Rare earth elements and yttrium in ferromanganese deposits from the South China Sea:distribution,composition and resource considerations

Ferromanganese nodules and crusts contain relatively high concentration of rare earth elements（REE） and yttrium（REY）,with a growing interest in exploitation as an alternative to land-based REY resources.On the basis of comprehensive geochemical approach,the abundance and distribution of REY in the ferromanganese nodules from the South China Sea are analyzed.The results indicate that the REY contents in ferromanganese deposits show a clear geographic regularity.Total REY contents range from 69.1×10^-6 to 2 919.4×10^-6,with an average value of 1 459.5×10^-6.Especially,the enrichment rate of Ce content is high,accounting for almost 60% of the total REY.This REE enrichment is controlled mainly by the sorption of ferromanganese oxides and clay minerals in the nodules and crusts.Moreover,the total REY are higher in ferromanganese deposits of hydrogenous origin than of diagenetic origin.Finally,Light REE（LREE） and heavy REE（HREE） oxides of the ferromanganese deposits in the study area can be classified into four grades： non-enriched type,weakly enriched type,enriched type,and extremely enriched type.According to the classification criteria of rare earth resources,the Xisha and Zhongsha platform-central deep basin areas show a great potential for these rare earth metals.

Cobalt‐N_(4) macrocyclic complexes for heterogeneous electrocatalysis of the CO_(2) reduction reaction

Metal-N_(4)(M-N_(4))macrocyclic complexes are interesting electrocatalysts due to their well-defined structures and rich molecular tuning.Among them,metal phthalocyanines have been widely studied for the carbon dioxide reduction reaction(CO_(2)RR)in heterogeneous systems and demonstrated good electrocatalytic performance.However,other complexes like metal corroles and metal porphyrins are much less explored,and often show inferior performances.In this study,three cobalt macrocyclic complexes,cobalt phthalocyanine,cobalt meso-tetraphenylporphyrin,and cobalt meso-triphenylcorrole(CoPc,CoTPP and CoTPC)are investigated in heterogeneous electrocatalysis of CO_(2)RR.Although CoPc/carbon nanotube(CNT)hybrid exhibits high electrocatalytic activity,CNT hybridization does not work for CoTPC and CoTPP that hold weak interactions with CNTs.By the drop-dry method with a high molecular loading of 5.4×10^(–7) mol cm^(–2),CoTPC and CoTPP could deliver appreciable electrode activities.Poly(4-vinylpyridine)(PVP)introduction is further demonstrated as a facile method to afford enhanced activities for CoTPP at low molecular loadings through enhancing molecule-substrate interactions.The partial current density of carbon monoxide for CoTPP+CNT/PVP is around 8 times higher than the sample without PVP at–0.67 V versus reversible hydrogen electrode.This work provides solutions to enhance the electrode activities of molecular electrocatalysts with weak substrate interactions in heterogeneous systems.

Intercalation of van der Waals layered materials: A route towards engineering of electron correlation

Being parent materials of two-dimensional (2D) crystals, van der Waals layered materials have received revived interest. In most 2D materials, the interaction between electrons is negligible. Introducing the interaction can give rise to a variety of exotic properties. Here, via intercalating a van der Waals layered compound VS2, we find evidence for electron correlation by extensive magnetic, thermal, electrical, and thermoelectric characterizations. The low temperature Sommerfeld coefficient is 64 mJ·K-2·mol-1 and the Kadowaki-Woods ratio rKW^0.20a0. Both supports an enhancement of the electron correlation. The temperature dependences of the resistivity and thermopower indicate an important role played by the Kondo effect. The Kondo temperature TK is estimated to be around 8 K. Our results suggest intercalation as a potential means to engineer the electron correlation in van der Waals materials, as well as 2D materials.

