Study on metal recovery process and kinetics of oxidative leaching from spent LiFePO_(4)Li-batteries

A green environmental protection and enhanced leaching process was proposed to recover all elements from spent lithium iron phosphate(LiFePO_(4)) lithium batteries.In order to reduce the influence of Al impurity in the recovery process,NaOH was used to remove impurity.After impurity removal,the spent LiFePO_(4) cathode material was used as raw material under the H_(2)SO_(4) system,and the pressure oxidation leaching process was adopted to achieve the preferential leaching of lithium.The E-pH diagram of the Fe-P-Al-H_(2)O system can determine the stable region of each element in the recovery process of spent LiFePO_(4)Li-batteries.Under the optimal conditions(500 r·min^(-1),15 h,363.15 K,0.4 MPa,the liquid-solid ratio was 4:1 ml·g^(-1)and the acid-material ratio was 0.29),the leaching rate of Li was 99.24%,Fe,Al,and Ti were 0.10%,2.07%,and 0.03%,respectively.The Fe and P were precipitated and recovered as FePO_(4)·2H_(2)O.The kinetic analysis shows that the process of high-pressure acid leaching of spent LiFePO_(4) materials depends on the surface chemical reaction.Through the life cycle assessment(LCA)of the spent LiFePO_(4) whole recovery process,eight midpoint impact categories were selected to assess the impact of recovery process.The results can provide basic environmental information on production process for recycling industry.

Brain Functional Network Changes in Patients with Poststroke Cognitive Impairment Following Acupuncture Therapy

Background: The mechanisms by which acupuncture affects poststroke cognitive impairment (PSCI) remain unclear. Objective: To investigate brain functional network (BFN) changes in patients with PSCI after acupuncture therapy. Methods: Twenty-two PSCI patients who underwent acupuncture therapy in our hospital were enrolled as research subjects. Another 14 people matched for age, sex, and education level were included in the normal control (HC) group. All the subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans;the PSCI patients underwent one scan before acupuncture therapy and another after. The network metric difference between PSCI patients and HCs was analyzed via the independent-sample t test, whereas the paired-sample t test was employed to analyze the network metric changes in PSCI patients before vs. after treatment. Results: Small-world network attributes were observed in both groups for sparsities between 0.1 and 0.28. Compared with the HC group, the PSCI group presented significantly lower values for the global topological properties (γ, Cp, and Eloc) of the brain;significantly greater values for the nodal attributes of betweenness centrality in the CUN. L and the HES. R, degree centrality in the SFGdor. L, PCG. L, IPL. L, and HES. R, and nodal local efficiency in the ORBsup. R, ORBsupmed. R, DCG. L, SMG. R, and TPOsup. L;and decreased degree centrality in the MFG. R, IFGoperc. R, and SOG. R. After treatment, PSCI patients presented increased degree centrality in the LING.L, LING.R, and IOG. L and nodal local efficiency in PHG. L, IOG. R, FFG. L, and the HES. L, and decreased betweenness centrality in the PCG. L and CUN. L, degree centrality in the ORBsupmed. R, and nodal local efficiency in ANG. R. Conclusion: Cognitive decline in PSCI patients may be related to BFN disorders;acupuncture therapy may modulate the topological properties of the BFNs of PSCI patients.

融入文献实例剖析的有机合成设计课教学实践

研究型人才是目前高校人才培养的重要目标之一,在本科生基础和专业选修课教学当中融入与课程内容紧密结合的文献教学,能够在巩固学生所学基础知识的同时,激发学生对相关专业领域的学习热情,培养学生的科学研究思维。围绕这一教学目标,探索了如何在本科生有机合成设计课教学中加入最新文献实例剖析,包括对文献内容的选择和采用的教学方法。

Two-dimensional dumbbell silicene as a promising anode material for(Li/Na/K)-ion batteries

Rechargeable ion batteries require anode materials with excellent performance,presenting a key challenge for researchers.This paper explores the potential of using two-dimensional dumbbell silicene as an anode material for alkali metal ion batteries through density functional theory(DFT)calculations.Our findings demonstrate that alkali metal ions have negative adsorption energies on dumbbell silicene,and the energy barriers for Li/Na/K ion diffusion are as low as0.032 e V/0.055 e V/0.21 e V,indicating that metal ions can easily diffuse across the entire surface of dumbbell silicene.Additionally,the average open circuit voltages of dumbbell silicene as anode for Li-ion,Na-ion,and K-ion batteries are 0.42 V,0.41 V,and 0.60 V,respectively,with corresponding storage capacities of 716 m Ah/g,622 m Ah/g,and 716 m Ah/g.These results suggest that dumbbell silicene is an ideal anode material for Li-ion,Na-ion,and K-ion batteries,with high capacity,low open circuit voltage,and high ion diffusion kinetics.Moreover,our calculations show that the theoretical capacities obtained using DFT-D2 are higher than those obtained using DFT-D3,providing a valuable reference for subsequent theoretical calculations.

