Qiqihar University is an institution for higher education, founded in 1953 and located in Qiqihar city of Heilongjiang province in northeast China. Its campus has an area of 1.15 km². It is the only provincial, comprehensive, regular institution of higher learning in the western part of Heilongjiang Province. It is located beside Labor Lake in the city of Qiqihar. Covering an area of 1.25 square kilometers with a building area of 720,000 square meters, it is nicknamed 'The Round Lake University' and has been awarded titles such as 'Garden University' and 'Provincial Model Unit' by the Heilongjiang Provincial Committee of the CPC and the People's Government of Heilongjiang Province. Wikipedia.
Ma S.,Qiqihar University |
Liu X.,China Pharmaceutical University |
Xun Q.,Heilongjiang Academy of Traditional Chinese Medicine |
Zhang X.,Guangdong Research Institute of Traditional Chinese Medicine
Biological and Pharmaceutical Bulletin | Year: 2014
Mitochondria and oxidative stress play important roles in neuronal cell death associated with cerebral ischemia. Elevated level of reactive oxygen species (ROS) and mitochondrial dysfunction are thought to be responsible for cerebral ischemia injury along with neural cells death through several apoptotic mechanisms. In this study, exposure of rat pheochromocytoma (PC12) cells to hydrogen peroxide (H2O2) at the concentration of 0.3 mM for 24 h caused significant loss of cell viability, lactate dehydrogenase (LDH) release from cells, ascent of ROS level and mitochondrial membrane potential (MMP) decrease. Moreover, the activities of caspase-9, caspase-8 and caspase-3 all were increased in H2O2-induced PC12 cells. However, pretreatment with ginkgolide K (GK) solutions of different concentrations (10, 50, 100μM) for 24 h prior to exposuring to H2O2 significantly increased cells viability, suppressed LDH release, attenuated ROS level, prevented cytochrome c release from mitochondria and boosted MMP expression. In addition, ginkgolide K notably inhibited the caspase-3 and caspase-9 but not caspase-8 activities in exogenous H2O 2-treated PC12 cells. These results demonstrated that ginkgolide K protected PC12 cells from H2O2-induced apoptosis by restoring MMP expression, ameliorating oxidative stress and subsequently leading to inhibit the activity of caspase-3 protein. Therefore, the present study supported that ginkgolide K may be a promising neuroprotective compound for cerebral ischemia treatment. © 2014 The Pharmaceutical Society of Japan.
Zhang J.,Qiqihar University
C e Ca | Year: 2017
Regarding to the problem of rare research on kNN query of historical moving object trajectories in spatial and temporal database, which cannot satisfy the complex and diverse information query requirements of users, the paper systematically studies the problem of effectively handling kNN queries and HCkNN queries on the TB tree structure in which the historical moving object trajectory information is stored. The kNN query of historical moving object trajectory is discussed. A new distance metric is introduced to reduce the searching space of the algorithm. A series of efficient pruning strategies are proposed to reduce the storage space of the algorithm. The HCkNN query of historical moving object trajectory is also discussed. Two HCkNN search algorithms based on the best first search paradigm are proposed, and an effective updating strategy is designed to maintain the k-most recent list of HCkNN query results. Finally, a large number of experiments have proved that the proposed algorithm outperforms the existing algorithms in terms of efficiency and scalability. To a certain extent, our outcomes promote the practical process of spatio-temporal database. © 2017 Techna Group Srl & ESMC Co., Ltd.
Zhang J.,Qiqihar University
International Journal Bioautomation | Year: 2017
The edge information of a medical image is the basis of the analysis and processing of that medical image. The medical image contains the muscle, blood vessels and other interference information, which is large but leads the edge detection to become very difficult. So the research into an image edge detection algorithm has become one of the key technologies in image processing, and has important significance in the field of practical application. A new edge detection algorithm based on wavelet transform is proposed in this paper on the basis of regression analysis. Firstly, the signal is decomposed into approximate part and detailed part by the wavelet transform. Secondly, the wavelet coefficients of the detailed part are influenced by the threshold. Finally, the regression function of the signal is obtained by reconstructing wavelet coefficients. The experimental results show that the signal-noise ratio of the improved algorithm is clearly higher than the original, and it is helpful for improving the regression accuracy in terms of the wavelet transform. The algorithm can effectively remove noise, and the local feature of the signals is fully retained. © 2017 by the authors.
Jia L.,Qiqihar University |
Han F.,Qiqihar University
Beilstein Journal of Organic Chemistry | Year: 2017
Background: Phthalides are privileged constituents of numerous pharmaceuticals, natural products and agrochemicals and exhibit several biological and therapeutic activities. Therefore, the development of new, facile, and sustainable strategies for the construction of these moieties is highly desired. Results: A broad substrate scope for β-keto acids was found to be strongly compatible with this catalytic process, affording a wide variety of 3-substituted phthalides in good to excellent yields. Conclusion: A concise and efficient synthesis strategy of 3-substituted phthalides from 2-formylbenzoic acid and β-keto acids via a catalytic one-pot cascade reaction in glycerol has been accomplished. © 2017 Jia and Han; licensee Beilstein-Institut. License and terms: see end of document.
