[en] The beyond design basis accident was analyzed to ensure safe operation of 49-2 Swimming Pool Reactor (SPR) after design life. Because it's difficult to use PSA method, the unconditional assumed severe accidents were adopted to obtain a conservative result. The main conclusions were obtained by analyzing anticipated transients without scram in station blackout (SBO ATWS), horizontal channel rupture, core uncovering after shutdown and emergency response capacity. The results show that the core is safe in SBO ATWS, and the fuel elements will not melt as long as the core are not exposed in 2.5 h in loss of coolant accident caused by horizontal channel rupture and other factors. The passive siphon breaker function and various ways of emergency core makeup can ensure that the core is not exposed. (authors)

[en] Based on safety considerations, a passive siphon breaker will be added to the primary cooling system of 49-2 Swimming Pool Reactor (SPR). With the breaker location determined, the capability of siphon breakers with diameters of 1.5 cm and 2.0 cm was calculated and analyzed respectively by RELAP5/MOD3.3 code. The results show that in the condition of large break loss of coolant accident these two sizes of siphon breakers are able to break the siphon phenomena, and maintain the pool water level above the reactor core when the reactor and the pump are shutdown. In the end, to be conservative, the siphon breaker with diameter of 2.0 cm is adopted. (authors)

[en] Low enriched uranium prototype miniature neutron source reactor (LEU MNSR) is designed on the physical with MCNP code. LEU MNSR detailed geometry structure is described in the design. According to excess reactivity requirements for LEU MNSR, 12.5% is selected for the fuel "2"3"5U enrichment. And then, minimum critical element number, thermal neutron flux density in inside irradiation seat, Central control rod efficiency, top beryllium efficiency are calculated. a suitable LEU MNSR core structure is chose. At last, using WIMSD-4, CITATION and EXTERMINATOR-2 code, Moderator temperature coefficient, Fuel reactivity coefficient, Prompt neutron lifetime and effective delayed neutron fraction are calculated. The stability characteristic of the reactor is studied with ELAP5/SCDAPSIM/MOD3.2 code. It has shown that LEU MNSR has good inherent safety. (authors)

[en] Objective: To investigate the hemodynamic changes in the rabbit liver and VX2 hepatic implantation tumor after treatment by transcatheter arterial chemoembolization (TACE)/endostatin using Doppler ultrasonography. Methods: Twenty rabbits with VX2 hepatic tumor were randomly distributed into the control group (n=10) and the anti- angiogenesis group (n=10). The rabbits were administered with endostatin and adriamycin-lipiodol in the anti-angiogenesis group and with 37℃ saline in the control group via hepatic artery. The hemodynamic changes of the tumors, hepatic artery, and portal vein were recorded with Doppler ultrasonography 1 week after the treatment. The results before and after the treatment were compared. Results: In the control group, the maximal hepatic artery blood flow velocity was significantly higher than that before the treatment (P<0.05). However, the resistance index and the portal vein blood flow velocities had no significantly change compared with those before the treatment (P>0.05). In the anti-angiogenesis group, the hepatic artery blood flow velocity was significantly lower than that before the treatment (P<0.05), and the resistance index was increased (P<0.05). However, the portal vein blood flow velocity had no significantly change (P>0.05). The blood flow signal in all tumors was rich before embolization. After TACE, the blood flow signal was significantly decreased, even partly disappeared in the anti-angiogenesis group. Conclusion: TACE with endostatin can effectively block the blood supplement of VX2 hepatic implantation tumor. Doppler ultrasonography can detected the blood flow changes and can be used in evaluating the therapeutic effect in hepatic implantation tumor. (authors)

[en] The transient thermal hydraulic characteristics of 49-2 Swimming Pool Reactor (SPR) were analyzed by RELAP5/MOD3.3 code to verify the capability of natural circulation and minus reactivity feedback for accident mitigation under the condition of station blackout (SBO). Then, the effects on accident consequence and sequence for core channels and primary pumps were briefly discussed. The calculation results show that the reactor can be shutdown by the effect of minus reactivity feedback, and the residual heat can be removed through the stable natural circulation. Therefore, it demonstrates that the 49-2 SPR is safe during the accident of SBO. (authors)