Clinical observation on the effect of electroacupuncture treatment for chloasma in young and middle-aged women

Objective:To evaluate the clinical effect of electroacupuncture treatment for chloasma in young and middle-aged women.Methods:Sixty young and middle-aged female patients with chloasma were divided into treatment group(n=30)and control group(n=30)according to random number table.In the treatment group,the electroacupuncture was applied to the facial acupoints and"Vagus"in the cavity of concha in the ear.The selection of facial acupoints was relating to the running course of facial nerve trunk:Yifeng(翳风TE17),Shangguan(上关GB3)-Sizhukong(丝竹空TE 23)(Temporal branch),Xiaguan(下关ST7)-Sibai(四白ST2)(Zygomatic branch),Qianzheng(牵正Extra)-Quanliao(颧髎SI18)(Zygomatic branch),Jiache(颊车ST6)-Jiachengjiang(夹承浆Extra)(Buccal branch),Hegu(合谷LI 4).Electro-stimulation was adopted at"Vagus"in the cavity of concha in the ear(two distribution points of the vagus in the cavity of concha of each ear).The control group received conventional acupuncture(surrounding method of needling at the Ashi points in the facial lesion area and 15 acupoints which were selected in the highest frequency in the conventional acupuncture treatment).After 8 weeks of treatment,the clinical effects were compared.The total score of facial skin lesion,score of skin lesion color,score of lesion area,and effective rate of treatment for chloasma were used to evaluate the clinical effect of the two groups before and after treatment.Results:After treatment,the effective rate of the treatment group was 95.00%,that of the control group was 67.50%.The effect of the treatment group was better than that of the control group,and the difference was statistically signifiicant(x2=9.928,P=0.002).Before treatment,there was no difference in the area score,color score,and total score of skin lesions between the two groups(P>0.05).After treatment,the area score,color score,and total score of skin lesions in the treatment group were(1.05±0.64),(1.05±0.64),and(2.10±0.98)points respectively,while those in the control group were(1.38±0.63),(1.28±0.75),and(2.65±1.19)points respectively.The area score,color score,and total score of skin lesions in the treatment group were lower than those in the control group,with statistically significant differences(all P<0.05).Conclusion:electroacupuncture is more effective than conventional acupuncture in treating chloasma in young and middle-aged women.

The development of China's Yangtze River Economic Belt:how to make it in a green way?

The Yangtze River is one of the largest and longest rivers in Asia.The river originates in the Tibet-Qinghai Plateau(headwater reach),passes through the mountainous provinces of Sichuan,Yunnan and Chongqing(upper reach),flows into the Central Plain(middle reach)and Lower Plain(lower reach),and finally empties into the East China Sea in Shanghai(estuary).The Yangtze River Economic Belt(YREB;Fig.1)has a surface area of 2.1

Molecular characterization of methanogenic microbial communities for degrading various types of polycyclic aromatic hydrocarbon

Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons(PAHs)is crucial to developing strategies for PAHs bioremediation.In this study,the linkage between the type of PAHs and microbial community structure was fully investigated through 16 S rRNA gene sequencing on four PAH-degrading cultures.Putative degradation products were also detected.Our results indicated that naphthalene(Nap)/2-methylnaphthalene(2-Nap),phenanthrene(Phe)and anthracene(Ant)sculpted different microbial communities.Among them,Nap and 2-Nap selected for similar degrading bacteria(i.e.,Alicycliphilus and Thauera)and methanogens(Methanomethylovorans and Methanobacterium).Nap and 2-Nap were probably activated via carboxylation,producing 2-naphthoic acid.In contrast,Phe and Ant shaped different bacterial and archaeal communities,with Arcobacter and Acinetobacter being Phe-degraders and Thiobacillus Ant-degrader.Methanogenic archaea Methanobacterium and Methanomethylovorans predominated Phe-degrading and Ant-degrading culture,respectively.These findings can improve our understanding of natural PAHs attenuation and provide some guidance for PAHs bioremediation in methanogenic environment.

