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41.
Kai Yang Xuan Zhang Enqin Fu Jingui Qin Minoru Kinoshita 《Journal of solid state chemistry》2004,177(11):4300-4304
Two new intercalation compounds were prepared by the reactions of Ni(II) cyclopolyamine complex cations with a preintercalate Mn1−xPS3K2x(H2O)y, respectively, through “ion exchange” process. Their structures were characterized by elemental analysis, X-ray powder diffraction and infrared spectroscopy. The lattice spacing increased 0.567 and 1.093 nm with respect to the pristine MnPS3. Ferrimagnetism of the intercalates was confirmed by SQUID experiment with Tc at 40 and 33 K, respectively. 相似文献
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43.
钯镁基体改进剂对铅,铋,锗在石墨炉中原子化影响的研究 总被引:7,自引:0,他引:7
通过原子吸收和X-射线衍射分析证明,加入钯镁基体改进剂在预热处理后对Pb、Bi和Ge三个元素分别生成金属间化合物PbPd_3、BiPd_3、Ge_9Pd_(23)和其他化合物,从而提高了最高允许灰化温度,改变了原子化机理。在原子化阶段这些金属间化合物直接分解为金属原子,结果提高测定灵敏度。 相似文献
44.
ABSTRACTThis study proposes a simple method of designing a high-speed liquid crystal variable retarder (LCVR) with reflection mode. First, a series of simple formulas is provided for analysing the effects of tilt incidence and birefringence of the liquid crystal on the phase retardation and response time of the LCVR. Then, a reflective LCVR is fabricated to validate the theoretical analysis. Measured results show that the response speed can reach 2.7 kHz with a phase retardation of 1 λ. Furthermore, the theoretical curve is close to the measured curve while the incident angle is less than 10°. However, the theoretical and measured values show a considerable difference under a large incident angle. This problem is discussed, and a modified method is given. This work is helpful for the design and fabrication of high-speed LCVR. 相似文献
45.
Yubin Xue Shun‐Chang Liu Xinsheng Liu Yusi Yang Yimin Zhang Ding‐Jiang Xue Jin‐Song Hu 《中国化学》2020,38(4):356-360
Colloidal quantum dots (CQDs) are attractive absorber materials for high‐efficiency photovoltaics because of their facile solution processing, bandgap tunability due to quantum confinement effect, and multi‐exciton generation. To date, all published performance records for PbS CQDs solar cells have been based on the conventional hot‐injection synthesis method. This method usually requires relatively strict conditions such as high temperature and the utility of expensive source material (pyrophoric bis(trimethylsilyl) sulfide (TMS‐S)), limiting the potential for large‐scale and low‐cost synthesis of PbS CQDs. Here we report a facile room‐temperature synthetic method to produce high‐quality PbS CQDs through inexpensive ionic source materials including Pb(NO3)2 and Na2S in the presence of triethanolamine (TEA) as the stabilizing ligand. The PbS CQDs were successfully prepared with an average particle size of about 5 nm. Solar cells based on the as‐synthesized PbS CQDs show a preliminary power conversion efficiency of 1.82%. This room‐temperature and low‐cost synthesis of PbS CQDs will further benefit the development of solution‐processed CQD solar cells. 相似文献
46.
[reaction: see text] A catalyst for enolate formation was designed that incorporates an amine base along with a thiourea to bind to the oxygen atom of the substrate and enolate through hydrogen bonding. A computational model of the transition state was developed in which the thiourea (modeled initially as a urea) and amine were separate molecules. This model and models incorporating one or two methanol molecules in place of the urea showed an out-of-plane hydrogen bond, apparently to the carbonyl pi-bond, in addition to an in-plane hydrogen bond to an unshared electron pair. In contrast, optimized complexes of the ketone and the fully formed enolate showed only in-plane hydrogen bonding. The transition state model with the urea and amine was used to define a database search with the computer program CAVEAT to identify structures suitable for linking the amine and urea/thiourea moieties in the transition state. On the basis of a group of structures identified from this search, a flexible but conformationally biased linker was designed to connect the two catalytic moieties. The molecule having the amine and thiourea moieties connected by this linker was synthesized and was shown to catalyze proton exchange between methanol and deuterated acetone. The catalyst was about 5-fold more efficient than the amine and thiourea as separate molecules and relative to a similar but less conformationally biased catalyst. 相似文献
47.
Shengrui Lin Yiting Cai Jiaxi Luo Ziyu Xuan Yicong Zhao 《Journal of Nonlinear Modeling and Analysis》2022,4(2):220-244
In this paper, we investigate the Novikov equation with weak dissipation terms. First, we give the local well-posedness and the blow-up scenario. Then, we discuss the global existence of the solutions under certain conditions. After that, on condition that the compactly supported initial data keeps its sign, we prove the infinite propagation speed of our solutions, and establish the large time behavior. Finally, we also elaborate the persistence property of our solutions in weighted Sobolev space. 相似文献
48.
热敏电阻温度计的设计与制作 总被引:1,自引:0,他引:1
本文介绍了设计性实验“热敏电阻的设计与制作”的实施情况。说明了只要选题合适、要求恰当,设计性实验不仅可行,而且对物理实验训练的总结提高十分有效。 相似文献
49.
50.
非晶态镍磷—镍钨磷双层组合镀层的耐蚀性能研究 总被引:2,自引:0,他引:2
本文对比研究了镍磷镀层、镍钨磷镀层及非晶态镍磷和镍钨磷双层组合镀层的耐蚀性能,分别进行了各种镀层的浸渍腐蚀实验,镀层的X射线衍射图象、镀层的扫描电镜图象、以及在工厂实际的腐蚀环境里进行的腐蚀实验。实验结果表明镍磷及镍钨磷双层组合镀层的耐 性优于镍磷镀层、镍钨磷镀层的耐蚀性。 相似文献