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三分仓回转式空气预热器积灰分段监测模型研究 被引量:4
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作者 岳峻峰 丁建良 +5 位作者 徐力刚 邹磊 张恩先 管诗骈 黄亚继 陈波 《动力工程学报》 CAS CSCD 北大核心 2016年第10期795-800,809,共7页
针对三分仓回转式空气预热器热段和冷段积灰分段监测的需求,基于空气预热器的传热模型,定义空气预热器利用系数作为清洁因子并建立积灰分段监测模型.通过分析空气预热器实时运行参数,根据热平衡原理确定了清洁因子计算步骤.以某1 000MW... 针对三分仓回转式空气预热器热段和冷段积灰分段监测的需求,基于空气预热器的传热模型,定义空气预热器利用系数作为清洁因子并建立积灰分段监测模型.通过分析空气预热器实时运行参数,根据热平衡原理确定了清洁因子计算步骤.以某1 000MW超超临界直流锅炉的三分仓回转式空气预热器为例,研究了热段、冷段清洁因子在空气预热器积灰和吹灰时的变化趋势.结果表明:根据所建模型计算出的分段清洁因子变化趋势在稳定负荷下能够反映此空气预热器的分段积灰情况,而在变负荷情况下虽有一定偏离,但由于电厂变负荷工况下很少吹灰故影响较小;该积灰监测模型可作为三分仓回转式空气预热器热冷分段积灰监测的有效手段. 展开更多
关键词 三分仓回转式空气预热器 积灰监测 利用系数 清洁因子 稳定负荷 变负荷
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Application of the third theory of quantification in coal and gas outburst forecast 被引量:1
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作者 吴财芳 秦勇 张许良 《Journal of Coal Science & Engineering(China)》 2004年第2期60-65,共6页
The essential principles of the third theory of quantification are discussed, the concept and calculated method of reaction degree are put forward which extend the ap- plying range and scientificalness of the primary ... The essential principles of the third theory of quantification are discussed, the concept and calculated method of reaction degree are put forward which extend the ap- plying range and scientificalness of the primary reaction. Taking the Zhongmacun Mine as example, on the base of analyzing the rules of gas geology synthetically and travers- ing the geological factors infecting coal and gas outburst, the paper adopts the method of combining carving up statistical units with the third theory of quantification, screens out 8 sensitive geological factors from 11 geological indexes and carries through the work of gas geology regionalism to the exploited area of Zhongmacun according to the researching result. The practice shows that it is feasible to apply the third theory of quantification to gas geology, which offers a new thought to screen the sensitive geo- logical factors of gas outburst forecast. 展开更多
关键词 the third theory of quantification reaction degree sensitive geological fac- tors gas outburst forecast
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Effect of electroacupuncture on brain-derived neurotrophic factor mRNA expression in mouse hippocampus following cerebral ischemia-reperfusion injury 被引量:15
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作者 Jianxin Zhao Huazhou Xu +2 位作者 Yuanxiang Tian Manxiang Hu Hongling Xiao 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2013年第2期253-257,共5页
OBJECTIVE: This work aims to observe the effects of electroacupuncture on brain-derived neuro- trophic factor (BDNF) mRNA expression in mouse hippocampus following cerebral ischemia-reperfu- sion injury. METHODS: ... OBJECTIVE: This work aims to observe the effects of electroacupuncture on brain-derived neuro- trophic factor (BDNF) mRNA expression in mouse hippocampus following cerebral ischemia-reperfu- sion injury. METHODS: The models of mouse cerebral isch- emia-reperfusion injury were established. A total of 96 healthy mice were randomly assigned into 4 groups, namely, the sham surgery, model, mod- el + electroacupuncture, and mode + hydergine groups. Mice in the model + electroacupuncturegroup were treated through electroacupuncture at the Shenshu (BL 23), Geshu (BL 17), and Baihui (GV 20) acupoints. Mice in the model+hydergine group were intragastrically administered with hy- dergine (0.77 mg/kg-1.day-l). The levels of BDNF mRNA expressions in the hippocampus were ana- lyzed through a semi-quantitative reverse transcrip- tion-polymerase chain reaction assay on days 1 and 7 after the surgeries. RESULTS: BDNF mRNA expressions in the mouse hippocampus of the model group on days 1 and 7 after the surgery were higher than those of the sham surgery group (both P〈0.01). On days 1 and 7 of the electroacupuncture treatment, BDNF mRNA expression in the mouse hippocampus of the mod- el + electroacupuncture group was significantly ele- vated compared with the model group (both P〈 0.01) or the model + hydergine group (both P〈 0.01). On days 1 and 7 of the hydergine treatment, BDNF mRNA expression in the mouse hippocam- pus of the model + hydergine group tended to in- crease compared with the model group; however, statistical significance was not achieved (both P〉 0.05). CONCLUSION: Electroacupuncture treatment en- hances endogenous BDNF expression, which may improve the survival environment for intracerebral neurons and inhibit the apoptosis of hippocampal cells. 展开更多
