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61.
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63.
抛光粉颗粒度对高功率激光玻璃材料抛光效率和粗糙度的影响 总被引:2,自引:0,他引:2
磷酸盐钕玻璃、熔石英和BK7是3类用于激光惯性约束聚变(ICF)装置主要光学元件材料.实验中采用不同平均粒径的氧化铈抛光粉对上述3类材料分别进行抛光,对特定材料抛光去除量和抛光粉平均粒径的关系进行了研究.实验表明:由于材料的物理和化学特性不同,特定的材料需选用相应平均粒径大小的抛光粉才能达到最佳的抛光效率.实验还就上述3类高功率激光玻璃材料抛光中各个阶段的抛光粗糙度与抛光粉平均粒径的关系进行了研究,结果表明:某一规格抛光粉的粒径对不同特性材料抛光后的表面粗糙度影响表征情况不同. 相似文献
64.
We investigate the removal mechanism of neodymium-doped phosphate glass dominated in loose abrasive grinding and bound abrasive grinding. Moreover, we investigate the surface roughness and subsurface damage change with optical fabrication parameters, such as different spindle speed, load and abrasive size under different grinding processes in details. For a range of experimental conditions, we find that fracture is the principal removal mechanism for loose abrasive grinding, while plastic scratching is the dominating mechanism for bound abrasive grinding. The load has more influence on subsurface damage for bound abrasive grinding than for loose abrasive grinding. However, the spindle speed has different effect on subsurface damage produced with loose abrasive grinding and bound abrasive grinding. Moderate spindle speed and low load is preferred to produce smaller subsurface damage for loose abrasive grinding. Moreover, higher spindle speed and lower load are preferred to plastic scratching for bound abrasive grinding. Bound abrasive grinding produces 4 times lower surface roughness and 3 times lower subsurface damage than loose abrasive grinding. 相似文献
65.
Synthesis and Characterization of Three Diverse Coordination Frameworks under Co-ligand Intervention
The chelating organic ligands of 2,2’-bipyridine (2,2’-bipy), di(pyrid-2-yl)amine (dpa) and 2,6-di(pyrid-2-ylamino)pyridine (dpap) were respectively applied to react with H2fum (fumaric acid) and copper salts, affording three different complexes [Cu2(fum)(2,2’-bipy)4]•2ClO4 (1), [Cu2(µ-OH)2(fum)(dpa)2]•2H2O (2) and [Cu(SO4)(H2O)(dpap)]•H2O (3). These complexes were determined by single-crystal X-ray diffraction. Each penta-coordinated Cu(II) ion exhibits a distorted trigonal bipyramidal geometry in 1. The fum ligand links copper ions to form a dinuclear copper unit. While in 2, the fum ligands connect [Cu2(µ-OH)2(dpa)2] unit to construct a 1D zigzag chain. Unexpectedly, when dpap instead of dpa was used under the same conditions, only one mononuclear complex 3 was formed. Crystal packings show that 1—3 form 3D supramolecular architectures through non-covalent interactions (multiple hydrogen bonds and C—H…π/π-π interactions). In addition, the study of the magnetic property reveals dominating ferromagnetic interactions between Cu(II) atoms in 1. 相似文献
66.
Yan Sun Laixin Luo Fang Wang Jianqiang Li Yongsong Cao 《Analytical and bioanalytical chemistry》2009,395(2):465-471
A novel method based on solid-phase extraction was studied for the extraction of amitrole (3-amino-1,2,4-triazole), and its
residue determination in apples has been developed. The samples were derivatized with 4-chloro-3,5-dinitrobenzotrifluoride
(CNBF). The derivatization conditions and the influence of elution composition on the separation were investigated. In pH
9.5 H3BO3–Na2B4O7 media, the reaction of amitrole with CNBF was complete at 60°C after 30 min. The separation of derivatized amitrole was achieved
at room temperature within 13 min by gradient elution mode with cetyltrimethylammonium bromide in mobile phase as ion-pair
reagent. The method correlation coefficient was 0.9996, in concentrations ranging from 1.66 to 415 mg L−1. The calculated recoveries of the proposed method were from 94.17% to 105.67%, and relative standard deviations were 1.57%
to 6.44% in the application to the quantitative determination of amitrole in apples. The detection limit of amitrole was 0.10 mg L−1 with a signal-to-noise ratio of 3.
Figure Residue determination of amitrole in apple by ion-pairing high-performance liquid chromatography 相似文献
67.
