Objective: To evaluate the clinical and radiological factors that affect therecurrence of the meningioma patient so as to effectively prevent and cure recurrence of meningiomapatients more earlier. Methods: The clinic...Objective: To evaluate the clinical and radiological factors that affect therecurrence of the meningioma patient so as to effectively prevent and cure recurrence of meningiomapatients more earlier. Methods: The clinical features and radiological aspects in 145 cases ofmeningiomas undergoing operation during 1993-1997 were retrospectively studied. The data of only 83cases of all 145 cases were available. The factors were evaluated with univariate and multivariateanalysis. Results: With univariate analysis, 7 factors showed highly significance to recurrence ofmeningiomas: tumor size, tumor location, tumor shape, edema, extent of resection, pathologicalgrade, CT enhancement. With multivariate analysis, 4 factors showed significant danger to recurrenceof meningiomas: pathological grade, extent of resection, tumor shape and CT enhancement.Conclusion: The main factors that affect the recurrence of meningioma patients are pathologicalgrade, extent of resection, tumor shape and CT enhancement.展开更多
1 广义循环不等式 1954年,美国数学家萨碧洛曾提出猜想:设a<sub>1</sub>∈R<sup>+</sup>,i=1,2,…,n,n≥3,n∈N,则 sum from i=1 to n(a<sub>i</sub>/(a<sub>i+1</sub>+a<sub>i+...1 广义循环不等式 1954年,美国数学家萨碧洛曾提出猜想:设a<sub>1</sub>∈R<sup>+</sup>,i=1,2,…,n,n≥3,n∈N,则 sum from i=1 to n(a<sub>i</sub>/(a<sub>i+1</sub>+a<sub>i+2</sub>))≥n/2 （1）其中,a<sub>n+1</sub>=a<sub>1</sub>,a<sub>n+2</sub>=a<sub>2</sub>,此即著名的循环不等式[1]。此不等式和谐匀称优美,但遗憾的是当n为不小于14的偶数及不小于25时,（1）式不成立,反例见[1]。为使（1）式成立,[2],[3]等文献分别从加强条件和改变结论两方面对（1）式进行校正。本文旨在对（1）式校正并加以推广,主要结果是:展开更多
In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the...In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the disturbance and stability problem of EFPI, which simplifies the sensing system, improves the sensor performance and reduces the cost. In this paper, the relations between the output interferential light intensity and the F P cavity length are calculated based on the theory of mode field coupling. The EFPI fiber optic sensor is adhered to a distributed smart laminate beam to detect vibration frequency and axial strain value, the results coincident with the results tested by PZT.展开更多
A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic syste...A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization.展开更多
Reflection data in CMP has influenced seriously in static calculations,especially in some highly weathered and structurally altered circumstances. Because of static correction in the existed problems and requests,the ...Reflection data in CMP has influenced seriously in static calculations,especially in some highly weathered and structurally altered circumstances. Because of static correction in the existed problems and requests,the authors studied the angle dependent tomographic static correction,and discussed its basic theory, including the establishment of forward model,the calculation theory of tomography and tomographic static correction. The usage of theoretical models and practical information on the method has been validated. The results show that using these methods to calculate static correction in a complex area,the quality of static correction is greatly improved.展开更多
Literature continues to generate controversies as to what it is and what it is for. That is one of the reasons for the proliferation of ＂literary theories.＂ The notion is here placed between quotation marks because ...Literature continues to generate controversies as to what it is and what it is for. That is one of the reasons for the proliferation of ＂literary theories.＂ The notion is here placed between quotation marks because it does not mean the same thing to all the scholars in the field. Some regard it in the same way that theory functions in the sciences, where it focuses on the object it is associated with. For example, the atomic theory of matter is concerned with the internal constitution or the characterizing properties of matter. Others, however, are looking beyond the object towards the reader and the extra-textual environment. The approaches to literary studies which look beyond the individual work to outside phenomena are many and increasing all the time as new issues and concerns arrive on the social scene. Issues of climate change are fairly topical now; and criticism is already responding with such ideas as eco-criticism. The question of the identity of the literary object has to be kept in the front burner, so that it is not swamped by the many different interests which attach to literature from time to time. Bringing attention back to the literary work is the central concern of this paper; and we are doing this by way of the metaphors of perception often used with respect to the literary work as these suggest that the work is something to focus on, rather than to see through to something else. Finally, I elaborate the concept of integrity as an appurtenance of the literary text that attracts and holds the gaze.展开更多
New writing systems for several of China’s minority languages were developed and implemented during a unique period in Chinese history.Throughout the different stages of modern Chinese history,these writing systems h...New writing systems for several of China’s minority languages were developed and implemented during a unique period in Chinese history.Throughout the different stages of modern Chinese history,these writing systems have had various societal functions and uses,including the improvement of education and literacy for China’s ethnic minorities.In the new era,the societal functions of these newly created systems have been weakened by the large-scale influence from both outside and within minority environment.Nevertheless,the newly created writing systems have undeniable value and significance,and they continue to serve positive functions that cannot be fulfilled by other writing systems.展开更多
The segregation effect of B on the [100]（010） edge dislocation core in NiA1 single crystals is investigated using the DMol method and the discrete variational method within the framework of density functional theory...The segregation effect of B on the [100]（010） edge dislocation core in NiA1 single crystals is investigated using the DMol method and the discrete variational method within the framework of density functional theory. The impurity segregation en- ergy and the charge distribution are calculated. The effects of B on the dislocation motion are discussed. The results show that B prefers to segregate at the Center-Al dislocation core. Moreover, B forms strong bonding states with its neighboring host atoms, which may not be beneficial to the motion of the dislocation. Therefore, it can be expected that the strength of NiAl single crystals may be increased.展开更多
文摘Objective: To evaluate the clinical and radiological factors that affect therecurrence of the meningioma patient so as to effectively prevent and cure recurrence of meningiomapatients more earlier. Methods: The clinical features and radiological aspects in 145 cases ofmeningiomas undergoing operation during 1993-1997 were retrospectively studied. The data of only 83cases of all 145 cases were available. The factors were evaluated with univariate and multivariateanalysis. Results: With univariate analysis, 7 factors showed highly significance to recurrence ofmeningiomas: tumor size, tumor location, tumor shape, edema, extent of resection, pathologicalgrade, CT enhancement. With multivariate analysis, 4 factors showed significant danger to recurrenceof meningiomas: pathological grade, extent of resection, tumor shape and CT enhancement.Conclusion: The main factors that affect the recurrence of meningioma patients are pathologicalgrade, extent of resection, tumor shape and CT enhancement.
