To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The m...To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The measurement is performed at the Back-n white neutron source with a 76-m time-of-flight path using the China Spallation Neutron Source. A multilayer fast fission chamber with 235U and 238U is employed as the neutron detector. The diameter and thickness of the natural graphite sample are 70 mm and 40 mm, respectively. Signal waveforms are collected using a data acquisition system. Off-line data processing was used to obtain the neutron time-of-flight spectra and transmissions. The uncertainty of the counting statistics is generally approximately 3% for each bin in the energy range of 1–20 MeV. It is determined that the results for the neutron total cross section of carbon obtained using ^235U cells are in good agreement with the results obtained using 238U cells within limits of statistical uncertainty. Moreover, the measured total cross sections show good agreement with the broadening evaluated data.展开更多
On the basis of the multi.channel seismic data and the other data, using 2DMove software, the tectonic evolution in three seismic profiles was restored since Pliocene. The tectonic restoration results show that： （1...On the basis of the multi.channel seismic data and the other data, using 2DMove software, the tectonic evolution in three seismic profiles was restored since Pliocene. The tectonic restoration results show that： （1） the initial active center lay in the west slope and then was transferred to east and south via trough center during the evolution process; （2） several main normal faults controlled the evolution of the southern Okinawa Trough; （3） since Late Pliocene, the southern Okinawa Trough has experienced two spreading stages. The early is depression in Early-Middle Pleistocene and the late is back-arc spreading in Late Pleistocene and Holocene, which is in primary oceanic crust spreading stage.展开更多
AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 3...AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 30.6±8.9y).Prior to treatment and an average 7mo after therapy,Scheimpflug analysis was performed using Pentacam HR.In addition to corneal thickness assessments,corneal radius,elevation,and aberrometric measurements were performed both on anterior and posterior corneal surfaces.Data obtained before and after surgery were statistically analyzed.RESULTS:In terms of horizontal and vertical corneal radius,and central corneal thickness no deviations were observed an average 7mo after operation.Corneal higher order aberration showed no difference neither on anterior nor on posterior corneal surfaces.During follow-up period,no significant deviation was detected regarding elevation values obtained by measurement in mm units between the 3.0-8.0 mm-zones.CONCLUSION:Corneal stabilization could be observed in terms of anterior and posterior corneal surfaces,elevation and higher order aberration values 7mo after collagen cross-linking therapy for keratoconus.展开更多
[ Objective] The study was to investigate the agronomic traits and breeding characteristics of genic male sterile material Mian 7AB-4- 2 in Brassica napus. [ Method] The differences in agronomic traits and polymorphis...[ Objective] The study was to investigate the agronomic traits and breeding characteristics of genic male sterile material Mian 7AB-4- 2 in Brassica napus. [ Method] The differences in agronomic traits and polymorphisms in SSR markers, between the genic male sterile material Mian 7AB-4-2 in Brassica napus and its sisterly line Mian 7AB-4-1 were investigated by hybridization and molecular identification; and the percentage of sterile individuals of Mian 7AB-4-2 and of the hybrids with its sisterly line Mian 7AB-4-1 from test cross and back cross were also studled. [ Result] Mian 7AB-4-2 was not significantly different in agronomic traits from its sisterly line Mian 7AB-4-1 at 0.05 probability level. The per- centages of sterile individuals in the pollinated fertile Mian 7AB-4-2 plants were over 60%, and that in its sisterly line Mian 7AB-4-1 was about 25%. In test crosses with other nine sterile lines, Mian 7AB-4-1 kept the percentage of sterile individuals of sterile lines over 90%, and the percentage of sterile individuals from back cross over 80%. With regard to molecular markers, Mian 7AB-4-2 and its sisterly line Mian 7AB-4-1 were different in the band number from SSR primers a2 and E10. [ Conclusion] The results indicate that Mian 7AB-4-2 is helpful for rapeseed breeding, quickening the application of new materials in field breeding.展开更多
基金supported by the National Key Research and Development Plan(No.2016YFA0401603)the National Natural Science Foundation of China(No.11675155)
文摘To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The measurement is performed at the Back-n white neutron source with a 76-m time-of-flight path using the China Spallation Neutron Source. A multilayer fast fission chamber with 235U and 238U is employed as the neutron detector. The diameter and thickness of the natural graphite sample are 70 mm and 40 mm, respectively. Signal waveforms are collected using a data acquisition system. Off-line data processing was used to obtain the neutron time-of-flight spectra and transmissions. The uncertainty of the counting statistics is generally approximately 3% for each bin in the energy range of 1–20 MeV. It is determined that the results for the neutron total cross section of carbon obtained using ^235U cells are in good agreement with the results obtained using 238U cells within limits of statistical uncertainty. Moreover, the measured total cross sections show good agreement with the broadening evaluated data.
