利用铝电解槽废旧阴极碳热还原铬铁矿（英文）

铝电解槽废旧阴极(SPL)是铝电解生产过程中产生的废料,被用作造渣熔剂与碳源来碳热还原铬铁矿。本研究的主要目标是促进碳热还原过程中铬铁合金颗粒的生长,以利于后续过程中合金与渣相的分离。实验证明相对于采用石墨作为还原剂,SPL中的碳组分能够更有效地还原铬铁矿。铬铁矿还原过程中矿物颗粒表面形成惰性的尖晶石层(MgAl_2O_4),从而阻碍反应的进行以及铬铁合金的生长。SPL中的造渣组分(例如霞石及NaF)在较低温度下(约1300℃)形成熔渣,并部分熔解尖晶石以及铬铁矿相。通过破坏铬铁矿颗粒表面的惰性尖晶石层、促进传质过程以及提高还原温度(例如1500℃)实现铬铁合金颗粒的生长。在还原温度为1500℃以及采用SPL作为添加剂条件下,还原得到较为粗大的铬铁合金颗粒,采用淘析法能够实现合金与渣相的有效分离。

Enhancement of the nickel converter slag-cleaning operation with the addition of spent potlining

The slag cleaning(or matte settling) process was experimentally investigated at 1573 K using a fayalitic nickel converter slag containing spinel and matte/alloy particles.The addition of various amounts of spent potlining(SPL) was studied in terms of its influence on matte settling and the overall metal recoveries.The slags produced were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and wet chemical analysis using inductively coupled plasma optical emission spectrometry.The presence of solid spinel particles in the molten slag hindered coalescence and settling of matte/alloy droplets.Matte settling was effectively promoted with the addition of as little as 2 wt% SPL because of the reduction of spinel by the carbonaceous component of the SPL.The reduced viscosity of the molten slag in the presence of SPL also contributed to the accelerated matte settling.Greater metal recoveries were achieved with larger amounts of added SPL.Fast reduction of the molten slag at 1573 K promoted the formation of highly dispersed metal particles/clusters via accelerated nucleation in the molten slag,which increased the overall slag viscosity.This increase in viscosity,when combined with rapid gas evolution from accelerated reduction reactions,led to slag foaming.

Improve meat production and virus resistance by simultaneously editing multiple genes in livestock using Cas12i^(Max)

The clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated gene(Cas) system is continually optimized to achieve the most efficient gene editing effect. The Cas12i^(Max), a Cas12i variant, exhibits powerful DNA editing activity and enriches the gene editing toolbox. However, the application of Cas12i^(Max)in large domestic animals has not yet been reported. To verify the efficiency and feasibility of multiple gene editing in large animals, we generated porcine fibroblasts with simultaneous knockouts of IGF2, ANPEP, CD163,and MSTN via Cas12i^(Max)in one step. Phenotypically stable pigs were created through somatic cell nuclear transfer technology. They exhibited improved growth performance and muscle quality. Furthermore, we simultaneously edited three genes in bovine fibroblasts. A knockout of MSTN and PRNP was created and the amino acid Q-G in CD18 was precisely substituted. Meanwhile, no off-target phenomenon was observed by sum-type analysis or off-target detection. These results verified the effectiveness of Cas12i^(Max)for gene editing in livestock animals and demonstrated the potential application of Cas12i^(Max)in the field of animal trait improvement for agricultural production.

废旧锂离子电池选择性提锂

新能源汽车行业的蓬勃发展不仅使锂离子电池需求量激增,大批锂离子电池在达到一定循环次数后也会因无法继续使用而报废。目前研究者们已经对废旧锂离子电池中有价金属的提取方法进行了许多研究,但回收过程中重点关注的对象是钴和镍,锂作为锂离子电池中的主要成分没有给予足够的重视。随着锂资源供需关系的日趋紧张,近年来通过将废旧锂离子电池中的锂优先选择性提取以提高其回收效率的研究不断增多。基于此,本文系统梳理了从不同正极材料(如钴酸锂、锰酸锂、镍钴锰酸锂和磷酸铁锂)中选择性提锂的方法,包括高温转型、选择性浸出、机械化学及电化学法,为后续有关退役锂离子电池选择性提锂的研究及产业实践提供参考。

Domesticated cynomolgus monkey embryonic stem cells allow the generation of neonatal interspecies chimeric pigs

