Empirical studies on the network of social groups: the case of Tencent QQ

Participation in social groups are important but the collective behaviors of human as a group are difficult to analyze due to the difficulties to quantify ordinary social relation, group membership, and to collect a comprehensive dataset. Such difficulties can be circumvented by analyzing online social networks. In this paper, we analyze a comprehensive dataset obtained from Tencent QQ, an instant messenger with the highest market share in China. Specifically, we analyze three derivative networks involving groups and their members -- the hypergraph of groups, the network of groups and the user network -- to reveal social interactions at microscopic and mesoscopic level. Our results uncover interesting behaviors on the growth of user groups, the interactions between groups, and their relationship with member age and gender. These findings lead to insights which are difficult to obtain in ordinary social networks.Comment: 18 pages, 9 figure

Efficient quantum direct communication with authentication

Two protocols of quantum direct communication with authentication [Phys. Rev. A 73, 042305(2006)] were recently indicated to be insecure against the authenticator Trent's attacks [Phys. Rev. A 75, 026301(2007)]. We present two efficient protocols by using four Pauli operations, which are secure against inner Trent's attacks as well as outer Eve's attacks. Finally, we generalize them to multiparty quantum direction communication.Comment: 4 pages, 4 table

Automated Three-dimensional Warehouse in the Field of Grain Storage Application Prospects

The development of grain storage warehouses has low high-tech coverage because of the special features of grain products. Traditional grain warehouses are facing problems including limited land resources, increased labor costs, and poorer health indicators. Accompanied by the development of information technology and the Internet of Things, automated three-dimensional warehouses have been widely used in industry with the advantages of unmanned, informationized, intensive, high-speed and seamless. In the field of grain warehousing, the finished grain three-dimensional warehouse based on mechatronics, automation, control and logistics is expected to solve the problem of grain warehousing. The traditional grain storage industry will be driven by new technology to ensure national food security

Copper thiosemicarbazones: Antiproliferative action against C6 glioma cells

2(E)-2-[1-(4-pyridinyl)ethylidene]hydrazinecarbothioammidehydrochloride (1) and two of its copper complexes were synthesized and structurally characterized. Cu(I) polymeric complex {[Cu(SCN)(3-Acpy)2]}n (2) was synthesized by in situ mixing of Cu(BF4)2.6H2O, 4-acetylpyridine (4-Acpy) and semicarbazide whereas a dinuclear Cu(II) complex (3) was obtained from the reaction of Cu(BF4)2.6H2O, 4-acetylpyridine and ammonium thiocyanate. Magnetic measurements were performed for the dinuclear complex. All the thiosemicarbazones were cytotoxic against malignant RT2 glioblastoma cells (expressing p53 protein) with IC50 values in the 5.1-13.2 µM range, and against malignant T98 glioblastoma cells (expressing mutant p53 protein) with IC50 values in the 4.5-31 µM range. Coordination to copper strongly increased the cytotoxic potential in complexes 2 and 3, when compared to that of free ligand and were found to be more potent than cisplatin. All the test compounds (1-3) were able to induce cell death by apoptosis

Progress in Research and Application of Insect-resistant Packaging for Grain Storage

Stored grain is extremely vulnerable to the storage insects during storage and processing. At present, chemical control is still the main method for controlling stored grain insects. However, the increasing resistance of insects caused by long-term use of chemical control raises unprecedented challenges. Insect-repellent packaging, as a traditional and emerging physical insect prevention method, has increasingly attracted widespread attention among people. The types and characteristics of food packaging materials, the types and application of insect-repellent packaging, the research and evaluating methods of insect-repellent packaging at home and abroad, and the problems existing in the practical application of insect-repellent packaging were reviewed, and the development trend of insect-repellent packaging was prospected, so as to provide reference information for the scientific and efficient use of insect-repellent packaging, development of new insect-repellent packaging to control stored grain insects in the future