An effective'salt in dimethyl sulfoxide/water'electrolyte enables high-voltage supercapacitor operated at-50℃

Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.

Synthesis of mordenite by solvent-free method and its application in the dimethyl ether carbonylation reaction

Mordenite with different Si/Al ratios were synthesized by solvent-free method and used for dimethyl ether(DME)carbonylation reaction.The influence of Si/Al ratio in the feedstock on the structure,porosity and acid sites were systematically investigated.The characterization results showed that with the increase of Si/Al ratio in the feedstock,part of silicon species fail to enter the skeleton and the specific surface area and pore volume of the samples decreased.The amount of weak acid and medium strong acid decreased alongside with the increasing Si/Al ratio,and the amount of strong acid slightly increased.The Al atoms preferentially enter the strong acid sites in the 8 member ring(MR)channel during the crystallization process.The high Si/Al ratio sample had more acid sites located in the 8 MR channel,leading to more active sites for carbonylation reaction and higher catalytic performance.Appropriately increasing the Si/Al ratio was beneficial for the improvement of carbonylation reaction activity over the mordenite(MOR)catalyst.

Hepatoprotective effect of Holothuria leucospilota methanolic extract on dimethyl nitrosamine-induced hepatotoxicity in rats

Background:Complementary medicine is an interesting field for extracting bio-active compounds from various plant and animal sources.The hepatoprotective effect of the methanolic extract of a species of sea cucumber called Holothuria leu-cospilota in an animal model of liver cancer caused by dimethyl nitrosamine(DMN)was studied.Methods:Wistar female rats were randomly divided into five groups(n=12):control(intact),positive control(received 1%DMN[10 mg/kg/week,intraperitoneally]for 12 weeks),and three treatment groups(received 50,100,and 200 mg/kg/day H.leu-cospilota extract orally for 12 weeks along with intraperitoneal administration of 1%DMN[10 mg/kg/week]).In all groups,ultrasound was performed on the liver every week to check its density.Blood sampling and liver isolation were performed on three occasions,at 4,8,and 12 weeks,to check liver enzymes and the histopathological condition of the liver tissue(every week,four animals from each group were randomly selected).Results:Liver density changes were evident from the eighth week onward in the positive control group.Histopathological results indicated pathologic changes in the positive control group after 4 weeks.The increase in liver enzymes in the posi-tive control group was significantly different from that in the treatment and control groups.Conclusions:We demonstrated the hepatoprotective effect of H.leucospilota on DMN-induced liver damage in rats using biochemical and histological parameters and ultrasonography.More additional research(in silico or in vitro)is needed to find the exact mechanism and the main biological compound in H.leucospilota.

Mechanism study on the influence of surface properties on the synthesis of dimethyl carbonate from CO_(2)and methanol over ceria catalysts

The direct synthesis of dimethyl carbonate(DMC)from CO_(2)and methanol has attracted much attention as an environmentally benign and alternative route for conventional routes.Herein,a series of cerium oxide catalysts with various textural features and surface properties were prepared by the one-pot synthesis method for the direct DMC synthesis from CO_(2)and methanol,and the structure-performance relationship was investigated in detail.Characterization results revealed that both of surface acid-base properties and the oxygen vacancies contents decreased with the rising crystallinity at increasingly higher calcination temperature accompanied by an unexpectedly volcano-shaped trend of DMC yield observed on the catalysts.In situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)studies indicated that the adsorption rate of methanol is slower than that of CO_(2)and the methanol activation state largely influences the formation of key intermediate.Although the enhanced surface acidity-basicity and oxygen vacancies brought by low-temperature calcination could facilitate the activation of CO_(2),the presence of excess strongly basic sites on low-crystallinity sample was detrimental to DMC synthesis due to the preferred formation of unreactive mono/polydentate carbonates as well as the further impediment of methanol activation.Moreover,with the use of 2-cyanopyridine as a dehydration reagent,the DMC synthesis was found to be both influenced by the promotion from the rapid in situ removal of water and the inhibition from the competitive adsorption of hydration products on the same active sites.

Tuning the cross-linked structure of basic poly(ionic liquid)to develop an efficient catalyst for the conversion of vinyl carbonate to dimethyl carbonate

Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol.However,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and recovery.To address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and functionalization.These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics.Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC.It was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant changes.The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.