文摘1 广义循环不等式 1954年,美国数学家萨碧洛曾提出猜想:设a<sub>1</sub>∈R<sup>+</sup>,i=1,2,…,n,n≥3,n∈N,则 sum from i=1 to n(a<sub>i</sub>/(a<sub>i+1</sub>+a<sub>i+2</sub>))≥n/2 （1）其中,a<sub>n+1</sub>=a<sub>1</sub>,a<sub>n+2</sub>=a<sub>2</sub>,此即著名的循环不等式[1]。此不等式和谐匀称优美,但遗憾的是当n为不小于14的偶数及不小于25时,（1）式不成立,反例见[1]。为使（1）式成立,[2],[3]等文献分别从加强条件和改变结论两方面对（1）式进行校正。本文旨在对（1）式校正并加以推广,主要结果是:
文摘In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the disturbance and stability problem of EFPI, which simplifies the sensing system, improves the sensor performance and reduces the cost. In this paper, the relations between the output interferential light intensity and the F P cavity length are calculated based on the theory of mode field coupling. The EFPI fiber optic sensor is adhered to a distributed smart laminate beam to detect vibration frequency and axial strain value, the results coincident with the results tested by PZT.
基金Project(911901204) supported by Youth Innovation Foundation of Beijing University of Aeronautics and Astronautics
文摘A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization.
文摘Reflection data in CMP has influenced seriously in static calculations,especially in some highly weathered and structurally altered circumstances. Because of static correction in the existed problems and requests,the authors studied the angle dependent tomographic static correction,and discussed its basic theory, including the establishment of forward model,the calculation theory of tomography and tomographic static correction. The usage of theoretical models and practical information on the method has been validated. The results show that using these methods to calculate static correction in a complex area,the quality of static correction is greatly improved.
文摘Literature continues to generate controversies as to what it is and what it is for. That is one of the reasons for the proliferation of ＂literary theories.＂ The notion is here placed between quotation marks because it does not mean the same thing to all the scholars in the field. Some regard it in the same way that theory functions in the sciences, where it focuses on the object it is associated with. For example, the atomic theory of matter is concerned with the internal constitution or the characterizing properties of matter. Others, however, are looking beyond the object towards the reader and the extra-textual environment. The approaches to literary studies which look beyond the individual work to outside phenomena are many and increasing all the time as new issues and concerns arrive on the social scene. Issues of climate change are fairly topical now; and criticism is already responding with such ideas as eco-criticism. The question of the identity of the literary object has to be kept in the front burner, so that it is not swamped by the many different interests which attach to literature from time to time. Bringing attention back to the literary work is the central concern of this paper; and we are doing this by way of the metaphors of perception often used with respect to the literary work as these suggest that the work is something to focus on, rather than to see through to something else. Finally, I elaborate the concept of integrity as an appurtenance of the literary text that attracts and holds the gaze.
文摘New writing systems for several of China’s minority languages were developed and implemented during a unique period in Chinese history.Throughout the different stages of modern Chinese history,these writing systems have had various societal functions and uses,including the improvement of education and literacy for China’s ethnic minorities.In the new era,the societal functions of these newly created systems have been weakened by the large-scale influence from both outside and within minority environment.Nevertheless,the newly created writing systems have undeniable value and significance,and they continue to serve positive functions that cannot be fulfilled by other writing systems.
基金supported by the National Natural Science Foundation of China (Grant No. 10705055)
文摘The segregation effect of B on the [100]（010） edge dislocation core in NiA1 single crystals is investigated using the DMol method and the discrete variational method within the framework of density functional theory. The impurity segregation en- ergy and the charge distribution are calculated. The effects of B on the dislocation motion are discussed. The results show that B prefers to segregate at the Center-Al dislocation core. Moreover, B forms strong bonding states with its neighboring host atoms, which may not be beneficial to the motion of the dislocation. Therefore, it can be expected that the strength of NiAl single crystals may be increased.
