期刊文献+
共找到141篇文章
< 1 2 8 >
每页显示 20 50 100
陕北吴堡话的文白异读与语音层次 被引量:13
1
作者 邢向东 《语言研究》 CSSCI 北大核心 2007年第1期29-35,共7页
在吴堡话的声母、韵母中,叠置着中古或唐宋西北方音与后来从权威方言或共同语借入的不同语音层次。
关键词 晋语 文白异读 语音层次
下载PDF
安顺屯堡方言研究之我见 被引量:4
2
作者 袁本良 《安顺师范高等专科学校学报》 2006年第1期5-7,共3页
安顺屯堡方言的研究应该包含本体性研究和投射性研究两个层面。目前相关的研究还比较薄弱,有待进一步加强和深化。
关键词 安顺 方言 本体性研究 投射性研究
下载PDF
明清河工堡夫问题研究 被引量:3
3
作者 金诗灿 《华北水利水电学院学报(社会科学版)》 2012年第1期17-20,共4页
明代堡夫与河夫是河道夫役的不同类型,至清代堡夫成为河夫的一种。在河工上,堡夫与铺夫的含义并不完全相同。清代河南堡夫制度一直存在,雍正时向江南、山东河工推广,取代了原来的铺夫。与明代相比,清代堡夫绝对数量增加,相对数量减少,... 明代堡夫与河夫是河道夫役的不同类型,至清代堡夫成为河夫的一种。在河工上,堡夫与铺夫的含义并不完全相同。清代河南堡夫制度一直存在,雍正时向江南、山东河工推广,取代了原来的铺夫。与明代相比,清代堡夫绝对数量增加,相对数量减少,劳作更加繁重。这与清代河兵制度的兴起有很大的关系。待遇差、劳作苦、缺乏上升空间,使得堡夫丧失护堤的积极性,给清代河工带来了消极的影响,是导致清代河政衰微的一个重要原因。 展开更多
关键词 明清 河工
下载PDF
蔡元培与威廉·洪堡教育思想之比较研究 被引量:8
4
作者 徐艳 《浙江海洋学院学报(人文科学版)》 2000年第3期27-34,共8页
对蔡元培和洪堡两位教育家的教育思想和实践做了一个粗略的比较,比较的重点是他们的教育独立观,他们对完全人格教育的看法以及他们的大学改革实践。
关键词 蔡元培 教育思想 比较研究 个性 群性 普通教育 专门教育 高校 改革
下载PDF
Rutting resistance of asphalt mixtures in the middle course 被引量:4
5
作者 杨军 于良溟 +2 位作者 万军 陈军 钱国超 《Journal of Southeast University(English Edition)》 EI CAS 2006年第2期270-272,共3页
In order to improve the rutting resistance of asphalt mixtures in the middle course to reduce the rutting of asphalt pavement, the influence of different types of gradation with their own optimal asphaltaggregate rati... In order to improve the rutting resistance of asphalt mixtures in the middle course to reduce the rutting of asphalt pavement, the influence of different types of gradation with their own optimal asphaltaggregate ratios is analyzed. Some investigations are made out on the mixture in the middle course through the modified wheel tracking test in air bath and the Hamburg wheel tracking test (HWTT) in water bath, and the results of which are compared with the corresponding research in Germany. Results show that the Sup20 and the modified AC-20I have better performance than that of AC-20I under the same test conditions. In addition, the high-quality bitumen and hard aggregate can improve the rutting performance of the mixture in water-submerged conditions. The selection of modified asphalt, hard aggregate and a reasonable gradation are essential to the improvement of the rutting resistance of the mixtures used in the middle course. 展开更多
关键词 middle course RUTTING modified asphalt modified wheel tracking test Hamburg wheel tracking test
下载PDF
Ice melting performance of deicers and their effect on stripping resistance of asphalt mixture 被引量:6
6
作者 刘嵩 郑南翔 +1 位作者 杨军 孟繁运 《Journal of Southeast University(English Edition)》 EI CAS 2016年第3期327-332,共6页
The ice melting performance of three types of deicers, including sodium chloride, calcium chloride and sodium acetate, were tested in laboratory under different temperature conditions, and their effects on asphalt mix... The ice melting performance of three types of deicers, including sodium chloride, calcium chloride and sodium acetate, were tested in laboratory under different temperature conditions, and their effects on asphalt mixture were evaluated from the point of the stripping resistance of asphalt mixture. Unsaturated Marshall samples were exposed to freeze-thaw cycling while immersed in the deicer solutions of different concentrations. After the freeze-thaw cycles, Cantabro tests were performed, and Cantabro loss was adopted to characterize the stripping resistance of asphalt mixture. The test results show that calcium chloride has the best comprehensive ice melting performance, and all deicers have detrimental effect on the stripping resistance of asphalt mixture at different degrees. The damage degree depends on deicer types and their concentration in the solution. Deicer solutions with about 2% concentration cause the greatest loss of stripping resistance due to serious freeze-thaw damage. Sodium acetate causes greater loss of stripping resistance than sodium chloride and calcium chloride at the same concentration. 展开更多
关键词 deicer ice melting performance strippingresistance FREEZE-THAW Cantabro test
下载PDF
Structure and magnetic properties of Zn ferrite nanoparticles 被引量:2
7
作者 张毅 王凯 +1 位作者 任志艳 翟亚 《Journal of Southeast University(English Edition)》 EI CAS 2009年第3期408-412,共5页
