Selective catalytic hydrogenation of naphthalene to tetralin over a NiMo/Al2O3 catalyst

The selective catalytic hydrogenation of naphthalene to high-value tetralin was systematically investigated.A series of Al2O3 catalysts containing different active metals(Co,Mo,Ni,W)were prepared by incipient wetness impregnation.The effects of different active metals forms(oxidation,reduction,sulfuration)and reaction conditions on naphthalene hydrogenation were investigated and the catalysts were characterized by XRD,XPS,BET,NH3-TPD and SEM.Especially,Ni-Mo/Al2O3 was first used in this reactive system.The results show that the oxidative4%Ni O-20%MoO3/Al2O3 is the best catalyst for the preparation of tetralin.The conversion of naphthalene and the selectivity of tetralin can reach 95.62%and 99.75%respectively at 200℃,8 h and 6 MPa.Compared with reduced and sulfureted 4%Ni O-20%MoO3/Al2O3 catalysts,oxidative 4%Ni O-20%MoO3/Al2O3 has a well dispersed and uniform monolayer of the active metals,larger pore volume and size,and larger total acidity.NiO-MoO3/Al2O3 has a synergistic effect between NiO activity and MoO3 selectivity.

Research Progress of Grassland Feed-animal Balance at Home and Abroad

Feed-animal balance is the key technique on the grassland ecosystem management,and attracts widespread attention in the world.Many studies have been conducted by former researchers,and most of their efforts were intended to keep the balance of feed-animal.However,there are still much more issue needed to be studied in details on the face of grassland degeneration and animal husbandry sustainable development.The author analyzed the feed-animal balance research progress,including the concept of stocking rate and its practical management techniques,especially on the stocking rate calculation methods.In addition,the social and economy effects on feed-animal balance were also discussed during the progress of improving the development of pastoral economy.In order to achieve feed-animal balance more effectively,it was concluded that the focus must be shift from only on animal number to the grassland quality,and it's necessary to strengthen market tax control.

Genetic variants in the Hedgehog signaling pathway genes are associated with gastric cancer risk in a Chinese Han population

The Hedgehog signaling pathway participates in the occurrence and progression of cancers including gastric cancer.We conducted this study to evaluate whether genetic variants in the Hedgehog signaling pathway genes would affect gastric cancer risk.Multi-marker Analysis of GenoMic Annotation(MAGMA)was used to investigate the aggregated genetic effects of single nucleotide polymorphisms(SNPs)assigned to candidate genes.The relationship between SNPs and gastric cancer risk was estimated by multivariate logistic regression analyses.Gene expression was calculated using databases obtained from The Cancer Genome Atlas(TCGA)and The Gene Expression Omnibus(GEO).Kaplan‐Meier plotter was used to evaluate the association between gene expression with gastric cancer survival.Tumor Immune Estimation Resource 2.0(TIMER 2.0)was applied to determine the correlation between selected gene expression and the immune cell infiltration degree.We identified that the G allele of rs2990912 in KIF27 was associated with higher gastric cancer risk,especially in the young and male subgroups.The expression of KIF27 in gastric cancer tissues was higher than that in normal tissues,leading to poor survival in gastric cancer patients.Besides,KIF27 expression was related to immune cell infiltration and positively correlated with PD-L1 expression.Our findings highlight the key role of genetic variation in the Hedgehog signaling pathway genes in gastric cancer susceptibility,which may provide important insights into the diagnosis,prognosis,and treatment of gastric cancer.

Non-escaping frost tolerant QTL linked genetic loci at reproductive stage in six wheat DH populations

