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101.
Shenghong Gu Yulan Yang Qingyao Liu Zhousheng Zhang 《Astrophysics and Space Science》1993,203(1):161-167
In this paper we present theBV photoelectric light curves of the W UMa-type eclipsing binary TY Pup. We have gained ephemerides by means of the times of minima. The obtained light curves have been solved using Wilson-Devinney's synthetic code. The results indicate that TY Pup is a contact system with mass ratio 0.185 and a large degree of overcontact of 52%. Combined with spectroscopic material, absolute parameters of TY Pup are derived. It may be concluded that TY Pup is an evolved contact binary. 相似文献
102.
The data such as the H-spectrum-spectroheliographic (SSHG) observations, the H-chromospheric observations, etc., of a flare loop prominence which occurred on the western solar limb on 1981 April 27 have been obtained at Yunnan Observatory. The distribution of the internal motions and the macroscopical motion of the flare loop prominence with time and space in the course of its eruption and ascension is derived from the comprehensive analysis of the data. The possible physical pictures and the instability of the motions of the loop are inferred and discussed. 相似文献
103.
104.
通过测定喂食水华微囊藻的尼罗罗非鱼胃PH值、不同颜色粪便的叶綠素/脱镁叶綠素比例,发现尼罗罗非鱼具有一个与摄食相关的胃酸分泌周期。摄食旺期胃平均PH值为1.47,最低值为0.8。停食后PH值升高,最大值为6.0。用不同浓度的盐酸处理水华微囊藻和对不同颜色粪便的营养分析结果表明,高浓度的胃酸(PH<2)溶解了水华微囊藻细胞壁,为肠消化酶对细胞内含物进行消化创造了先决条件。 相似文献
105.
The effects of ferrous ions on cathodic and anodic polarization behavior of the X60 steel in CO2 saturated salty water were studied by potentio-dynamic polarization method. The results show that the reducing current peak
of cathodic polarization is affected significantly if FeCl2 is added to the salty solution of controlled pH, but not the anodic polarization. It is considered that the ferrous ions
accelerate the formation of a protective ferrous carbonate film. Films formed by addition of ferrous ions and those formed
by ferrous ions produced from steel corrosion have the same forming mechanism. The former can fully meet the formative condition
of the film and can play the role of inhibitor. 相似文献
106.
????Z???ζ????????????????ο?????FLAC??3D??????о????????????????????????9??????????????????????й???????????????о?????????????λ???????м????????????????????м??????????????????????????????Щ??????????й???????Щ???????????й??????????????????????????д?????????????????????????? 相似文献
107.
Haitao Zhang Long Guo Jiaying Chen Peihong Fu Jianli Gu Guangyu Liao 《中国地理科学(英文版)》2014,24(2):191-204
This study used spatial autoregression(SAR) model and geographically weighted regression(GWR) model to model the spatial patterns of farmland density and its temporal change in Gucheng County,Hubei Province,China in 1999 and 2009,and discussed the difference between global and local spatial autocorrelations in terms of spatial heterogeneity and non-stationarity. Results showed that strong spatial positive correlations existed in the spatial distributions of farmland density,its temporal change and the driving factors,and the coefficients of spatial autocorrelations decreased as the spatial lag distance increased. SAR models revealed the global spatial relations between dependent and independent variables,while the GWR model showed the spatially varying fitting degree and local weighting coefficients of driving factors and farmland indices(i.e.,farmland density and temporal change). The GWR model has smooth process when constructing the farmland spatial model. The coefficients of GWR model can show the accurate influence degrees of different driving factors on the farmland at different geographical locations. The performance indices of GWR model showed that GWR model produced more accurate simulation results than other models at different times,and the improvement precision of GWR model was obvious. The global and local farmland models used in this study showed different characteristics in the spatial distributions of farmland indices at different scales,which may provide the theoretical basis for farmland protection from the influence of different driving factors. 相似文献
108.
We examined the structure and spatial organization of ciliature base-associated microtubules (BAM) in three hypotrichous ciliates
(Stylonychia mytilus, Pseudourostyla cristata, Euplotes woodruffi) in fluorescence microscopy. The results revealed that BAM, including the anterior (ALM), posterior longitudinal microtubule
(PLM) and the transverse microtubule (TM) bands, are composed of tubulin. The respective microtubular bands have cytoplasmic
polarization patterns that are significantly asymmetric. The BAM of the midventral files in P. cristata appear cord-shaped compared with the ALM bands of transverse cirri in both S. mytilus and E. woodruffi, which extend to the left anterior side of the cell before converging. The TM bands of the left marginal cirri (MC) in S. mytilus extend to the right side of the cell, while those of the right MC bands extend to the left. Our observations suggest that
BAM traits are common in hypotrichous ciliates even though different species possess different microtubule arrangements related
to the conserved cirral morphogenetic patterns in the respective species. The differing development of BAM in the three ciliate
suggests that the microtubules may be conserved in different hypotrichs. We have also demonstrated that the BAM, which appear
polar and asymmetric, are localized in specific cytoskeletal positions and extend in different orientations within the cortex
to connect with other ciliature-associated structures and, thus, strengthen the cortex. These BAM features indicate that they
are directly associated with cell motion. 相似文献
109.
谷川 《大地测量与地球动力学》2010,30(2):58-62
?????????????ó??????????????????????Ψ???????????????????????????????????п?????????????????;????????????????????????????????????????????????????????????ù???????????÷????????????????????????????? 相似文献
110.
为了探索BP网络的参数调整特性,进行了参数α、β的选取对BP算法的收敛速度和模型的稳定性的影响研究。通过BP网络用于气象预测建模的参数调整个例分析表明:参数α、β的取值对BP模型的稳定性无显著影响,但参数值的调整尤其是β值的调整对建模的收敛速度有明显的影响。 相似文献