石油磺酸镁清净剂过碱化工艺研究

研究了超碱值石油磺酸镁合成过程中过碱化反应时间、过碱化反应温度、水和氧化镁加入量对产品碱值的影响,得到了合成超碱值石油磺酸镁的最佳过碱化反应条件:石油磺酸胺为80g,反应时间为3h,反应温度为46℃,水的加入量为10mL,氧化镁的加入量为24g,可得到碱值大于390mgKOH/g的超碱值石油磺酸镁产品;最后通过红外光谱及冷冻蚀刻电镜观测技术,对产物结构和稳定性进行了测定。

纳米磺酸钙镁复合清净剂合成工艺条件研究

目的以减二线油生产的石油磺酸铵为原料,研究和优化纳米磺酸钙镁复合清净剂合成的工艺条件。方法采用单因素和正交实验法研究影响产品碱值的主要因素,利用傅里叶红外(FT-IR)和冷冻蚀刻电子显微镜观测技术(FERTEM)对产品的结构进行表征。结果纳米磺酸钙镁复合清净剂最佳合成工艺条件为:石油磺酸铵65 g、氧化镁22 g、水10 mL、甲醇16 mL、过碱化反应温度42℃、过碱化反应时间4 h、二氧化碳通入速率120 mL/min、基础油28 g。结论所得到的纳米磺酸钙镁复合清净剂合成工艺条件具有良好的重复性,产品的结构符合润滑油纳米清净剂的结构特点。

一种软脂酸镁清净剂的研制

以软脂酸、二氧化碳、活性-60氧化镁为原料合成润滑油类清净剂,实验结果表明,软脂酸质量为5 g,活性-60氧化镁为8 g,甲醇8 mL,70℃反应2 h,可得到碱值为282 mg(KOH)/g的软脂酸镁盐清净剂;红外谱图(IR)显示软脂酸镁清净剂含有无定型的MgCO3。

Simulation Study on the Alkalized-salinized Grassland Ecosystem in the Songnen Plain

Using Object-oriented design and a new programming language JAVA, a physically-based model was built to simulate the hydrological, alkalization/de-alkalization and salinization/desalinization processes in soil. Furthermore, a process-based model was built to evaluate the dynamics of four herbaceous ecosystems (including dynamics of above-ground biomass, below-ground biomass, and litter biomass), each dominated by Aneurolepidium chinense (Trin.) Kitag., Chloris virgata Sw., Puccinellia tenuiflora (Turcz.) Scribn. et Merr. and Suaeda glauca Bunge. This model is a daily-time step model, suitable for simulating hydrological, alkalization/de-alkalization and salinization/desalinization processes of heterogeneous soil, and growth dynamics of different grassland communities. With climatic data and experimental data of Changling Experimental Site in Jilin Province, the soil moisture content (in 1991, 1996, 1997 and 1998), soil salt concentration, exchangeable cation percentage and pH in soil and growth dynamics of these four sorts of grassland communities (in 1991) were simulated and the results were verified to be in accord with observed data.

Cloning and Differential Gene Expression of Two Catalases in Suaeda salsa in Response to Salt Stress

Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ( L.) Pall aerial tissue. Sscat1 (1.7 kb) contains a full open reading frame of 492 amino acids and Sscat2 (1.1 kb) is a partial clone. BLAST analysis indicates that the two clones share 71.9% identity in nucleotide sequence and 75% identity in deduced amino acid sequence within the last 287 amino acid residues of Sscat1. Southern blotting analysis showed that Sscat1 is multicopy in S. salsa genome, while Sscat2 is a single copy gene. Northern blotting analysis showed a rapid increase in the steady-level of both genes in roots after 48 It salt treatment, but only Sscat1 was induced in salinity treated leaves. Time-course analysis carried out in leaves confirmed that Sscat1 was induced by salt stress, in contrast to Sscat2. These implied that the expression of Sscat1 and Sscat2 genes are differentially regulated in S. salsa. The activity of total catalase is dramatically increased in response to salt stress.