A series of ZnxFe3-xO4(x = 0, 0. 15, 0. 30, 0o 40, 0. 48, 0. 60, 0. 70 ) nanoparticles prepared by hydrothermal method are studied by use of transmission electron microscope, X-ray diffraction, vibrating sample magn... A series of ZnxFe3-xO4(x = 0, 0. 15, 0. 30, 0o 40, 0. 48, 0. 60, 0. 70 ) nanoparticles prepared by hydrothermal method are studied by use of transmission electron microscope, X-ray diffraction, vibrating sample magnetometer, superconducting quantum interference device magnetometer and Mossbauer spectrometer. All samples present a spinel structure. The lattice constant increases with the increase in the Zn content while the grain size decreases from 18 nm to 9 nm. Moreover, the saturation magnetzafion at 5 K and 293 K increases initially when x ≤ 0. 40 and subsequently decreases when x 〉 0. 40. At room temperature, Mossbauer spectra exhibit a change from a well-defined sextet spectrum to a doublet spectrum as the Zn content increases. The doublet spectrum begins to appear when x = 0. 6, while it begins when x = 0. 80 for the bulk materials. The results of magnetization and Curie temperature measurements indicate that the doublet spectrum is due to the surperparamagnetic state of the nanoparticles. Furthermore, the relationship between the hyperfine field variation and the cation distribution is discussed. The variation of magnetic properties is interpreted by the three-sublattice Yafet-Kittel (Y-K)model. 展开更多
关键词 magnetic materials Zn ferrite Mossbauer spectra magnetic properties
下载PDF
Relationship between repeated triaxial test and Hamburg wheel tracking test on asphalt mixtures 被引量:4
8
作者 朱浩然 杨军 +1 位作者 史啸 陆海珠 《Journal of Southeast University(English Edition)》 EI CAS 2010年第1期117-121,共5页
Both the repeated triaxial test (RTT) and the Hamburg wheel tracking test (HWTT) are adopted to evaluate the high temperature performance of the stone mastic asphalt (SMA) and the mastic asphalt (MA). The corr... Both the repeated triaxial test (RTT) and the Hamburg wheel tracking test (HWTT) are adopted to evaluate the high temperature performance of the stone mastic asphalt (SMA) and the mastic asphalt (MA). The correlation of the permanent deformations of the MA and the correlation of the deformation developments of the SMA between the two tests are analyzed, respectively. Results show that both the two tests can effectively identify the high temperature performance of mixtures, and the correlation between the final results of the two tests as well as that between the deformation developments of the two tests are excellent with R20.9. In order to further prove the correlation, viscoelastic parameters estimated from the RTT results is used to simulate the rutting development in the HWTT slabs by the finite element method (FEM). Results indicate that the correlation between the two tests is significant with errors less than 10%. It is suitable to predict the rutting development with the viscoelastic parameters obtained from the RTT. 展开更多
关键词 asphalt mixture repeated triaxial test Hamburg wheel tracking test CORRELATION high temperature performance finite element method
下载PDF
Mssbauer spectroscopic characterization of ferrites as adsorbents for reactive adsorption desulfurization 被引量:2
9
作者 陈霄 朱凯新 +2 位作者 M.A.Ahmed 王军虎 梁长海 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第5期727-734,共8页
Sulfur in transportation fuels is a major source of air pollution. New strategies for the desulfurization of fuels have been explored to meet the urgent need to produce cleaner gasoline. Adsorptive desulfurization(AD... Sulfur in transportation fuels is a major source of air pollution. New strategies for the desulfurization of fuels have been explored to meet the urgent need to produce cleaner gasoline. Adsorptive desulfurization(ADS) is one of the most promising complementary and alternative methods. Herein,nanocrystalline ferrite adsorbents were synthesized from metal nitrates and urea using a microwave assisted combustion method. A series of ADS experiments were performed using a fixed‐bed reactor to evaluate the ADS reactivity over the ferrites, which was found to have the order MgFe2O4〉NiFe2O4〉CuZnFe2O4〉ZnFe2O4〉CoFe2O4. This effect is explained by the fact that the low degree of alloying of Mg‐Fe and the doped Mg increased the interaction between Fe and S compounds,leading to a significant improvement in the desulfurization capability of the adsorbent.Additionally, Mg can dramatically promote the decomposition of thiophene. X‐ray diffraction and Mosbauer spectroscopy were used to characterize the fresh, regenerated, and sulfided adsorbents.Although the ferrite adsorbents were partially sulfided to bimetallic sulfides during the adsorption process, they were successfully regenerated after calcining at 500 °C in air. 展开更多
