The polar ionosphere at Zhongshan Station on May 11, 1999, the day the solar wind almost disappeared

The solar wind almost disappeared on May 11,1999: the solar wind plasma density and dynamic pressure were less than 1cm-3 and 0.1 nPa respectively, while the interplanetary magnetic field was northward. The polar ionospheric data observed by the multi-instruments at Zhongshan Station in Antarctica on such special event day was compared with those of the control day (May 14). It was shown that geomagnetic activity was very quiet on May 11 at Zhongshan. The magnetic pulsation, which usually occurred at about magnetic noon, did not appear. The ionosphere was steady and stratified, and the F2 layer spread very little. The critical frequency of dayside F2 layer, foF2, was larger than that of control day, and the peak of foF2 appeared 2 hours earlier. The ionospheric drift velocity was less than usual. There were intensive auroral Es appearing at magnetic noon. All this indicates that the polar ionosphere was extremely quiet and geomagnetic field was much more dipolar on May 11. There were some signatures of auroral substorm before midnight, such as the negative deviation of the geomagnetic H component, accompanied with auroral Es and weak Pc3 pulsation.     

Multiple ground-based observations at Zhongshan Station during the April/May 1998 solar events

Simultaneous observations at Zhongshan Station, Antarctica, during May 1-7, 1998 are presented to show the responses of the polar ionosphere to the April/May 1998 solar events. One of the main geo-effects of the solar events resulted in the major magnetic storm on May 4. At the storm onset on May 2 the ionosphere F2 layer abruptly increased in altitude, the geomagnetic H-component started negative deviation and the spectral amplitude of the ULF wave intensified. Both large isolated riometer absorption and large negative deviation of the geomagnetic H-component occurred at about 0639UT. There was a time lag of about one hour and ten minutes between the storm onset and the IMF southward turning, as measured by the WIND satellite. The polar ionosphere was highly disturbed, as shown by frequent large deviations of the geomagnetic H-component, large riometer absorption events and strong ULF waves in all the courses of the storm. The absorption increased greatly causing the digisonde to be blackout most of the time. However, the data still showed a substantial decrease in the F2 electron density and oscillation of the F2 layer peak height with an amplitude exceeding 200 km.     

The sudden increase in ionospheric total electron content caused by the very intense solar flare on July 14, 2000

The present paper studies the sudden increase in total electron content (SITEC) on the ionosphere caused by the very intense solar flare on July 14, 2000. According to the well-known Chapman theory of ionization, we derive the relationship between the temporal variation rate, of the total electron content (TEC) and the flare parameters. It is shown that is proportional to the effective flare radiation flux, If, and inversely proportional to the Chapman function, ch(χ), of the zenith angle χ. TEC data observed by the GPS networks located in China, Southeast Asia and Australia during the very intense solar flare on July 14, 2000 are used to statistically investigate the relation between the observed and ch(χ). The analyses show that the two quantities are inversely proportional to each other, as the theory predicted. The present work shows that GPS observation is a powerful tool for studying solar flare effects on the ionosphere, I.e. The sudden ionospheric disturbances (SIDs). Because of its advantages of high precision, large geographical distribution and good temporal resolution, GPS TEC observation may reveal quantitatively the process of ionospheric disturbances caused by solar flares. Therefore, our results are of significance in the space weather research.     

The sudden increase in ionospheric total electron content caused by the very intense solar flare on july 14, 2000

The present paper studies the sudden increase in total electron content (SITEC) on the ionosphere caused by the very intense solar flare on July 14, 2000. According to the well-known Chapman theory of ionization, we derive the relationship between the temporal variation rate, ?TEC/?t of the total electron content (TEC) and the flare parameters. It is shown that ?TEC/?t is proportional to the effective flare radiation flux, I_f, and inversely proportional to the Chapman function, ch(χ), of the zenith angle χ. TEC data observed by the GPS networks located in China, Southeast Asia and Australia during the very intense solar flare on July 14, 2000 are used to statistically investigate the relation between the observed ?TEC/?t and ch(χ). The analyses show that the two quantities are inversely proportional to each other, as the theory predicted. The present work shows that GPS observation is a powerful tool for studying solar flare effects on the ionosphere, i.e. the sudden ionospheric disturbances (SIDs). Because of its advantages of high precision, large geographical distribution and good temporal resolution, GPS TEC observation may reveal quantitatively the process of ionospheric disturbances caused by solar flares. Therefore, our results are of significance in the space weather research.     

The Hubbard Model at Half-Filling, Part III: the Lower Bound on the Self-Energy

We complete the proof that the two-dimensional Hubbard model at half- filling is not a Fermi liquid in the mathematically precise sense of Salmhofer, by establishing a lower bound on a second derivative in momentum of the first nontrivial self-energy graph.submitted 20/12/04, accepted 10/12/05     

改良超长降调节方案启动日LH、E2水平与EMs患者IVF- ET结局的关系

目的探讨改良超长降调节方案启动日LH、E2水平与子宫内膜异位症（EMs）患者体外受精-胚胎移植技术（IVF- ET）结局的关系。方法50例EMs患者（腹腔镜确诊）接受改良超长降调节方案治疗,患者接受GnRH- a治疗3～6个月,每次1.88 mg（1/2支）达菲林肌内注射,间隔28d,第2次注射达菲林后2周开始检测血清CA125,CA125降至18U/L以下后注射末次达菲林1/2支,于末次达菲林注射后2～6周开始用人绝经期促性腺激素（HMG）肌肉注射促进卵泡发育,按启动日血清LH水平分为两组,A1组25例,LH＜0.5U/L,B1组25例,LH≥0.5U/L,比较两组IVF- ET结局。另按启动日E2水平分为两组,A2组E2＜20pg/ml,B2组E2≥20pg/ml,比较两组IVF- ET结局。结果 A1组平均用药天数[（14.71±4.13）d]多于B1组[（8.86±0.49）d],A1组种植率（24.5%）低于B1组（33.3%）,差异均有统计学意义（均P＜0.05）。A2组与B2组间各项指标未见明显差异。结论改良超长降调节方案治疗EMs患者启动日LH过低将增加HMG用药天数,降低种植率,LH应作为超排启动的主要指标。     

The forms of energy and their transformations : Plenary report of the 5-th All-Union Congress on theoretical and applied mechanics. Alma-Ata, May 27, 1981

The meaning of various model concepts, particularly those devised for space and time, or of chosen general reference systems of various kinds, of general or tetrad coordinate systems, and of universal and particular physical characteristic concepts having the property of covariance is expounded. Basic relations, such as force or scalar energy laws for purely mechanical phenomena or small individual volumes of matter and fields in physical processes of general form in the presence of internal and external interactions accompanied by transformation among themselves of various forms of energy, are noted.