As an important functional material for water treatment,ion exchange resin is widely used in medicine,chemical industry,nuclear industry and other fields.Due to its high efficiency and reliability,it is also widely used in the water circulation system of China Space Station,such as urine treatment subsystem,water treatment subsystem,and electrolytic oxygen production subsystem,which effectively guarantees the normal operation of the equipment and the safe use of water resources.Considering its renewability,the development of ion exchange resin regeneration technology for manned space missions can further reduce the supply demand of long-term missions,which is of great significance for the development of manned space flight to deep space.This paper focuses on the application characteristics and research progress of three kinds of ion exchange resin electro-regeneration technology,and the potential auxiliary regeneration technologies such as thermal regeneration,biological regeneration,ultrasonic regeneration and carbon dioxide regeneration are introduced,and the application prospect analysis of ion exchange regeneration technology is given according to the application characteristics of manned spaceflight.

In response to the challenge of sintering silicon carbide ceramic into complex part,which limits it application in certain mechanical seal,a design was developed that integrates silicon carbide ring with metal component to create a mechanical sealed with intricate structure.Type tests and durability tests were designed and conducted in the context of urine processor assembly for space stations,the test results indicate that the static liquid leakage rate of mosaic type mechanical seal did not exceed 0.88 mL/h under a pressure differential of 50 kPa,and the dynamic liquid leakage rate did not exceed 0.47 mL/h at a rotational speed of 400 r/min.The vibration and impact qualification tests of dynamic environment were conducted under the conditions of mechanical seals installed.There was no change in sealing performance observed before and after the tests.Following that,a 4 500-hour durability test was performed in pretreated urine.The results showed good sealing performance.After the test,the mechanical seals were disassembled and checked.the installation and appearance of ceramic rings were found to be in good condition,with no visible corrosion or wear.The results suggest that this integrated structure meets the requirements for complex mechanical structures and can operate stably over extended periods under acidic and corrosive liquid conditions.

When conducting long-term experimental verification of urine regeneration using ground equipment of manned space water regeneration system,it was found that the ion exchange removal ability of the water regeneration system is also affected when the pre-treatment agent changes.Therefore,the influence behavior and mechanism of pre-treatment agent changes on the ion exchange removal capacity of water regeneration systems were studied through small sample experiments,water quality composition analysis,and other means.The results showed that with the increase of CrO3 content in the pre-treatment agent,the organic acid content in distilled water increased,leading to an increase in the conductivity,an increase in the organic carbon content,and a decrease in pH value of distilled water.Organic acids have low degree of dissociation in water,and their selectivity coefficients are low when exchanging with strong alkaline anion exchange resins.This results in a slow ion exchange rate of the acid ion.As the organic acid content in distilled water increases,the ion exchange band of acid ion widens and shifts backwards,causing resin penetration,resulting in a decrease in the ion exchange removal ability of the water regeneration system.

Chemical characteristics of callosal neurons in the frontal and occipital cortex of Wistar rat were studied by means of combined method of HRP retrograde tracing andimmunocytochemistry of glutamate (Glu) and ?-aminobutyric acid (GABA). Glutamate containing callosal neurons were large or medium sized pyramidal cells and mainly localized in layers Ⅱ/Ⅲ, Ⅴ and Ⅵ. They tended to appear in clusters. GABA containing callosal neurons were also found. They were medium sized nonpyramidal cells with round, elliptic, or fusiform soma and were mostly localized in layers Ⅴ and Ⅵ. They also tended to appear in clusters. The percentage of GABA containing callosal neurons (about 8% and 10% in frontal and occipital cortex respectively)was much less than that of glutamate containing callosal neurons (about 17% and 29% in frontal and occipital cortex respectively). These results further confirmed that part of callosal cells used glutamate as an excitatory transmitter and firstly confirmed that some callosal neurons contained an inhibitory transmitter GABA morphologically. In view of the existence of GABA containing callosal neurons, it also suggested that at least in rat cerebral cortex,some GABA containing neurons had longer projections than local circuit neurons. According to the results of ours and other authors, we suggested that callosal system was the one that contained different kinds of neurotransmitters, and that diversification of the transmitters and their interaction in the callosal system was one of the neuroanatomical bases of the complicated and advanced functions of the callosal neurons.

Objective To observe the protective effects of salidroside on glutamate-induced injury in cultured hippocampal neurons.Methods Primarily cultured hippocampal neurons from fetal Wistar rat were incubated with salidroside(10,20 and 40mg/L) for 24 hours,then glutamate(125?mol/L) was added for 15 minutes to induce injury.Cell viability was detected by MTT assay,the vigor of LDH was determined by biochemistry method,the apoptosis rates were anallyzed using Annexin V-FITC and PI labelling and Hoechst 33342 staining and flow cylometric assay.Fluorescent intensity of intracellular free calcium was observed with laser scanning confocal microscopy(LSCM).Results After the pretreatment with salidroside for 24 hours,the increases of LDH vigor and apoptosis rates and the decrease of cell viability caused by glutamate were resisted obviously.Salidroside inhibited the increase of Ca~2+ in cytoplasm significantly.Conclusion Salidroside can significantly resist the injury induced by glutamate.The neuroprotective activities of salidroside can be related to its ability to reduce Ca~2+ overload in cytoplasm.