Reproductive stage frost poses a major constraint for wheat production in countries such as Australia.However,little progress has been made in identifying key genes to overcome the constraint.In the present study,a severe frost event hit two large-scale field trials consisting of six doubled haploid(DH)wheat populations at reproductive stage(young microspore stage)in Western Australia,leading to the identification of 30 robust frost QTL on 17 chromosomes.The major 18 QTL with the phenotype variation over 9.5%were located on 13 chromosomes including 2 A,2 B,2 D,3 A,4 A,4 B,4 D,5 A,5 D,6 D,7 A,7 B and7 D.Most frost QTL were closely linked to the QTL of anthesis,maturity,Zadok stages as well as linked to anthesis related genes.Out of those,six QTL were repetitively detected on the homologous regions on 2 B,4 B,4 D,5 A,5 D,7 A in more than two populations.Results showed that the frost damage is associated with alleles of Vrn-A1 a,Vrn-D1 a,Rht-B1 b,Rht-D1 b,and the high copy number of Ppd-B1.However,anthesis QTL and anthesis related genes of Vrn-B1 a and Ta FT3-1 B on chromosomes 5 B and 1 B did not lead to frost damage,indicating that these early-flowering phenotype related genes are compatible with frost tolerance and thus can be utilised in breeding.Our results also indicate that wild-type alleles Rht-B1 a and Rht-D1 a can be used when breeding for frost-tolerant varieties without delaying flowering time.

Mesenchymal stem cells:As a multi-target cell therapy for clearingβ-amyloid deposition in Alzheimer’s disease

Extracellularβ-amyloid(Aβ)plaques and neurofibrillary tangles(NFTs)are the pathological hallmarks of Alzheimer’s disease(AD).Studies have shown that aggregates of extracellular Aβcan induce neuroinflammation mediated neurotoxic signaling through microglial activation and release of pro-inflammatory factors.Thus,modulation of Aβmight be a potential therapeutic strategy for modifying disease progression.Recently,a large number of reports have confirmed the beneficial effects of mesenchymal stem cells(MSCs)on AD.It is believed to reduce neuroinflammation,reduce Aβamyloid deposits and NFTs,increase acetylcholine levels,promote neurogenesis,reduce neuronal damage,and improve working memory and cognition.In this review,we focus on the role of MSCs in clearing Aβdeposition.MSCs have the potential to modulate Aβ-related microenvironments via enhancement of autophagy,proteolysis of Aβaggregates,phagocytic clearance of Aβby microglial M2 polarization,decrease oxidative stress(OS),and correction of abnormal sphingolipid(SL)metabolism.With advantages in clinical applications,these data suggest that the use of MSCs as a multi-target modulator of Aβwould be an effective therapeutic approach in AD.

Cloning,Expression and Bioinformatic Analysis of Dorsal Gene in Delia antique

[ Objective ] The aim was to explore the relationship between the Dorsal and diapause development of Delia araiqua. [ Method ] The full-length cDNA of Dorsal in D. antiqua was cloned through RACE. The similarity among deduced amino acid sequence of Dorsal cDNA and the Dorsals of other 14 insect species were compared, and the phylogenetic analysis of these Dorsals was conducted. The expression level of Dorsal gene in winter-, summer- and non-diapausing pupae was analyzed. [ Result] The full-length of Dorsal cDNA sequence, 2 412 bp, was obtained with ORF 1974 bp, which coded 657 amino acids with predicted Mw 72.9 kDa and PI 8.5. The result of similarity comparison indicated that the DaDorsal was most related to those of Drosophlia melanogaster and Drosophlia pseudoobscura. The result of semi-quantitative RT-PCR analysis showed the expression level of Dorsal gene increased in characteristic duration of winter-, summer- and non- diapansing pupae, especially at the late diapanse, which might imply its relationship to D. antiqua diapause and development. [ Conclusion] The study lays the foundation for further study on gene function of Dorsal in insect diapause and development.

Breeding and Cultivation Techniques for New Edible Orange-Fleshed Sweet Potato Variety Nanshu 012

The carotenoid in sweet potato has a high health value for the human body,and Harvest Plus has also carried out the breeding to improve the nutritional quality of sweet potatoes in order to address the health problems of people nutrient-deficient areas.Nanshu 012 is a new high-quality orange-fleshed sweet potato variety rich in carotenoid,bred by Nanchong Academy of Agricultural Sciences from the " Boga × Sanheshu" hybrid.In the regional test of sweet potato varieties in Sichuan Province during 2009-2010,the average fresh potato yield was 24600 kg/ha,the average dry matter percentage was 29.0 % and the average preserved sweet potato yield was 7152.0 kg/ha;in the production test,the average fresh potato yield was 28410.0 kg/ha and the average preserved sweet potato yield was 8734.5 kg/ha.The multi-point sampling analysis showed that the total sugar content of fresh potato was 5.28 %,protein content was 1.43 %,vitamin C content was 28.9 mg/100 g and carotenoid content was 5.21 mg/100 g.This variety was identified by Sichuan Crop Variety Approval Committee in March 2012,with high fresh potato yield,sweetness,rich carotenoid and resistance to black spot.It is an orange-fleshed sweet potato variety suitable for eating and food processing,and it should be planted in the plot with moderate fertility or above,and should be planted and harvested as early as possible.