Enhancement on Synthesis of Boehmite Through a Precarbonizationassisted Hydrogen Peroxide Route in Highly Alkaline Sodium Aluminate Solutions

Hydrogen peroxide(H2O2)precipitation from sodium aluminate(SA)solution at close-ambient temperature is an efficient method to synthesize boehmite and its derived alumina with high surface area,but the precipitation yield of Al2O3 is usually below 50%in highly alkaline SA solutions.Here the synthesis of boehmite is enhanced through a precarbonization-assisted H2O2 route in highly alkaline SA solutions.It is found that the crystal structure of the precipitation product is evidently influenced by the precipitation conditions.As the precipitation temperature increases from 273 to 325 K,a small amount of gibbsite by-product is formed.As the aging temperature increases from 301 to 333 K,the crystallinity of boehmite decreases and part of the boehmite dissolves due to an increase in the pH value.Based on the above results,a precarbonization-assisted H2O2 route is proposed to obtain pure boehmite with more complete recovery of Al2O3 from highly alkaline SA solutions.The route includes a controllable precarbonization step of SA solutions with a molar ratio of Na2O to Al2O3 higher than 2:1,followed by the H2O2-precipitated step with a molar ratio of H2O2 to Al2O3 less than 7:1.Because of its facile operation conditions,no extraneous impurity,time saving and a possible recycle of the filtrate,the route has great potential to be an alternative method for preparation of boehmite and its derived alumina.

Tentative Research of Short Process of Jute Degumming and Bleaching

The feasibility of combination process of jute degumming and bleaching with alkali-hydrogen peroxide in one-step-one-bath was discussed. The combination process basically has the similar function as the traditional two-step-two-bath method. The factors such as hydrogen peroxide concentration, CBI concentration, sodium hydroxide concentration, treatment time and temperature were studied respectively, and then an orthogonal experiment was designed to study the interactions among the hydrogen peroxide concentration, CBI concentration, sodium hydroxide concentration. After the designed experiments, the optimum treatment conditions were obtained as follows: hydrogen peroxide of 12g/L, sodium hydroxide of 4g/L, CBI of 4g/L, JFC of 1g/L, treatment time of 60min and temperature of 75℃.

Copper solvent extraction from alkaline cyanide solution with guanidine extractant LIX 7950

The use of the guanidine extractant LIX 7950 extracting copper and cyanide from alkaline cyanide solution was investigated.The extraction of copper and cyanide under different initial copper and extractant concentrations was examined and the stoichiometric extraction constant of Cu(CN)32- with LIX 7950 was calculated.Both the distribution coefficient and the stoichiometric extraction constant of Cu(CN)3 2-with LIX 7950 decrease when the temperature is varied from 25℃to 45℃, indicating the extraction process is exothermic.The calculated enthalpy change of the reaction(-HΘ)is about-190 kJ/mol.The copper extraction isotherms under different molar ratios of cyanide to copper are established.The preferential extraction of Cu(CN)32- over Cu(CN)4 3-and CN -has been confirmed and a high cyanide-to-copper molar ratio tends to suppress copper loading. The loaded copper and cyanide can be stripped efficiently by the moderately strong NaOH solutions(0.5-1.0 mol/L)and the presence of NaCN in the stripping solution facilitates copper stripping.

Treatment of spent caustic by three kinds of photocatalyticoxidation processes

The investigation of the performance of UV/H2O2, UV/O3 and UV/H2O2/O3 oxidation systems treating spent caustic from an ethylene plant shows that in UV/H2O2 system, with the increase of H2O2dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand （BOD） to chemical oxygen demand （COD） of the effluent were increased and a better performance was obtained than the H2O2system alone. In UV/H2O2 system, removal efficiency of COD reached 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0.22 to 0.52. In UV/O3 system, with the increase of O3dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O3system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0.22 to 0.48. In UV/H2O2/O3 system, COD removal efficiency was found to be 22.0% higher than UV/O3 system.

Effects of Refining on the Fiber Properties of Poplar APMP

Poplar alkaline peroxide mechanical pulp （APMP） was refined in a PFI mill at varied revolution and the properties of the refined fibers and the resulting hand sheets were tested. The raw poplar APMP fibers are stiff and have been detached from the lamella during APMP pulping process. During the refining process, the APMP fibers did not swell and fibrillate; they were easily broken and formed into fragments. The breaking length of formed hand sheets increased as the heating degree increased because lots of hydrogen bonds were formed between fibers and fine pieces. The tear strength of hand sheets first increased and then decreased as the beating degree changed from 17 to 70~SR. The maximum tear strength was achieved at 61 ~SR of the beating degree. These results indicated that the hydrogen bond between the fibers was the main factor influencing the tear index followed by the fiber length. Along with the increase of the beating degree, the sheet density increased while the opacity decreased.

