Ultra-longer fiber cantilever taper for simultaneous measurement of temperature and relative humidity

An ultra-longer fiber cantilever taper for simultaneous measurement of the temperature and relative humidity (RH) with high sensitivities was proposed. The structure was fabricated by using the simple and cost-effective method only including fiber cleaving, splicing, and tapering. The length of the cantilever taper is about 1.5 mm. The dip A and dip B were measured simultaneously, owing to the ultra-long length and super-fine size, the temperature sensitivities of the dip A and dip B reached as high as 127.3 pm/℃ and 0 pm/℃ between 25 ℃ and 50 ℃, and the RH sensitivities are -31.2 pm/% RH and -29.2 pm/% RH with a broad RH interval ranging from 20% RH to 70% RH. Besides, the proposed structure showed good linearity in the sensing process and small temperature crosstalk. It will be found in wide applications in environmental monitoring, food processing, and industries.     

Electronic and optical properties of 3N-doped graphdiyne/MoS2 heterostructures tuned by biaxial strain and external electric field

The construction of van der Waals (vdW) heterostructures by stacking different two-dimensional layered materials have been recognised as an effective strategy to obtain the desired properties. The 3N-doped graphdiyne (N-GY) has been successfully synthesized in the laboratory. It could be assembled into a supercapacitor and can be used for tensile energy storage. However, the flat band and wide forbidden bands could hinder its application of N-GY layer in optoelectronic and nanoelectronic devices. In order to extend the application of N-GY layer in electronic devices, MoS₂ was selected to construct an N-GY/MoS₂ heterostructure due to its good electronic and optical properties. The N-GY/MoS₂ heterostructure has an optical absorption range from the visible to ultraviolet with a absorption coefficient of 10⁵ cm^-1. The N-GY/MoS₂ heterostructure exhibits a type-Ⅱ band alignment allows the electron-hole to be located on N-GY and MoS₂ respectively, which can further reduce the electron-hole complexation to increase exciton lifetime. The power conversion efficiency of N-GY/MoS₂ heterostructure is up to 17.77%, indicating it is a promising candidate material for solar cells. In addition, the external electric field and biaxial strain could effectively tune the electronic structure. Our results provide a theoretical support for the design and application of N-GY/MoS₂ vdW heterostructures in semiconductor sensors and photovoltaic devices.     

Reference-frame-independent quantum key distribution of wavelength division multiplexing with multiple quantum channels

Reference-frame-independent quantum key distribution (RFI-QKD) can allow a quantum key distribution system to obtain the ideal key rate and transmission distance without reference system calibration, which has attracted much attention. Here, we propose an RFI-QKD protocol based on wavelength division multiplexing (WDM) considering finite-key analysis and crosstalk. The finite-key bound for RFI-QKD with decoy states is derived under the crosstalk of WDM. The resulting secret key rate of RFI-QKD, which is more rigorous, is obtained. Simulation results reveal that the secret key rate of RFI-QKD based on WDM is affected by the multiplexing channel number, as well as crosstalk between adjacent channels.     

部分均匀荷载作用下圆板塑性极限统一解

本文采用俞茂宏双剪统一屈服准则求解部分均匀荷载下简支圆板的塑性极限，已有的最大主应力准则、Ｔｒｅｓｃａ准则，Ｍｉｓｅｓ准则的解答均是该解答的特例或线性逼近。该解答可以适合于多种工程材料，具有普遍性和适用性，从得出的解析解和图示中可得出一些新的有益的认识     

查尔酮衍生物E-2-(甲氨基)-7-(3-(吡啶基)丙烯酰基)卓酮的合成(英文)

以2-乙酰基-7-(甲氨基)卓酮(1)为原料,经由与各种吡啶醛的Claisen-Schmidt缩合反应得到查尔酮衍生物E-2-(甲氨基)-7-(3-(吡啶基)丙烯酰基)卓酮(2～5).全部合成产物均为新化合物,未见文献报道;其结构均由红外光谱分析、1H核磁共振、质谱及元素分析得以证实.     

酚醛树脂层压基板真空热裂解产物分析表征

利用程序升温的热解炉反应器对酚醛树脂层压基板进行真空热裂解,通过元素分析、傅里叶红外(FT-IR)分析和气相色谱-质谱(GC-MS)分析,对原料及产物油成分进行了表征。研究表明,热解油上层清液主要是一些较易溶于水的物质,如苯酚、甲酚、二甲酚、糖类、乙内酰脲类、吗啉类、吡喃酮类和吡啶类化合物等;而下层沉淀则主要为不溶或难溶于水的物质,如大取代基酚类(取代基碳原子数≥2)、磷酸三芳基酯类、脂肪酸酯类和腈类化合物等。其中,三聚氰胺在上层清液和下层沉淀中都有较高的含量。     

