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In this study, the multi-source optical remote sensing and radar remote sensing from 2008 to 2017 are used to perform long-term sequential monitoring of Chaohu blooms. A spatio-temporal fusion model is employed to fill the gap period to obtain temporal and spatial changes of Chaohu bloom in the past ten years. Through the principal component analysis technology, the mechanisms of the main climate-driven factors in the change of water area are explored. The experimental results show that the combination of multi-source optical and radar remote sensing and spatio-temporal fusion model can be well applied to long-term bloom monitoring; besides, it has also been found that the area of water bloom in Chaohu Lake increases with the increase of temperature, wind speed and sunshine duration.

A new three-dimensional cellular system based on the elongated octahedron model [1] is analyzed and discussed mathematically for its compressibility properties. It is shown that there exists negative linear and area compressibility for some certain conformations in this model. In addition, when compared with the octahedral structure, it can be found that this structure has better negative compression effect in the horizontal direction.

This paper examines individual radiation effects caused by 110 KeV electrons, 70 KeV electrons and 170 KeV protons, and combined radiation effects induced by 110 KeV electrons together with 170 KeV protons and 70 KeV electrons with 170 KeV protons on the forward current gain of bipolar junction transistors (3CG130, PNP). The combined radiation effects include simultaneous and sequential radiation effects. Key parameters were measured in-situ and the change in current gain of the PNP transistors is obtained at a fixed voltage of emitter-base junction . Experimental results show that the current gain degradation of the PNP transistors is sensitive to both of ionization and displacement damage. The ionization damage is primarily caused by 110 KeV and 70 KeV electrons, while the displacement damage is mainly induced by 170 KeV protons in this investigation. Based on the simultaneous and sequential exposure results, the ionization damage caused by 110 KeV and 70 KeV electrons could give annealing-like and enhancing effects to displacement damage induced by 170 KeV protons for PNP BJTs.

The characteristic degradation in silicon NPN bipolar junction transistors (BJTs) of 3DG112 type is examined under the irradiation with 25 MeV carbon (C) ions and various bias conditions. Different electrical parameters were measured in-situ during the exposure under each bias condition. From the experimental data, larger variation of base current (IB) is observed after irradiation at a given value of base-emitter voltage (VBE), while the collector current is only slightly affected by irradiation at a given VBE. The gain degradation is mostly affected by the behavior of the base current. The change in the reciprocal of current gain (Δ(1/β)) increases linearly with increasing the C ions fluence. The degradation of the NPN BJTs under various bias conditions during irradiation was studied. Compared to the case where the terminals are grounded, at a given fluence, the change in the reciprocal of current gain varies slightly less when the base-emitter junction is forward biased. On the other hand, there is no distinction for the change in the reciprocal of current gain between the case of reverse-biased base-emitter junction and that of all terminals grounded for the NPN BJTs at a given fluence.

Electrical degradation of two type NPN bipolar junction transistors (BJTs) with different emitter sizes was examined under exposures of 70 and 110 keV electrons. Base and collector currents as a function of base–emitter voltage were in-situ measured during exposure. Experimental results show that both the 70 and 110 keV electrons produce an evident ionization damage to the NPN BJTs. With increasing fluence, collector currents of the NPN BJTs hardly change in the whole range of base–emitter voltage from 0 to 1.2 V, while base currents increase in a gradually mitigative trend. Base currents vary more at lower base–emitter voltages than at higher ones for a given fluence. The change in the reciprocal of current gain at a fixed base–emitter voltage of 0.65 V increases non-linearly at lower fluences and tends to be gradually saturated at higher fluences. Sensitivity to ionization damage increases for BJTs with an emitter having a larger perimeter-to-area ratio.

This paper examines individual radiation effects caused by 110 keV electrons, 70 keV protons and 170 keV protons, and combined radiation effects induced by 110 keV electrons together with 70 keV protons and 110 keV electrons with 170 keV protons on the forward current gain of bipolar junction transistors (3DG112D, NPN). Key parameters were measured in-situ and the change in current gain of the NPN transistors is obtained at a fixed collector current. Experimental results show that the current gain degradation of the NPN transistors is sensitive to both of ionization and displacement damage. The ionization damage is primarily caused by 110 keV electrons, while the displacement damage is mainly induced by 170 keV protons in this study. Under the combined exposure of 170 keV protons and 110 keV electrons, the current gain degradation lies between those given by the individual irradiations. The current gain degradation is mainly caused by the 170 keV protons, and the 110 keV electrons mitigate the degradation to some extent. In the case of combined irradiation of 110 keV electrons and 70 keV protons, no synergistic effect occurs, the current gain degradation is basically controlled by the 110 keV electrons.

The current gain degradation in silicon NPN bipolar junction transistors (BJTs) was examined under irradiation with 3–10 MeV protons and 20–60 MeV bromine (Br) ions with various dose levels. To characterize the radiation damage of the NPN BJTs, the ionizing dose Di and displacement dose Dd as a function of chip depth in the NPN BJTs were calculated for both the protons and Br ions with different energies. Based on the irradiation testing and calculated results, it is shown that the current gain degradation of NPN BJTs is sensitive to the ratio of Dd/(Dd+Di) in the sensitive region given by protons and Br ions. The irradiation particles (protons and Br ions), which give larger Dd/(Dd+Di) at a given total dose, would generate more severe damage to the NPN BJTs. The reciprocal of the gain variation as a function of the displacement dose was compared, showing that the Messenger–Spratt equation becomes relevant to describe the experimental data, when the ratio of the Dd/(Dd+Di) are larger and the displacement dose are higher than a certain value.

The radiation responses of the NPN bipolar junction transistors (BJTs) and the TTL bipolar integrated circuits (ICs) have been examined using 20, 40 and 60 MeV Br ions. Key electric parameter was measured and compared after each energy irradiation. Experimental results demonstrate that the degradation in electric parameters caused by the Br ions shows a common feature for the NPN BJTs and TTL ICs, in which the degradation is strengthened with decreasing the Br ions energy. The ionizing dose ( D i ) and displacement dose ( D d ) as a function of the chip depth in the bipolar devices were calculated using the SRIM code, in order to analyze the radiation effects on the NPN BJTs and the Bipolar ICs. From the experiment and calculation results, it could be deduced that the Br ions mainly cause displacement damage to both the NPN BJTs and the TTL ICs, and the higher the ratio of D d /( D d +D i ), the larger the degradation in electric parameters at a given total dose.