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401.
402.
以 CX6 0 0型车铣加工中心为例 ,讨论了如何利用主电机具有Cs轴功能的特点 ,来实现车铣加工中心用传统方法无法实现的主轴的大变速比问题 相似文献
403.
404.
Liang Li Jinhang Liu Qin Liang Yu Feng Chao Wang Shaohua Wu Yongyu Li 《International journal of molecular sciences》2021,22(21)
Bud endodormancy is an important, complex process subject to both genetic and epigenetic control, the mechanism of which is still unclear. The endogenous hormone abscisic acid (ABA) and its signaling pathway play important roles in the endodormancy process, in which the type 2C protein phosphatases (PP2Cs) is key to the ABA signal pathway. Due to its excellent effect on endodormancy release, hydrogen cyanamide (HC) treatment is considered an effective measure to study the mechanism of endodormancy release. In this study, RNA-Seq analysis was conducted on endodormant floral buds of pear (Pyrus pyrifolia) with HC treatment, and the HC-induced PP2C gene PpPP2C1 was identified. Next, software prediction, expression tests and transient assays revealed that lncRNA PpL--derived Pp-miRn182 targets PpPP2C1. The expression analysis showed that HC treatment upregulated the expression of PpPP2C1 and downregulated the expression of PpL- T31511 and Pp-miRn182. Moreover, HC treatment inhibited the accumulation of ABA signaling pathway-related genes and hydrogen peroxide (H2O2). Furthermore, overexpression of Pp-miRn182 reduced the inhibitory effect of PpPP2C1 on the H2O2 content. In summary, our study suggests that downregulation of PpL- T31511-derived Pp-miRn182 promotes HC-induced endodormancy release in pear plants through the PP2C-H2O2 pathway. T31511相似文献
405.
沉淀法分离Cs和Rb的研究 总被引:8,自引:1,他引:7
以^137Cs和^86Rb为示踪剂对硅钨酸铯和碘铋酸铯两种沉淀法分离Cs和Rb进行了研究。结果表明,碘铋酸铯沉淀法比硅钨酸铯沉淀法分离效果好;采用亚化学计量的碘铋酸钾分离时,Cs沉淀率可达70%~80%,Cs、Rb的分离因数大于100。 相似文献
406.
Zhi Zheng Haiyang Li Liang Hai Ruiqi Ma Rui Liu Chunpeng Zhai Zongdong Sun Fei Wang Ying Ma Qingguo Xie Xiaoding Lou Tianyou Zhai Fan Xia 《Advanced functional materials》2024,34(1):2307093
2D perovskites have attracted wide attention for optoelectronic applications because of their unique layer structure and tunable outstanding optical/electrical properties. In addition, 2D Cs3Bi2Br9 nanoflakes possess large effective atomic number, high resistivity, high density as well as excellent stability, rendering it a promising material for X-ray detection. Nevertheless, it is full of challenges to synthesize 2D Cs3Bi2Br9 nanoflakes by conventional inversion temperature crystallization (ITC) strategy due to the existence of Br- vacancies in the Cs3Bi2Br9 crystal nucleus. Herein, an Ag+ assisted ITC (SAITC) strategy to grow 2D Cs3Bi2Br9 nanoflakes is proposed. The synthesis mechanism revealed by both experiments and theoretical calculations can be mainly ascribed to the passivated Br− vacancies and enhanced structure stability by adding Ag+ which can effectively prevent the oxidation of 2D Cs3Bi2Br9 nanoflakes from growth of hybrid crystals. The synthesized high-crystallinity 2D Cs3Bi2Br9 nanoflakes possess direct bandgap characteristic, and the mobility lifetime can reach 9.8 × 10−4 cm2 V−1. Excitingly, the fabricated device based on 2D Cs3Bi2Br9 nanoflakes demonstrates ultrahigh sensitivity of detecting X-ray (1.9 CGyair−1cm−2) at very low driven voltage (0.5 V) due to the photoconductive gain mechanism. The 2D Cs3Bi2Br9 nanoflakes synthesized by SAITC method have great potential for developing highly sensitive optoelectronic devices. 相似文献
407.