Analysis on Operational Safety and Efficiency of FAO System in Urban Rail Transit

This paper discusses two urgent problems that need to be solved in fully automatic operation(FAO)for urban rail transit.The first is the analysis of safety in FAO,while another is the analysis of efficiency in FAO.Firstly,this paper establishes an operational safety evaluation index system from the perspective of operation for the unique or typical risk sources of the FAO system,and uses the analytic hierarchy process(AHP)to evaluate the indicators,analyzes various factors that affect the safe operation of FAO,and provides safety management recommendations for FAO lines operation to maintain the FAO system specifically.Secondly,taking the Yanfang Line as an example,this paper uses OpenTrack software to analyze the efficiency of FAO operation,and conducts simulation calculations for key links such as the mainline tracking interval,train entry and exit,and return limit interval.The fault impact surface of the FAO trains is simulated and discussed to verify whether FAO can meet the long-term operation requirements of Yanfang Line.Finally,this paper compares the simulation data of FAO on the Yanfang Line with manual operation(MO)to verify the advantages of FAO and guide the engineering construction of subsequent fully automated driving lines.

综合生物信息学分析神经胶质瘤中的关键基因及信号通路

鉴定出与患者生存相关的特异性差异表达基因(DEGs)是一种揭示各种癌症(包括神经胶质瘤)治疗方法的新策略。然而,与胶质瘤发生发展相关的关键靶基因仍有待进一步发现。本文对17个GSE数据集进行了生物信息学分析,确定了神经胶质瘤相关的DEGs。我们发现了74个共同DEGs,这些DEGs在胶质瘤中的表达水平较正常组织显著降低,且其与GABA能突触传递、氯离子跨膜转运、谷氨酸分泌、γ-氨基丁酸信号通路有关。γ-氨基丁酸A型受体亚基γ2[GABRG2]被鉴定为蛋白互作网络中的关键基因,在IDH野生型星型胶质瘤中,GABRG2的表达较IDH突变型明显降低,其与胶质瘤患者的预后不良有关。GABRG2可能通过影响GABA受体相关通路促进胶质瘤的发生发展,是胶质瘤诊疗中的潜在生物学标志物。

聚(氨酯-脲-酰胺)热塑性弹性体的合成及表征

以双端氨基的尼龙1212预聚物(OPA)为硬段、异氰酸酯封端的聚醚型聚氨酯预聚物(OPU)为软段,通过改变软、硬段的摩尔比制得了不同相对分子质量的聚(氨酯-脲-酰胺)热塑性弹性体(PUUA)。通过傅里叶变换红外光谱(FT-IR)考察了OPU合成过程中-NCO基团与C-O-C醚键的相对强度变化,进而确定了合成OPU的反应时间为60 min。通过核磁氢谱和FT-IR确定了产物结构。凝胶渗透色谱法(GPC)测试结果表明,硬、软段摩尔比在1.2~1.5范围内,产物重均分子量可在(1.82~3.59)×104范围内调控。差示扫描量热分析(DSC)结果表明,随着硬、软段摩尔比由1.2提高至1.5,硬段的熔点由185℃降低至174℃,结晶温度由167℃降低至138℃,但OPU软段的熔点和结晶温度基本不变。PUUA的力学性能测试结果表明,其拉伸强度为28 MPa,断裂伸长率可达417%,缺口冲击未能冲断,是一种性能优异的热塑性弹性体。

抑郁倾向对劳动收入的影响——基于LASSO回归的工具变量识别

本文采用2010年中国家庭调查数据实证检验了居民抑郁倾向对劳动收入的影响,结果表明抑郁倾向能显著降低居民的劳动收入,对个人就业产生负向影响。为克服个人精神状况与收入之间的反向因果关系所导致的内生性问题,本文使用机器学习方法筛选工具变量,使得工具变量估计结果相比于传统方法更加精确,进一步验证了抑郁倾向对个人劳动收入的负向影响。异质性分析表明男性个体、位于农村地区的个体、青年个体受到抑郁倾向的影响更为严重,收入下降程度更为显著,而受教育程度的提高则能够在一定程度上减少抑郁倾向给收入带来的负面影响。机制分析表明,抑郁倾向通过抑制个人的社交能力与社交意愿、损害个人的劳动能力等方式来影响个人的劳动参与和劳动收入。