Zhang W.-G.,Qiqihar University
Acta Crystallographica Section E: Structure Reports Online | Year: 2011
The title hydrazone compound, C14H10ClFN 2O, adopts an E configuration about the C=N double bond. The dihedral angle between the two substituted benzene rings is 11.6 (2)°. The F atom is disordered over two sites with occupancies of 0.488 (2) and 0.512 (2). In the crystal, molecules are linked through intermolecular N - H⋯O hydrogen bonds, forming chains along the a axis. C - H⋯F and C - H⋯O interactions also occur.
Wu W.,Qiqihar University |
Tian L.,Qiqihar University
Applied Clay Science | Year: 2013
In the present work the formulation and morphology of novel kaolin-filled rubber composites were investigated. The kaolin-filled rubber composites were obtained by filling rubbers such as natural rubber (NR), styrene-butadiene rubber (SBR), polybutadiene rubber (ER), nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), chloroprene rubber (CR) and methyl vinyl silicon rubber (MVQ). The best formulation of filled rubbers was determined by determining the mechanical and thermal properties of the composites. Structural characterization was carried out by using infrared spectroscopy (IR) and a polarizing light microscope (PLM). The kaolin/rubber composites have outstanding mechanical and thermal properties except elongation at break, and good compatibility. The best formulation of kaolin filled rubbers is respectively 40 parts per hundred rubber (phr), 40 phr, 50 phr, 40 phr, 50 phr, and 50 phr for NR, SBR, BR, NBR, EPDM and CR. Kaolin can replace silica in the specific rubber products, and is suitable to reinforce more steric rigid rubber. © 2013 .
Shi C.-W.,Qiqihar University
Chung-kuo Tsao Chih/China Pulp and Paper | Year: 2012
Treatment of deinking waste water with coagulation process was studied. The coagulants type, coagulants dosage, coagulants aid dosage, and pH were determined by orthogonal experiment. The results showed that the coagulants type, coagulants dosage, coagulants aid dosage are the key factors in coagulation of deinking wastewater, the treatment efficiency is the highest when PAC dosage is 200 mg/L and coagulants aid dosage is 3 mg/L.
Yan X.,Qiqihar University
Nuclear Engineering and Design | Year: 2016
The concentrations of thorium (232Th) in soil from a uranium mill tailings repository in South China were analyzed. The results showed that all the soil samples were acidic and the concentrations of 232Th in all the soil samples were more than the natural radionuclide content in soil of China. Through the field investigation, twelve kinds of dominant plants were discovered. The total quantity of 232Th in the whole plant is highest in rice flat sedge. We also found that Miscanthus floridulus has the greatest transfer factor (TF) for 232Th, rice flat sedge has the greatest bioconcentration factor (BF) for 232Th. At the mean time, M. floridulus has the greatest phytoremediation factor (PF) for 232Th. On the basis of the above conclusions and the definition for hyperaccumulator, rice flat sedge and M. floridulus could be the candidates of phytoremediation for radionuclide 232Th in the soil. © 2016 Elsevier B.V. All rights reserved.
Miao F.,Qiqihar University |
Tao B.,Qiqihar University
Electrochimica Acta | Year: 2011
The use of silicon microchannel plates (MCP) modified with nickel-palladium (Ni-Pd) nanoparticles by electroless plating was studied for the electrocatalytic oxidation of methanol and ethanol by cyclic voltammetry and chronoamperometry in alkaline media. The electrocatalyst was characterized by EDS, SEM and cyclic voltammetry, and the effective parameters on electrocatalytic oxidation of the alcohol, i.e. the concentration of KOH and alcohol, medium temperature and working potential limit in anodic direction were investigated. The modified electrode shows a superior electrooxidation performance with the operating temperature increasing and a strong current response to methanol and ethanol even during long-term oxidation of alcohol. All results show that the Ni-Pd/Si-MCP nanocomposite electrode is very attractive for integrated fuel cell applications. © 2011 Elsevier Ltd. All rights reserved.
Zheng Y.,Qiqihar University
Physica A: Statistical Mechanics and its Applications | Year: 2013
The ideal gas has been reinvestigated in the framework of Tsallis nonextensive statistics, which can be called nonextensive gas. According to the modified thermodynamic relationships, and applying the nonextensive gas model to analyze actual gas, the relationship between the nonextensive parameter and the second virial coefficient can be deduced. On the other hand, this coefficient can also be expressed as the integration of interaction potential between the molecules of actual gas. This indicates that the nonextensive parameter may be related to the interaction potential. Our further analysis to the relation seems to imply that the nonextensive parameter is irrelevant to the thermodynamic temperature of the gas. © 2013 Elsevier B.V. All rights reserved.