Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： In the present paper, we briefly introduce the planetary cryosphere of solar planets and exoplanets. Planets and satellites in the solar system have very different surface temperatures. Therefore, they have very different cryosphere. Mercury and the Moon likely have water ice in the permanent dark areas of craters in polar regions. Venus is too hot to have a cryosphere. Mars has permanent polar ice caps that include both water ice and carbon-dioxide dry ice. Beyond the snowline of the solar system, there are many dwarf planets and satellites that are mainly consisted of water ice. With extremely low temperatures, water ice becomes even harder than the rocks on Earth and is actually the shell layer of these satellites and dwarf planets. In addition to water ice, other gases over Earth, such as CO2, CH4, N2, CO, and so on, are condensed to solid states under conditions of extremely low temperatures. They form different cryosphere from water ice. Therefore, planetary cryosphere is very different from that on Earth, and they have plenty divergences. Studies on planetary cryosphere would largely broaden our understanding on Earth’s cryosphere and benefit our understanding of the formation of the solar system, origin of water on Earth, evolution of life and climate environment on Earth, and extra-solar life detection in future.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-04-13 Cooperative journals: 《广西植物》
Abstract： Bryophytes are important indicators of environmental pollution. However, bryophytes are mainly used to monitor atmospheric pollution in China. In fact, bryophytes have been widely applied to monitor water quality abroad. In the present paper, we firstly analyzed the literature of applying bryophytes to monitor water environmental quality abroad, then summarized relevant content of bryomonitoring, which included the types of water pollutants monitored by bryophytes, the species of bryophytes used for bryomonitoring, the influences of the survival status of bryophytes on monitoring effect, the environmental factors affecting the enrichment of heavy metal elements in water by bryophytes, the active and passive methods of applying bryophytes to monitor water pollutions, and the sample preparation, as well as some European cases of bryomonitoring for water environmental quality. Finally we also proposed some suggestions about bryomonitoring researches and application in the future.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-12-13 Cooperative journals: 《计算机应用研究》
Abstract： According to the slow convergence speed and low searching precision of traditional backtracking search optimization algorithm, this paper proposed an improved algorithm based on cellular automaton and orthogonal experimental design. Firstly, the algorithm introduced orthogonal experimental design method into the crossover operator to obtain representative high-quality offspring individuals; Then based on the neighbor model of cellular automaton, the method carried out the orthogonal crossover operation of multiple parents in the domain for individuals, which was beneficial to improve the mining capacity and search efficiency of the algorithm; Finally, in order to balance the global searching and local searching ability of the algorithm, the method introduced the dynamic proportional weight of excellent individuals into the cross-population to select and update them, with adopted a new dynamic variation equation. The simulation experiments selected 12 standard test functions and compared with 6 other well-behaved algorithms, the results show that the improved algorithm has obvious advantages in convergence speed and optimization accuracy.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-11-29 Cooperative journals: 《计算机应用研究》
Abstract： Recommender systems (RS) help users to find interesting information in plenty of data resources, and provide accurate personalized recommendation. While the recommendation algorithm based on information core can greatly reduce the time cost in the recommendation process. Aiming at the scalability problem in collaborative filtering recommendation algorithm, On the basis of the original information core extraction method based on frequency (frequency-based, FB) and ranking (rank-based, RB) , this paper proposes an improved extraction information core method IFB (IFrequency-based) and IRB(IRank-based) . When in search of the most similar neighbors, we proposed a concept : optimization set, and found the most similar neighbors for each user on this set. The experimental results showed that this method can get more accurate recommendation results, and reduce the mean average absolute error(MAE) effectively. At the same time, it has higher precision and recall, so it has better recommendation effect.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-07-09 Cooperative journals: 《计算机应用研究》
Abstract： According to the scarcity of wireless spectrum resources and low utilization rate, this paper presented a spectrum allocation method based on binary fireworks optimization algorithm. Each firework individual carries out distributed explosion search, and the method proposed an improved formula to update the explosion radius of the optimal fireworks dynamically. For the lack of information exchange between particles in the variation process, the algorithm introduced the crossover operator and mutation operator of the genetic algorithm to further enhance the population diversity. In order to avoid falling into a local optimum, the algorithm used simulated annealing with Metropolis criterion to perturb the selected optimal individuals. The simulation experiment shows that the method has the characteristics of high optimization accuracy and high convergence speed. It can achieve the maximization of the network efficiency and the proportional fairness among different users.
