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1.
In the framework of the Skyrme-Hartree-Fock approach with 36 sets of the TI J parameterizations,the tensor force effect on the evolution of the single-proton states in the calcium isotopes is systematically investigated.It is shown that the single-proton states with higher angular momenta are influenced significantly by the tensor force and the trend in the evolution of somesingle-particle energy differences with the mass number of the isotopes depends sensitively on a parameter βT associated with the intensity of the tensor force.To understand this phenomenon,we analyze the spin-orbit potentials and the radial wave functions of relevant single-proton orbits in detail.In addition,it is found that some TI J interactions could cause the 2s1/21d3/2 energy level inversion in 48Ca.  相似文献   
2.
The frequency distribution of different ingredients in-ray spectra,e.g.,photo-peak,fluctuations of counts and Compton region,is separately analyzed.After wavelet transform of-ray spectra,the wavelet coefficients of a photo-peak increase with transforming scales and these coefficients show direct proportion with intensity of peak at determinate scale.A novel algorithm based on wavelet transform is proposed and studied.The results indicate that most of the photo-peaks in multi-spectra can be determined accurately,the-rays energy and intensity of the peak can also be determined.This method has the prospect of being applied in on-line multi-spectra analysis in such fields as radioprotection and nuclear safety monitoring.  相似文献   
3.
Grafting of styrene/maleic anhydride and methyl methacrylate/maleic anhydride binary monomers onto the low density polyethylene film was performed using the γ-ray irradiation technique. Then, the synthesized grafted films were treated with different ammonia derivatives for developing chelating functionalization. These chelating products were characterized by the gravimetric method as well as by the Fourier transformed infrared spectroscopic method, and were used for removal of arsenic and some heavy metals from aqueous solutions. The optimum absorbed dose of 30 kGy reveals the graft yielding of about 325% in the films. Uptake of arsenic and some heavy-metal ions (Cr(III), Mn(II), Fe(III), Ni(II), Cu(II) and Pb(II)) from contaminated water by the chelating functionalized films (CFF) was examined by an atomic absorption spectrophotometer. The maximum arsenic removal capacity of 5062 mg/kg has been observed for the film treated with hydroxylamine hydrochloride. The CFF prepared by semicarbazide and thiol analogs show affinity toward the metal ions with an order: Cu(II)>Fe(III)>Mn(II) etc. The results obtained from this study indicate that the functionalized films show good chelating and ion-exchange property for metal ions.  相似文献   
4.
毛细管柱气相色谱法测定烟用香精中黄樟素和香豆素   总被引:1,自引:0,他引:1  
烟用香精样品以甲醇超声提取,提取液经高速离心、0.45μm滤膜过滤后,供气相色谱测定。采用SE-54毛细管柱分离样品,经火焰离子化检测器(FID)检测,外标法定量。黄樟素和香豆素的质量浓度均在1.0~50.0 mg.L-1范围内与其色谱峰面积呈线性关系,方法的检出限(3S/N)分别为0.3,0.4 mg.L-1。黄樟素、香豆素的回收率分别在88.0%~94.7%和89.0%~94.0%之间;相对标准偏差(n=6)分别在0.8%~4.5%和1.2%~5.7%之间。  相似文献   
5.
A new triazole-substituted ligand H2L (H2Trza = 3-amino-1H-1,2,4-triazole-5-acetate) and its two new isomorphic compounds [M(HTrza)2(H2O)2] ? 2H2O (Co(I) and Mn(II)) have been synthesized and characterized structurally. Their X-ray crystal structures (CIF files CCDC nos. 906893 for I and 906892 for II) show that H2L belongs to a tetragonal system; space group P43 with a = b = 5.0445(13), c = 27.054(10) Å; Z = 4. Complex I belongs to a monoclinic system; space group P21/n with a = 7.6543(8), b = 7.3453(8), c = 13.6283(14) Å; β = 91.5990(10)°, Z = 2. Complex II belongs to a triclinic system; space group with a = 6.8550(15), b = 8.0630(18), c = 15.173(4) Å; α = 84.794(4)°, β = 79.005(3)°, γ = 73.779(4)°, Z = 2. X-ray analysis demonstrates that compound H2L is found to contain a H2Trza and a lattic water molecule; complexes I and II are discrete mononuclear species. The central Co(II) and Mn(II) atoms exhibit octahedral coordinations, type 4 + 2. In two compounds, the coordination entities are further organized via hydrogenbonding interactions to generate uniform supramolecular networks. Thermal stabilities of two compounds were examined by thermogravimetric analysis.  相似文献   
6.
A simple and mild method for the separation of sulfonamide residues based on a condensation reaction with O-phthalaldehyde solution (OPA) as labeling reagent with capillary electrophoresis has been developed. A 58.5 cm × 50 μm i.d. (50 cm effective length) untreated fused-silica capillary was used. To optimize the separation conditions, the background electrolyte concentration, pH, column temperature, voltage and other factors were evaluated. The optimal separation conditions were as follows: 20 mmol L?1 borate buffer; pH 9.1; column temperature 20 °C; separation voltage 18 kV, pressure 50 mbar and injection time 8 s. Under the optimal conditions, 10 kinds of sulfonamide derivatives could be well-separated within 8 min, and the linear ranges were 0.35–100 μg kg?1. The detection limit (at a signal-to-noise ratio of 3) was in the range of 0.12–0.25 μg kg?1, and the quantification limit (at a signal-to-noise ratio of 10) was in the range of 0.35–0.70 μg kg?1. The sulfonamide residues from cultured sea cucumber samples were determined under the optimal conditions with satisfactory results.  相似文献   
7.
Wu  Zhaofeng  Zhang  Min  Cao  Shuai  Wang  Long  Qin  Zhangjie  Zhong  Furu  Duan  Haiming 《Cellulose (London, England)》2022,29(10):5817-5832

