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72.
如今,计算机的普及已经遍布我国的各行各业各个人群中,其中学生代表一个先进的群体,代表国家的未来,在学生中,几乎没有人不会使用计算机。校园是国家的知识基地和人才基地,它代表着信息产业技术发展的前沿,但是目前校园网在国内发展还不够成熟,对校园网络的安全还不够重视,对校园网络安全问题带有一定的盲目性和偏见。文章主要介绍校园网的特点,针对这些特点目前存在的一些威胁,之后介绍校园网络的安全架构。 相似文献
73.
遥感图像信息提取研究是遥感研究中的一个关键问题,也是遥感研究的热点和难点之一。使用2000~2010年MODIS-NDVI 16 d合成数据和物候记录,借助GIS空间分析和统计分析方法,重构了古尔班通古特沙漠梭梭林地Mean NDVI时间序列特征曲线。分析物候与Mean NDVI时间序列表明,梭梭林地内的短命植物生长期早于梭梭。研究梭梭林地Mean NDVI时间序列曲线发现,曲线中存在一个明显区别于其他地物的特征点,该点可以作为梭梭林地信息“诊断点”。根据“诊断点”特征构建了梭梭林地特征指数模型(HFFI),进而反演了古尔班通古特沙漠梭梭林地信息,并利用地面实际观测资料进行验证,结果表明分类精度达到83%。 相似文献
74.
应用卫星导航、软件无线电、计算机控制、电磁兼容等技术,研制了基于"工控机+DSP+FPGA"架构的多模卫星信号模拟器;该模拟器在国内最先实现了GPS、GLONASS和北斗一号信号的任意组合、时空同步仿真;详细论述了模拟器硬件方案,介绍了其软件构成和各模块功能,最后通过成熟商业多模接收机验证了模拟器所仿真信号的有效性和任意时空性;此外,该模拟器无需更改硬件即可在未来向北斗二号系统扩展。 相似文献
75.
Towards a theoretical framework of strategic decision, supporting capability and information sharing under the context of Internet of Things 总被引:2,自引:2,他引:0
The effective strategy of Internet of Things (IoT) can help firms to grasp the emerging opportunities from the IoT and then improve their competitive advantage. In this article, based on organizational capability perspective, we provide a theoretical framework which classifies IoT strategies into four archetypes from two dimensions of managers’ strategic intent and industrial driving force, and propose that market-based exploratory capabilities play a more important role for firms adopting get-ahead strategy, and market-based exploitative capabilities play a more important role for firms adopting catch-up strategy in market. The technology-based exploratory capabilities play a more important role for firms adopting get-ahead strategy in technology, and technology-based exploitative capabilities play a more important role for firms adopting catch-up strategy in technology. Especially, external industry information sharing more efficiently contributes to the enhancement of both market-based and technology-based exploratory capabilities, and internal industry information sharing more efficiently contributes to the enhancement of both market-based and technology-based exploitative capabilities. 相似文献
76.
单元测试是软件测试过程的第一站,高质量的单元测试是软件质量保证的必要条件,本文就单元测试的概念、测试类型及规程作了简单的阐述,同时就单元测试进行了案例分析。 相似文献
77.
本文通过介绍Applet的体系结构和其生命周期以及如何创建和执行Applet程序,介绍了电子相册的制作过程。 相似文献
78.
Manqi Zhang Degang Li Tianbao Dong Xiaoxiao Hou Xiao Zhang Hongliang Liu Lihong Liu Shouyu Tang Shaomin Liu 《乙烯基与添加剂工艺杂志》2021,27(3):519-532
Global bacterial infections associated with conventional polyvinyl chloride (PVC) medical devices place a heavy burden on healthcare systems and thus it will be desirable if medical devices are made from antimicrobial PVC. There are numerous studies focusing on polymer surface modifications to either leach antimicrobial agents or kill pathogenic microbes upon direct contact. In this work, mannitol fumarate ester-based aluminum metal alkoxide (MFE-Al) additive was developed to confer simultaneously improved antibacterial property and enhanced high temperature sterilization resistance of the resultant PVC. Data obtained confirm that the MFE-Al stabilized PVC sheets significantly inhibit 98% bacterial growth. They also show biocompatibility with cultured H9C2 cardiomyocytes and hemocompatibility in vitro. Dry heat sterilization is generally not suitable for PVC medical wares due to their poor thermal compatibility. Surprisingly, our antimicrobial-biocompatible PVC can maintain stability at 180°C for 90 min. Such a high thermal stability indicates the MFE-Al stabilized PVC can endure 90 cycles of dry-heat sterilization without significant damage. This study may provide a solution to reduce PVC medical waste for a maximum benefit without compromising human health or the environment. 相似文献
79.