关键词 FERRITE Adsorptive desulfurization Msbauer spectroscopy REGENERATION
下载PDF
Study on High Temperature Behaviour of Gussasphalt 被引量:11
10
作者 杨军 Gharabaghy Cyrus Steinauer Bernhard 《Journal of Southeast University(English Edition)》 EI CAS 2002年第4期297-301,共5页
Rutting is one of the most damages in the asphalt surfaces for the orthotropic steel bridge decks. With Hamburg wheel tracking device, the suitable test conditions for Gussasphalt in Germany are pointed out, the high ... Rutting is one of the most damages in the asphalt surfaces for the orthotropic steel bridge decks. With Hamburg wheel tracking device, the suitable test conditions for Gussasphalt in Germany are pointed out, the high temperature behaviour of Gussasphalt with different binders are tested and compared. The polymer modified binder has higher resistance stability to rutting. The retained time and mixed frequency have obvious effects on Gussasphalt behaviour during Gussasphalt retained period. 展开更多
关键词 GUSSASPHALT high temperature behaviour Hamburg wheel tracking test polymer modified binder
下载PDF
Effect of Parent Internal Excitation on Product State Distribution in Methyl Radical Photodissociation at 212.5nm
11
作者 吴国荣 张竟辉 +1 位作者 Steven A.Harich 杨学明 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第2期109-116,共8页
Photodissociation dynamics of the CH3 radical at 212.5 nm excitation has been studied experimentally using the H atom Rydberg tagging time-of-flight method. CH3 radicals are produded by photodissociation of CH3I at 26... Photodissociation dynamics of the CH3 radical at 212.5 nm excitation has been studied experimentally using the H atom Rydberg tagging time-of-flight method. CH3 radicals are produded by photodissociation of CH3I at 266 nm. Translational energy distribution and angular distribution for the CH2 product from CH3 photodissociation at different vibrational levels via the 3s Rydberg state have been measured. From these distributions, product J state distributions are obtained for photodissociation of different vibrationally excited CH3 radicals. The effect of parent vibrational as well as rotational excitation on the dissociation dynamics of CH3 is also investigated in detail. Experimental results in this work show that parent vibrational excitation in the umbrella mode has a significant effect on both rotational excitation and angular distribution of the CH2 product, while parent rotational excitation has obvious effect only on the angular distribution of CH2 product. 展开更多
关键词 High Rydberg state CH3 radical PHOTODISSOCIATION
下载PDF
Status quo and Existing Problems of Seismic Prevention Planning in Counties and Districts——a Case Study of Hongsibao District, Wuzhong City,Ningxia Hui Autonomous Region
12
作者 杨银科 刘聪 +1 位作者 苗丁丁 南静静 《Agricultural Science & Technology》 CAS 2016年第6期1488-1492,1497,共6页
This paper introduced domestic and overseas status, the historical evolution and the development history of earthquake disaster reduction planning. The urgencies and realistic significance were analyzed to carry out e... This paper introduced domestic and overseas status, the historical evolution and the development history of earthquake disaster reduction planning. The urgencies and realistic significance were analyzed to carry out earthquake disaster reduction planning for districts or countries in the northwest. With Hongsibao District in Wuzhong City, Ningxia Province as an example, this article analyzed in detail the present situation and the special problems of earthquake disaster reduction planning in Northwest China. The relevant solving measures were put forward in order to offer a reference for the scientific establishment and effective implementation of earth- quake disaster reduction planning in Northwest China. The foundation of earthquake disaster reduction in the Hongsibao District is still very weak, there is a single earthquake monitoring means, the emergency rescue system is not complete, the working mechanism is not perfect, and the lack of funding for the work of earthquake disaster reduction. 展开更多
