一种同时测量平行偏差、倾斜偏差的方法

提出了一种仅由接收物镜和CCD构成的接收器,通过物镜位置的调整,可以同时完成平行偏差（平偏）和倾斜偏差（角偏）这两个参量的测量.通过对系统像差的分析,提出了可显著降低物镜像差对测量结果影响的算法.理论和实验数据表明,对于平偏测量范围为±10 mm、角偏测量范围为±2°、接收物镜焦距为50 mm、CCD尺寸为1/1.6 inch的系统,平偏测量准确度可达0.02 mm,角偏测量准确度可达9.5″.     

维生素C的历史——从征服"海上凶神"到诺贝尔奖

This paper reviews the course of understanding vitamin C. From the "sea god" that sailors first encountered to the scurvy that caused the British Navy to suffer, understanding vitamin C is improved little by little. Until modern times, with the guidance of advanced theory and the rapid development of chemical research, human beings finally got to known vitamin C and conquered scurvy. This marks the arrival of a new era.     

基于轨道角动量的循环差分相移量子密钥分发

提出了一种基于标记配对相干态(HPCS)和轨道角动量的循环差分相移量子密钥分发(RRDPS-QKD)方案,以光子轨道角动量作为信息载体,使用多种不同拓扑荷的轨道角动量的叠加态进行RRDPS-QKD的信息编码,显著提高了密钥生成率。使用HPCS作为量子光源,有效减小了空脉冲和多光子脉冲的比例,提高了密钥生成率。分析了光源在湍流大气信道中的传输特性,考虑了信道衰减和大气湍流对系统性能的影响。     

The Unexpected Stability of Hydrazine Molecules in Hydrous Environment under Pressure

The incomplete decomposition product of metastable hydrazine(N2H4)instead of the energetically favorable ammonia(NH3)upon decompression is one drawback in applications of energetic material oligomeric hydronitrogens.We explore the stability of hydrazine molecules in hydrazine hydrate(N2H4 H2O)under pressure in diamond anvil cells(DACs)combined with in situ Raman spectroscopy and synchrotron x-ray diffraction(XRD)measurements.The results show that one NH2 branch forms NH3 group by hydrogen bonds between hydrazine and water molecules after the sample crystallizes at 3.2 GPa.The strengthening hydrogen bonds cause the torsion of hydrazine molecules and further dominate a phase transition at 7.2 GPa.Surprisingly,the NN single bonds are strengthened with increasing pressure,which keeps the hydrazine molecules stable up to the ultimate pressure of 36 GPa.Furthermore,the main diffraction patterns show continuous shift to higher degrees in the whole pressure range while some weak lines disappear above 8.2 GPa.The present peak-indexing results of the diffraction patterns with Materials Studio show that the phase transition occurs in the same monoclinic crystal system.Upon decompression,all of the hydrazine molecules extract from hydrazine hydrate crystal at 2.3 GPa,which may provide a new way to purify hydrazine from hydrate.     

Twin-Field Quantum Key Distribution Protocol Based on Wavelength-Division-Multiplexing Technology

Quantum key distribution(QKD) generates information-theoretical secret keys between two parties based on the physical laws of quantum mechanics. Following the advancement in quantum communication networks, it becomes feasible and economical to combine QKD with classical optical communication through the same fiber using dense wavelength division multiplexing(DWDM) technology. This study proposes a detailed scheme of TF-QKD protocol with DWDM technology and analyzes its performance, considering t...     

化学实验室玻璃仪器管理工作的改进与拓展

This paper introduces the recent improvements and developments of glassware managements in the chemistry laboratories of Nanjing University. Considering the importance of glassware in university chemistry experiments (UCEs) laboratories, the self-service management for glassware reservation and compensation system has been developed. This novel management model evidently reduces the workload of technicians and leads to more efficient laboratory operations, which has been proved by practice. In addition, the damage of glassware in UCEs in recent years was evaluated. From the viewpoint of problems in glassware damaging, an effective rectification scheme and further developments have been proposed, and then the self-service Cloud-cabinets has been put forward. Our practice proves that the Cloud-cabinet for glassware reservation system can make a great seamless connection between students and technicians based on the platform and booking terminals, which has produced a safer and more convenient pattern for glassware claims and compensations.     

N-doped peanut membrane carbon quantum dots as a " off-on" fluorescence probe determination of hydroquinoneEI北大核心CSCD

N-doped peanut membrane carbon quantum dots (N-CQDs) were prepared by one-step hydrothermal method using peanut membrane and urea as materials. On the basis of investigating the spectral characteristics of the N-CQDs, we found that KMnO4 could cause the fluorescence signal of the N-CQDs to "turn-off" in the B-R buffer system with pH 10. 38. Once hydroquinone was added, the fluorescence signal of the N-CQDs-KMnO4 system gradually recovered and the fluorescence signal "turned on". Based on this, a new "off-on" fluorescence probe method for the detection of hydroquinone-N-CQDs-KMnO4 system was developed. Under the optimized conditions, the recovered fluorescence of N-CQDs was linearly related with the hydroquinone concentration in the range of 0. 10-200 mmol / L, the linear equation was ΔF = 1. 6819c + 153. 84 (r = 0. 9992), with the detection limit of 30 μmol / L. The method has been successfully applied to the determination of hydroquinone in simulated samples. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

4′-(二茂铁基)-2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物混合价态的电荷转移

设计合成了4′-(二茂铁基)-2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物1以及参比配合物4′-(4-甲苯基)-2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物2和2,2′∶6′,2″-三联吡啶钴(Ⅱ)配合物3,配合物1中二茂铁基给电子基团的引入使其在可见光区的吸收明显增强,并在部分氧化时呈现混合价态的电荷转移(MVCT)吸收.     

尿素/乙醇胺复配增塑聚乙烯醇性能的研究

采用尿素/乙醇胺为复合增塑剂,利用流延法制备了增塑改性的PVA膜.通过FTIR法研究了尿素/乙醇胺复合体系与PVA的相互作用,采用XRD、DSC考察了增塑改性PVA膜的结晶性能和热性能.研究结果表明,乙醇胺作为尿素的良溶剂,能有效抑制尿素从PVA基体中析出.由尿素、乙醇胺组成的复合增塑剂能破坏PVA分子中的氢键作用、降低PVA的结晶度和熔点,对PVA的增塑作用显著.增塑改性后的PVA膜在水中的溶胀率(DS)下降,溶失率(S)增加.力学性能测试表明增塑改性后的PVA膜拉伸强度(TS)降低,断裂伸长率(E%)提高.含30phr尿素/乙醇胺的PVA膜的拉伸强度、断裂伸长率分别为23.89MPa和542.88%.     

有机磷阻燃改性水性聚氨酯

以聚醚(N-210)、异佛尔酮二异氰酸酯(IPDI)为基本单体,[(双(2-羟乙基)氨基)甲基]磷酸二乙酯(FRC-6)、一缩二乙二醇(EX)为扩链剂,二羟甲基丙酸(DMPA)为亲水扩链剂,3-(2-氨乙基)氨丙基甲基二甲氧基硅烷(KH-602)为后扩链剂,合成了一系列有机磷(P)阻燃改性的水性聚氨酯乳液。研究表明:随着FRC-6用量的增加,聚氨酯(PU)的起始热分解温度降低,但热释放速率也降低,而PU的阻燃性能得到很大的提高。当FRC-6中P的含量占预聚体的质量分数为2.31%时,其氧指数为28%,垂直燃烧测试显示PU的阻燃性能已达到UL-94V-2级。