Tang T Qu J Müllen K Webber SE 《Langmuir : the ACS journal of surfaces and colloids》2006,22(18):7610-7616
Recently the synthesis of water-soluble and fluorescent perylene diimides has been reported (Müllen, K.; et al. Angew. Chem., Int. Ed. 2004, 43, 1528; Chem.-Eur. J. 2004, 10, 5297). We have characterized the photophysics of two of these compounds (anionic n-PDI, CAS Reg. No. 694438-88-5. and cationic p-PDI, CAS Reg. No. 817207-4-7) in pure water, dimethyl sulfoxide (DMSO), and aqueous NaCl. These studies, supported by molecular dynamics simulations, have led to the conclusion that these compounds form weakly interacting aggregated species in pure water. n-PDI and p-PDI have been incorporated in polyelectrolyte films of poly(styrene sulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDAC) following the layer-by-layer (LBL) methodology. The optical density and fluorescence intensity of the PDI-LBL films grew linearly with the number of layers, and the PDI was not extracted by subsequent polyelectrolyte deposition. The PDI fluorescence quantum yield was substantially diminished in these films, which we interpret as a self-quenching effect, enhanced by inter- and intralayer energy transfer. Energy-transfer studies to the incorporated cationic dye Brilliant Green (BG) has demonstrated that the BG resides in the same PSS-rich region as p-PDI and is largely excluded from the region that contains n-PDI (PDAC-rich). 相似文献
68.
Jianqiang Feng 《数学研究通讯:英文版》2014,30(1):51-59
In this article, we study the Lie supertriple system (LSTS) $T$ over a field$\mathbb{K}$ admitting a nondegenerate invariant supersymmetric bilinear form (call such a $T$ metrisable). We give the definition of $T^∗_ω$-extension of an LSTS $T$, prove a necessary
and sufficient condition for a metrised LSTS ($T$, $ϕ$) to be isometric to a $T^∗$-extension
of some LSTS, and determine when two $T^∗$-extensions of an LSTS are "same", i.e.,
they are equivalent or isometrically equivalent. 相似文献
69.
谐波平衡法在动导数快速预测中的应用研究 总被引:4,自引:0,他引:4
谐波平衡法以傅里叶级数展开为基础,将周期性非定常流场的非定常求解过程转化为几个定常流场的耦合求解过程,并通过重建得到整个流场的非定常过程. 建立了基于谐波平衡法的动导数快速预测方法,数值模拟了超声速带翼导弹俯仰的动态流场,并通过积分法获取了俯仰动导数,与实验结果吻合很好;且在同等计算精度下,谐波平衡法的计算效率是双时间步方法的13 倍. 应用谐波平衡法研究了较大范围内减缩频率对俯仰动导数的影响规律. 研究发现,对于本外形,当减缩频率降低到一定值后,俯仰动导数的值迅速变化,甚至发生变号;对此现象产生的原因进行了深入分析,并通过对导弹自激俯仰运动的数值模拟验证了该结果. 此外,针对大攻角条件下动态流场非线性强的特点,开展了谐波平衡法在大攻角下的适用性研究. 结果表明,谐波平衡法在大攻角下也能取得很好的计算结果. 相似文献
70.
Ling Mu Lin Peng Junji Cao Qiusheng He Fan Li Jianqiang Zhang Xiaofeng Liu Huiling Bai 《中国颗粒学报》2013,11(1):86-93
This study set out to assess the characteristics of polycyclic aromatic hydrocarbon(PAH) emission from coking industries,with field samplings conducted at four typical coke plants.For each selected plant,stack flue gas samples were collected during processes that included charging coal into the ovens(CC),pushing coke(PC) and the combustion of coke-oven gas(CG).Sixteen individual PAHs on the US EPA priority list were analyzed by gas chromatography/mass spectrometry(GC/MS).Results showed that the total PAH concentrations in the flue gas ranged from 45.776 to 414.874μg/m3,with the highest emission level for CC(359.545μg/m3).The concentration of PAH emitted from the CC process in CP1(stamp charging) was lower than that from CP3 and CP4(top charging).Low-molecular-weight PAHs(i.e.,two- to three-ring PAHs) were predominant contributors to the total PAH contents,and Nap,AcPy,Flu,PhA,and AnT were found to be the most abundant ones.Total BaPeq concentrations for CC(2.248μg/m3) were higher than those for PC(1.838μg/m3) and CG(1.082μg/m3),and DbA was an important contributor to carcinogenic risk as BaP in emissions from coking processes.Particulate PAH accounted for more than 20%of the total BaPec| concentrations,which were significantly higher than the corresponding contributions to the total PAH mass concentration(5%).Both particulate and gaseous PAH should be taken into consideration when the potential toxicity risk of PAH pollution during coking processes is assessed.The mean total-PAH emission factors were 346.132 and 93.173μg/kg for CC and PC,respectively. 相似文献