The effect of scintillator materials on the fast neutron multiplicity measurement

Journal of Radioanalytical and Nuclear Chemistry - To analyze the effect of scintillator detectors on the fast neutron multiplicity, this paper uses Geant4 and Matlab to simulate and study three...     

Effects of additional salts on the interfacial tension of crude oil/zwitterionic gemini surfactant solutions

Zwitterionic gemini surfactants, which have the advantages of both zwitterionic and gemini surfactants, have been widely used in various disciplines. Sulfobetaine-type zwitterionic gemini surfactants consisting of 1,2-bis[N-methyl-N-(3-sulfopropyl)-alkylammonium]ethane (2C_nSb with 6, 8 and 10 carbon atoms) were evaluated for their interfacial activities at the water/crude oil interface. The 2C₁₀Sb molecules showed a remarkable ability to decrease the interface tension (IFT) of water/crude oil, and the degree of decrease was much greater than those in either zwitterionic or gemini surfactant systems by at least two orders of magnitude. Furthermore, the effects of salts (NaCl, CaCl₂, and MgCl₂) on the IFT of the 2C₁₀Sb system were thoroughly investigated. Interestingly, the delicate balance between the effects of additional cations and the intramolecular interactions of 2C₁₀Sb molecules played crucial roles in the interfacial arrangements of 2C₁₀Sb molecules, which were mainly dependent on the bonding abilities of the cations. Moreover, a zwitterionic surfactant and a cationic gemini surfactant were employed in control experiments to verify the proposed mechanisms.     

光纤传感材料SnO2的气敏光反射特性研究

作者研究了二氧化锡的气敏光反射特性,测量了它在乙醇,氨,丙酮气体中的浓度与气敏反射光谱关系,发现它对氨气的气敏光谱波长灵敏范围最大,而且不同波长有不同的灵敏度。解释SnO₂气敏光反射机理。     

SnO_2ZnO膜反射光谱的气敏灵敏度研究

研究SnO_2:ZnO薄膜在丙酮,乙醇、氨蒸汽中的气毓反射光谱,发现反射光强随气体浓度增加而减弱。这三种蒸汽具有不同的灵敏度,并解释了它的机理。     

连续统与Turing度

令Ｄ为所有Ｔｕｒｉｎｇ度的集合，≤为Ｄ上的图林化归关系．一函数ｆ：Ｄ→Ｄ称为前进函数如果对任何ａ∈Ｄ，ａ≤ｆ（ａ）。对于一个前进函数ｆ，我们说Ｄ中的两个度ａ，ｂ是ｆ－不可比较的，如果ａ≮ｆ（ｂ）且ｂ ≮ｆ（ａ），否则是ｆ－可比较的．本文的一个主要结果是：在ＺＦＣ中连续统假设成立当且仅当存在一个前进函数ｆ：Ｄ→Ｄ使得Ｄ中任何两个度都是ｆ－可比较的.     

Determination of ferric ion via its effect on the enhancement of the chemiluminescece of the permanganate-sulfite system by nitrogen-doped graphene quantum dots

Nitrogen-doped graphene quantum dots (NGQDs) are shown to strongly enhance the integrated chemiluminescence (CL) of the permanganate-sulfite system. The mechanism of enhancement was investigated, and the catalytic effect of the NGQDs was proven. In contrast to other carbon-based nanomaterials, the enhancement by NGQDs is independent of particle size and surface. However, the pyridinic nitrogen on the surface of the NGQDs facilitates the transformation of dissolved oxygen into H₂O₂ and the generation of hydroxyl radicals. This induces the increase of CL intensity. However, in the presence of Fe³⁺, the nitrogen functions and phenol groups on the surface of the NGQDs will chelate it, and the CL signal is decreased as a result. This effect was used to design an assay for Fe³⁺ that has a wide response range (1?×?10^?8 - 1?×?10^?6 M) and a 4 nM detection limit. The method was successfully applied to the determination of Fe³⁺ in spiked real water samples.

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Graphical abstract Nitrogen-doped graphene quantum dots (NGQDs) are demonstrated to strongly enhance the integrated chemiluminescence (CL) of the permanganate-sulfite system. The pyridinic N-atoms in NGQDs facilitate the transformation from dissolved oxygen into H₂O₂ and the generation of ?OH radicals. This leads to the highly enhanced CL of the system. In the presence of Fe³⁺, which will be chelated by the nitrogen functions and phenol groups on the surface of the NGQDs, the CL signal is decreased.