Solid-state NMR study on sodium intercalation at low voltage window for Na_(3)V_(2)(PO_(4))_(3) as an anode

In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.

Effects of sodium substitution on properties of LiMn_2O_4 cathode for lithium ion batteries

Na-doped Li1.05Mn2O4 cathodes were synthesized using a sol-gel process.The samples were characterized by X-ray diffractometry(XRD),cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and charge-discharge measurements. The results show that all the samples exhibit the same cubic spinel phase structure without impurity.The lattice constant and unit cell volume decrease with increasing the sodium dopant amount.As the molar ratio of sodium to manganese(x=n(Na)/n(Mn))increases from 0 to 0.03,the initial discharge capacity of the Li1.05Mn2O4 cathodes decreases from 119.2 to 107.9 mA·h/g,and the discharge capability at large current rate and the storage performance decline dramatically,while cycling performance at room temperature and 55℃are improved.The CV and EIS studies indicate that reversibility of Li1.05Mn2O4 cathodes decreases and the electrochemical impedance increases with increasing the sodium dopant amount.

Enhanced photocatalytic Cr(Ⅵ) reduction and diclofenac sodium degradation under simulated sunlight irradiation over MIL-100(Fe)/g-C_3N_4 heterojunctions

Metal‐organic framework MIL‐100(Fe)and g‐C3N4 heterojunctions(MG‐x,x=5%,10%,20%,and 30%,x is the mass fraction of MIL‐100(Fe)in the hybrids)were facilely fabricated through ball‐milling and annealing,and characterized by powder X‐ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric analysis,transmission electron microscopy,UV‐visible diffuse‐reflectance spectrometry,and photoluminescence emission spectrometry.The photocatalytic activities of the series of MG‐x heterojunctions toward Cr(VI)reduction and diclofenac sodium degradation were tested upon irradiation with simulated sunlight.The influence of different organic compounds(ethanol,citric acid,oxalic acid,and diclofenac sodium)as hole scavengers and the pH values(2,3,4,6,and 8)on the photocatalytic activities of the series of MG‐x heterojunctions was investigated.MG‐20%showed superior photocatalytic Cr(VI)reduction and diclofenac sodium degradation performance than did the individual MIL‐100(Fe)and g‐C3N4 because of the improved separation of photoinduced electron‐hole charges,which was clarified via photoluminescence emission and electrochemical data.Moreover,the MG‐x exhibited good reusability and stability after several runs.

A New One-dimensional Sodium Polymer Constructed from 4-Carboxy-benzenesulfonic Acid

A new one-dimensional double chain coordination polymer, [Na（cbsH）（H2O）3]n （cbsH = 4-carboxy-benzenesulfonic anion）, has been synthesized by aqueous reaction, structurally described, and thermally characterized. It crystallizes in the triclinic system, space group P with a = 5.645（4）, b = 7.905（5）, c = 13.043（8） , α = 89.391（7）, β = 80.637（7）, γ = 82.845（7）°, V = 569.8（6） 3, Z = 2, C7H11NaO8S, Mr = 278.21, Dc = 1.622 Kg/m3, F（000） = 288, R = 0.0260 and wR = 0.0697. The title compound consists of one-dimensional double chains. 4-Carboxy-benzenesulfonic acid acts as a bridging bidentate ligand to link two sodium（I） ions to form a binuclear structure. Remarkably, the sodium（I） ion behaves as a metal bridge so that the binuclear structure units are connected to construct a one-dimensional double chain polymer. Furthermore, a 3-D framework is assembled through intermolecular hydrogen bonds. Thermogravimetric analysis shows that this compound begins losing the free solvent molecules at 106 ℃ and decompounding completely at 580 ℃.

Microwave-Assisted Synthesis of NiCo_2O_4 Double-Shelled Hollow Spheres for High-Performance Sodium Ion Batteries

The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo_2O_4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt,and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized productwas tested as an anode material in a sodium ion battery,was found to exhibit a high reversible specific capacity of 511 m Ahg^(-1) at 100 m Ag^(-1), and deliver high capacity retention after 100 cycles.