Subjects: Astronomy >> Astrophysical processes submitted time 2018-05-17 Cooperative journals: 《天文研究与技术》
Abstract： 随着计算机数字技术的高速发展，甚长基线干涉仪测量（Very Long Baseline Interferometry， VLBI）所需的关键观测终端设备基带转换器（Base Band Converter， BBC）已从模拟系统（Analog BBC， ABBC）发展为数字系统（Digital BBC， DBBC）。相对于模拟系统，数字系统具有很高的灵活性，并能成倍地提高VLBI观测带宽，进而能满足各种高灵敏度的VLBI观测需求。考虑到这些技术优势，以及新疆天文台南山站在国内和国际VLBI网中的重要作用，南山站2016年对VLBI终端系统进行了升级，引进了一套意大利Hat-Lab公司研发的DBBC2终端。介绍了欧洲DBBC2系统的主要构成模块和工作原理以及系统的组装、连接、配置、校准和调试方法。在对系统硬件和软件进行全面的检测和测试后，与国内和国际的主要台站开展了联合观测，并多次成功获得相关干涉条纹。这一系列的成功观测表明, 南山DBBC2系统已成功安装，并具有很高的可靠性。应用新的DBBC2系统，南山站可参与2/4Gbps的记录速率的宽带VLBI观测，极其有助于天文学家对宇宙中更暗弱的射电源开展毫角秒分辨率的成图观测。
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-27 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To investigate the expression of p16INK4a protein in breast cancer and analyze its clinical significance. Methods A total of 132 surgical specimens of primary breast cancer obtained between 2014 and 2015 were examined for expressions of ER, PR, CK5/6, Her-2 and p16INK4a proteins using immunohistochemistry. Results The breast cancer samples were classified into 5 molecular subtypes, namely Luminal A (58 cases), Luminal B (32 cases), Her-2-positive (21 cases), basal-like (12 cases) and normal-like (9 cases) types. p16INK4a expression was negative in 7/132 (5.30%) cases, weakly positive in 15/132 (11.36%) cases, positive in 40/132 (30.30%) cases, and strongly positive in 70/132 (53.03%) cases. When categorizing negative and weakly positive cases into negative group and the positive and strongly positive cases into positive group, the total negative and positive expression rates of p16INK4a were 16.67% (22/132) and 83.33% (110/132) in the carcinoma tissues. Statistical analysis showed the expression intensity of p16INK4a differed significantly between the age groups (P<0.05) but was not significantly correlated with ER, PR, Her-2, molecular subtypes or metastasis of the tumors. Conclusion The compensatory high expression of p16INK4a is the main mechanism of cell cycle deregulation in invasive breast cancer and can be an important specific molecular marker for invasive breast cancer.
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-07 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To explore the effect of ouabain on intracellular Ca2+ concentration ([Ca2+]i) in thoracic aorta vascular smooth muscle cells (VSMCs) in vitro. Methods Primacy SD rat thoracic aorta VSMCs were cultured by tissue adherent method and identified by immunochemistry. The binding ability between ouabain and VSMCs was detected by autoradiography，and fluo 3-AM (a Ca2+ fluorescent probe) was employed to investigate whether ouabain affected VSMCs within a short period of time. The effect of a truncated fragment of the sodium pump a2 subunit was assayed in antagonizing the effect of ouabain on [Ca2+]i in the VSMCs. Results Within the concentration range of 0.1-100 nmol/L, ouabain was found to dose-dependently bind to the VSMCs. Different concentrations of ouabain (0-3200 nmol/L) caused a transient, dose-dependent increase in [Ca2+]i in the VSMCs, which was antagonized by the application of the truncated fragment of sodium pump a2 subunit. Conclusions Elevations in [Ca2+]i in the VSMCs can be the cytological basis of high ouabain-induced hypertension. The truncated fragment of the sodium pump a2 subunit can antagonize ouabain-induced increase of [Ca2+]i in the VSMCs, which provides a clue for understanding the pathogenesis of and devising a therapeutic strategy for high ouabain-induced hypertension.
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：随着计算机数字技术的高速发展，甚长基线干涉仪测量（Very Long Baseline Interferometry， VLBI）所需的关键观测终端设备基带转换器（Base Band Converter， BBC）已从模拟系统（Analog BBC， ABBC）发展为数字系统（Digital BBC， DBBC）。 相对于模拟系统，数字系统具有很高的灵活性，并能成倍地提高VLBI观测带宽，进而能满足各种高灵敏度的VLBI观测需求。考虑到这些技术优势，以及新疆天文台南山站在国内和国际VLBI网中的重要作用，南山站2016年对VLBI终端系统进行了升级，引进了一套意大利Hat-Lab公司研发的DBBC2终端。介绍了欧洲DBBC2系统的主要构成模块和工作原理以及系统的组装、连接、配置、校准和调试方法。在对系统硬件和软件进行全面的检测和测试后，与国内和国际的主要台站开展了联合观测，并多次成功获得相关干涉条纹。这一系列的成功观测表明, 南山DBBC2系统已成功安装，并具有很高的可靠性。应用新的DBBC2系统，南山站可参与2/4Gbps的记录速率的宽带VLBI观测，极其有助于天文学家对宇宙中更暗弱的射电源开展毫角秒分辨率的成图观测。
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