of ESCC were analyzed. Results: The rate of positive expression of HIF-1α and VEGF which were 80% and 84% in ESCC were significantly higher than those in intraepithelial neoplasia and normal esophageal mucosal epithelium tissues (P 〈 0.01) and so did the MVD value which was71.10 ±15.02 in ESCC (P 〈 0.01). The expression of HIF-1α and VEGF were positively correlated with the depth of tumor invasion, lymph node metastasis and TNM staging of ESCC. The expressions of HIF-1α were positively correlated with the expressions of VEGF and the value of MVD. Conclusion: Overexpression of HIF-1α is found in ESCC. HIF-1α may induce the angiogenesis in ESCC by upregulating the transcription of VEGF gene. It may play an important role in the carcinogenesis and aggression in ESCC, HIF-1α, VEGF and MVD may be a useful marker for evaluating the biological behaviors of ESCC.
基金Sponsored by the Major Program of National Natural Science Foundation of China (Grant No.60710002)the Program for Changjiang Scholars and Innovative Research Team in University
文摘To realize the stabilization and the tracking of flight control for an air-breathing hypersonic cruise vehicle, the linearization of the longitudinal model under trimmed cruise condition is processed firstly. Furthermore, the flight control problem is formulated as a robust model tracking control problem. And then, based on the robust parametric approach, eigenstructure assignment and reference model tracking theory, a parametric optimization method for robust controller design is presented. The simulation results show the effectiveness of the proposed approach.
基金supported by the National Twelfth Five-year Technology Support Projects of China (Grant Nos. 2009BAJ28B04, 2011BAK07B01,2011BAJ08B03, and 2011BAJ08B05)the National Natural Science Foundation of China (Grant No. 51208017)+1 种基金Beijing Postdoctoral Research Foundation (Grant No. 2012ZZ-17)China Postdoctoral Science Foundation Funded Project (Grant No. 2011M500199)
文摘This paper describes a non-linear information dynamics model for integrated risk assessment of complex disaster system from an evolution perspective. According to the occurrence and evolution of natural disaster system with complicated and nonlinear characteristics, a non-linear information dynamics mode is introduced based on the maximum flux principle during modeling process to study the integrated risk assessment of complex disaster system. Based on the non-equilibrium statistical mechanics method, a stochastic evolution equation of this system is established. The integrated risk assessment of complex disaster system can be achieved by giving reasonable weights of each evaluation index to stabilize the system. The new model reveals the formation pattern of risk grade and the dynamics law of evolution. Meanwhile, a method is developed to solve the dynamics evolution equations of complex system through the self-organization feature map algorithm. The proposed method has been used in complex disaster integrated risk assessment for 31 provinces, cities and autonomous regions in China mainland. The results have indicated that the model is objective and effective.