真空蒸馏预富集-电感耦合等离子体发射光谱法测定铂

建立了真空蒸馏预富集-电感耦合等离子体发射光谱法测定铅试样中微量铂的方法.在真空条件下,利用Pb和Pt在较高温度下蒸汽压的差别进行分离,富集后的铂溶解制成溶液后进行电感耦合等离子体发射光谱检测,实现了真空密闭回收铅.针对试样的特点,对真空蒸馏方法理论上的可行性进行研究.结果表明:在蒸馏温度为1250 K,真空度为30 Pa,蒸馏时间为3 h条件下,铂的富集分离效果最好,可富集至99.01%以上.线性范围为0.023～20 mg/L,检出限(3σ)为0.0069 mg/L,对样品测定的相对标准偏差为1.7%(n=6).用本方法对样品中加入的铂标准溶液进行了测定,回收率为99.8%～103.0%.本方法简便快速、无污染,已应用于废电路板贵金属冶余物料中铂的测定.     

An ab initio Study on the Structural and Bonding Properties of Li_2Si_3O_7

A theoretical study on the structural and electronic properties of Li2Si3O7 is performed by using density functional theory(DFT) method.The molecular structure of the crystal and two kinds of [SiO4]-tetrahedra with different number of non-bridging oxygen(Qn) are analyzed.The structure of crystal Li2Si3O7 can be considered as a framework of corner-sharing tetrahedra.From the band structure(BS),total density of state(TDOS) and projected density of state(PDOS) of the crystal,the structures of Q3,Q4,and LiO4 tetrahedra as well as their bonding characters are presented.For lithium trisilicate,we find the bond cation-NBO(nonbridging oxygen and oxygen atoms bonding to one silicon atom only) is stronger than the bond cation-BO(bridging oxygen and oxygen atoms bonding to two silicon atoms).By analyzing the ionicity of two different types of bonds of silicon-oxygen according to the Mulliken population analysis,we also find that the Si-NBO bonds have higher ionicity than Si-BO for crystalline lithium trisilicate,which agrees with other lithium silicates.     

模拟微重力条件下C离子辐射对小鼠生殖器官的影响

探究模拟微重力条件下不同剂量C离子辐射对雄性动物生殖器官的急性影响, 以期了解空间环境辐射所致机体生殖系统的损伤。采用小鼠尾部悬吊模型地面模拟微重力状态1周后, 利用重离子加速器提供的C离子辐照处理, 检测了生殖器官脏器系数及精子密度、组织形态变化、DNA损伤以及细胞凋亡各项指标。结果表明, 微重力和C离子辐射均能引起睾丸损伤, 且1 Gy单纯辐照组中损伤最为严重。此外发现, 模拟微重力能够在一定程度上降低辐射诱导的损伤, 其内在机制有待于进一步的研究。In this paper it was investigated that the effect of modeled microgravity on the acute injury induced by low doses of carbon ions in the male reproductive organs of mice, assessing the risk associated with the space environments. In our study, outbred Kunming mice were stimulated in microgravity by tail suspension, and then were irradiated with the low doses of carbon ions diliuered by HIRFL, and measured the testis and epididymis coefficient, sperm number of epididymis, histological alterations, DNA strand breaks and cell apoptosis. The results demonstrated that carbon ions and stimulated microgravity could induce the damage in the present study. Moreover, most serious injury all occurred in the irradiation group. In addition, it was also found that the damage of the carbon ion irradiation combined microgravity group were lower than those of the irradiation group, while the related mechanism needs the further investigation.     

Spectroscopic investigations on NO+(x1∑+,a3∑+,A1Ⅱ) ion using multi-reference configuration interaction method and correlation-consistent sextuple b

Three low-lying electronic states (x¹∑⁺,a³∑⁺,and A¹Ⅱ) of NO⁺ ion are studied using the complete active space self-consistent-field (CASSCF) method followed by highly accurate valence internally contracted multi-reference configuration interaction (MRCI) approach in combination of the correlation-consistent sextuple basis set augmented with diffuse functions, aug-cc-pV6Z. The potential energy curves (PECs) of the NO⁺(x¹∑⁺,a³∑⁺,A¹Ⅱ) are calculated. Based on the PECs, the spectroscopic parameters R_e, D_e, ω_e, ω_eχ_e, α _e, B_e, and D₀ are reproduced, which are in excellent agreement with the available measurements. By numerically solving the radial Schrödinger equation of nuclear motion using the Numerov method, the first 20 vibrational levels, inertial rotation and centrifugal distortion constants of NO⁺(x¹∑⁺,a³∑⁺,A¹Ⅱ) ion are derived when the rotational quantum number J is equal to zero (J = 0) for the first time, which accord well with the available measurements. Finally, the analytical potential energy functions of these states are fitted, which are used to accurately derive the first 20 classical turning points when J = 0. These results are compared in detail with those of previous investigations reported in the literature.