Differences and Similarities of Photocatalysis and Electrocatalysis in Two-Dimensional Nanomaterials:Strategies,Traps,Applications and Challenges

Photocatalysis and electrocatalysis have been essential parts of electrochemical processes for over half a century.Recent progress in the controllable synthesis of 2D nanomaterials has exhibited enhanced catalytic performance compared to bulk materials.This has led to significant interest in the exploitation of 2D nanomaterials for catalysis.There have been a variety of excellent reviews on 2D nanomaterials for catalysis,but related issues of differences and similarities between photocatalysis and electrocatalysis in 2D nanomaterials are still vacant.Here,we provide a comprehensive overview on the differences and similarities of photocatalysis and electrocatalysis in the latest 2D nanomaterials.Strategies and traps for performance enhancement of 2D nanocatalysts are highlighted,which point out the differences and similarities of series issues for photocatalysis and electrocatalysis.In addition,2D nanocatalysts and their catalytic applications are discussed.Finally,opportunities,challenges and development directions for 2D nanocatalysts are described.The intention of this review is to inspire and direct interest in this research realm for the creation of future 2D nanomaterials for photocatalysis and electrocatalysis.

Solid phase microwave-assisted fabrication of Fe-doped ZIF-8 for single-atom Fe-N-C electrocatalysts on oxygen reduction

Fe-N-C endowed with inexpensiveness,high activity,and excellent anti-poisoning power have emerged as promising candidate catalysts for oxygen reduction reaction(ORR).Single-atom Fe-N-C electrocatalysts derived from Fe-doped ZIF-8 represent the top-level ORR performance.However,the current fabrication of Fe-doped ZIF-8 relies on heavy consumption of time,energy,cost and organic solvents.Herein,we develop a rapid and solvent-free method to produce Fe-doped ZIF-8 under microwave irradiation,which can be easily amplified in combination with ball-milling.After rational pyrolysis,Fe-N-C catalysts with atomic FeN4 sites well dispersed on the hierarchically porous carbon matrix are obtained,which exhibit exceptional ORR performance with a half-wave potential of 0.782 V(vs.reversible hydrogen electrode(RHE))and brilliant methanol tolerance.The assembled direct methanol fuel cells(DMFCs)endow a peak power density of 61 mW cm^(-2) and extraordinary stability,highlighting the application perspective of this strategy.

High performance silicon-based GeSn p–i–n photodetectors for short-wave infrared application

An investigation of germanium-tin(GeSn) on silicon p–i–n photodetectors with a high-quality Ge0.94 Sn0.06 absorbing layer is reported. The Ge Sn photodetector reached a responsivity as high as 0.45 A/W at the wavelength of 1550 nm and 0.12 A/W at the wavelength of 2 μm. A cycle annealing technology was applied to improve the quality of the epitaxial layer during the growth process by molecular beam epitaxy. A low dark-current density under 1 V reverse bias about 0.078 A/cm2 was achieved at room temperature. Furthermore, the Ge Sn photodetector could detect a wide spectrum region and the cutoff wavelength reached to about 2.3 μm. This work has great importance in silicon-based short-wave infrared detection.

Low-frequency HIFU induced cancer immunotherapy:tempting challenges and potential opportunities

Immunotherapy is playing an increasingly important role in the treatment of tumors.Different from the traditional direct killing or excision therapies,immunotherapy depends on autologous immunity to kill tumor cells and tissues by activating or enhancing the body's immune system.Large numbers of recent studies suggest that low-frequency HIFU can not only enhance the intensity of the body's anti-cancer immune response,but also improve the efficiency of immunotherapy drug delivery to strengthen the effects of tumor immunotherapy.The focused ultrasound(FUS)destructs the tumor and simultaneously generates tumor debris and tumor-associated antigens,which enhances the immunogenicity of the tumor and stimulates the immune cells,inducing the body's immune response.Microbubbles are clinically used as a contrast.As a matter of fact,the addition of microbubbles can reinforce the destructive effect of FUS on the tumor and activate a stronger immune response.The combined application of ultrasound and microbubbles can more effectively open the blood brain barrier(BBB),which is beneficial to improving the intake of immune cells or immunotherapy drugs and exerting a positive influence in the lesion area.Currently,microbubbles and nanoparticles are commonly used as gene and drug carriers.Using ultrasound,the immune-related gene or antigen delivery itself can enhance the immune response and improve the efficacy of the immunotherapy.