关键词 ELECTROACUPUNCTURE Nerve growth fac- tor Reperfusion injury HIPPOCAMPUS Reverse tran-scriptase polymerase chain reaction
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Phytochrome Signaling in Green Arabidopsis Seedlings: Impact Assessment of a Mutually Negative phyB-PIF Feedback Loop 被引量:22
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作者 Pablo Leivar Elena Monte +1 位作者 Megan M. Cohn Peter H. Quail 《Molecular Plant》 SCIE CAS CSCD 2012年第3期734-749,共16页
The reversibly red (R)/far-red (FR)-Iight-responsive phytochrome (phy) photosensory system initiates both the deetiolation process in dark-germinated seedlings upon first exposure to light, and the shade-avoidan... The reversibly red (R)/far-red (FR)-Iight-responsive phytochrome (phy) photosensory system initiates both the deetiolation process in dark-germinated seedlings upon first exposure to light, and the shade-avoidance process in fully deetiolated seedlings upon exposure to vegetational shade. The intracellular signaling pathway from the light-activated photoreceptor conformer (Pfr) to the transcriptional network that drives these responses involves direct, physical inter- action of Pfr with a small subfamily of bHLH transcription factors, termed Phy-lnteracting Factors (PIFs), which induces rapid PIF proteolytic degradation. In addition, there is evidence of further complexity in light-grown seedlings, whereby phyB-PIF interaction reciprocally induces phyB degradation, in a mutually-negative, feedback-loop configuration. Here, to assess the relative contributions of these antagonistic activities to the net phenotypic readout in light-grown seedlings, we have examined the magnitude of the light- and simulated-shade-induced responses of a pentuple phyBpiflpif3pif4pif5 (phyBpifq) mutant and various multiple pif-mutant combinations. The data (1) reaffirm that phyB is the predominant, if not exclusive, photoreceptor imposing the inhibition of hypocotyl elongation in deetiolating seedlings in response to pro- longed continuous R irradiation and (2) show that the PIF quartet (PIF1, PIF3, PIF4, and PIF5) retain and exert a dual capacity to modulate hypocotyl elongation under these conditions, by concomitantly promoting cell elongation through intrinsic transcriptional-regulatory activity, and reducing phyB-inhibitory capacity through feedback-loop-induced phyB degrada- tion. In shade-exposed seedlings, immunoblot analysis shows that the shade-imposed reduction in Pfr levels induces increases in the abundance of PIF3, and mutant analysis indicates that PIF3 acts, in conjunction with PIF4 and PIF5, to promote the known shade-induced acceleration of hypocotyl elongation. Conversely, although the quadruple pifq mutant displays clearly reduced hypocotyl elongation compared to wild-type in response to prolonged shade, immunoblot analysis detects no elevation in phyB levels in the mutant seedlings compared to the wild-type during the majority of the shade-induced growth period, and phyB levels are not robustly correlated with the growth phenotype across the pif-mutant combinations compared. These results suggest that PIF feedback modulation of phyB abundance does not play a dominant role in modulating the magnitude of the PIF-promoted, shade-responsive phenotype under these conditions. In seedlings grown under diurnal light-dark cycles, the data show that FR-pulse-induced removal of Pfr at the beginning of the dark period (End-of-Day-FR (EOD-FR) treatment) results in longer hypocotyls relative to no EOD-FR treatment and that this effect is attenuated in the pif-mutant combinations tested. This result similarly indicates that the PIF quartet members are capable of intrinsically promoting hypocotyl cell elongation in light-grown plants, independently of the effects of PIF feedback modulation of photoactivated-phyB abundance. 展开更多
关键词 Light regulation light signaling genetics molecular biology transcriptional control and transcription fac- tors PHOTOMORPHOGENESIS
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