Tuning the product selectivity of dimethyl oxalate hydrogenation over WO_(x) modified Cu/SiO_(2) catalysts

Product selectivity and reaction pathway are highly dependent on surface structure of heterogeneous catalysts.For vapor-phase hydrogenation of dimethyl oxalate(DMO),"EG route"(DMO→methyl glycolate(MG)ethylene glycol(EG)→ethanol(ET))and"MA route"(DMO→MG→methyl acetate(MA))were proposed over traditional Cu based catalysts and Mo-based or Fe-based catalysts,respectively.Herein,tunable yield of ET(93.7%)and MA(72.1%)were obtained through different reaction routes over WO_(x) modified Cu/SiO_(2) catalysts,and the corresponding reaction route was further proved by kinetic study and in-situ DRIFTS technology.Mechanistic studies demonstrated that H_(2) activation ability,acid density and Cu-WO_(x) interaction on the catalysts were tuned by regulating the surface W density,which resulted in the different reaction pathway and product selectivity.What's more,high yield of MA produced from DMO hydrogenation was firstly reported with the H_(2) pressure as low as 0.5 MPa.

Selective hydrogenation of dimethyl toluene-2,4-dicarbamate over supported Rh-based catalysts:Effect of support properties

The selective hydrogenation of dimethyl toluene-2,4-dicarbamate(TDC)to methyl cyclohexyl-2,4-dicarbamate(also called hydrogenated TDC,HTDC)is an essential process for non-phosgene synthesis of methylcyclohexane-2,4-diisocyanate.Herein,we prepared a series of supported Rh-based catalysts by the excessive impregnation method and investigated their catalytic performance for the selective hydrogenation of TDC.The emphasis was put on the influence of support properties on the catalytic performance.Among the prepared catalysts,Rh/g-Al_(2)O_(3)performed the best:a HTDC yield of 88.4%was achieved with a 100%conversion of TDC under the conditions of 100℃,3 MPa and 1 h.Furthermore,Rh/γ-Al_(2)O_(3)could be repetitively used for 4 times without a significant loss of its catalytic activity.TEM,XRD,N_(2)adsorption-desorption,H_(2)-TPR,NH_(3)/CO_(2)-TPD,XPS and ICP characterizations were employed to distinguish the properties of the prepared catalysts and the results were correlated with their catalytic performance.It is indicated that the yield of HTDC shows a positive relevance with the percentage of moderate-to-strong acid sites and the content of Rh^(n+)(n≥3)in the catalysts.High values of the percentage and the content can promote a strong interaction between Rh nanoparticles and the supports,facilitating both the transfer of electrons from Rh to the support and the formation of Rh^(n+)species.This is conducive to activating the benzene ring of TDC and thereby improving the yield of HTDC.

Deactivation mechanism of CaO in a flow type dimethyl carbonate synthesis process

It is well known that calcium oxide (CaO) has better catalytic efficiency than most heterogeneous catalysts in many transesterification reactions. However, the gradual deactivation problem prevents its large-scale application in industry. In this paper, the deactivation mechanism of CaO in a fixed-bed reactor is investigated based on the transesterification reaction of propylene carbonate and methanol. The leaching amount of CaO during the reaction was estimated by the concentration of Ca in the products. The pretreated and recovered catalysts were characterized by FT-IR, XRD, TG-MS and SEM-EDS. It is evident from experiments and characterization that the deactivation process of CaO is accompanied by the leaching of calcium species and the generation of CaCO3, which are also verified by DFT calculations. At high temperature and high weight hourly space velocity, the deactivation was attributed to the formation of dense CaCO3 shell, which prevents the contact between the feedstock and the active species inside.

Synthesis of Methyl Acetate by Dimethyl Ether Carbonylation over Cu/HMOR： Effect of Catalyst Preparation Method

Dimethyl ether carbonylation to methyl acetate was comparatively investigated over mor- denite supported copper （Cu/HMOR） catalysts prepared by different methods including evaporation, urea hydrolysis, incipient wetness impregnation and ion-exchange. The results showed that Cu/HMOR prepared via iron-exchange method exhibited the highest catalytic activity due to the synergistic effect of active-site metal and acidic molecular sieve support. Conversion of 95.3% and methyl acetate selectivity of 94.9% were achieved under conditions of 210℃, 1.5 MPa, and GSHV of 4883 h-1. The catalysts were characterized by nitrogen absorption, X-ray diffraction, NH3 temperature program desorption, and CO temperature program desorption techniques. It was found that Cu/HMOR prepared by ion-exchange method possessed high surface area, moderate strong acid centers, and CO adsorption centers, which improved catalytic performance for the reaction of CO insertion to dimethyl ether.