In-situ structural evolution analysis of Zr-doped Na_(3)V_(2)(PO_(4))_(2)F_(3) coated by N-doped carbon layer as high-performance cathode for sodium-ion batteries

With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges on its poor intrinsic electronic conductivity and the controversial de/sodiation mechanism.Herein,a series of Zr-doped NVPF coated by N-doped carbon layer(~5 nm in thickness,homogenously)materials are fabricated by a sol-gel method,and the optimized heteroatom-doping amounts of Zr and N doping improve intrinsic properties on enlarging lattice distance and enhancing electronic conductivity,respectively.Specifically,among all samples of Na_(3) V_(2-x)Zr_(x)(PO_(4))_(2) F_(3)/NC(NVPF-Zr-x/NC,x=0,0.01,0.02,0.05,and 0.1),the optimized electrode of NVPF-Zr-0.02/NC delivers high reversible capacities(119.2 mAh g^(-1) at0.5 C),superior rate capability(98.1 mA h g^(-1) at 20 C)and excellent cycling performance.The structural evolution of NVPF-Zr-0.02/NC electrode,in-situ monitored by X-ray diffractometer,follows a step-wise Na-extraction/intercalation mechanism with reversible multi-phase changes,not just a solid-solutionreaction one.Full cells of NVPF-Zr-0.02/NC//hard carbon demonstrate high capacity(99.8 mA h g^(-1) at 0.5 C),high out-put voltage(3.5 V)and good cycling stability.This work is favorable to accelerate the development of high-performance cathode materials and explore possible redox reaction mechanisms of SIBs.

Effects of Na_4EDTA and EDTA on seeded precipitation of sodium aluminate solution

Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.

简易合成MgCo_(2)O_(4)纳米线及其电化学性能研究

通过水热路径引入表面活性剂十二烷基磺酸钠在泡沫镍上成功合成出比表面积较大、超薄多孔的MgCo_(2)O_(4)纳米线。研究表明,MgCo_(2)O_(4)纳米线展示出紧密交织透明的网格状结构且在5 A/g的电流密度下,比电容高达2128 F/g。在40 A/g的情况下循环6000周次后,比电容保持了原始容量的98.4%。将该纳米线和活性炭分别作为正极和负极组装成非对称超级电容器,其比电容可达65.32 F/g且在功率密度为338.95 W/kg下能量密度可达20.41 Wh/kg。上述结果表明该非对称超级电容器是一个较好的储能装置,在实际应用中拥有良好的潜力。

Novel Reduction of Sodium Alkyl Thiosulfates to Disulfides with TiCl_4/Sm System

Sodium alkyl thiosulfates(Bunte salts) can be readily reduced to the corresponding disulfides with TiCl4/Sm system in good to excellent yields under mild conditions

Boosting rate and cycling performance of K-doped Na_(3)V_(2)(PO_(4))_(2)F_(3) cathode for high-energy-density sodium-ion batteries

As a promising cathode material,Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)has attracted wide attention for sodium-ion batteries(SIBs)because of its high operating voltage and high structural stability.However,the low intrinsic electronic conductivity and insufficient Na ion mobility of NVPF limit its development.Herein,K-doping NVPF is prepared through a facile ball-milling combined calcination method.The effects of K-doping on the crystal structure,kinetic properties and electrochemical performance are investigated.The results demonstrate that the Na_(2.90)K_(0.10)V_(2)(PO_(4))_(3)F_(3)(K0.10-NVPF)exhibits a high capacity(120.8 mAh g^(-1) at 0.1 C),high rate capability(66 mAh g^(-1) at 30 C)and excellent cycling performance(a capacity retention of 97.5%at 1 C over 500 cycles).Also,the occupation site of K ions in the lattice,electronic band structure and Na-ion transport kinetic property in K-doped NVPF are investigated by density functional theory(DFT)calculations,which reveals that the K-doped NVPF exhibits improved electronic and ionic conductivities,and located K^(+) ions in the lattice to contribute to high reversible capacity,rate capability and cycling stability.Therefore,the K-doped NVPF serves as a promising cathode material for high-energy and high-power SIBs.

Sodium 4-phenylbutyrate Attenuates High-fat Diet-induced Impaired Spermatogenesis

Objective To determine the mitigating effects of sodium 4-phenylbutyrate(4-PBA) on high-fat diet(HFD)-induced spermatogenesis dysfunction. Methods Male rats(n = 30) were randomly divided into three groups: control, HFD, and 4-PBA(HFD +4-PBA). After 13 weeks, rats were euthanized. Testes and epididymis were harvested for further analysis. Sex hormones were detected, and hematoxylin and eosin staining was performed to examine the histological changes in the testes. Semen samples were collected to evaluate sperm quality. Spermatogenic cell apoptosis was detected by TUNEL assay. Results Compared with the control group, the final body weight and body weight gain were significantly higher in HFD-fed rats, while the testicle/body weight ratios were lower(P < 0.05). In HFD-fed rats, obvious pathological changes in the testicular tissue were observed. Treatment with 4-PBA attenuated HFD-induced histological damage, ameliorated the HFD-induced decrease in serum testosterone(T), and reduced the rate of testicular cell apoptosis(P < 0.05) in obese male rats. Finally, 4-PBA significantly improved semen parameters in HFD rats(P < 0.05). Conclusion HFD exposure induced detrimental effects on spermatogenesis, semen quality, serum T level, and testicular cell apoptosis in rats. Treatment with 4-PBA ameliorated HFD-induced impaired spermatogenesis via inhibition of apoptosis in rats. 4-PBA may have therapeutic value in the treatment of obesity-related impairment of spermatogenesis.

