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991.
A broadband switching experiment was presented at the ISS'87 and Telecom'87 conferences in Phoenix, Arizona, and Geneva, Switzerland, respectively and at the March 1988 Fair in Hanover, West Germany. This experiment was significant in that it illustrated techniques for switching broadband signals with a wide range of frequencies, formats and ultimate purposes. In particular, simultaneous switching (within the same switch fabric) of 30 MHz PFM, 45 Mb/s PCM, and 140 Mb/s PCM was demonstrated. These signals carried full-motion, full-colour NTSC video for desk-to-desk video teleconferencing, off-the-air broadcast video programming, and surveillance camera video. They also carried RGB video, digitized stored video images, and computer-computer communications. Software features afforded a friendly human interface, allowing multiple, flexible service capabilities. Further, the experimental system, when deployed in Phoenix, demonstrated control of its capabilities via a narrowband ISDN link to an optically remoted 5ESS® switch module one km distant, which homed on a 5ESS host switch about 32 km further away. The technologies employed in the switch and the surrounding equipment are detailed, and the significance of this experiment relative to the broadband ISDN (BISDN) thinking is discussed. 相似文献
992.
The disinfection of drinking water with chlorine produces carcinogenic by-products called trihalomethanes or (THM's). These compounds are formed when the chlorine reacts with the organic matter in the raw water. The four major THM's are chloroform, bromodichloromethane, dibromochromethane, and bromoform. Direct aqueous injection is used for the rapid screening THM's and other volatile organic compounds (VOC's) in water by direct on column injection of the water sample in to wide bore capillary columns, to which is attached an electron capture detector. 相似文献
993.
The (α–d) cluster model with parameters determined from electron scattering and pion photoproduction processes is used to calculate
the muon capture rate in6Li. The result is found to be better than the results calculated in other models and is in agreement with the experimental
data. 相似文献
994.
Video compression is essential for uploading videos to online platforms which usually have bandwidth limitations. However, the compression reduces the visual quality. To overcome this problem, the visual quality of the low bitrate compressed videos for various standards, including H.264 and HEVC in decoders, needs to be improved. Accordingly, this paper proposes a novel method for improving video quality based on 3D convolutional neural networks (CNNs). This method is totally compatible with the encoders of video compression standards, i.e., H.264, VVC, and HEVC, and can be implemented easily. In particular, the proposed neural network model receives five frames of the low bitrate compressed video as input and subsequently predicts the compression error of frames using the first and fifth frames. Finally, it reconstructs an improved version of the frame with high quality. The CNN is an Additive (3D) model that can predict the eliminated inter-frame redundancies resulting from compression. Our goal is to increase the peak signal to noise ratio (PSNR) and structural index similarity (SSIM) of the luminance (Y) and chrominance (U, V) frames in the video. Additive 3D-CNN achieves an average of 12.4%, 9.9% and 5% BD-rate increases for LP, LB and RA for the Y component. The results indicate that the new proposed algorithm outperforms the previous methods in terms of PSNR, SSIM, and BD-rate. 相似文献
995.
Tilt and pan camera movements are common in computer games or social media videos. These types of videos contain numerous perspective transforms while today’s video codecs rely on translational and affine motion models for motion compensation. The general perspective motion model with 8 parameters (8PMM) has unreasonably high processing time. In this paper, the eight-parameter perspective transform is simplified into a six-parameter transform to keep the time complexity within an acceptable range while modeling the most relevant transforms. Also, two motion prediction modes, Advanced Perspective Motion Vector Prediction (APMVP) and Perspective Model Merge (PMM), are proposed. The implementation results show an average of 7.0% BD-rate reduction over H.266/VVC Test Model with a maximum of 20% encoding time overhead. The results also show a 71% processing time reduction in comparison to 8PMM while experiencing an average of 5.6% increase in BD-Rate. Much better visual quality is measured through VMAF quality meter. 相似文献
996.
Achintya K. Bandyopadhyaya Sureshbabu Narayanasamy Rolf F. Barth Werner Tjarks 《Tetrahedron letters》2007,48(26):4467-4469
Texaphyrin macrocycles that contain gadolinium or lutetium, such as motexafin gadolinium and motexafin lutetium, are versatile anticancer therapeutics and diagnostics. Gadolinium texaphyrins substituted with carborane clusters could also find application in combined gadolinium and boron neutron capture therapy (GdB-NCT). The synthesis and characterization of novel texaphyrins containing gadolinium or lutetium in the pentaaza core and two carborane clusters bound to opposite pyrrol units of the macrocycle are described. 相似文献
997.
毛细管气相色谱法测定牛奶中有机氯和有机磷农药残留量 总被引:18,自引:0,他引:18
采用一个较快速、简单的方法测定牛血中有机氯和有机磷农药残留物。牛奶中农残经氯仿萃取和固相提取净化后,分别用气相色谱-电子捕获检测器和气相色谱-火焰光度检测器直接测定,色谱柱为HP-1接HP-5、DB17大口径石英毛细管柱。本法对17种有机氯农残的回收效率范围为71.2% ̄99.7%,检测限为0.5 ̄9μg/kg。而11种有机磷农残的回收率范围为70.1% ̄96.1%,检测限则为0.01 ̄0.04m 相似文献
998.
C. Salt A. J. Lennox M. Takagaki J. A. Maguire N. S. Hosmane 《Russian Chemical Bulletin》2004,53(9):1871-1888
The principles of neutron capture therapy of tumor diseases, the types of drugs, and the results of their clinical applications are discussed.Based on the report presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry dedicated to the 50th anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences (Moscow, May 30–June 4, 2004).Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1795–1812, September, 2004. 相似文献
999.
V. K. Mavrodiev I. I. Furlei Sh. Sultanov Yu. S. Nekrasov Yu. A. Belousov 《Russian Chemical Bulletin》1997,46(6):1113-1115
Negative ion mass spectra of cyclopentadienyltricarbonylmanganese and-rhenium derivatives RC5H4M(CO)3 (R=H, CN, COOH, COMe, COOMe, CH2OH, CHO; M=Mn, Re) were studied. The subsequent detachment of carbonyl groups is the main process of the fragmentation of
these compounds under the conditions of the resonance capture of electrons. On going fron the rhenium complexes to manganese
derivatives, the maxima of the yields of the ions [M-nCO]− (n=1–3) shift to the lower energy region indicating that the stability of the Re−CO bond is higher than that of Mn−CO. The average
lifetimes of the molecular negative ions relative to the autodetachment of an electron (τa) and to dissociation (τd) were measured. It was found that electron-accepting substituents increase the τa value and decrease τd.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1161–1164, June, 1997. 相似文献
1000.
气相色谱法测定纺织品中五氯苯酚残留量 总被引:6,自引:0,他引:6
建立了纺织品中五氯苯酚残留量的测定方法。试样用碳酸钾溶液提取 ,加乙酸酐乙酰化后 ,以正己烷提取乙酰化五氯苯酚 ,用气相色谱 电子俘获检测器 (GC ECD)测定 ,以外标法定量。五氯苯酚的检出限 0 .0 2mg·kg-1,加标回收率 90 %~ 10 5 % ,相对标准偏差≤ 6.7%。 相似文献