Effect of Calcination Temperature on Catalytic Activity and Textual Property of Cu/HMOR Catalysts in Dimethyl Ether Carbonylation Reaction

The effect of calcination temperature on the catalytic activity for the dimethyl ether （DME） carbonylation into methyl acetate （MA） was investigated over mordenite supported copper （Cu/HMOR） prepared by ion-exchange process. The results showed that the catalytic activity was obviously affected by the calcination temperature. The maximal DME conversion of 97.2% and the MA selectivity of 97.9% were obtained over the Cu/HMOR calcined at 430 ℃ under conditions of 210 ℃, 1.5 MPa, and GSHV of 4883 h^-1. The obtained Cu/HMOR catalysts were characterized by powder X-ray diffraction, N2 absorption, NH3 temperature program desorption, CO temperature program desorption, and Raman techniques. Proper calcination temperature was effective to promote copper ions migration and diffusion, and led the support HMOR to possess more acid activity sites, which exhibited the complete decomposing of copper nitrate, large surface area and optimum micropore structure, more amount of CO adsorption site and proper amount of weak acid centers.

SYNTHESIS OF 3,7-DIMETHYL-2-TRIDECANYL ACETATE--Active Component of Sex Pheromone of Pine Sawfly Diprion pini

The total synthesis of 3,7 dimethyl 2 tridecanyl acetate,the active component of the sex pheromone of diprion pini,was investigated in this paper.The two key synthins blocks,2 methyl octan 1 yl lithium and 3,4 dimethyl γ butyrolactone,were obtained from diethyl malonate and 2,3 epoxybutane.2 Methyl octan 1 yl lithium reacted with 3,4 dimethyl γ butyrolactone to yield the ketoalcohol and then followed by Huang Minlong reduction to afford 3,7 dimethyl 2 tridecanol,acylated with acetic anhydide to give 3,7 dimethyl 2 tridecanyl acetate.

Production of Light Olefins from Biosyngas by Two-stage Catalytic Conversion Process via Dimethyl Ether

NiSAPO-34 and NiSAPO-34/HZSM-5 were prepared and evaluated for the performance of dimethyl ether （DME） conversion to light olefins （DTO）. The processes of two-stage light olefin production, DME synthesis and the following DTO, were also investigated using biosyngas as feed gas over Cu/Zn/A1/HZSM-5 and the optimized 2%NiSAPO-34/HZSM- 5. The results indicated that adding 2%Ni to SAPO-34 did not change its topology structure, but resulted in the forming of the moderately strong acidity with decreasing acid amounts, which slightly enhanced DME conversion activity and C2=-C3= selectiw ity. Mechanically mixing 2%NiSAPO-34 with HZSM-5 at the weight ratio of 3.0 further prolonged DME conversion activity to be more than 3 h, which was due to the stable acid sites from HZSM-5. The highest selectivity to light olefins of 90.8% was achieved at 2 h time on stream. The application of the optimized 2%NiSAPO-34/HZSM-5 in the second-stage reactor for DTO reaction showed that the catalytic activity was steady for more than 5 h and light olefin yield was as high as 84.6 g/m3syngas when the biosyngas （H2/CO/CO2/N2/CH4=41.5/26.9/14.2/14.6/2.89, vol%） with low H/C ratio of 1.0 was used as feed gas.

