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排序方式: 共有103条查询结果,搜索用时 15 毫秒
1.
采用新癸酰氯(C10H19CIO)对超支化聚乙烯亚胺(HPEI)进行改性,合成了双亲性超支化破乳剂HPEI-C10,并对其化学组分、热稳定性及润湿性进行了表征。考察了破乳剂的质量浓度、破乳温度、沉降时间以及pH对HPEI和HPEI-C10的破乳效率的影响,并借助偏光显微镜观察破乳过程。结果表明:在质量浓度为50 mg·L-1、破乳温度为20℃、沉降时间为30 min以及pH为6的条件下,HPEI-C10破乳效率可达91.95%。HPEI-C10在破乳温度为20~60℃时的破乳效率均大于90.00%。与HPEI相比,HPEI-C10具有添加量少、适用温度范围广和沉降时间短等优势,为HPEI-C10的广泛应用提供了数据支撑。 相似文献
2.
Xiande Yang Yongqian Wang Zhengshu Wang Qun Ma Junhan Kong Hanxiang Jia Meihua Yu 《Crystal Research and Technology》2015,50(8):658-667
In this article, flower‐like CdS structures have been prepared by a hydrothermal method with SDBS as surfactant. The influences of different experimental conditions on the morphologies, UV‐Vis and fluorescence properties of CdS have been investigated. The performances of CdS have been analyzed by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet‐visible (UV–Vis) and room‐temperature photoluminescence (PL). The XRD result indicates that the flower‐like CdS structures are of hexagonal phase. The FESEM results indicate that the main role of SDBS is to make the CdS crystals assemble together to form the flower‐like structures. The UV–Vis results show CdS has a strong absorption in the ultraviolet region and visible‐light region. The PL results show CdS has two emission peaks, respectively at 461 nm and 553 nm. The growth mechanism for the formation of flower‐like CdS structures is also described. 相似文献
3.
Xiande Yang Yongqian Wang Tingting Jiang Jun Yang Yinchang Li Qun Ma 《Crystal Research and Technology》2015,50(4):338-345
In this article, dendritic‐like CdS has been prepared by a hydrothermal method using thiourea as the sulfur source, and the effects of experimental conditions on the morphologies of CdS have been investigated. The performances of CdS have been analyzed by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and the fluorescence and photodegradation properties of CdS have also been investigated. The XRD result indicates that the dendritic‐like CdS are of hexagonal phase and they are highly crystallized. Also, the FESEM results show that the ratio of raw material affects the yield of CdS, the reaction time affects the morphology of CdS. The best morphology of CdS is dendritic structures and the length is about 6 μm. The fluorescence spectrum shows three peaks at 470 nm, 513 nm and 547 nm, which indicates that the dendritic‐like CdS mainly emits green and blue fluorescence. Moreover, the dendritic‐like CdS exhibits good photocatalytic activity and its photodegradation rate to methylene blue can reach 92%. The growth mechanism for the formation of CdS with dendritic structure is also described. 相似文献
4.
Chao Wang Felix S. Kim Guoqiang Ren Yongqian Xu Yi Pang Samson A. Jenekhe Li Jia 《Journal of polymer science. Part A, Polymer chemistry》2010,48(21):4681-4690
Head‐to‐tail regioregular poly(3‐heptanoylthiophene) (PHOT) was synthesized by Ni‐catalyzed polycondensation of the 2,2‐dimethyl‐1,3‐propanediol‐protected Grignard monomer followed by deprotection. Cyclic voltammetric (CV) study demonstrates that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of PHOT are 0.5 eV lower in energy than those of the head‐to‐tail poly(3‐hexylthiophene) (HT‐P3HT). Their optical band gaps are essentially the same. Incomplete photoluminescence (PL) quenching was observed in thin films of the 1:1 blend of PHOT and HT‐P3HT. PHOT displayed a glass transition at ~269 °C and decomposed at ~300 °C according to differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Wide‐angle X‐ray diffraction (WAXD) study showed that PHOT exists in a not highly ordered state in solid films especially in the π‐stacking direction. Only p‐channel activity was observed in field‐effect transistors (FETs) for PHOT. The hole mobility was on the order of 10?4 cm2 V?1 s?1. Photovoltaic devices with an active layer of 1:1 blend of PHOT and PC71BM had a power conversion efficiency (PCE) of ~0.5%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
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Jia Wen Pengyi Xiaa Ziming Zhenga Yongqian Xua Hongjuan Lia Fengyu Liub Shiguo Suna 《中国化学快报》2017,28(10):2005-2008
The pH values of lysosomes in cancer cells is slightly lower than that in normal cells, which can be used to distinguish cancer cells from normal cells. According to this, a naphthalimide-rhodamine based fluorescent probe(hereafter referred to as RBN) with a pK_a of 4.20 was designed and synthesized for ratiometric sensing of cellular pH via fluorescence resonance energy transfer(FRET), which can respond to different pH precisely through ratiometric fluorescence intensity(Ⅰ_(577)/Ⅰ_(540)). RBN can be employed to distinguish cancer cells from normal cells on the basis of different fluorescent response, in particular, RBN showed excellent water solubility and low cell toxicity, all these are quite significant for potential application in cancer diagnose and therapy. 相似文献
7.
We present exact blow-up solutions for multidimensionalLandau--Lifshitz equations. It is shown that for any prescribed blow-up timethere are exact C∞--solutions which are blow-up at the blow-up timeand that the solutions are smooth except at theblow-up time. 相似文献
8.
GalnAsSb是直接带隙、窄禁带的半导体材料,其波长范围为0. 87-12μm,粗盖了2-4 m, 3-5μm和8-12μm三个重要的红外应用波段,可制作室温下工作的红外光电器件,在光纤通信、环境监测、资源勘探、空间技术及军事等方面有广泛的应用前景. 相似文献
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10.
Zhang Yongqian 《东北数学》1994,(3)
TheCauchyProblemforaClassofSemilinearWaveEquationswithPiecewiseConstantsDataZhangYongqian(张永前)(InstituteofMathematics,FudanUn... 相似文献