SAPO-34 facilitates the formation of benzene,toluene and xylenes in direct syngas conversion over MnCrO_(x)-SAPO-34-ZSM-5

Direct conversion of syngas to aromatics over metal oxide and zeolite(OXZEO) composite catalysts is promising.However,the selectivity of more valuable products such as benzene,toluene and xylenes(BTX) is limited due to undesired secondary methylation of BTX.Herein,we report that the introduction of SAPO-34 into MnCrO_(x)-ZSM-5 catalyst enhances significantly the formation of BTX without sacrificing the aromatics selectivity.Under optimized conditions,the fraction of BTX in aromatics reaches 64.7% versus 28.9% over the catalyst without SAPO-34.A number of model reaction tests and characterizations reveal that SAPO-34 consumes partially the intermediates such as ketene,by converting them to light olefins.Thus,the methylation of BTX by ketene to heavy aromatics is inhibited over the external acid sites of ZSM-5,leading to an enhanced BTX selectivity in the products.This hybrid catalyst provides an efficient method for highly selective synthesis of BTX from syngas.

Tribological properties and tribomechanism of nickel nanoparticles in-situ synthesized in rapeseed oil

Nickel(Ni)nanoparticles can be enriched on the surface of iron-based frictional pairs,which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives thereon.In this paper,nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil(RO)as the reducing agent,surface modifier,and solvent as well.The tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer,and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3%can reduce the wear scar diameter(WSD)of the steel ball by 36%.This is because,on the one hand,the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves thereon.On the other hand,Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal load.In addition,an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni nanoparticles.The adsorbed Ni layer,the tribochemical reaction film,and the carbon layer comprise a composite tribofilm composed of amorphous carbon,polar fatty acid,metallic nickel,iron oxides,and nickel oxides on the rubbed steel surfaces,which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel-steel sliding pair.

Study on the mechanism of rapid formation ofu ultra-thick tribofilm by CeO_(2)nano additive and ZDDP

CeO_(2)nanoparticles are potential anti-wear additives because of their outstanding anti-wear and load-bearing capacity.However,the shear-sintering tribo-film formation mechanism of oxide nanoparticles limits the tribo-film formation rate and thickness greatly.In this study,by compounding with zinc dioctyl dithiophosphate(ZDDP),ultra-fine CeO_(2)nanoparticles modified with oleylamine(OM)can quickly form 2μm ultra-thick tribo-film,which is 10-15 times thicker than that of ZDDP and CeO_(2),respectively.The ultra-thick tribo-film presents a nanocomposite structure with amorphous phosphate as binder and nano-CeO_(2)as filling phase,which leads to the highest loading capacity of composite additives.The results of adsorption experiments tested by dissipative quartz crystal microbalance(QCM-D)showed that the Ps value of additive has nothing to do with its equilibrium adsorption mass,but is directly proportional to its adsorption rate in 10 s.The compound additive of CeO_(2)and ZDDP presented the co-deposition mode of ZDDP monolayer rigid adsorption and CeO_(2)viscoelastic adsorption on the metal surface,which showed the highest adsorption rate in 10 s.It is found that the tribo-film must have high film forming rate and wear resistance at the same time in order to achieve super thickness.Cerium phosphate was formed from ZDDP and CeO,through tribochemistry reaction,which promotes the formation of an ultra-thick tribo-film with nanocomposite structure,which not only maintains the low friction characteristics of CeO,but also realizes high Pg and high load-carrying capacity.