Sensitively detecting antigen of SARS-CoV-2 by NIR-Ⅱ fluorescent nanoparticles

Early detection of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection is an efficient way to prevent the spread of coronavirus disease 2019(COVID-19).Detecting SARS-CoV-2 antigen can be rapid and convenient,but it is still challenging to develop highly sensitive methods for effective diagnosis.Herein,a lateral flow assay(LFA)based on fluorescent nanoparticles emitting in the second near-infrared(NIR-II)window is developed for sensitive detection of SARS-CoV-2 antigen.Benefiting from the NIR-II fluorescence with high penetration and low autofluorescence,such NIR-II based LFA allows enhanced signal-to-background ratio,and the limit of detection is down to 0.01 ng·mL^(−1)of SARS-CoV-2 antigen.In the clinical swab sample tests,the NIR-II LFA outperforms the colloidal gold LFA with higher overall percent agreement with the polymerase chain reaction test.The clinical samples with low antigen concentrations(~0.015–~0.068 ng·mL^(−1))can be successfully detected by the NIR-II LFA,but fail for the colloidal gold LFA.The NIR-II LFA can provide a promising platform for highly sensitive,rapid,and cost-effective method for early diagnosis and mass screening of SARS-CoV-2 infection.

QAUST:Protein Function Prediction Using Structure Similarity,Protein Interaction,and Functional Motifs

The number of available protein sequences in public databases is increasing exponentially.However,a sig-nificant percentage of these sequences lack functional annotation,which is essential for the understanding of how bio-logical systems operate.Here,we propose a novel method,Quantitative Annotation of Unknown STructure(QAUST),to infer protein functions,specifically Gene Ontology(GO)terms and Enzyme Commission(EC)numbers.QAUST uses three sources of information:structure information encoded by global and local structure similarity search,biological network information inferred by protein–protein interaction data,and sequence information extracted from functionally discriminative sequence motifs.These three pieces of information are combined by consensus averaging to make the final prediction.Our approach has been tested on 500 protein targets from the Critical Assessment of Functional Annotation(CAFA)benchmark set.The results show that our method provides accurate functional annotation and outperforms other prediction methods based on sequence similarity search or threading.We further demonstrate that a previously unknown function of human tripartite motif-containing 22(TRIM22)protein predicted by QAUST can be experimentally validated.

3D-printed fuel-cell bipolar plates for evaluating flow-field performance

In the last decade,many researchers have focused on developing fuel-cell flow-field designs that homogeneously distribute reactants with an optimum pressure drop.Most of the previous studies are numerical simulations and the few experimental studies conducted have used very simple flow-field geometries due to the limitations of the conventional fabrication techniques.3D printing is an excellent rapid prototyping method for prototyping bipolar plates(BPPs)to perform experiments on new flow-field designs.The present research investigates the applicability of different 3D-printed BPPs for studying fluid-dynamic behaviour.State-of-the-art flow-field designs are fabricated using PolyJet 3D printing,stereolithographic apparatus(SLA)3D printing and laser-cutter technologies,and the pressure-drop and velocity profiles are measured for each plate.The results demonstrate that SLA BPPs have great promise in serving as a screening tool in modifying flow-field design with a small feature size.

Price-Based Power Allocation in Two-Tier Spectrum Sharing Heterogeneous Cellular Networks

Attributable to the using of the same spec-trum resources,heterogeneous cellular networks have serious interference problems,which greatly restricts the performance of the network.In this paper,the price-based power allocation for femtocells underlaying a macrocell heterogeneous cellular network is investigated.By ex-ploiting interference pricing mechanism,we formulate the interference management problem as a Stackelberg game and make a joint utility optimization of macrocells and femtocells.Specially,the energy consumption of macrocell users and the transmission rate utility of femtocell users are considered in this utility optimization problem.In the game model,the macrocell base station is regarded as a leader,which coordinates the interference from femtocell users to the macrocell users by pricing the inter-ference.On the other hand,the femtocell base stations are modelled as followers.The femtocell users obtain their power allocation by pricing.After proving the existence of the Stackelberg equilibrium,the non-uniform and uniform pricing schemes are proposed, and distributed interference pricing algorithm is proposed to address uniform interference price problem. Simulation results demonstrate that the proposed schemes are effective on interference management and power allocation.