火箭基组合循环(Rocket Based Combined Cycle,RBCC)推进系统大大拓展了飞行器的高度—速度包线,是重复使用运载器动力的主要发展方向。对RBCC推进系统研究的现状进行了总结,论述了RBCC推进在单级入轨、两级入轨及临近空间飞行器方面的...火箭基组合循环(Rocket Based Combined Cycle,RBCC)推进系统大大拓展了飞行器的高度—速度包线,是重复使用运载器动力的主要发展方向。对RBCC推进系统研究的现状进行了总结,论述了RBCC推进在单级入轨、两级入轨及临近空间飞行器方面的应用前景,提出了RBCC推进及飞行器研制过程存在的若干问题和关键技术,并给出了发展建议。展开更多
肺胎盘样变形(placental transmogrification of the lung,PTL)为一种肺部罕见良性囊性病变,其特征为组织学形态类似未成熟胎盘结构。本文报道1例本院确诊的PTL患者,为75岁老年男性,影像学表现为局限性分隔样囊腔性病变。免疫组织化学...肺胎盘样变形(placental transmogrification of the lung,PTL)为一种肺部罕见良性囊性病变,其特征为组织学形态类似未成熟胎盘结构。本文报道1例本院确诊的PTL患者,为75岁老年男性,影像学表现为局限性分隔样囊腔性病变。免疫组织化学表现为绒毛结构表面增生的肺泡上皮甲状腺转录因子1、细胞角蛋白7弥漫阳性,绒毛样间质内细胞CD10及波形蛋白阳性,绒毛样间质内血管CD34及D2-40阳性,HMB45、人绒毛膜促性腺激素β均阴性,Ki-67低表达。描述其组织学特点、免疫表型、诊断要点,并复习相关文献。展开更多
With high-resolution data of the Magnetospheric Multiscale(MMS) mission, we observe a magnetic flux rope(MFR) in the Earth's magnetosheath. This MFR, showing a clear bipolar variation of the magnetic field in the ...With high-resolution data of the Magnetospheric Multiscale(MMS) mission, we observe a magnetic flux rope(MFR) in the Earth's magnetosheath. This MFR, showing a clear bipolar variation of the magnetic field in the normal component to local current sheet, contains a strong core field. We use the FOTE method to reconstruct the topology of this MFR and find it is consistent with previous expectation. For the first time, the spiral field and core field of the MFR are both revealed from the FOTE method. Comparing topologies reconstructed at different times, we suggest that the axis of the MFR rotates about 88° at different spatial location. Shape and size of the normal projection to axis vary with the spatial location as well. Inside the MFR, a significant increase of plasma density from 40 to 80 cm^(-3), a sharp decrease of ion temperature from 200 to 50 eV, an enhancement of cold ions and a series of filamentary currents are found.展开更多
This paper studies the effective polytropic index in the central plasma sheet （CPS） by using the method of Kartalev et al. （2006）, which adopts the denoising technique of Haar wavelet to identify the homogeneous M...This paper studies the effective polytropic index in the central plasma sheet （CPS） by using the method of Kartalev et al. （2006）, which adopts the denoising technique of Haar wavelet to identify the homogeneous MHD Bernoulli integral （MBI） and has been frequently used to study the polytropic relation in the solar wind. We chose the quiet CPS crossing by Cluster C1 during the interval 08：51：00-09：19：00 UT on 03 August 2001. In the central plasma sheet, thermal pressure energy per unit mass is the most important part in MBI, and kinetic energy of fluid motion and electromagnetic energy per unit mass are less important. In the MBI, there are many peaks, which correspond to isothermal or near isothermal processes. The interval lengths of homogenous MBI regions are generally less than 1 min. The polytropic indexes are calculated by linearly fitting the data of lnp and Inn within a 16 s window, which is shifted forward by 8 s step length. Those polytropic indexes with IRI ≥0.8 （R is the correlation coefficient between lnp and inn） and p-value≤0.1 in the homogeneous regions are almost all in the range of [0, 1]. The mean and median effective polytropic indexes with high R and low p-value in homogeneous regions are 0.34 and 0.32 respectively, which are much different from the polytropic index obtained by traditional method （αtrad=-0.15）. This result indicates that the CPS is not uniform even during quiet time and the blanket applications of polytropic law to plasma sheet may return misleading value of polytropic index. The polytropic indexes in homogeneous regions with a high correlation coefficient basically have good regression significance and are thus credible. These results are very important to understand the energy transport in magnetotail in the MHD frame.展开更多