Room Temperature Phosphorescence of 1-Bromo-4-(bromoacetyl) naphthalene Induced by Sodium Deoxycholate

Sodium deoxycholate (NaDOC) could induce 1-bromo-4-(bromoacetyl) naphthalene (BBAN) to emit strong room temperature phosphorescence (RTP). Measurements of phosphore- scence spectra, peak intensity and polarization were used to investigate the solubilization of BBAN as a function of NaDOC concentration.

Novel design and synthesis of 1D bamboo-like CNTs@Sn_(4)P_(3)@C coaxial nanotubes for long-term sodium ion storage

In this work,a novel bamboo-like carbon nanotubes@Sn4P3@carbon(BLCNTs@Sn_(4)P_(3)@C)coaxial nanotubes are designed and prepared using a newly developed hydrothermal method followed by a phophidation process.The prepared Sn_(4)P_(3) nanoparticles are uniformly coated and wrapped on the one-dimensional(1D)bamboo-like CNTs,which is covered by a uniform carbon layer to form a sandwich-like structure with Sn_(4)P_(3) in between.The inner CNT and outer carbon can effectively maintain the structural stability and serve as the good electron conductors.Additionally,the outer carbon coating layer can effectively keep BLCNTs@Sn_(4)P_(3)@C nanotubes separate each other,preventing aggregation of Sn_(4)P_(3) during charge/discharge when this material is used as anode for sodium ion batteries.The anode of BLCNTs@Sn_(4)P_(3)@C shows excellent reversible capacity and a long cycling of over 2000 cycles.The unique design of coaxial nanotubes is greatly beneficial to the electrochemical performance of Sn_(4)P_(3) for sodium ion storage.

Separation of potassium from sodium in alkaline solution by solvent extraction with 4-tert-butyl-2-(α-methylbenzyl)phenol

This work investigated the separation of potassium from sodium in alkaline solution using substituted phenol-based extractants.Superior potassium extraction was achieved with 4-tert-butyl-2-(α-methylbenzyl)phenol(t-BAMBP)than 4-sec-butyl-2-(α-methylbenzyl)phenol(BAMBP).The optimum conditions for the extraction were 1 mol/L t-BAMBP,3:1 volumetric phase ratio(O/A),and two extraction stages.After cross-current extraction,the extraction ratio of potassium reached 90.8%.After scrubbing with deionised water at phase ratio of 4:1 and scrubbing stage of 4,a sodium scrubbing efficiency of 88.2%was obtained.After stripping using 1 mol/L H_(2)SO_(4) at phase ratio of 3:1,the stripping efficiency of potassium reached 94.2%.The potassium/sodium(K/Na)concentration ratio increased 14.3 times from 0.15 in the feed solution to 2.3 in the stripping solution.The efficient separation of potassium from sodium in alkaline solution was achieved via solvent extraction with t-BAMBP.

Two-step carbon modification of NaTi_2(PO_4)_3 with improved sodium storage performance for Na-ion batteries

NASICON-type structured NaTi2(PO4)3 has been regarded as a promising anode material for non-aqueous and aqueous Na-ion batteries,whereas its sodium storage performance was greatly restricted by its inherent inferior electronic conductivity.In the present work,a two-step carbon modification method using prefabricated carbon spheres as support and phenolic resin as carbon source was proposed to prepare advanced NaTi2(PO4)3/C.The as-prepared composite with carbon spheres displayed a much higher reversible capacity(126.7 mA?h/g vs 106.7 mA?h/g at 0.5C)than the control sample without carbon spheres.Superior rate capability with discharge capacities of 115.1,95.5,80.8 mAh/g at 1C,10C,20C,respectively and long-term cycling stability with capacity retention of 92.4%after 1000 cycles at 5C were also observed.Owing to the designing of two-step carbon modification,although the as-prepared sample shows much smaller surface area,it possesses much better conductive network and more uniform particle distribution,resulting in higher electronic conductivity and faster ionic conductivity,thereby superior sodium storage ability at high rate.