Carbon quantum dots (CQDs) co-doped with N, P and S derived from expired milk was prepared by a simple hydrothermal method. By dipping pure cotton face towel (PCFT) into CQDs ink, a flexible all-biomass CQDs/PCFT sensor was prepared for the first time. Due to the heteroatom doping, extremely small particle size of CQDs and excellent permeability of CQDs/PCFT film, the flexible CQDs/PCFT sensor showed the high sensitivity and bending stability. In the range of 0–60° bending states, the responses of CQDs/PCFT sensor to four target analytes changed by less 5.0%. After 3000 bending of 60°, the maximum change of the response to the target analytes was only 6.4%. Interestingly, due to the abundant functional groups and defects of CQDs, the flexible CQDs/PCFT sensor displayed sensing curves of different shapes for different target analytes. In this way, by establishing a database of sensing curves of target analytes, multiple analytes can be detected discriminatively by relying only on single sensor with the help of image recognition. This work provided a reference for the development of cotton fiber based all biomass flexible gas sensor.

Graphical abstract
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8.
《中国化学快报》2023,34(5):107821
We report the Lewis acid catalysis of aryldiazonium salts, and their Lewis acidity applications in photogeneration of aryl radicals under additive-, photocatalyst- and transition metal-free conditions. In this visible light-mediated transformation, the Lewis acidic character of aryldiazonium salts enables access to the photoactive charge transfer complex with dichalcogenides. The usefulness and versatility of this new protocol are demonstrated through the chalcogenation of a variety of aryldiazonium salts.  相似文献   
9.
设计合成了具有荧光基团的新型硝酮类自由基捕获探针并对其结构进行了表征.自由基捕获实验结果表明,该探针能实现对超氧阴离子自由基与碳中心自由基的捕获.此外,该自由基捕获探针反应产物的荧光强度与被捕获自由基浓度之间存在相关性,有望建立依据荧光强度分析被捕获自由基浓度的新方法.  相似文献   
10.
    
Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 (particulate matter less than 2.5 μm) in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.5 studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.5 concentration. Sulfate, ammonium, and nitrate carried by PM2.5, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.5 is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PM2.5 mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices (PECD) such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.5 pollution in China.  相似文献   
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