脱水和脱液型防锈油的应用研究

进行实验室内的防锈油性能对比试验，确定防锈性能较好的脱水和脱液型防锈，对不同材料的金属产品进行封存试验，确定对不同金属材料不同状态适合的防锈油和防锈封存期。通过以上的试验研究，确定出适合生产实际．满足机加工序防锈要求的防锈材料、防锈．Y-艺和防锈封存期。

Effects of Exogenous Organic Acids on Dehydrogenase Activity in Dark Brown Forest Soils under Nutrient Deficiency

Objective] This study aimed to investigate the effects of exogenous or-ganic acids on dehydrogenase activity in dark brown forest soils under nutrient defi-ciency. [Method] Different proportions of A1 and B horizon dark brown forest soils （A1∶B=1∶2） were utilized to establish soil conditions with nutrient deficiency for cultivation of Larix olgensis seedlings. The effects of oxalic acid, citric acid and succinic acid on dehydrogenase activity in dark brown forest soils under nutrient deficiency were studied systematical y by adding different concentrations of organic acid solutions. [Result] Under nutrient deficiency, dehydrogenase activity in dark brown forest soils was reduced significantly, and the reduction increased with the extension of stress duration. Most organic acid treatments improved dehydrogenase activity in nutrient-deficient dark brown forest soils, and the effects varied with different treatment du-ration and types and concentrations of organic acids. Furthermore, 10.0, 5.0 and 10.0 mmol/L organic acid treatments exhibited the most significant effects on day 10, 20 and 30, respectively. The increment of dehydrogenase activity in different durations showed a downward trend of 30 d〉20 d〉10 d; the improvement effects of three organic acids on dehydrogenase activity showed a downward trend of succinic acid〉 citric acid〉oxalic acid. [Conclusion] Exogenous organic acids improved signifi-cantly dehydrogenase activity in dark brown forest soils under nutrient deficiency and also improved the microbial activity and soil fertility to a certain extent.

Changes in sulfur form during coal desulfurization with microwave:Effect on coal properties

The changes in sulfur form in coal were analyzed by sulfur K-XANES(K-edge X-ray absorption near edge structures) spectra before and after the coal microwave desulfurization in a Na OH solution. After the desulfurization, the pyritic sulfur content of coal decreased significantly from 53.6% to 39.2%, while the sulfate sulfur content increased from 17.3% to 34.6%. Only a small amount of thiophene sulfur(20.1–16.1%) was removed. Some sulfur-containing components were oxidized to sulfate sulfur. Under the optimum conditions, the ash content decreased, while the volatile content increased. The calorific value of coal slightly decreased with a slight variation in the amplitudes. The overall structure of coal did not change significantly based on Fourier transform infrared(FTIR) spectral analyses. Thus, the desulfurization of coal with microwave irradiation in a Na OH solution did not significantly change the properties of coal.

Adsorption and desorption properties of D318 resin for Cr(Ⅵ)

The adsorption capability of D318 resin for Cr（Ⅵ） was investigated by chemistry analysis. Experimental results show that D318 resin has the best adsorption ability for Cr（Ⅵ） at pH=3.16 in HAc-NaAc medium. The statically saturated adsorption capacity of the resin is 265.4 mg/g. The thermodynamic adsorption parameters, enthalpy change AH and free energy change AG298 of the adsorption reaction are 4.81 and -5.16 kJ/mol, respectively. The apparent activation energy Ea is 22.4 kJ/mol. The adsorption behavior obeys the Freundlich isotherm. The molar coordination ratio of the functional group of resin to Cr（Ⅵ） is 3：2. Cr（Ⅵ） adsorbed on D318 resin can be eluted by 5%NaOH-5%NaCl quantitatively.

Thermodynamics and kinetics of fluoride removal from simulated zinc sulfate solution by La(Ⅲ)-modified zeolite

To understand the mechanism of fluoride removal from the simulated zinc sulfate solution by the La(III)-modified zeolite,the adsorbent was characterized by XRD,SEM and EDS.The effects of absorbent dose and contact time,the adsorption isotherms and the sorption kinetics were investigated.The experimental results were compatible with the Langmuir isotherm model.The theoretical maximum adsorption capacities are 20.83 and 23.04 mg/g at 303 and 313 K,respectively.And the physisorption is revealed using the Temkin isotherm model and the D-R isotherm model.The sorption process is more suitable by the pseudo-second-order kinetic models.Thermodynamic parameters such as standard free energy change(ΔGΘ<0 kJ/mol),standard enthalpy change(ΔHΘ=8.28 kJ/mol)and standard entropy change(ΔSΘ=0.030 kJ/(mol?K))indicate the spontaneity of adsorption and endothermic physical sorption.Furthermore,the fluoride concentration in the industrial zinc sulfate solution decreases from 98.05 to 44.09 mg/L with the adsorbent dosage of 15 g/L.

Design of the Metal Precursors Molecular Structures in Impregnating Solutions for Preparation of Efficient Ni Mo/Al_2O_3 Hydrodesulfurization Catalysts

The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.

