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91.
设计了由超大口径前置望远系统和超大视场光谱仪组成的超大口径高光谱海洋水色仪.前置望远系统采用同轴三反光学系统结构,口径为4 m,视场为0.64°,焦距为21.6 m,波段范围为400~1 000nm.超大视场光谱仪采用改进的Offner结构,视场为240mm,光谱分辨率为10nm.探测器像元尺寸为15μm×15μm,4片探测器交错拼接实现400km幅宽.超大视场光谱仪在400~1 000nm的宽波段内,点列图半径的均方根值均小于3.9μm,静止轨道高光谱海洋水色仪全系统不同波长的MTF在33.3lp/mm处大于0.52,各项指标均满足应用要求.  相似文献   
92.
The effects of the types and contents of surfactants, alkali types and concentrations, oil-water ratios, mixing speeds, and emulsifying temperatures on the rheology of heavy oil-in-water (O/W) emulsions were studied. The experimental results showed that the apparent viscosity increased as the formulated surfactant content increased. The organic/inorganic alkali played a twofold role in the apparent viscosity of the O/W emulsion, promoting the ionization of these interfacial active components and compressing the diffused double layer, the competition of which determined whether the apparent viscosity increased or decreased. With increasing oil-water ratios, the apparent viscosity increased, whereas an increase in the emulsifying temperature resulted in a decrease of the apparent viscosity. When the mixing speed was increased from 500 to 1000?r/min, the apparent viscosity increased. However, the apparent viscosity changed minimally for mixing speeds in the range of 1000–1500?r/min. To further discuss the impacts of these factors on the emulsion rheology and pressure drop, the results of an orthogonal test were analyzed through ANOVA using SPSS software; the pressure drops in the samples were calculated using Matlab software. The results demonstrated that the effects of the oil-water ratios on emulsion viscosity and pressure drop were the most prominent.  相似文献   
93.
The influences of thioketo substitution on the properties of uracil monomer and dimer and their interactions with Zn2+ have been systematically investigated at the B3LYP/6-311+G*level of theory. Those properties include the structural characteristics, acidities, ionization potentials, and singlet–triplet energy gaps of SU monomers and their dimers, where SU=2-thiouracil, 4-thiouracil, and 2,4-dithiouracil, respectively. Computational results suggest that thioketo substitution leads to an increase in the acidities of the N-H groups for both uracil and its dimer, where the N1–H group is still the most acidic site relative to that of N3–H group. However, the opposite behaviors are true for the ionization potentials and the singlet–triplet energy gaps of uracil monomer and its dimer, suggesting that thiouracils are more susceptible to radiation damage relative to the unsubstituted uracil. For uracil and 2-thiouracil, the corresponding triplet excited-state geometries are predicted to be highly nonplanar compared with the planar geometries of the ground state as well as 4-thiouracil and 2,4-dithiouracil upon triplet excitation. As a rule, the intermolecular H-bonds involving the sulfur atom directly have been influenced more significant than those the oxygen atom directly involved for U::U and SU::SU base pairs upon ionization and excitation. Additionally, Zn2+ binding is expected to lead to an increase in the stability of U::U and SU::SU base pairs.  相似文献   
94.
95.
设计和研制了一套土壤剖面CO2气体通量原位测试的方法和装置,该方法和装置可用于土壤剖面不同深度(0~200 cm)土壤CO2气体通量的观测、不同深度土壤层CO2气体存储量的估测、土地利用/土地覆盖变化引起土壤CO2气体释放量变化的测算和估计,以及植被或地力恢复速率的评价等。  相似文献   
96.
裂解气相色谱一质谱联用法(PGC-MS)在对高聚物的定性,揭示高聚物的结构,如高聚物的单体、高聚物的链节和链节间的连接,以及高聚物中的添加剂和固化剂等的鉴定,尤其是在研究高聚物的结构与性能间的关系方面,具有很大的潜力[1-3].  相似文献   
97.
Herein, we report divergent additions of 2,2′-diazidobiphenyls to C60 and Sc3N@Ih-C80. In stark contrast to that of the previously reported bis-azide additions, the unexpected cascade reaction leads to the dearomative formation of azafulleroids 2 fused with a 7-6-5-membered ring system in the case of C60. In contrast, the corresponding reaction with Sc3N@Ih-C80 switches to the C−H insertion pathway, thereby resulting in multiple isomers, including a carbazole-derived [6,6]-azametallofulleroid 3 and a [5,6]-azametallofulleroid 4 and an unusual 1,2,3,6-tetrahydropyrrolo[3,2-c]carbazole-derived metallofullerene 5 , whose molecular structures have been unambiguously determined by single-crystal X-ray diffraction analyses. Among them, the addition type of 5 is observed for the first time in all reported additions of azides to fullerenes. Furthermore, unexpected isomerizations from 3 to 5 and from 4 to 5 have been discovered, providing the first examples of the isomerization of an azafulleroid to a carbazole-derived fullerene rather than an aziridinofullerene. In particular, the isomerism of the [5,6]-isomer 4 to the [5,6]-isomer 5 is unprecedented in fullerene chemistry, contradicting the present understanding that isomerization generally occurs between [5,6]- and [6,6]-isomers. Control experiments have been carried out to rationalize the reaction mechanism. Furthermore, representative azafulleroids have been applied in organic solar cells, thereby resulting in improved power conversion efficiencies.  相似文献   
98.
磷酸对TiO2纳米粒子光催化剂的改性   总被引:2,自引:0,他引:2  
通过浸渍过程实现了磷酸对溶胶水热法合成的锐钛矿相TiO2纳米粒子的改性.重点研究了磷酸修饰对纳米锐钛矿相TiO2的热稳定性及光催化活性的影响.结果表明,磷酸修饰显著地提高了纳米锐钛矿相TiO2热稳定性,甚至经过800℃热处理后仍然具有以锐钛矿相为主的相组成.在光催化降解罗丹明B(RhB)过程中经过700℃热处理的磷酸修饰的样品表现出了优于商品P25-TiO2的活性.  相似文献   
99.
The cycloaddition reaction mechanisms between interstellar molecule ketenimine and unsaturated hydrocarbon (ethyne and ethylene) have been systematically investigated employing the second-order Møller-Plesset perturbation theory (MP2) method. Geometry optimizations and vibrational analyses have been performed for the stationary points on the potential energy surfaces of the system. The calculated results show that it can be produced the five-membered cyclic carbene intermediates through pericyclic reaction processes between ketenimine and ethyne (or ethylene). For the reaction between ketenimine and ethyne, through the following H-transferred processes, carbene intermediate can be isomerized to the pyrrole compounds. For the reaction between ketenimine and ethylene, carbene intermediate can be isomerized to the pyrroline compounds. The present study is helpful to understand the reactivity of nitrogenous cumulene ketenimine and the formation of prebiotic species in interstellar space.  相似文献   
100.
 利用若丹明B乙醇溶液的荧光改变了二硫化碳的一至三阶Stokes喇曼谱线的强度分布,选择性地增强了三阶Stokes喇曼谱线。在泵浦功率密度为~560MW.cm-2时,对染料摩尔浓度分别为~10-5、cm-5散射池和~10-4、1cm散射池进行实验,观察到二硫化碳的三阶Stokes喇曼谱线与染料激光形成的共振增强现象及、二阶Stokes喇曼谱线的部分或完全耗尽。  相似文献   
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