Novel Reduction of Arylsulfonyl Chlorides and Sodium Alkyl Thiosulfates to Disulfides with TiCl_4/Zn System

T1Cl4/Zn system reduces arylsulfonyl chlorides and sedium aldyl thiosulfates to corresponding disulfides in moderate to good yields

Synthesis of Sodium 2-[4(S)-4-Amido-3-oxo-2-isoxazolidinyl]-5-oxo-2-tetrahydrofurancarboxylate and Its Antibacterial Activities

Lactivicin,a novel inhibitor of bacterial cell wall synthesis,was isolated from the culture fil-trates of microorganism YK-258 and YK-422.It exhibits biological activities similar to those ofthe β-lactam antibiotics,although it does not have a β-lactam ring in its molecule.Since the discovery of lactivicin,hundreds of its derivatives have been synthesized.

聚(4-苯乙烯磺酸钠)对活化石英的浮选性能及机理研究

磷矿是一种重要的不可再生资源,其中脉石矿物主要以白云石、硅酸盐矿物为主。前期的研究表明,聚(4-苯乙烯磺酸钠)(PSS)作为新型白云石抑制剂在正浮选短流程脱镁中发挥了重要的作用。然而,石英易被金属离子活化是浮选中常见的问题,目前的研究也忽略了PSS对于石英的影响。因此,拟进一步探究PSS对于活化石英浮选行为的影响。通过单矿物浮选试验探究活化剂浓度、捕收剂浓度、抑制剂浓度、矿浆pH值等因素对石英浮选的影响,并通过Zeta电位、接触角分析、扫描电镜-能谱分析(SEM-EDS)、FTIR分析、XPS分析等表征手段探究了PSS在浮选中的抑制作用及其机理。浮选试验结果表明,PSS在pH值为8~12内能够有效地抑制活化石英的浮选。在钙离子浓度为80 mg/L,PSS浓度仅为50 mg/L或镁离子浓度为20 mg/L,PSS浓度为120 mg/L时,石英的上浮率均降至20%以下;接触角测量结果表明,PSS可有效抑制钙镁离子对石英的活化。Zeta电位、SEM-EDS、FTIR和XPS分析结果综合表明,PSS能以化学吸附的形式吸附在活化石英表面,并阻碍NaOL在活化石英表面的吸附,从而实现对于活化石英的抑制。

Radiation-Induced Graft Polymerization of Sodium 4-Styrene Sulfonate onto Multiwalled Carbon Nanotubes and Their Application as Electrogenerated Chemiluminescence Biosensors

Sulfonate groups were introduced to the surfaces of multiwalled carbon nanotubes by the radiation-induced graft polymerization of sodium 4-styrene sulfonate for the use as biosensor supports. Alcohol dehydrogenase was immobilized onto a sulfonated nanotube-supporting electrode with tris（2,2＇-bipyridyl） ruthenium（II） complex to form an electrogenerated chemilluminesce sensor of alcohol. When it was used to detect alcohol in cyclic voltammetric measurements, the sensor showed the linearity over the range of 1.0 × 10^-4 M-5.0 ×10^-2 M, with a correlation coefficient of 0.992 and a detection limit of 1.9 ×10^-6 M. In electrogenerated chemilluminesce detection, it showed linearity over 5.0 × 10^-4 M-1.0 × 10^-2 M, with a correlation coefficient of 0.986 and a detection limit of 1.0 × 10^-6 M. The sensor was demonstrated to be able to detect ethanol in commercial drinks.

Systematic pharmacology analysis of Sodium 8-(((carboxymethyl)amino)methyl)-4',7-bishydroxy-isoflavone-3'-sulfonate

The purpose of this study is to use the newly synthesized molecule Sodium 8-(((carboxymethyl)amino)methyl)-4',7-bishydroxy-isoflavone-3'-sulfonate(M)as a research object,the pharmacological mechanism of the molecule was analyzed by using a series of Systematic pharmacology methods.The results show that the M molecule has a higher drug-like DL value of 0.59 and better molecular property parameters,namely Hdon=4,Hacc=10 and AlogP=0.94;A total of 11 M molecules related targets,namely F2,ESR1,AR,F10,CA2,DPP4,CCNA2,PRSS1,CDK2,GSK3B and PTPN1;A total of 140 diseases are associated with M molecule targets,and these diseases are mainly related to cancer and cardiovascular diseases;A total of 52 pathways involve the pharmacological mechanisms of M molecules,which are mainly related to cancer and other related diseases;GO-enriched analysis showed that these targets are closely related to the regulation of peptidase activity and biological processes such as blood coagulation and hemostasis.This article clearly demonstrated the pharmacological mechanism of M molecule,which provides references for exploring the pharmacological mechanism of new compounds.