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671.
在分析多区蜂窝CDMA系统干扰的基础上,提出了开,闭环结合的功控方式,要求和以载干比(CIR)为基础的功控算法,从而抑制干扰,改善系统性能,增加系统容量。 相似文献
672.
Reinhold Wurster Werner Zittel 《Mitigation and Adaptation Strategies for Global Change》2007,12(3):367-386
Some lessons for the introduction of hydrogen fueled vehicles can be learned from experience gained by the introduction of
natural gas fueled vehicles, either in Europe or in Argentina. While the European efforts have failed, at least until today,
Argentina has achieved a remarkable market share of about 20% natural gas vehicles since the early 80ies. Beyond a short review
on the constituents of a hydrogen refueling infrastructure, the Compressed Natural Gas (CNG)-example is analyzed to formulate
some ‘must be’s’ for the successful introduction of hydrogen refueling infrastructure: Clear concerted signals have to be
sent by all important players, the politicians as well as the involved industry from car producers to fuel suppliers. Bi-fueled
hybrid vehicles are not seen as a proper tool, as they are forcing neither the user to look for hydrogen nor the supplier
to provide hydrogen. After general considerations, various strategies and policies of different countries and manufacturers
are reviewed. For instance, the electric hybrid cars as already today introduced by some Japanese manufacturers offer the
chance of settling a maintenance infrastructure for electric drive systems already today which can be easily extended to cover
full fuel cell drive systems, once they are available. 相似文献
673.
1 IntroductionThechlorine alkaliindustryisoneofthesubstantialpartsofthechemicalindustry .Now ,threetypesofelectrolyticcellsareusedtoproducechlorinegasandcausticsoda:theHgcell,thediaphragmcell,andthemembranecell.Chinaisusingthediaphragmcellasthemaintype.Na… 相似文献
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Human amniotic fluid cells exhibit a higher cloning efficiency and rate of cell proliferation when maintained on dishes coated with a naturally produced extracellular matrix (ECM) in comparison with the regular tissue culture plastic. In 22 out of 31 amniotic fluid samples there was by plating the cells on ECM a 2–6 fold increase in number and size of colonies and in the cell density per colony as detected by actual staining and viewing of each colony. These effects yielded, in 21 of 41 additional samples, a reduction ranging from 2–8 days, in the culture time elapsing between amniocentesis and the first harvesting of cells for chromosomal analysis. An even greater effect was obtained with primary cells that failed to attach to plastic surfaces and stayed floating in the medium but did attach and proliferate when seeded on ECM. Cells that were left firmly attached to ECM after the first trypsinization and harvesting of cells for chromosomal analysis yielded colonies ready for second karyotyping in less than half the time required for cells maintained on plastic. Studies with secondary cultures of human amniotic fluid cells have demonstrated a 5–10 fold decrease in serum requirement of cells cultured on ECM as compared with plastic. Addition of fibroblast growth factor (FGF) to the cultures further potentiated the effects of ECM. The ECM induced stimulation of cell attachment and proliferation was not associated with any chromosomal anomalies, nor did it interfere with the handling procedure. ECM coated dishes may be useful to reduce the time interval between amniocentesis and diagnosis, in particular when the amniotic cells exhibit an exceedingly slow rate of proliferation on plastic or when large quantities of cells are required for enzymatic studies. 相似文献
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We report a case in which a discrepancy emerged between the prenatal diagnosis of female chromosomal sex and male sex at ultrasound examination. The FSH dosage performed on an amniotic fluid sample previously stored confirmed the male phenotype of the fetus. The effectiveness of the AF-FSH level dosage in prenatal diagnosis was taken into consideration. 相似文献
679.
研究了硒化合物对长春花(C.roseus)细胞悬浮生长的影响.在pH5.5培养介质中,当Se(Ⅵ)>0.5ppm或Se(Ⅳ)>0.6ppm时,将抑制C.roseus细胞悬浮生长,其致死浓度分别是100ppm Se(Ⅵ)和2.0ppm Se(Ⅳ).C.roseus对硒化合物有效强的富集作用.硒化合物的毒性和培养介质的pH值有关.在本试验条件下,硒酸钠和亚硒酸钠对Hg2+无拮抗作用. 相似文献
680.