Incorporation of flexible ionic polymers into a Lewis acid-functionalized mesoporous silica for cooperative conversion of CO2 to cyclic carbonates

A rational integration of multiple reactive centers into a combined unit to facilitate their cooperative effects is a smart approach for accelerating the catalytic activity.Here,to achieve this goal,linear imidazolium-based ionic polymers were confined into the nanopores of mesoporous silica nanospheres anchored with homogeneously distributed zinc salts.Owing to the flexible character and the reinforced cooperative effects of the ionic liquid(nucleophile)and zinc species(Lewis acid)in the confined mesoporous structure,the resultant composite exhibited dramatically improved catalytic performance in the cycloaddition of CO2 with epoxides to form cyclic carbonates.This was in contrast to that observed for the individual catalytic components.Moreover,such a solid catalyst could be easily recovered and reused four times without a significant loss of activity.

Iron-based binary metal-organic framework nanorods as an efficient catalyst for the oxygen evolution reaction

First-row transition metal compounds have been widely explored as oxygen evolution reaction(OER)electrocatalysts due to their impressive performance in this application.However,the activity trends of these electrocatalysts remain elusive due to the effect of inevitable iron impurities in alkaline electrolytes on the OER;the inhomogeneous structure of iron-based(oxy)hydroxides further complicates this situation.Bimetallic metal-organic frameworks(MOFs)have the advantages of well-defined and uniform atomic structures and the tunable coordination environments,allowing the structure-activity relationships of bimetallic sites to be precisely explored.Therefore,we prepared a series of iron-based bimetallic MOFs(denoted as Fe_(2)M-MIL-88B,M=Mn,Co,or Ni)and systematically compared their electrocatalytic performance in the OER in this work.All the bimetallic MOFs exhibited higher OER activity than their monometallic iron-based counterpart,with their activity following the order FeNi>FeCo>FeMn.In an alkaline electrolyte,Fe2Ni-MIL-88B showed the lowest overpotential to achieve a current density of 10 mA cm^(–2)(307 mV)and the smallest Tafel slope(38 mV dec^(–1)).The experimental and calculated results demonstrated that iron and nickel exhibited the strongest coupling effect in the series,leading to modification of the electronic structure,which is crucial for tuning the electrocatalytic activity.

Intravoxel Incoherent Motion Diffusion Weighted Imaging for the Therapeutic Response of Transarterial Chemoembolization for Hepatocellular Carcinoma

Background: Intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) can not only observe the diffusion of tissue water molecules but also reflect the blood perfusion information of tissue microcirculation. IVIM-DWI has been applied in many clinical areas. However, few studies have addressed the use of IVIM-DWI for the evaluation of transarterial chemoembolization (TACE) response in hepatocellular carcinoma (HCC) patients. Objectives: The purpose of the present study was to explore the role of IVIM-DWI for the therapeutic response of TACE for HCC. Materials and Methods: Twenty patients underwent IVIM-DWI scan on a 3.0T magnetic resonance imaging instrument 1 - 3 days before and 30 to 40 days after TACE. The values of IVIM-DWI parameters, including standard apparent diffusion coefficient (ADC), pure diffusion coefficient (Dslow), pseudo-diffusion coefficient (Dfast) and perfusion fraction (f) were measured. The values of IVIM-DWI parameters before and after TACE were compared using paired t tests. The values between responsive and non-responsive groups were compared using independent-samples t test. P 0.05 indicated statistical significance. Results: After TACE, the ADC and Dslow values in the tumors increased significantly, and the values of Dfast decreased significantly, while the values of f value did not change obviously. The ADC values in responsive group were remarkably higher than those in non-responsive group, the Dfast values in responsive group were significantly lower than those in non-responsive group, but the values of Dslow and f between the two groups were not different significantly. Conclusions: IVIM-DWI parameters can be used as potential markers for the therapeutic response of TACE for HCC.