Synergistic tribological effect between polyisobutylene succinimide-modified molybdenum oxide nanoparticle and zinc dialkyldithiophosphate for reducing friction and wear of diamond-like carbon coating under boundary lubrication

Organic molybdenum lubricant additive like molybdenum dialkyl dithiocarbamate(MoDTC)can cause wear acceleration of diamond-like carbon(DLC)coating coupled with steel under boundary lubrication,which hinders its industrial application.Therefore,polyisobutylene succinimide(PIBS),an organo molybdenum amide,was adopted to modify molybdenum oxide affording molybdenum polyisobutylene succinimidemolybdenum oxide nanoparticles(MPIBS-MONPs)with potential to prevent the wear acceleration of DLC coating.The thermal stability of MPIBS-MONPs was evaluated by thermogravimetric analysis.Their tribological properties as the additives in di-isooctyl sebacate(DIOS)were evaluated with MoDTC as a control;and their tribomechanism was investigated in relation to their tribochemical reactions and synergistic tribological effect with zinc dialkyldithiophosphate(ZDDP)as well as worn surface characterizations.Findings indicate that MPIBS-MONPs/ZDDP added in DIOS can significantly reduce the friction and wear of DLC coating,being much superior to MoDTC.This is because MPIBS-MONPs and ZDDP jointly take part in tribochemical reactions to form a composite tribofilm that can increase the wear resistance of DLC coating.Namely,the molybdenum amide on MPIBS-MONPs surface can react with ZDDP to form MoS2 film with excellent friction-reducing ability;and MPIBS-MONPs can release molybdenum oxide nanoparticle to form deposited lubrication layer on worn surfaces.The as-formed composite tribofilm consisting of molybdenum oxide nanocrystal,amorphous polyphosphate,and molybdenum disulfide as well as a small amount of Mo2C accounts for the increase in the wear resistance of DLC coating under boundary lubrication.

MXene材料用于放射性元素及重金属离子去除的研究进展

二维过渡金属碳/氮化物(MXene)是2011年发现的一类结构新颖、性质独特的层状纳米材料,目前已被广泛应用于能源存储以及环境治理等领域. MXene材料拥有较大的比表面积、丰富的活性吸附位点、良好的亲水性以及可控的层间距,并且这类纯无机材料表现出优异的抗辐照性能以及良好的导热性能,因此是容纳放射性元素与重金属离子的理想载体.本文归纳总结了近年来MXene材料的可控制备及其对放射性元素和重金属离子的去除研究进展,对相关的实验技术手段、吸附行为与相互作用机理进行了系统梳理,此外还对该领域的发展趋势进行了展望.

Synthesis of water-soluble Cu nanoparticles and evaluation of their tribological properties and thermal conductivity as a water-based additive

Efficient and sustainable use of water-based lubricants is essential for energy efficiency.Therefore,the use of water-lubricated mechanical systems instead of conventional oil lubricants is extremely attractive from the viewpoint of resource conservation.In this study,water-soluble Cu nanoparticles of size approximately 3 nm were prepared at room temperature(around 25 °C) via in-situ surface modification.The tribological behavior of the as-synthesized Cu nanoparticles as an additive in distilled water was evaluated using a universal micro-tribotester.The results show that the as-synthesized Cu nanoparticles,as a water-based lubricant additive,can significantly improve the tribological properties of distilled water.In particular,the lowest friction coefficient of 0.06 was obtained via lubrication with a concentration of 0.6 wt% of Cu nanoparticles in distilled water,which is a reduction of 80.6% compared with that obtained via lubrication with distilled water alone.It is considered that some Cu nanoparticles entered the contact area of the friction pairs to form a complex lubricating film and prevent direct contact of the friction pairs.Furthermore,some Cu nanoparticles in the solution accelerate the heat transfer process,which also results in good tribological properties.