[en] In this paper we present a novel fabrication technique that utilizes polycaprolactone (PCL) as a bonding medium due to its low melting temperature property. PCL is biodegradable polyester with a melting point of 60 °C, and a glass transition temperature of −60 °C [1–10]. It is used as a rapid bonding medium in the fabrication process that readily produces complete microfluidic chips. The microchannels are produced via laser ablation micromachining and thermal embossing, followed by bonding with PCL. The PCL is uniformly coated on a piece of polymer sheet to produce a thin film on its surface. A complete microfluidic channel is formed by enclosing the open channel with the PCL-coated polymer piece. This fabrication technique lends itself readily to various polymers, such as (poly)methylmethacrylate (PMMA), polycarbonate (PC), polyetherimide (PEI) and poly(ethylene terephthalate) (PETE), facilitating device production for a variety of application, even permitting hybrid polymer chips. The bonding was performed rapidly at 60 °C. This approach provides a more direct method to generate hard polymer microfluidic chips than classical techniques and is therefore highly amendable to rapid prototyping. This work also explores the use of PCL as an alternative approach to making simple, cost-effective universal adhesive for bonding interconnects. Bonding is performed at 60 °C, by placing the adhesive layer in between an interconnect port and a microchip. This method allows for connections to be made easily and quickly. (paper)

[en] A nondoped full-exciplex approach is applied in white organic light-emitting diodes (WOLEDs). Both the blue emission and yellow emission are from exciplex, which makes it possible to exceed the 25% internal quantum efficiency limit of normal fluorescent OLEDs via reverse intersystem crossing from triplet to singlet states because of the small energy gap between them. White emission can be realized by simply stacking the blue and yellow exciplex materials because the same acceptor material is used in the emitting systems. And a two-color WOLED with an external quantum efficiency (EQE) of 6.11% is demonstrated, exceeding the efficiencies of the exciplex-based blue and yellow monochrome devices. The higher efficiency is attributed to redistribution of the exciplex excitons, which suppresses the exciton concentration quenching at the emission interface. By adopting a quantum-well-like structure, the EQE can be further improved. This approach sheds light on the simple fabrication of high-efficiency WOLEDs in the future. (© 2021 Wiley‐VCH GmbH)

[en] High-quality In_0.2Ga_0.8N epilayers were grown on a GaN template at temperatures of 520 and 580 °C via plasma-assisted molecular beam epitaxy. The X-ray rocking curve full widths at half maximum (FWHM) of (10.2) reflections is 936 arcsec for the 50-nm-thick InGaN layers at the lower temperature. When the growth temperature increases to 580 °C, the FWHM of (00.2) reflections for these samples is very narrow and keeps similar, while significant improvement of (10.2) reflections with an FWHM value of 612 arcsec has been observed. This improved quality in InGaN layers grown at 580 °C is also reflected by the much larger size of the crystalline column from the AFM results, stronger emission intensity as well as a decreased FWHM of room temperature PL from 136 to 93.9 meV.

[en] The Large High Altitude Air Shower Observatory (LHAASO) detectors would be operated at Yangbajing, under the condition of high altitude (4300 m, 0.6 atm) and large dynamic temperature variation (from -25 ℃ to 40 ℃). To keep the gains of the photomultiplier tubes used stable within 5%, it is required that the temperature coefficient and ripple index of the power supplies should be less than 0.01%/C and 0.01%, respectively. Different types of power supplies were tested in an environment simulation system, where the temperature and air pressure are controllable, three of which meet the requirements and are chosen as the candidates. (authors)

[en] We report the specific contact resistance for ITO with both metal and a semiconductor. Good quality ITO was deposited by electron beam evaporation with the resistivity of 2.32 × 10"−"4 Ω·cm and an averaged transmittance of 92.8% in the visible light region. The circular transmission line model (c-TLM) method was used to evaluate and compare the properties of the ITO/metal and ITO/semiconductor ohmic contacts. The lowest specific contact resistance of the ITO/Ni is 2.81 × 10"−"6 Ω·cm"2, while that of ITO/n-GaAs is 7 × 10"−"5 Ω·cm"2. This is the best ohmic contact between ITO and n-GaAs ever reported. These results suggest that good quality ITO has strong potential to be used to realize highly efficient solar cells. (paper)