基金This paper is supported by the Knowledge Innovation Project of Chinese Academy of Sciences (Nos. KZCX3-SW-219, KZCX3-SW-224) the Taishan Scholarship Project of Shandong Province.
文摘On the basis of the multi.channel seismic data and the other data, using 2DMove software, the tectonic evolution in three seismic profiles was restored since Pliocene. The tectonic restoration results show that： （1） the initial active center lay in the west slope and then was transferred to east and south via trough center during the evolution process; （2） several main normal faults controlled the evolution of the southern Okinawa Trough; （3） since Late Pliocene, the southern Okinawa Trough has experienced two spreading stages. The early is depression in Early-Middle Pleistocene and the late is back-arc spreading in Late Pleistocene and Holocene, which is in primary oceanic crust spreading stage.
文摘AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 30.6±8.9y).Prior to treatment and an average 7mo after therapy,Scheimpflug analysis was performed using Pentacam HR.In addition to corneal thickness assessments,corneal radius,elevation,and aberrometric measurements were performed both on anterior and posterior corneal surfaces.Data obtained before and after surgery were statistically analyzed.RESULTS:In terms of horizontal and vertical corneal radius,and central corneal thickness no deviations were observed an average 7mo after operation.Corneal higher order aberration showed no difference neither on anterior nor on posterior corneal surfaces.During follow-up period,no significant deviation was detected regarding elevation values obtained by measurement in mm units between the 3.0-8.0 mm-zones.CONCLUSION:Corneal stabilization could be observed in terms of anterior and posterior corneal surfaces,elevation and higher order aberration values 7mo after collagen cross-linking therapy for keratoconus.
基金Supported by National High-tech R&D Program of China(2001AA241104, 2004AA241104)Key Breeding Project of Sichuan Province (200107001-1-6-1, 2006YZGG-5)Key Quality Project of Sichuan Province(2006YZGG-23)~~
文摘[ Objective] The study was to investigate the agronomic traits and breeding characteristics of genic male sterile material Mian 7AB-4- 2 in Brassica napus. [ Method] The differences in agronomic traits and polymorphisms in SSR markers, between the genic male sterile material Mian 7AB-4-2 in Brassica napus and its sisterly line Mian 7AB-4-1 were investigated by hybridization and molecular identification; and the percentage of sterile individuals of Mian 7AB-4-2 and of the hybrids with its sisterly line Mian 7AB-4-1 from test cross and back cross were also studled. [ Result] Mian 7AB-4-2 was not significantly different in agronomic traits from its sisterly line Mian 7AB-4-1 at 0.05 probability level. The per- centages of sterile individuals in the pollinated fertile Mian 7AB-4-2 plants were over 60%, and that in its sisterly line Mian 7AB-4-1 was about 25%. In test crosses with other nine sterile lines, Mian 7AB-4-1 kept the percentage of sterile individuals of sterile lines over 90%, and the percentage of sterile individuals from back cross over 80%. With regard to molecular markers, Mian 7AB-4-2 and its sisterly line Mian 7AB-4-1 were different in the band number from SSR primers a2 and E10. [ Conclusion] The results indicate that Mian 7AB-4-2 is helpful for rapeseed breeding, quickening the application of new materials in field breeding.