文摘火箭基组合循环(Rocket Based Combined Cycle,RBCC)推进系统大大拓展了飞行器的高度—速度包线,是重复使用运载器动力的主要发展方向。对RBCC推进系统研究的现状进行了总结,论述了RBCC推进在单级入轨、两级入轨及临近空间飞行器方面的应用前景,提出了RBCC推进及飞行器研制过程存在的若干问题和关键技术,并给出了发展建议。
文摘肺胎盘样变形(placental transmogrification of the lung,PTL)为一种肺部罕见良性囊性病变,其特征为组织学形态类似未成熟胎盘结构。本文报道1例本院确诊的PTL患者,为75岁老年男性,影像学表现为局限性分隔样囊腔性病变。免疫组织化学表现为绒毛结构表面增生的肺泡上皮甲状腺转录因子1、细胞角蛋白7弥漫阳性,绒毛样间质内细胞CD10及波形蛋白阳性,绒毛样间质内血管CD34及D2-40阳性,HMB45、人绒毛膜促性腺激素β均阴性,Ki-67低表达。描述其组织学特点、免疫表型、诊断要点,并复习相关文献。
基金supported by the National Natural Science Foundation of China(Grant Nos.41574153,41431071,and 41404133)
文摘With high-resolution data of the Magnetospheric Multiscale(MMS) mission, we observe a magnetic flux rope(MFR) in the Earth's magnetosheath. This MFR, showing a clear bipolar variation of the magnetic field in the normal component to local current sheet, contains a strong core field. We use the FOTE method to reconstruct the topology of this MFR and find it is consistent with previous expectation. For the first time, the spiral field and core field of the MFR are both revealed from the FOTE method. Comparing topologies reconstructed at different times, we suggest that the axis of the MFR rotates about 88° at different spatial location. Shape and size of the normal projection to axis vary with the spatial location as well. Inside the MFR, a significant increase of plasma density from 40 to 80 cm^(-3), a sharp decrease of ion temperature from 200 to 50 eV, an enhancement of cold ions and a series of filamentary currents are found.
基金supported by the National Natural Science Foundation of China(Grant Nos.41431071,41174141,41474124)the National Basic Research Program of China(Grant No.2011CB811404)
文摘This paper studies the effective polytropic index in the central plasma sheet （CPS） by using the method of Kartalev et al. （2006）, which adopts the denoising technique of Haar wavelet to identify the homogeneous MHD Bernoulli integral （MBI） and has been frequently used to study the polytropic relation in the solar wind. We chose the quiet CPS crossing by Cluster C1 during the interval 08：51：00-09：19：00 UT on 03 August 2001. In the central plasma sheet, thermal pressure energy per unit mass is the most important part in MBI, and kinetic energy of fluid motion and electromagnetic energy per unit mass are less important. In the MBI, there are many peaks, which correspond to isothermal or near isothermal processes. The interval lengths of homogenous MBI regions are generally less than 1 min. The polytropic indexes are calculated by linearly fitting the data of lnp and Inn within a 16 s window, which is shifted forward by 8 s step length. Those polytropic indexes with IRI ≥0.8 （R is the correlation coefficient between lnp and inn） and p-value≤0.1 in the homogeneous regions are almost all in the range of [0, 1]. The mean and median effective polytropic indexes with high R and low p-value in homogeneous regions are 0.34 and 0.32 respectively, which are much different from the polytropic index obtained by traditional method （αtrad=-0.15）. This result indicates that the CPS is not uniform even during quiet time and the blanket applications of polytropic law to plasma sheet may return misleading value of polytropic index. The polytropic indexes in homogeneous regions with a high correlation coefficient basically have good regression significance and are thus credible. These results are very important to understand the energy transport in magnetotail in the MHD frame.