Yi Zhang Jianzi Huang Qiongzhao Hou Yujuan Liu Jun Wang Shulin Deng 《International journal of molecular sciences》2021,22(7)
Salt stress is a major increasing threat to global agriculture. Pongamia (Millettia pinnata), a semi-mangrove, is a good model to study the molecular mechanism of plant adaptation to the saline environment. Calcium signaling pathways play critical roles in the model plants such as Arabidopsis in responding to salt stress, but little is known about their function in Pongamia. Here, we have isolated and characterized a salt-responsive MpCML40, a calmodulin-like (CML) gene from Pongamia. MpCML40 protein has 140 amino acids and is homologous with Arabidopsis AtCML40. MpCML40 contains four EF-hand motifs and a bipartite NLS (Nuclear Localization Signal) and localizes both at the plasma membrane and in the nucleus. MpCML40 was highly induced after salt treatment, especially in Pongamia roots. Heterologous expression of MpCML40 in yeast cells improved their salt tolerance. The 35S::MpCML40 transgenic Arabidopsis highly enhanced seed germination rate and root length under salt and osmotic stresses. The transgenic plants had a higher level of proline and a lower level of MDA (malondialdehyde) under normal and stress conditions, which suggested that heterologous expression of MpCML40 contributed to proline accumulation to improve salt tolerance and protect plants from the ROS (reactive oxygen species) destructive effects. Furthermore, we did not observe any measurable discrepancies in the development and growth between the transgenic plants and wild-type plants under normal growth conditions. Our results suggest that MpCML40 is an important positive regulator in response to salt stress and of potential application in producing salt-tolerant crops. 相似文献
80.
Wei-Chieh Huang Kao-Chang Lin Chih-Wei Hsia Chih-Hsuan Hsia Ting-Yu Chen Periyakali Saravana Bhavan Joen-Rong Sheu Shaw-Min Hou 《International journal of molecular sciences》2021,22(7)
Platelets play a crucial role in the physiology of primary hemostasis and pathological processes such as arterial thrombosis; thus, developing a therapeutic target that prevents platelet activation can reduce arterial thrombosis. Pterostilbene (PTE) has remarkable pharmacological activities, including anticancer and neuroprotection. Few studies have reported the effects of pterostilbene on platelet activation. Thus, we examined the inhibitory mechanisms of pterostilbene in human platelets and its role in vascular thrombosis prevention in mice. At low concentrations (2–8 μM), pterostilbene strongly inhibited collagen-induced platelet aggregation. Furthermore, pterostilbene markedly diminished Lyn, Fyn, and Syk phosphorylation and hydroxyl radical formation stimulated by collagen. Moreover, PTE directly hindered integrin αIIbβ3 activation through interfering with PAC-1 binding stimulated by collagen. In addition, pterostilbene affected integrin αIIbβ3-mediated outside-in signaling, such as integrin β3, Src, and FAK phosphorylation, and reduced the number of adherent platelets and the single platelet spreading area on immobilized fibrinogen as well as thrombin-stimulated fibrin clot retraction. Furthermore, pterostilbene substantially prolonged the occlusion time of thrombotic platelet plug formation in mice. This study demonstrated that pterostilbene exhibits a strong activity against platelet activation through the inhibition of integrin αIIbβ3-mediated inside-out and outside-in signaling, suggesting that pterostilbene can serve as a therapeutic agent for thromboembolic disorders. 相似文献