机械化学法强化废弃锂离子电池中钴和锂的浸出

以SiO_(2)为助磨剂,采用机械化学法提高废弃锂离子电池中Co和Li的浸出率。实验结果表明,在SiO_(2)与LiCoO_(2)质量比为1:1、研磨转速为500 r/min及研磨时间为30 min的最优条件下,Co和Li在柠檬酸中的浸出率分别达到94.91%和97.22%。表征结果表明,通过机械化学研磨,LiCoO_(2)形成新的活性表面,表面性质发生变化。同时,LiCoO_(2)晶格结构发生缺陷,原子配位不全使反应活性增强。在机械作用下,炭黑的还原作用提高了Co^(3+)的浸出效率。结果表明,该工艺能有效地从LiCoO_(2)中回收Co和Li。

Total cholesterol to high-density lipoprotein ratio and nonalcoholic fatty liver disease in a population with chronic hepatitis B

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is characterized by hypertriglyceridemia,increased low-density lipoprotein cholesterol levels,and reduced highdensity lipoprotein cholesterol(HDL-C)particles.Previous studies have shown that the total cholesterol to high-density lipoprotein cholesterol ratio(TC/HDL-C)was superior to other lipid metabolism biomarkers for predicting NAFLD risk and could be a new indicator of NAFLD.However,the association between TC/HDL-C and NAFLD in patients with hepatitis B virus(HBV)has not yet been determined.AIM To investigate the association between TC/HDL-C and NAFLD in a population with chronic hepatitis B(CHB).METHODS In this study,183 HBV-infected patients were enrolled.All participants underwent blood chemistry examinations and abdominal ultrasound.Univariate and multivariate logistic regression models,curve fitting analysis,and threshold calculation were used to assess the relationship between TC/HDL-C and NAFLD.RESULTS The overall prevalence of NAFLD was 17.49%(n=32)in the 183 CHB participants.The TC/HDL-C of non-NAFLD and NAFLD patients were 3.83±0.75 and 4.44±0.77,respectively(P<0.01).Logistic regression analysis showed that TC/HDL-C was not associated with NAFLD after adjusting for other pertinent clinical variables.However,at an optimal cutoff point of 4.9,a non-linear correlation between TC/HDL-C and NAFLD was detected.The effect size of the left and right sides of the inflection point were 5.4(95%confidence interval:2.3-12.6,P<0.01)and 0.5(95%confidence interval:0.1-2.2,P=0.39),respectively.On the left side of the inflection point,TC/HDL-C was positively associated with NAFLD.However,no significant association was observed on the right side of the inflection point.CONCLUSION This study demonstrated a non-linear correlation between TC/HDL-C and NAFLD in a population with CHB.TC/HDL-C was positively associated with NAFLD when TC/HDL-C was less than 4.9 but not when TC/HDL-C was more than 4.9.

Increased southerly and easterly water vapor transport contributed to the dry-to-wet transition of summer precipitation over the Three-River Headwaters in the Tibetan Plateau

The Three-River Headwaters(TRH)region in the Tibetan Plateau is vulnerable to climate change;changes in summer(June–August)precipitation have a significant impact on water security and sustainability in both local and downstream areas.However,the changes in summer precipitation of different intensities over the TRH region,along with their influencing factors,remain unclear.In this study,we used observational and ERA5 reanalysis data and employed a precipitation categorization and water vapor budget analysis to quantify the categorized precipitation variations and investigate their possible linkages with the water vapor budget.Our results showed an increasing trend in summer precipitation at a rate of 0.9 per year(p<0.1)during 1979–2020,with a significant dry-to-wet transition in 2002.The category‘very heavy precipitation’(10 mm d−1)contributed 65.1%of the increased summer precipitation,which occurred frequently in the northern TRH region.The dry-to-wet transition was caused by the effects of varied atmospheric circulations in each subregion.Southwesterly water vapor transport through the southern boundary was responsible for the increased net water vapor flux in the western TRH region(158.2%),while southeasterly water vapor transport through the eastern boundary was responsible for the increased net water vapor flux in the central TRH(155.2%)and eastern TRH(229.2%)regions.Therefore,we inferred that the dry-to-wet transition of summer precipitation and the increased‘very heavy precipitation’over the TRH was caused by increased easterly and southerly water vapor transport.