Objective： To analyze the CT findings of renal masses and to investigate the value of CT imaging in qualitative diagnosis of these diseases. Methods： Twenty-eight cases of renal masses, proven surgically and patholo...Objective： To analyze the CT findings of renal masses and to investigate the value of CT imaging in qualitative diagnosis of these diseases. Methods： Twenty-eight cases of renal masses, proven surgically and pathologically, were retrospectively analyzed. Pre- and post-contrast CT scans were performed in all cases. Results： Twenty-one of 28 cases （75%） were diagnosed as having malignant tumors with 16 cases of renal cell carcinoma （RCC） showing as irregular-shaped low density soft tissue mass with no or slight enhancement. Ten of 21 cases were diagnosed as having carcinoma of the renal pelvis showing as soft tissue mass in renal pelvis with no or slight enhancement. Three of 21 cases were diagnosed as having nephroblastoma （Wilms＇ tumor） showing as larger irregular lobucated mass with no enhancement. Three of 28 cases （11%） of benign tumors were diagnosed as having angiomyolipoma （AML）. Two cases showed a mixed density mass while another case showed iso-density mass. The soft tissue part of the tumor showed enhancement while the area of fat didn＇t show any enhancement of the contrast medium. Four of 28 （14%） included 3 cases of renal cysts showing as classic cystic lesions with clear-margin. No enhancement was found. In the remaining one case of renal abscess, CT showed a mixed density mass of soft tissue and cyst with slight enhancement of soft tissue part while no enhancement of cystic part. Conclusion： Pre-contrast and post-contrast CT scans in combination with history play an important role in the diagnosis of renal展开更多
The state of deep mine rigid shaft fUrniture horizontal force calculation in China is introduced and the calculating model of horizontal force is determined. Based on the interaction between hoisting vessel and shaft ...The state of deep mine rigid shaft fUrniture horizontal force calculation in China is introduced and the calculating model of horizontal force is determined. Based on the interaction between hoisting vessel and shaft furniture, the vertical mobel test device is built and a large number of model tests and analyses are carried out. At last, the relationship between horizontal force and hoisting end load, hoisting speed or bunton level interval is gained. The three parameters horizontal force calculating equation of beep mine rigid shaft furniture is given and it can guide the design and calculation of shaft engineering.展开更多
The classical chi-squared goodness of fit test assumes the number of classes is fixed,meanwhile the test statistic has a limiting chi-square distribution under the null hypothesis.It is well known that the number of c...The classical chi-squared goodness of fit test assumes the number of classes is fixed,meanwhile the test statistic has a limiting chi-square distribution under the null hypothesis.It is well known that the number of classes varying with sample size in the test has attached more and more attention.However,in this situation,there is not theoretical results for the asymptotic property of such chi-squared test statistic.This paper proves the consistency of chi-squared test with varying number of classes under some conditions.Meanwhile,the authors also give a convergence rate of KolmogorovSimirnov distance between the test statistic and corresponding chi-square distributed random variable.In addition,a real example and simulation results validate the reasonability of theoretical result and the superiority of chi-squared test with varying number of classes.展开更多
The purpose of this paper is to test the underlying serial correlation in a partially linear single-index model. Under mild conditions, the proposed test statistics are shown to have standard chi- squared distribution...The purpose of this paper is to test the underlying serial correlation in a partially linear single-index model. Under mild conditions, the proposed test statistics are shown to have standard chi- squared distribution asymptotically when there is no serial correlation in the error terms. To illustrate their finite sample properties, simulation experiments, as well as a real data example, are also provided. It is revealed that the finite sample performances of the proposed test statistics are satisfactory in terms of both estimated sizes and powers.展开更多
文摘Objective： To analyze the CT findings of renal masses and to investigate the value of CT imaging in qualitative diagnosis of these diseases. Methods： Twenty-eight cases of renal masses, proven surgically and pathologically, were retrospectively analyzed. Pre- and post-contrast CT scans were performed in all cases. Results： Twenty-one of 28 cases （75%） were diagnosed as having malignant tumors with 16 cases of renal cell carcinoma （RCC） showing as irregular-shaped low density soft tissue mass with no or slight enhancement. Ten of 21 cases were diagnosed as having carcinoma of the renal pelvis showing as soft tissue mass in renal pelvis with no or slight enhancement. Three of 21 cases were diagnosed as having nephroblastoma （Wilms＇ tumor） showing as larger irregular lobucated mass with no enhancement. Three of 28 cases （11%） of benign tumors were diagnosed as having angiomyolipoma （AML）. Two cases showed a mixed density mass while another case showed iso-density mass. The soft tissue part of the tumor showed enhancement while the area of fat didn＇t show any enhancement of the contrast medium. Four of 28 （14%） included 3 cases of renal cysts showing as classic cystic lesions with clear-margin. No enhancement was found. In the remaining one case of renal abscess, CT showed a mixed density mass of soft tissue and cyst with slight enhancement of soft tissue part while no enhancement of cystic part. Conclusion： Pre-contrast and post-contrast CT scans in combination with history play an important role in the diagnosis of renal
文摘The state of deep mine rigid shaft fUrniture horizontal force calculation in China is introduced and the calculating model of horizontal force is determined. Based on the interaction between hoisting vessel and shaft furniture, the vertical mobel test device is built and a large number of model tests and analyses are carried out. At last, the relationship between horizontal force and hoisting end load, hoisting speed or bunton level interval is gained. The three parameters horizontal force calculating equation of beep mine rigid shaft furniture is given and it can guide the design and calculation of shaft engineering.
基金supported by the Natural Science Foundation of China under Grant Nos.11071022,11028103,11231010,11471223,BCMIISthe Beijing Municipal Educational Commission Foundation under Grant Nos.KZ201410028030,KM201210028005Jishou University Subject in 2014(No:14JD035)
文摘The classical chi-squared goodness of fit test assumes the number of classes is fixed,meanwhile the test statistic has a limiting chi-square distribution under the null hypothesis.It is well known that the number of classes varying with sample size in the test has attached more and more attention.However,in this situation,there is not theoretical results for the asymptotic property of such chi-squared test statistic.This paper proves the consistency of chi-squared test with varying number of classes under some conditions.Meanwhile,the authors also give a convergence rate of KolmogorovSimirnov distance between the test statistic and corresponding chi-square distributed random variable.In addition,a real example and simulation results validate the reasonability of theoretical result and the superiority of chi-squared test with varying number of classes.
基金supported by CCNU under Grant No.09A01002the SCR of Chongqing Municipal Education Commission under Grant No.KJ110713the National Natural Science Foundation of China under Grant Nos.11101452 and 71172093
文摘The purpose of this paper is to test the underlying serial correlation in a partially linear single-index model. Under mild conditions, the proposed test statistics are shown to have standard chi- squared distribution asymptotically when there is no serial correlation in the error terms. To illustrate their finite sample properties, simulation experiments, as well as a real data example, are also provided. It is revealed that the finite sample performances of the proposed test statistics are satisfactory in terms of both estimated sizes and powers.
