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排序方式: 共有3339条查询结果,搜索用时 15 毫秒
1.
如何在互联网时代打造一个信息化的管理模式,已经成为广大学校图书管理发展过程中亟待处理的问题。文章就互联网时代下的高职图书管理信息化建设进行了详细探讨,以期能够给广大同仁提供一些借鉴参考,共同为图书管理工作的现代化改革和发展贡献力量。 相似文献
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Developing the thermal stability of metal-based ceramic composites or their films has always been challenging and bottlenecks for the utilization of energy. In this paper, the novel mesh-like functional Al doped-MoO3 nanocomposite film with even distribution and high purity was firstly fabricated by the high-efficiency electrophoretic deposition and surface modification. The optimal suspension turned out to be the mixture of isopropanol and the additives of polyethyleneimine and benzoic acid. The microtopography, crystalline structure, environmental resistance and thermal stability were analyzed by field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), X-ray diffractometer (XRD), exposure and droplet-impacting test, DSC analysis and ignition test, respectively. The water contact angle and sliding angle of product can reach ~170° and <1°, indicating the excellent anti-wetting property. In addition, the high heat-release (~3180 J/g) of product all kept almost unchangeable after six months exposure experiments, demonstrating the outstanding thermostability. The exquisite design idea here can perfectly match microelectromechanical system (MEMS), providing the valuable reference for fabricating other metal-based high-energy composites with long lifespan for real industrial applications. 相似文献
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Concerning the problem that the Neural Network speech enhancement algorithm cannot fully represent the nonlinear structure of speech due to feature selection,which leads to speech distortion.This paper proposes the combination of dynamic features with a new mask to optimize neural network speech enhancement.First,three features of noisy speech are extracted and spliced to obtain static features.Then,the first and second difference derivatives are obtained to capture the instantaneous signals of speech and fuse them into dynamic features.The combination of dynamic and static features completes internal complementarity of features and reduced speech distortion.Second,in order to enhance the intelligibility and clarity of speech at the same time,an adaptive mask is proposed,which can adjust the energy ratio of speech and noise as well as the ratio of the traditional mask and the square root mask.The Gammatone channel weight is used to modify the mask value in each channel to simulate the human auditory system and further improve the speech intelligibility.Finally,the simulation of multiple voices under different noise backgrounds shows that compared with different literature algorithms,the algorithm has a higher SNR,subjective speech quality and short-term objective intelligibility,which verifies the effectiveness of the algorithm. 相似文献
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针对选煤机排料系统的刮板易出现磨损、弯曲等问题,通过对刮板结构、受力情况进行详细分析,并提出了相应的优化设计方案.仿真结果表明,该设计方案可满足煤矿安全高效的生产需求,对实际生产中的刮板结构设计有一定应用价值. 相似文献
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Yuhuan Sun Hongshuang Qin Zhengqing Yan Chuanqi Zhao Jinsong Ren Xiaogang Qu 《Advanced functional materials》2019,29(14)
Recently, quorum sensing (QS) inhibitors (QSIs) have been combined with antibiotics to enhance antibiofilm efficacy in vitro and in vivo. However, targeting QS signals alone is not enough to prevent bacterial infections. Drug resistance and recurrence of biofilms makes it difficult to eradicate. Herein, photodynamic therapy (PDT) is selected to unite QSIs and antibiotics. A synergistically antibiofilm system, which combines QSIs, antibiotics, and PDT based on hollow carbon nitride spheres (HCNSs) is envisaged. First, HCNS provides the multidrug delivering ability, enabling QSIs and antibiotics to be released in sequence. Subsequently, multistage releases sensitize bacteria effectively, potentiating the chemotherapeutic effects of the antibiotics. Finally, the integration of QSIs and PDT not only minimizes the possibility of drug resistance, but also overcomes the problem of limited mass and extension of PDT. Even after 48 h of incubation, the bacterial biofilm is obviously inhibited. And its biofilm disperse efficiency exceeds 48% (compared with QSI‐potentiated chemotherapy group) and 40% (compared with PDT group). Besides, the inhibition of the QS system influences phenotypes related to virulence factor production and surface hydrophobicity, which weaken biofilm invasion and formation. Eventually, this system is applied to disperse bacterial biofilm in vivo. Overall, PDT and QS modulation are devoted to eradicate drug resistance and recurrence of the biofilm. 相似文献
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Jixian Wang Bo Han Rong Nie Yanjie Xu Xiaogang Yu Yapeng Dong Jianguo Wang Huanwang Jing 《Topics in Catalysis》2018,61(15-17):1563-1573
The CO2 reduction is a very attracting research field in the environmental, material and chemical sciences in light of the energy crisis and greenhouse effect. A new photoelectrocatalytic system composed of a photoanode BiVO4 and a photocathode of nickel foam supported ZnO semiconductor was designed, assembled and applied to CO2 reduction in water. The photocathodes with different morphology could be made from electrochemical deposition method and well characterized by SEM, UV–Vis, XRD, and XPS. The photoelectrocatalytic cell of ZnO/Ni-30|KHCO3|BiVO4 can produce ethanol and acetic acid in a rate of 12.5 µM h?1 cm?2 with 100% selectivity for C2 product, attributing to the controlling of 3D-spaces of nanorod. The cell of A-ZnO/Ni-15|KHCO3|BiVO4 produces ethanol and acetic acid with 75% selectivity for C2 product under 100 mW cm?2 simulated sunlight irradiation, attributing to controlling of both amine ligand and morphology of ZnO, which reveal a new way to increase the selectivity of products. 相似文献
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Haiyi Peng Haishen Ren Mingzhao Dang Yi Zhang Xiaogang Yao Huixing Lin 《Ceramics International》2018,44(6):6527-6532
Ca0.9La0.067TiO3 (abbreviated as CLT) ceramics doped with different amount of Al2O3 were prepared via the solid state reaction method. The anti-reduction mechanism of Ti4+ in CLT ceramics was carefully investigated. X-ray diffraction (XRD) was used to analyze the phase composition and lattice structure. Meanwhile, the Rietveld method was taken to calculate the lattice parameters. X-ray photoelectron spectroscopy (XPS) was employed to study the valence variation of Ti ions in CLT ceramics without and with Al2O3. The results showed that Al3+ substituted for Ti4+ to form solid solution and the solid solubility limit of Al3+ is near 1.11 mol%. Furthermore, the reduction of Ti4+ in CLT ceramics was restrained by acceptor doping process and the Q × f values of CLT ceramics were improved significantly. The CLT ceramic doped with 1.11 mol% Al2O3 exhibited good microwave dielectric properties: εr = 141, Q × f = 6848 GHz, τf = 576 ppm/°C. 相似文献
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