富马酸二甲酯减轻帕金森病模型鼠神经损伤的作用机制

背景:帕金森病是一种特征为多巴胺能神经元进行性丢失的多因素神经系统疾病,富马酸二甲酯(dimethyl fumarate,DMF)在神经退行性疾病中具有强大的神经保护和免疫调节作用。目的:探究DMF对MPTP诱导的帕金森病小鼠模型的神经保护机制。方法:选取24只C57BL/6系小鼠,随机将其分为对照组、模型组及DMF低剂量和DMF高剂量组。除对照组外,其余各组小鼠腹腔注射MPTP 30 mg/kg,1次/d,连续注射5 d,建立帕金森病的动物模型。每次注射MPTP后间隔30 min给予小鼠灌胃,DMF低剂量组和DMF高剂量组每天分别灌胃DMF 30,50 mg/kg,1次/d,对照组和模型组灌同等剂量的生理盐水,连续灌胃7 d。通过行为学检测、Western Blot、氧化应激标志物检测和免疫组织化学染色等方法,分析DMF对MPTP诱导的帕金森病小鼠氧化应激和Keap1/Nrf2信号通路的调节作用,以及DMF对多巴胺神经元变性的保护机制。结果与结论:①与模型组比较,DMF低剂量组小鼠的运动迟缓和姿势平衡障碍得到明显改善(P<0.01),在DMF高剂量组中的改善更为显著(P<0.01)。②与对照组相比,模型组氧化应激标志物丙二醛明显升高,超氧化物歧化酶表达降低(P<0.01);与模型组相比,DMF低、高剂量组降低了丙二醛的产生,增加了超氧化物歧化酶的表达(P<0.01)。③模型组小鼠的中脑黑质多巴胺能神经元数目和酪氨酸羟化酶蛋白表达较对照组明显减少(P<0.01),而DMF低剂量组小鼠的黑质多巴胺能神经元数目和蛋白表达增多(P<0.01),DMF高剂量组改善更明显(P<0.01)。④模型组Keap1蛋白表达升高伴随Nrf2蛋白表达降低;与模型组相比,DMF组降低了Keap1蛋白表达且伴随Nrf2蛋白表达增多(P<0.01)。⑤结果说明,DMF对帕金森病小鼠黑质区Keap1/Nrf2通路有调控作用,且与剂量呈现正相关(P<0.01),推测DMF依赖于Keap1/Nrf2信号发挥神经元保护作用。

Structures and Intermolecular Interactions in Dimethyl Sulfoxide-Water System Studied by All-atom Molecular Simulations

An all-atom dimethyl sulfoxide （DMSO） and water model have been used for molecular dynamics simulation. The NMR and IR spectra are also performed to study the structures and interactions in the DMSO-water system. And there are traditional strong hydrogen bonds and weak C-H- ~ ~ O contacts existing in the mixtures according to the analysis of the radial distribution functions. The insight structures in the DMSO-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Interestingly, the molar fraction of DMSO 0.35 is found to be a special concentration by the network. It is the transitional region which is from the water rich region to the DMSO rich region. The stable aggregates of （DMSO）m＇S=O…… HW-OW-（H20）n might play a key role in this region. Moreover, the simulation is compared with the chemical shifts in NMR and wavenumbers in IR with concentration dependence. And the statistical results of the average number hydrogen bonds in the MD simulations are in agreement with the experiment data in NMR and IR spectra.

Characterization of V_2O_5/MoO_3 composite photocatalysts prepared via electrospinning and their photodegradation activity for dimethyl phthalate

Vanadium pentoxide（V2O5）/molybdenum trioxide（MoO 3） composites with different molar ratios of vanadium（V） to molybdenum（Mo） were synthesized via a simple electrospinning technique. The photocatalytic activity of the composites were evaluated by their ability to photodegrade methylene blue and dimethyl phthalate（DMP） under visible-light irradiation. Compared with pure V2O5 and MoO 3,the V2O5/MoO 3 composites showed enhanced visible-light photocatalytic activity because of a V 3d impurity energy level and the formation of heterostructures at the interface between V2O5 and MoO 3. The optimal molar ratio of V to Mo in the V2O5/MoO 3 composites was found to be around 1/2. Furthermore,high-performance liquid chromatographic monitoring revealed that phthalic acid was the main intermediate in the photocatalytic degradation process of DMP.

DMSO诱导HL60细胞分化过程中的吞噬和杀伤功能

目的探究HL60分化过程中吞噬和杀伤的功能变化。方法本研究首先使用流式细胞术和髓系过氧化物酶(MPO)检测方法监测二甲亚砜(DMSO)诱导HL60细胞的成熟过程。接着利用金黄色葡萄球菌体外感染实验分析了此过程中细胞的吞噬和杀伤功能变化。结果CD11b的表达随诱导时间延长而升高,到第8天达到高峰,MPO表达量显著下降,6 d以后达到最低。DMSO诱导HL60细胞后第4天达到最佳吞噬和杀伤效果。结论HL60经DMSO诱导后,吞噬和杀伤功能的变化与类中性粒细胞成熟过程并不完全一致。这为DMSO诱导的HL60细胞在吞噬和杀伤实验的应用提供了参考。