关键词 Earthquake control and disaster prevention and reduction planning Statics quo Influential factors Hongsibao District
下载PDF
场离子显微镜在析出强化微合金钢中的应用
13
作者 朱晓勇 王晓姣 +2 位作者 钟柳明 刘庆冬 刘文庆 《材料热处理学报》 EI CAS CSCD 北大核心 2011年第7期51-56,共6页
将实验V-Nb-Mo微合金钢在1200℃固溶处理,在500℃回火不同时间,用场离子显微镜(FIM)研究实验钢中碳化物的析出过程。结果表明:回火0.5 h的样品中,碳化物处于形核长大时期,与基体的{110}呈共格关系;随着回火时间的延长,碳化物形成独立的... 将实验V-Nb-Mo微合金钢在1200℃固溶处理,在500℃回火不同时间,用场离子显微镜(FIM)研究实验钢中碳化物的析出过程。结果表明:回火0.5 h的样品中,碳化物处于形核长大时期,与基体的{110}呈共格关系;随着回火时间的延长,碳化物形成独立的晶体结构,与基体{110}之间呈半共格关系;回火100 h后,碳化物粗化长大,与基体呈非共格关系;形状系数随着回火时间的延长先变大再变小,析出相尺寸从1.6 nm逐渐增大至15 nm。500℃回火30 h的实验钢力学性能最佳,表明碳化物的析出强化效果最明显,相应的碳化物尺寸约为4 nm。 展开更多
关键词 场离子显微镜 回火 析出 V-Nb-Mo微合金钢
下载PDF
New mythology of the Russian symbolism
14
作者 吴倩 《Sino-US English Teaching》 2007年第11期74-78,共5页
Mythology originated from the Greek. It refers to the ancient legends and stories. Up to the end of the 19^th century and the early part of the 20^th century, mythology attained a new meaning and the new mythology cam... Mythology originated from the Greek. It refers to the ancient legends and stories. Up to the end of the 19^th century and the early part of the 20^th century, mythology attained a new meaning and the new mythology came into being. The Russian symbolists took the mythology as a form to create the new mythology. Petersburg by Andrej Belyj and Meregkovskiy is characterized by "the new mythology". 展开更多
关键词 MYTHOLOGY new mythology Perterburg
下载PDF
Andrej Belyj's Novel-myth Perterburg
15
作者 吴倩 《Sino-US English Teaching》 2007年第3期57-60,共4页
Andrej Belyj is the main representative of Russia symbolism. Symbolists pursue the text mystique with massive utilization of myth. But here myth has changed and obtained new myth characteristic, which is manifested in... Andrej Belyj is the main representative of Russia symbolism. Symbolists pursue the text mystique with massive utilization of myth. But here myth has changed and obtained new myth characteristic, which is manifested in Perterburg. 展开更多
关键词 Andrej Belyj Perterburg new mythology novel-myth
下载PDF
High Resolution Crossed Molecular Beams Study on the F+HD→HF+D Reaction at Collision Energy of 8.19-18.98 kJ/mol 被引量:1
16
作者 董文锐 肖春雷 +3 位作者 汪涛 戴东旭 王秀岩 杨学明 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第5期521-528,I0003,共9页
The crossed beams scattering dynamics of the F+HD→HF+D reaction have been studied at collision energies ranging from 8.19 k J/tool to 18.98 k J/tool using the high resolution H-atom Rydberg tagging time-of-flight m... The crossed beams scattering dynamics of the F+HD→HF+D reaction have been studied at collision energies ranging from 8.19 k J/tool to 18.98 k J/tool using the high resolution H-atom Rydberg tagging time-of-flight method. Product rotational state-resolved differential cross sections have been measured. Most of the DF products are backward scattered at low collision energies and then gradually shift to the sideway as the collision energy increases. In addition to the backward and sideway scatterings, we have also observed the DF(v'=4) product in the forward direction for the first time for this reaction. The forward scattering DF(v=4) product also increases with the collision energy. Angular and collision energy dependence of the product energy disposals in different degrees of freedom have been determined. Collision energy dependence of the vibrational branching ratios has also been examined. Possible dynamical origins of the forward scattering DF(v'=4) products were discussed. 展开更多
关键词 F+HD→HF+D Crossed molecular beam Rydberg tagging
下载PDF
Advancing Hierarchical Equations of Motion for Efficient Evaluation of Coherent Two-dimensional Spectroscopy 被引量:2
17
作者 许健 徐瑞雪 +2 位作者 Darius Abramavicius 张厚道 严以京 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第5期497-506,I0003,共11页
To advance hierarchical equations of motion as a standard theory for quantum dissipative dynamics, we put forward a mixed Heisenberg-SchrSdinger scheme with block-matrix implementation on efficient evaluation of nonli... To advance hierarchical equations of motion as a standard theory for quantum dissipative dynamics, we put forward a mixed Heisenberg-SchrSdinger scheme with block-matrix implementation on efficient evaluation of nonlinear optical response function. The new approach is also integrated with optimized hierarchical theory and numerical filtering algorithm. Different configurations of coherent two-dimensional spectroscopy of model excitonic dimer systems are investigated, with focusing on the effects of intermolecular transfer coupling and bi-exciton interaction. 展开更多