Changhee Jang Kangyong Kim Hak-Won Nho Seung Min Lee Hanif Mubarok Joo Hyeong Han Hyeonjung Kim Dongryeol Lee Yangpil Jang Min Hyung Lee Oh-Hoon Kwon Sang Kyu Kwak Won Bin Im Myoung Hoon Song Jongnam Park 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(17):2206668
Low-dimensional Cu(I)-based metal halide materials are gaining attention due to their low toxicity, high stability and unique luminescence mechanism, which is mediated by self-trapped excitons (STEs). Among them, Cs5Cu3Cl6I2, which emits blue light, is a promising candidate for applications as a next-generation blue-emitting material. In this article, an optimized colloidal process to synthesize uniform Cs5Cu3Cl6I2 nanocrystals (NCs) with a superior quantum yield (QY) is proposed. In addition, precise control of the synthesis parameters, enabling anisotropic growth and emission wavelength shifting is demonstrated. The synthesized Cs5Cu3Cl6I2 NCs have an excellent photoluminescence (PL) retention rate, even at high temperature, and exhibit high stability over multiple heating–cooling cycles under ambient conditions. Moreover, under 850-nm femtosecond laser irradiation, the NCs exhibit three-photon absorption (3PA)-induced PL, highlighting the possibility of utilizing their nonlinear optical properties. Such thermally stable and highly luminescent Cs5Cu3Cl6I2 NCs with nonlinear optical properties overcome the limitations of conventional blue-emitting nanomaterials. These findings provide insights into the mechanism of the colloidal synthesis of Cs5Cu3Cl6I2 NCs and a foundation for further research. 相似文献
408.
Hongqiang Cui Yongze Cao Lei Zhang Ying Li Yuhang Zhang Lei Li Jinsu Zhang Baojiu Chen 《Journal of the American Ceramic Society》2023,106(5):3024-3034
A series of Er3+/Yb3+ co-doped Cs3GdGe3O9 (CGG) phosphors were prepared by solid-phase sintering method, and the microstructure and upconversion luminescence (UCL) properties were tested by variable-temperature X-ray diffractometry and variable-temperature spectrometer. Abnormal UCL phenomena were found, which include UCL intensity continuously increasing under 980 nm laser continuous irradiation and UCL thermal enhancement. After 10 min of continuous irradiation by 980 nm laser at 513 K, the UCL intensity increased 2.91 times compared with the initial UCL intensity. The phenomenon is due to the electron releasing of host defects. The green UCL intensity of CGG:0.1Er3+/0.2Yb3+ decreases at 303–423 K and increases at 423–723 K, which reaches 13.23 times compared with that at 423 K. The phenomenon is due to Er3+–Yb3+ distance change by temperature and phonon-assisted transitions. In addition, the absolute temperature sensitivities of samples are calculated by luminescence intensity ratio technology, the maximum absolute sensitivity of CGG:0.1Er3+/0.4Yb3+ is 0.00691 K−1 at 546 K, and the maximum relative sensitivity of CGG:0.1Er3+/0.1Yb3+ is 0.01224 K−1 at 303 K. These results indicate that CGG:Er3+/Yb3+ phosphors can be used as a high-temperature optical thermometer. 相似文献
409.
Yafei Zhang Fangzhou Liu Huhu Su Wenjin Yu Yu Zou Cuncun Wu Xian Zhang Jiaqi Zhang Yuchao Liang Jiaheng Han Yan Guan Yangyang Zhang Zhengqing Ye Ri Li Lixin Xiao Shijian Zheng 《Advanced functional materials》2023,33(40):2304063
Lead-free 2D antimony-based halide perovskites with excellent optoelectronic properties, low toxicity, and good intrinsic stability are promising for photovoltaic devices. However, the power conversion efficiency (PCE) of antimony-based perovskite solar cells (PSCs) is still lower than 3% due to the poor crystallinity and random orientation. Herein, it is found that the Cs3Sb2ClxI9-x films prepared by adding methylamine chloride as an additive to the precursor solution can form a mixed intermediate phase with 0D dimer phase and 2D layered phase after low pressure treatment. During the annealing process, the 0D dimer phase will completely transition to 2D layered phase due to the partial replacement of I by Cl. Compared to adding SbCl3 directly, this method considerably increases the crystallinity of Cs3Sb2IxCl9-x films. The obtained films have a preferential orientation along the (201) direction, which is beneficial for charge carrier transportation. Consequently, the champion device shows a PCE of 3.2%, which is one of the highest efficiencies achieved for inorganic Sb-based PSCs with the n-i-p architecture to date. 相似文献