我国碳酸酯类电解液溶剂的产业现状

电解液溶剂与电池的综合性能息息相关。介绍了目前国内常用的电解液溶剂及其物理性质,其中碳酸二甲酯和碳酸甲乙酯用量最大。同时主要介绍了碳酸二甲酯和碳酸甲乙酯的现阶段生产技术,对比了碳酸二甲酯生产工艺的优缺点,介绍了酯交换法合成碳酸二甲酯的主流工艺。最后分析了当前两种主要电解液溶剂的产能及市场情况,并提出未来产业发展的方向。

水曲柳挥发物(E)-4,8-二甲基-1,3,7-壬三烯对长白落叶松针叶抗虫次生物质质量分数的影响

为探明水曲柳(Fraxinus mandshurica Rupr.)挥发物对长白落叶松(Larix olgensis Henry)针叶抗虫次生物质影响的潜在机制,采用动态顶空吸附法收集行间混交的长白落叶松幼树与水曲柳幼树的挥发物,利用气相色谱-质谱联用技术(GC-MS)鉴定挥发物的组分,使用水曲柳挥发物(E)-4,8-二甲基-1,3,7-壬三烯(DMNT)对长白落叶松进行熏蒸处理,检测长白落叶松针叶的总酚、类黄酮与单宁的质量分数。结果表明:水曲柳幼树与长白落叶松幼树挥发物组成成分相差较大,长白落叶松挥发物种类多,以单萜类物质为主,其主要挥发物有α-蒎烯、β-蒎烯与3-蒈烯;而水曲柳挥发物种类仅有5种,其主要挥发物为DMNT。DMNT熏蒸处理能够短时间内(4~6 d)显著提高长白落叶松针叶的类黄酮与单宁质量分数,但对总酚质量分数无明显影响。研究结果表明,水曲柳通过释放DMNT影响混交林内长白落叶松针叶内类黄酮与单宁质量分数,进而提升长白落叶松的抗虫性。

兔离断后肢深低温冻存中二甲基亚砜导入效果的定量分析

背景:保护剂导入效果在器官深低温冻存中至关重要,定量分析保护剂二甲基亚砜导入效果可为器官深低温冻存成功提供理论依据。目的:研究兔离断后肢深低温冻存中二甲基亚砜导入效果。方法:采用随机数字表法将50只新西兰大白兔随机分为A1组(n=8)、A2组(n=8)、B1组(n=8)、B2组(n=8)、C1组(n=6)、C2组(n=6)、C3组(n=6),均建立离断后肢深低温保护剂灌注模型,A1组、A2组分别使用10%,20%二甲基亚砜溶液经股动脉持续灌注50min,利用微透析-冰点渗透压仪检测肌肉组织中二甲基亚砜浓度;B1组、B2组分别使用10%,20%二甲基亚砜溶液经股动脉持续灌注30,20 min,利用核磁共振波谱检测血管周围、肌肉与皮下组织中二甲基亚砜浓度;C1组、C2组、C3组分别浸泡于50%,35%,20%二甲基亚砜溶液中30 min,利用核磁共振波谱检测血管周围、肌肉与皮下组织中二甲基亚砜浓度。结果与结论:①A1组、A2组肌肉组织中的二甲基亚砜浓度随着灌注时间的延长而升高,A1组在灌注30 min后浓度稳定在5%左右,A2组在灌注20 min后浓度稳定在12%左右;A2组各灌注时间点肌肉组织中二甲基亚砜浓度均高于A1组(P<0.05);②B2组肌肉组织、血管周围与皮下组织中二甲基亚砜浓度分别为12%,20%,8.6%,B1组血管周围、肌肉组织与皮下组织中二甲基亚砜浓度分别为10.9%,6.9%,1%,两组间相同组织中二甲基亚砜浓度比较差异有显著性意义(P<0.05);③C1组、C2组、C3组肌肉组织和血管周围未检测到二甲基亚砜存在,C1组、C2组、C3组皮下组织中二甲基亚砜浓度分别为6.5%,2.3%,1.85%,组间比较差异有显著性意义(P<0.05);④结果表明,对于兔离断后肢模型,深低温保护剂二甲基亚砜通过传统的浸泡法导入是无效的,而通过动脉灌注法导入20%二甲基亚砜溶液后可在大部分组织达到或接近有效的玻璃化浓度。