Pilot Study on Powder Active Carbon / Flotation/Microflocculation / Ultrafiltration Combined Process for Treatment of Reservoir Water

[Objective] The study aimed to discover the effects of powder active carbon（ PAC） /flotation /micro-flocculation /ultrafiltration combined process on the treatment of reservoir water. [Method]Taken the water from a mountainous reservoir for the initial samples,the parameters such as turbidity,COD Mn,chlorophyll-a and methylisobormeol（ MIB） of water samples were monitored before and after treated with combined processes of micro-flocculation /ultrafiltration, flotation /micro-flocculation /ultrafiltration, PAC /flotation /micro-flocculation /ultrafiltration. [Result] The results showed that the removal rates of turbidity of water samples by the above three processes were 97. 5%,98. 0% and 98. 6%,respectively. The removal rates of COD Mn were 30. 9%,35. 0% and 52. 0%. The removal rates of chlorophyll-a were 80. 6%,91. 0% and 99. 0%. The removal rates of MIB were 17. 0%,34. 2% and 97. 0%. [Conclusion]The PAC /flotation /micro-flocculation ultrafiltration combined process can be flexibly combined based on the characteristics of algae and odor in water,and is suitable for water plant construction or reconstruction.

微液滴限域合成和调控空心多孔Ir基电解水催化剂及其传质促进作用

Maximally exploiting the active sites of iridium catalysts is essential for building low-cost proton exchange membrane(PEM)electrolyzers for green H_(2)production.Herein,we report a novel microdrop-confined fusion/blasting(MCFB)strategy for fabricating porous hollow IrO_(1-x)microspheres(IrO_(1-x)-PHM)by introducing explosive gas mediators from a NaNO_(3)/glucose mixture.Moreover,the developed MCFB strategy is demonstrated to be general for synthesizing a series of Ir-based composites,including Ir-Cu,Ir-Ru,Ir-Pt,Ir-Rh,Ir-Pd,and Ir-Cu-Pd and other noble metals such as Rh,Ru,and Pt.The hollow structures can be regulated using different organics with NaNO_(3).The assembled PEM electrolyzer with IrO_(1-x)-PHM as the anode catalyst(0.5 mg/cm^(2))displays an impressive polarization voltage of 1.593and 1.726 V at current densities of 1 and 2 A/cm^(2),respectively,outperforming commercial IrO_(x)catalysts and most of the ever-reported iridium catalysts with such low catalyst loading.More importantly,the breakdown of the polarization loss indicates that the improved performance is due to the facilitated mass transport induced by the hollowness.This study offers a versatile platform for fabricating efficient Irbased catalysts for PEM electrolyzers and beyond.

Machine Learning-Based Temperature and Wind Forecasts in the Zhangjiakou Competition Zone during the Beijing 2022 Winter Olympic Games

Weather forecasting for the Zhangjiakou competition zone of the Beijing 2022 Winter Olympic Games is a challenging task due to its complex terrain.Numerical weather prediction models generally perform poorly for cold air pools and winds over complex terrains,due to their low spatiotemporal resolution and limitations in the description of dynamics,thermodynamics,and microphysics in mountainous areas.This study proposes an ensemble-learning model,named ENSL,for surface temperature and wind forecasts at the venues of the Zhangjiakou competition zone,by integrating five individual models—linear regression,random forest,gradient boosting decision tree,support vector machine,and artificial neural network(ANN),with a ridge regression as meta model.The ENSL employs predictors from the high-resolution ECMWF model forecast(ECMWF-HRES) data and topography data,and targets from automatic weather station observations.Four categories of predictors(synoptic-pattern related fields,surface element fields,terrain,and temporal features) are fed into ENSL.The results demonstrate that ENSL achieves better performance and generalization than individual models.The root-mean-square error(RMSE) for the temperature and wind speed predictions is reduced by 48.2% and 28.5%,respectively,relative to ECMWF-HRES.For the gust speed,the performance of ENSL is consistent with ANN(best individual model) in the whole dataset,whereas ENSL outperforms on extreme gust samples(42.7% compared with 38.7% obtained by ECMWF-HRES in terms of RMSE reduction).Sensitivity analysis of predictors in the four categories shows that ENSL fits their feature importance rankings and physical explanations effectively.

Cas12a-based on-site, rapid detection of genetically modified crops

Genetically modified(GM)crops that impart herbicide resistance,improved tolerance to biotic and abiotic stresses,and enhanced yield or nutritional quality have been developed and grown worldwide(ISAAA Brief 55-2019:International Servicefor theAcquisition ofAgri-biotech Applications(ISAAA),2019).In response topublic concern on genetically modified organisms(GMOs),DNA-based and protein-based methods have been developed to detect GMOs infood/feed samples(Fraitureetal.,2015).These methods,however,require expensive equipment and technical expertise and are unsuitable for field diagnosis(DNA-based methods)or cannot detect non-coding sequences such as promoters or terminators(protein-based methods).

Tungsten-potassium:a promising plasma-facing material

Tungsten-potassium(potassium-doped tungsten or WK),initially known from the electric filament industry,is a promising plasma-facing material(PFM)in future fusion facilities like International Thermonuclear Experimental Reactor(ITER).However,the brittle nature of W and irradiation-induced defects of WK materials may result in a risk of deuterium-tritium reaction failure in fusion reactors.Previous studies revealed that advanced W with ultrafine grains and nanostructures might be able to address these problems.However,K-doped W,a rapidly developed material for PFMs,lacks a systematical sum-mary.In this review,we firstly describe the powder metallurgy and plastic deformation for the preparation of WK.Then,the mechanical properties of WK and thermal shock resistance results are reviewed.Important issues such as irradiation damages from neutron,heavy ion,and plasma(H isotope or He)irradiation are also discussed.Hitherto,WK under irradia-tions shows comparable or even better performances compared with other counterparts such as ITER grade pure tungsten.This review could be benefitial to the future efforts of improving the ductility and irradiation tolerance of WK materials.

An adaptive policy-based framework for China's Carbon Capture and Storage development

China's political leadership has taken an increasingly public and proactive stance on climate change since 2014. This stance includes making a commitment that Chinese carbon dioxide (CO2) emissions will peak around 2030 and enacting measures through the 13th Five- Year Plan to support energy efficiency, clean energy technology, and carbon management. Chinese policymakers consider carbon capture and storage (CCS) a critical bridging technology to help accelerate the decarbonization of its economy. This paper reviews and analyzes Chinese CCS support policies from the perspective of an adaptive policymaking framework, recognizing uncertainty as an inherent element of the policymaking process and drawing general lessons for responding to changing circumstances. Notably, the political support for CCS in China remains fragmented with uncoordinated government leadership, undecided industry players, and even with opposing voices from some leading scientists. There is scope for expanding the framework to provide more granularity, in particular relating to the development of a CCS infrastructure and the development of storagefocused CO2-EOR. Overall, given the role CCS can play to decarbonize China's power and other industrial sectors, a commitment to CCS from top policymakers and major stakeholders is needed.