Characterization of Basic Nitrogen Aromatic Species Obtained during Fluid Catalytic Cracking by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

The basic-nitrogen aromatic compounds in feedstocks and liquid products from the micro-reactor and soluble components of coke obtained during fluid catalytic cracking （FCC） process were analyzed by the micro-electrospray ioniza- tion （ESI） 9.4T Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS） with an average mass resolving power of 300 000 at a mass range of 100--1 200. The analytical results revealed that the coker gas oil （CGO） contained a higher abundance of basic-nitrogen aromatic compounds with the type of-SN to -9N compared with those in deasphalted oil （DAO） and mixed FCC feedstock. After catalytic cracking, the abundance of lowly condensed basic-nitrogen aromatic compounds was much less than those of highly condensed aromatics in the liquid products, with the carbon number mainly ranging from 6 to 25 and the average carbon number of the side-chains equating to 1--5. On the contrary, with respect to the soluble components of coke, the abundance of lowly condensed basic-nitrogen aromatic compounds was more than those of highly condensed aromatics, and the carbon number ranged from 12 to 30, which was much smaller than that of the mixed FCC feedstock but slightly larger than that of the cracked liquid products. These results have provided some fundamental information on FCC process.

Acute toxicity of organochlorine insecticide endosulfan to the giant freshwater prawn Macrobrochium rosenbergii

Endosulfan, an organochlorine pesticide, is highly toxic and effective at controlling pests in agriculture, horticulture, and public health programs. In this study, static bioassays were used to evaluate the toxicity of endosulfan to freshwater prawns( Macrobrachium rosenbergii) of various lengths(1.5±0.03,4±0.08, and 7±0.06 cm). Additionally, the activities of peroxidase(POD), acid phosphatase(ACP),alkaline phosphatase, acetylcholinesterase(AChE), and Na + /K +-ATPase were analyzed to refl ect the effects of endosulfan exposure. The 96 h LC 50 of endosulfan for prawns 1.5, 4, and 7 cm long were 1.86, 4.53,and 6.09μg/L, respectively, improved tolerance to endosulfan with growth. The POD activities of test organisms exposed to low concentrations of endosulfan were inhibited, indicating the presence of oxygen damaged tissue. Moreover, a notable decrease in AChE activity was observed due to overstimulation of neurotransmission, which might result in abnormal behavior. The effect caused by endosulfan on phosphatase production in the hepatopancreas of prawns 1.5, 4, and 7 cm long was different because the ability of nonspecifi c immune regulation increased with growth. The 96 h LC 50 values obtained in this study could be used in the formulation of water-quality criteria in China. Moreover, the changes in enzymes activities of M. rosenbergii under stress of endosulfan could be applied in the establishment of early warning indicators for bio-safety.

Enhancement of Superoxide Dismutase and Catalase Activities and Salt Tolerance of Euhalophyte Suaeda salsa L. by Mycorrhizal Fungus Glomus mosseae

Arbuscular mycorrhizal （AM）-mediated plant physiological activities could contribute to plant salt tolerance. However, the biochemical mechanism by which AM fungi enhance salt tolerance of halophytie plants is unclear. A pot experiment was conducted to determine whether salt tolerance of the C3 halophyte Suaeda salsa was enhanced by the AM fungus Glomus rnosseae. When 60-day-old S. salsa seedlings were subjected to 400 mmol L-1 NaC1 stress for 35 days, plant height, number of leaves and branches, shoot and root biomass, and root length of G. mosseae-colonized seedlings were significantly greater than those of the nonmycorrizal seedlings. Leaf superoxide dismutase （SOD） activity at all sampling times （weekly for 35 days after salt stress was initiated） and leaf catalase （CAT） activity at 2 and 3 weeks after salt stress was initiated were also significantly enhanced in G. mosseae-colonized S. salsa seedlings, while the content of leaf malondialdehyde （MDA）, a product of membrane lipid peroxidation, was significantly reduced, indicating an alleviation of oxidative damage. The corresponding leaf isoenzymes of SOD （Fe-SOD, Cu/Zn-SOD1, and Cu/Zn-SOD2） and CAT （CAT1 and CAT2） were also significantly increased in the mycorrhizal seedlings after 14 days of 400 mmol L-1 NaC1 stress. Our results suggested that G. rnosseae increased salt tolerance by increasing SOD and CAT activities and forming SOD and CAT isoforms in S. salsa seedlings.