关键词 Hierarchical equations of motion Two-dimensional spectroscopy Mixed Heisenberg-Schrodinger scheme
下载PDF
Photodissociation of HOD via the C1B1 State: OD/OH Branching Ratio and OD Bond Dissociation Energy
18
作者 程丽娜 程元 +4 位作者 袁开军 郭庆 汪涛 戴东旭 杨学明 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第2期129-133,I0003,共6页
Photodissociation of jet-cooled HOD via the C state around 124 nm has been studied using the H(D)-atom Rydberg tagging time-of-flight technique. Rotational state resolved action spectrum and the product translationa... Photodissociation of jet-cooled HOD via the C state around 124 nm has been studied using the H(D)-atom Rydberg tagging time-of-flight technique. Rotational state resolved action spectrum and the product translational energy distribution spectra have been recorded for both D+OH and H+OD dissociation channels. Product channel OH/OD branching ratios for the individual C-X rotational transition have been determined. A comparison is also given with the B-X and A-X transitions. In addition, the dissociation energy of the OD bond in HOD has been determined accurately to be 41751.3±5 cm-1. 展开更多
关键词 PHOTODISSOCIATION Rydberg tagging Branching ratio Dissociation energy
下载PDF
High Resolution Crossed Molecular Beams Study on the F+HD→HF+D Reaction at Collision Energy of 5.43-18.73 kJ/mol
19
作者 董文锐 肖春雷 +3 位作者 汪涛 戴东旭 王秀岩 杨学明 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第5期507-514,I0003,共9页
The dynamics of F+HD→HF+D reaction has been studied at ten collision energies ranging from 5.43 kJ/mol to 18.73 kJ/mol using high-resolution H/D atom Rydberg tagging time-of-flight method. Product vibrational and r... The dynamics of F+HD→HF+D reaction has been studied at ten collision energies ranging from 5.43 kJ/mol to 18.73 kJ/mol using high-resolution H/D atom Rydberg tagging time-of-flight method. Product vibrational and rotational state-resolved differential cross sections have been determined. The intensity of the HF(v1=2) forward products decreases as the collision energy increases, suggesting that the resonance contribution is reduced as the collision energy increases. The forward peak of HF(vl=3) product has also been observed above the threshold of this product channel. Product energy disposals in different degrees of freedom have been analyzed. The collision energy dependence of the HF vibrational product branching was also determined. This work presents a comprehensive dynamic picture of this resonance mediated reaction in a wide collision energy regime, providing a good test ground for theoretical understandings of this interesting reaction at higher collision energies. 展开更多
关键词 F+HD→HF+D Crossed molecular beam Rydberg tagging Reactive resonance
下载PDF
Ion-Pair Photodissociation of Trichloromonofluoromethane
20
作者 陈刘利 田善喜 +4 位作者 徐云峰 储根柏 刘付轶 单晓斌 盛六四 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第3期261-266,I0003,共7页
fragments, F- and Cl- including two isotope species 35Cl- and 37Cl-, are observed in the photoexcitations of CFC13. The ion-pair anion efficiency spectra of 35Cl- and 37Cl- are recorded in the photon energy range of 7... fragments, F- and Cl- including two isotope species 35Cl- and 37Cl-, are observed in the photoexcitations of CFC13. The ion-pair anion efficiency spectra of 35Cl- and 37Cl- are recorded in the photon energy range of 7.75-22.00 eV. The threshold of ion-pair dissociation CFCl3-CFC12++Cl- is experimentally determined to be 7.944-0.04 eV. With the references of the high-resolution photoabsorption spectra reported in the literatures, we make tentative assignments of the electron valence-to-Rydberg transitions. Furthermore, the multibody ion-pair fragmentation processes to Cl- are discussed by comparison between the calculated thermochemical thresholds and the experimental efficiency spectrum. 展开更多
关键词 Trichloromonofluoromethane Ion-pair dissociation Rydberg state Ion-pair anion efficiency spectrum Time-of-flight mass spectrometer
下载PDF
上一页 1 2 8 下一页 到第
使用帮助 返回顶部