Platinum in-situ catalytic oleylamine combustion removal process for carbon supported platinum nanoparticles

Colloidal synthesis method such as oleylamine(OAm)-stabilized process is of great interest for obtaining uniform and highly dispersed platinum nanoparticle catalysts, yet the ligand may unavoidably inhibit their electro-catalytic performance. Thus, fully removing these ligands is critical to activate catalyst surface. Previous research of OAm removal process pointed that thermal annealing was the most effective way in comparison with other methods such as chemical washing, UV–Ozone irradiation and cyclic voltammetry sweeping, but generally resulting in undesired growth of platinum nanoparticle. Few studies concerning a more efficient ligand removal process have been published yet. In this work we proposed a platinum in-situ catalytic OAm combustion strategy to elucidate the removal mechanism of OAm ligands in thermal process and the key experimental parameters were also optimized. In addition, heat flow signal based on differential scanning calorimetry(DSC) measurement as a sensitive indicator, is suggested to reveal the ligand removal efficiency, which is much more reliable than the traditional spectroscopy.In comparison with commercial Pt/C sample, such a surface clean Pt/C electrocatalyst has shown an enhanced specific activity for oxygen reduction reaction. Our removal strategy and the evaluation method are highly instructive to efficient removal of different organic ligands.

Promoting wetting of Mg on the SiC surfaces by addition of Al,Zn and Zr elements:A study via first-principle calculations

When preparing SiC/Mg composites,alloy elements play key roles in the nucleation and interfacial wetting.In this paper,effects of Al,Zn and Zr additions on the Mg/SiC interfacial bonding properties were investigated comprehensively via method of first-principle calculations.Mg(0001)/SiC(0001)interfaces with different terminations and stacking sequences were built and CⅡ-T CⅡtop interface has the largest work of adhesion(W_(ad)).Zn dopants can not improve the W_(ad)for both C-T and Si-T interfaces.Al atom can only strengthen the C-T interface.Zr addition can greatly improve the W_(ad)for both C-T and Si-T interfaces.W_(ad)of C-T interfaces can reach up to 11.55 J/m^(2) and 12.55 J/m^(2) after doping 1 monolayer(ML)of Al and Zr atoms.Larger W_(ad)can lead to lower contact angles of Mg on SiC surfaces,which can improve wetting and nucleation in SiC/Mg composites.Analysis of electronic structure shows that Al-C and Zr-C bonds have more covalent composition than the Mg-C bond,which is responsible for the improvement of interfacial bonding strength.Experimental results in references were also analyzed,which are in well agreement with our calculation results.

Decoding the complexity of metastasis

Cancer metastasis remains one of the most confounding questions in oncology1,2.Although current cutting-edge techniques enable very early detection of tumors,profiling whether a tumor has already begun to spread and where it has attempted to colonize remains a major hurdle.Indeed,metastatic seeding events exhibit remarkable temporal and spatial heterogeneity,wherein the origin(primary site)and destination(metastatic site)are highly dynamic.For example,liver metastasis is particularly common and remains a leading cause of mortality3.

Functional identification of lncRNAs in sweet cherry(Prunus avium)pollen tubes via transcriptome analysis using single-molecule long-read sequencing

Sweet cherry(Prunus avium)is a popular fruit with high nutritional value and excellent flavor.Although pollen plays an important role in the double fertilization and subsequent fruit production of this species,little is known about its pollen tube transcriptome.In this study,we identified 16,409 transcripts using single-molecule sequencing.After filtering 292 transposable elements,we conducted further analyses including mRNA classification,gene function prediction,alternative splicing(AS)analysis,and long noncoding RNA(lncRNA)identification to gain insight into the pollen transcriptome.The filtered transcripts could be matched with 3,438 coding region sequences from the sweet cherry genome.GO and KEGG analyses revealed complex biological processes during pollen tube elongation.A total of 2043 AS events were predicted,7 of which were identified in different organs,such as the leaf,pistil and pollen tube.Using BLASTnt and the Coding-Potential Assessment Tool(CPAT),we distinguished a total of 284 lncRNAs,among which 154 qualified as natural antisense transcripts(NATs).As the NATs could be the reverse complements of coding mRNA sequences,they might bind to coding sequences.Antisense transfection assays showed that the NATs could regulate the expression levels of their complementary sequences and even affect the growth conditions of pollen tubes.In summary,this research characterizes the transcripts of P.avium pollen and lays the foundation for elucidating the physiological and biochemical mechanisms underlying sexual reproduction in the male gametes of this species.

Hadoop-Based Similarity Computation System for Composed Documents

There exist a large number of composed documents in universities in the teaching process. Most of them are required to check the similarity for validation. A kind of similarity computation system is constructed for composed documents with images and text information. Firstly, each document is split and outputs two parts as images and text information. Then, these documents are compared by computing the similarities of images and text contents independently. Through Hadoop system, the text contents are easily and quickly separated. Experimental results show that the proposed system is efficient and practical.