Effect of hypoxia on the blood of large yellow croaker (Pseudosciaena crocea)

Large areas of hypoxic water have recently been reported in the East China Sea. It is hypothesized that hypoxia may be partially responsible for the decline of some fish stocks. We evaluated the effect of hypoxia on large yellow croaker (Pseudosciaena crocea). The fish were exposed to three concentrations of dissolved oxygen (DO; 1.5 mg/L and 2.0 mg/L, and 6.5 mg/L control). We collected blood after 6, 12, 24, 48, and 96 h exposure. There was a significant increase in red blood count, hematocrit, hemoglobin concentration, and mean corpuscular hemoglobin in the group exposed to 1.5 mg/L DO after 6 h or 12 h, and a delayed increase (only elevated after 48 h and 96 h) in these indices in the group exposed to 2.0 mg/L DO. Plasma glucose concentrations increased significantly in both hypoxic groups after 24 h. Furthermore, plasma lactate and lactate dehydrogenase activity increased significantly after the first 6 h exposure in both hypoxic groups. Our results suggest that large yellow croakers could not maintain the aerobic pathway and instead use anaerobic metabolism for survival when DO levels fall below 2.0 mg/L. We conclude that the occurrence of hypoxia (<2 mg/L DO) in the East China Sea could cause metabolic stress for large yellow croakers and may be partially responsible for the population decline of this species.

Performance of simultaneous desulfurization and denitration in liquid phase with new-style complex absorbent

Performance of simultaneous desulfurization and denitration using the solution of NaClO2 and NaClO as new-style complex absorbent was investigated experimentally in self-designed bench scale bubbling reactor. The effects of main parameters, such as the concentrations of NaClO2 and of NaClO, solution pH and reaction temperature and so on, on removal efficiencies of SO2 and NOx, were examined, then the optimal conditions were established, in which the molar ratio of NaClO to NaClO2 was 1：1, the reaction temperature was 50℃ and the solution pH was 5.5. The removal efficiencies of SO2 and NO under the optimal conditions were 100% and 89.2%, respectively. The mechanism of simultaneous removal based on complex absorbent was proposed by analyzing the removal products and the electrode potentials of related species, namely SO2 and NO are oxi- dized by chlorite anion, hypochlorite, chlorine dioxide and chlorine contained in complex absorbent. In thermodynamic aspect, simultaneous desulfurization and denitration reactions in liquid phase can happen spontaneously and completely, and are all exothermic reactions. It was confirmed by kinetics that for simultaneous desulfurization and denitration, the reaction order and average activation energy of SO2 were 1 and 21.6 kJ·mol^-1, respectively, and those of NO were 1 and 8.2 kJ·mol^-1, respectively.

Regulating sulfur removal efficiency of fuels by Lewis acidity of ionic liquids

It is urgent to develop a new deep desulfurization process of fuels as the environmental pollution increases seriously. In this work, a series of Lewis acidic ionic liquids （ILs） [C43MPy]Cl/nZnCl2 （n=1, 1.5, 2, 3） were synthesized and used in extraction and catalytic oxidative desulfurization （ECOD） of the fuels. The effects of the Lewis acidity of ILs, the molar ratio of H2O2/sulfur, temperatures, and different substrates including dibenzothiophene （DBT）, benzothiophene （BT） and thiophene （TS）, on sulfur removal were investigated. The results indicated that [C43MPy]Cl/3ZnCl2 presented near 100% DBT removal of model oil under conditions of 323 K, H2O2/DBT molar ratio 6：1. Kinetics for the removal of DBT, BT and TS by the [C43MPy]Cl/3ZnCl2-H2O2 system at 323 K is first-order with the apparent rate constants of 1.1348, 0.2226 and 0.0609 h-1, and the calculated apparent activation energies for DBT, BT and TS were 61.13, 60.66, and 68.14 kJ/mol from 298 to 308 K, re- spectively. After six cycles of the regenerated [C43MPy]Cl/3ZnCl2, the sulfur removal had a slight decrease. [C43MPy]Cl/ 3ZnCl2 showed a good desulfurization performance under optimal conditions.

NiRh nanoparticles supported on nitrogen-doped porous carbon as highly efficient catalysts for dehydrogenation of hydrazine in alkaline solution

Well-dispersed bimetallic NiRh nanoparticles （NPs） with different compositions supported on nitrogen-doped porous carbon （NPC） derived from metal-organic frameworks （ZIF-8） were synthesized through a co-reduction method. The NPC-900 supported NiRh catalyst exhibits the highest catalytic activity and 100% hydrogen selectivity toward hydrogen generation from hydrazine. These properties might be attributed to the high surface area and high graphitization of the NPC. This strategy may open up a new avenue for designing high-performance catalysts by utilizing NPC as a support to anchor active metal NPs for additional applications.

Bottom-up fabrication of three-dimensional nanoporous gold from Au nanoparticles using nanowelding

Three-dimensional(3D)nanoporous gold(NPG)shows promising applications in various fields.However,its most common fabrication strategy(i.e.,dealloying)faces the problems of high energy consumption,resource waste,the use of corrosive solvent,and residue of the sacrificial component.Here,we report a general bottom-up nanowelding strategy to fabricate high-purity NPG from Au nanoparticles(NPs),accomplished via interfacial self-assembly of the Au NPs into monolayer Au NP film,its subsequent layer-by-layer transfer onto a solid substrate,and direct current(DC)nanowelding.We show that the DC nanowelding process can gradually evolve the layered Au NP film into NPG at low temperatures within 10 s,while not damaging their spherical structure.This is because during the nanowelding,electrons are preferred to be localized at the high-resistance NP/NP junctions,whose electrostatic repulsion in turn strengthens their surface atom diffusion to initiate a mild solid-state diffusion nanowelding.Furthermore,when using differently sized Au NPs as the starting building blocks,this strategy allows readily tuning the thickness,ligament size,and pore size,thereby offering great flexibility to create functional porous nanomaterials,e.g.,electrocatalyst for methanol electrooxidation.Surely,low-temperature nanowelding can play a role for the production of diverse nanoporous materials from other NPs beyond Au NPs.