A study on the energetic electron precipitation observed by CSES

High energy particles are the main target of satellite space exploration; particle storm events are closely related to solar activity,cosmic ray distribution, and magnetic storms. The commonly seen energetic particle(electron) precipitation anomalies include mainly the inner and outer Van Allen radiation belts, the South Atlantic Anomaly, and the anomalous stripes excited by artificial electromagnetic waves. The China Seismo-Electromagnetic Satellite(CSES), launched in February of 2018, provides a platform for studying ionospheric particle disturbances. This paper reports the first studies of electron precipitation phenomenon based on high energy particle data from the CSES. We find that the global distribution of electron fluxes in the low energy band(0.1–3 MeV) can relatively well reflect the anomalous precipitation belt, which is consistent with results based on the DEMETER satellite, indicating that the quality of the lowenergy band payload of the CSES is good. In addition, this paper makes an in-depth study of the electron precipitation belt excited by the NWC artificial VLF electromagnetic transmitter located in Australia, which appears as a typical wisp structure on the energy spectrum. The magnetic shell parameter L corresponding to the precipitation belt ranges from 1.44 to 1.74, which is close to the L value(～1.45) of the NWC transmitter; the energy of the precipitation electrons is between 100 keV and 361.57 keV, among which the precipitation of 213.73 keV electrons is most conspicuous.

The first joint experimental results between SURA and CSES

In June 2018, for the first time, the SURA heating facility in Russia, together with the in-orbit China Seismo-Electromagnetic Satellite(CSES), carried out a series of experiments in emitting high frequency(HF) O-mode radio waves to disturb the ionosphere. This paper reports data from those experiments, collected onboard CSES, including electric field, in-situ plasma parameters, and energetic particle flux. Five cases are analyzed, two cases in local daytime and three in local nighttime. We find that the pumping wave frequencies f_0 in local daytime were close to the critical frequency of the F_2 layer f_oF_2, but no pumping waves were detected by the electric field detector(EFD) on CSES even when the emitted power reached 90 MW, and no obvious plasma disturbances were observed from CSES in those two daytime cases. But on June 16, there existed a spread F phenomena when f_0 was lower than f_oF_2 at that local daytime period.During the three cases in local nighttime, the pumping waves were clearly distinguished in the HF-band electric field at the emitted frequency with the emitted power only 30 MW; the power spectrum density of the electric field was larger by an order of magnitude than the normal background, with the propagating radius exceeding 200 km. Due to the small f_oF_2 over SURA in June at that local nighttime period, f_0 in these three cases were significantly higher than f_oF_2, all belonging to under-dense heating conditions. As for the plasma parameters, only an increase of about 100 K in ion temperature was observed on June 12; in the other two cases(with one orbit without plasma data on June 17), no obvious plasma disturbances were found. This first joint SURA-CSES experiment illustrates that the present orbit of CSES can cross quite close to the SURA facility, which can insure an effective heating time from SURA so that CSES can observe the perturbations at the topside ionosphere excited by SURA in the near region. The detection of plasma disturbances on June 12 with under-dense heating mode in local nighttime provides evidence for likely success of future related experiments between CSES and SURA,or with other HF facilities.

Study on the relationship of iodine nutritional status with thyroid function and autoantibodies in pregnant women in Baotou

Objective:To investigate the relationship of iodine nutritional status with thyroid function in pregnant women in Baotou,and provide a scientific basis for the guide of reasonable iodine supplementation.Methods:By use of As-Ce catalysis spectrophotometry,the urinary iodine concentration was determined in 90 women during different periods of pregnancy admitted to Baogang Hospital of Inner Mongolia from January 2017 to December 2017.The determination of thyroid function and the autoantibody level was carried out by electro-chemiluminescence immunoassay(ECLIA).Results:In the early trimester of pregnancy,pregnant women with iodine deficiency,iodine sufficiency and iodine excess accounted for 36.67%,40.00%and 23.33%respectively;in the middle trimester of pregnancy,they accounted for 66.67%,26.67%and 6.66%respectively;they made up 40.00%,40.00%and 20.00%respectively in the late trimester of pregnancy.The rate of iodine deficiency in women in the middle trimester of pregnancy was significantly higher than that in women in the early and the late trimesters of pregnancy respectively,and the difference was statistically significant(p<0.05).The rate of iodine deficiency in pregnant women was positively correlated to the positivity of thyroid peroxidase antibody.Moreover,it had no relationship with the positivity of thyroglobulin antibody.No matter in the pregnant women with iodine deficiency or with iodine excess,the abnormality rate of thyroid function and autoantibodies was significantly higher than that in the pregnant women with iodine sufficiency.The difference was statistically significant(p<0.05).Conclusions:The iodine deficiency in the women in the middle trimester of pregnancy is more severe than that in the women in the early and the late trimesters of pregnancy.Iodine deficiency during pregnancy is positively correlated with the positivity of thyroid peroxidase antibody.Pregnant women with iodine deficiency and iodine excess show a higher abnormality rate of thyroid function and autoantibodies.It is recommended to advocate health education on iodine nutrition to pregnant women,and conduct the dynamic monitoring of urinary iodine concentration and the screening of thyroid function and autoantibodies during pregnancy.