Core/shell FePd/Pd catalyst with a superior activity to Pt in oxygen reduction reaction

Developing high-efficient non-platinum （Pt） catalysts for oxygen reduction reaction （ORR） is the key to reduce the usage of Pt and the palladium （Pd）-based cata- lyst is a promising alternative. Here, we presented a facile approach to core/shell FePd/Pd nanoparticle （NP） catalyst with the FePd core in chemically ordered face-centered tetragonal （fct-） structure and the shell in controlled thickness from 0.32 to 0.81 nm via the thermal annealing of FePd NP followed by an electro-anodization process. With a 0.71 nm-thick Pd shell, the fct-FePd/Pd shows a robust catalytic activity and durability for ORR with the mass activities at 0.85 and 0.90 V reaching 453 and 96.7 A/mgpd, respectively, which are about 3.0 and 2.1 times higher than those of commercial Pt in alkaline media. This work presents a new class of non-Pt catalyst with superior performance to Pt for ORR catalysis, and the strategy demonstrated here can be extended to design highefficient catalysts for other chemical reactions.

Osteogenic differentiation of mesenchymal stem cells promoted by overexpression of connective tissue growth factor

Objective:Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques.The aim of this study is to investigate the effect of connective tissue growth factor(CTGF) on the proliferation and osteogenic differentiation of the bone marrow mesenchymal stem cells(MSCs).Methods:A CTGF-expressing plasmid(pCTGF) was constructed and transfected into MSCs.Then expressions of bone morphogenesis-related genes,proliferation rate,alkaline phosphatase activity,and mineralization were examined to evaluate the osteogenic potential of the CTGF gene-modified MSCs.Results:Overexpression of CTGF was confirmed in pCTGF-MSCs.pCTGF transfection significantly enhanced the proliferation rates of pCTGF-MSCs(P<0.05).CTGF induced a 7.5-fold increase in cell migration over control(P<0.05).pCTGF transfection enhanced the expression of bone matrix proteins,such as bone sialo-protein,osteocalcin,and collagen type I in MSCs.The levels of alkaline phosphatase(ALP) activities of pCTGF-MSCs at the 1st and 2nd weeks were 4.0-and 3.0-fold higher than those of MSCs cultured in OS-medium,significantly higher than those of mock-MSCs and normal control MSCs(P<0.05).Overexpression of CTGF in MSCs enhanced the capability to form mineralized nodules.Conclusion:Overexpression of CTGF could improve the osteogenic differentiation ability of MSCs,and the CTGF gene-modified MSCs are potential as novel cell resources of bone tissue engineering.

Revealing interfacial space charge storage of Li^(+)/Na^(+)/K^(+)by operando magnetometry

Interfacial space charge storage between ionic and electronic conductor is a promising scheme to further improve energy and power density of alkali metal ion batteries(AMIBs).However,the general behavior of space charge storage in AMIBs has been less investigated experimentally,mostly due to the complicated electrochemical behavior and lack of proper characterization techniques.Here,we use operando magnetometry to verify that in FeSe_(2)AMIBs,abundant Li^(+)/Na^(+)/K^(+)(M^(+))can be stored at M_(2)Se phase while electrons accumulate at Fe nanoparticles,forming interfacial space charge layers.Magnetic and dynamics tests further demonstrate that with increasing ionic radius from Li^(+),Na^(+)to K^(+),the reaction kinetics can be hindered,resulting in limited Fe formation and reduced space charge storage capacity.This work lays solid foundation for studying the complex interfacial effect in electrochemical processes and designing advanced energy storage devices with substantial capacity and considerable power density.