Blastocyst complementation by pluripotent stem cell(PSC)injection is believed to be the most promising method to generate xenogeneic organs.However,ethical issues prevent the study of human chimeras in the late embryonic stage of development.Primate embryonic stem cells(ESCs),which have similar pluripotency to human ESCs,are a good model for studying interspecies chimerism and organ generation.However,whether primate ESCs can be used in xenogenous grafts remains unclear.In this study,we evaluated the chimeric ability of cynomolgus monkey(Macaca fascicularis)ESCs(cmESCs)in pigs,which are excellent hosts because of their many similarities to humans.We report an optimized culture medium that enhanced the anti-apoptotic ability of cmESCs and improved the development of chimeric embryos,in which domesticated cmESCs(D-ESCs)injected into pig blastocysts differentiated into cells of all three germ layers.In addition,we obtained two neonatal interspecies chimeras,in which we observed tissue-specific D-ESC differentiation.Taken together,the results demonstrate the capability of D-ESCs to integrate and differentiate into functional cells in a porcine model,with a chimeric ratio of 0.001-0.0001 in different neonate tissues.We believe this work will facilitate future developments in xenogeneic organogenesis,bringing us one step closer to producing tissue-specific functional cells and organs in a large animal model through interspecies blastocyst complementation.

Effects of chlortetracycline,Cu and their combination on the performance and microbial community dynamics in swine manure anaerobic digestion

Swine manure was typical for the combined pollution of heavy metals and antibiotics. The effects of widely used veterinary antibiotic chlortetracycline（CTC）, Cu and their combination on swine manure anaerobic digestion performance and microbial community have never been investigated. Thus, four 2 L anaerobic digestion reactors were established including reactor A（control）, B（CTC spiked by 0.5 g/kg dry weight, dw）, C（Cu spiked by 5 g/kg dw） and D（combination of CTC, 0.5 g/kg dw, and Cu, 5 g/kg dw）, and dynamics of bacterial and archaeal community structure was investigated using high throughput sequencing method. Results showed that addition of CTC and Cu separately could increase the total biogas production by21.6% and 15.8%, respectively, while combination of CTC and Cu severely inhibited anaerobic digestion（by 30.3%）. Furthermore, corresponding to different stages and reactors, four kinds of microbes including bacteria and archaea were described in detail, and the effects of CTC, Cu and their combination mainly occurred at hydrolysis and acidification phases. The addition of Cu alone changed the dynamics of archaeal community significantly. It was genus Methanomassiliicoccus that dominated at the active methane production for A, B and D, while it was genus Methanobrevibacter and Methanoculleus for C.

Single-cell RNA Sequencing Reveals Thoracolumbar Vertebra Heterogeneity and Rib-genesis in Pigs

Development of thoracolumbar vertebra(TLV)and rib primordium(RP)is a common evolutionary feature across vertebrates,although whole-organism analysis of the expression dynamics of TLV-and RP-related genes has been lacking.Here,we investigated the single-cell transcriptome landscape of thoracic vertebra(TV),lumbar vertebra(LV),and RP cells from a pig embryo at 27 days post-fertilization(dpf)and identified six cell types with distinct gene expression signatures.In-depth dissection of the gene expression dynamics and RNA velocity revealed a coupled process of osteogenesis and angiogenesis during TLV and RP development.Further analysis of cell type-specific and strand-specific expression uncovered the extremely high level of HOXA103′-UTR sequence specific to osteoblasts of LV cells,which may function as anti-HOXA10-antisense by counteracting the HOXA10-antisense effect to determine TLV transition.Thus,this work provides a valuable resource for understanding embryonic osteogenesis and angiogenesis underlying vertebrate TLV and RP development at the cell type-specific resolution,which serves as a comprehensive view on the transcriptional profile of animal embryo development.

Effects of hydraulic retention time on net present value and performance in a membrane bioreactor treating antibiotic production wastewater

A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24 h)were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater.Field experimental data from the membrane bioreactor,both full-scale(500 m/d)and pilot(1.0 m3/d),were used to calculate the net present value(NPV),incorporating both capital expenditure(CAPEX)and operating expenditure.The results showed that the tank cost was estimated above membrane cost in the 38.2%,where capital expenditure contributed 24.2%more than operational expenditure.Tank construction cost was decisive in determining the net present value contributed 62.1%to the capital expenditure.The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane,while flux decline was tolerable.The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent.The upgrade to the membrane bioreactor also benefited further treatments by 10.1%-44.7%lower direct investment.