Preparation and catalytic performance of Fe-SBA-15 and FeO_x/SBA-15 for toluene combustion

High-surface-area and well-ordered mesoporous Fe-incorporated SBA-15(xFe-SBA-15)and SBA-15-supported FeOx(yFeOx/SBA-15)with the Fe surface density between 0.09 to 1.11 Fe-atom/nm2have been prepared using the one-step synthesis and incipient wetness impregnation methods,respectively.Physicochemical properties of these materials were characterized by means of numerous techniques,and their catalytic activities for the combustion of toluene were evaluated.It is found that the xFe-SBA-15 and yFeOx/SBA-15 samples possessed rod-or chain-like morphologies.The Fe species were of high dispersion when the Fe surface density was lower than0.76 Fe-atom/nm2in xFe-SBA-15 and 0.64 Fe-atom/nm2in yFeOx/SBA-15.At a similar Fe surface density and space velocity,the xFe-SBA-15 catalysts showed better activity than the yFeOx/SBA-15 catalysts,in which the xFe-SBA-15 catalyst with Fe surface density 0.59 Fe-atom/nm2performed the best.It is concluded that the good performance of the xFe-SBA-15 sample with Fe surface density0.59 Fe-atom/nm2was associated with its large surface area,high Fe species dispersion,and good low-temperature reducibility.

Effects of magnetic ionic liquid as a lubricant on the friction and wear behavior of a steel-steel sliding contact under elevated temperatures

A magnetic ionic liquid(abridged as MIL)[C_(6)mim]_(5)[Dy(SCN)_(8)]was prepared and used as the magnetic lubricant of a steel-steel sliding pair.The tribological properties of the as-prepared MIL were evaluated with a commercially obtained magnetic fluid lubricant(abridged as MF;the mixture of dioctyl sebacate and Fe_(3)O_(4),denoted as DIOS-Fe_3O_4)as a control.The lubrication mechanisms of the two types of magnetic lubricants were discussed in relation to worn surface analyses by SEM-EDS,XPS,and profilometry,as well as measurement of the electric contact resistance of the rubbed steel surfaces.The results revealed that the MIL exhibits better friction-reducing and antiwear performances than the as-received MF under varying test temperatures and loads.This is because the MIL participates in tribochemical reactions during the sliding process,and forms a boundary lubrication film composed of Dy_(2)O_(3),FeS,FeSO_(4),nitrogen-containing organics,and thioether on the rubbed disk surface,thereby reducing the friction and wear of the frictional pair.However,the MF is unable to form a lubricating film on the surface of the rubbed steel at 25°C,though it can form a boundary film consisting of Fe_(3)O_(4) and a small amount of organics under high temperature.Furthermore,the excessive Fe_(3)O_(4) particulates that accumulate in the sliding zone may lead to enhanced abrasive wear of the sliding pair.

Controllable synthesis of different morphologies of CuO nanostructures for tribological evaluation as water-based lubricant additives

In this study,water soluble CuO nanostructures having nanobelt,nanorod,or spindle morphologies were synthesized using aqueous solutions of Cu(NO_(3))_(2)·3H_(2)O and NaOH by adjusting the type of surface modifier and reaction temperature.The effect of morphologies of these various CuO nanostructures as water‐based lubricant additives on tribological properties was evaluated on a UMT‐2 micro‐friction tester,and the mechanisms underlying these properties are discussed.The three different morphologies of CuO nanostructures exhibited excellent friction‐reducing and anti‐wear properties.Tribological mechanisms differed in the initial stage of frictional interactions,but in the stable stage,a tribochemical reaction film and adsorbed lubricious film on the rubbing surfaces played important roles in hindering direct contact between friction pairs,leading to improved tribological properties.

Self-polymerization and co-polymerization kinetics of gadolinium methacrylate

Gadolinium methacrylate（Gd（MAA）3） was synthesized by using gadolinium oxide and methacrylic acid as the starting materials and its self-polymerization kinetic was studied based on non-isothermal and isothermal analysis. Moreover, the monomer reactivity ratios of methyl methacrylate（MMA） and Gd（MAA）3 were evaluated by using Kelen-Tiidos method. The thermal neutron shielding properties of PMMA and poly（MMA-co-Gd（MAA）3） were calculated by MCNP program. The results show that the selfpolymerization of Gd（MAA）3 can be initiated by thermal and free radical and its activation energy is103.35 kJ/mol or 58.55 kJ/mol correspondingly in the solid state or aqueous solution. The polymerization rate,Rp,under low conversion at 65 ℃ is expressed as Rp = K[M]^（1.05）[I]^（0.60）. The reactivity ratios of r1（MMA） and r2（Gd（MAA）3） are 0.225 and 1.340, respectively. The ability of thermal neutron shielding of poly（MMA-co-Gd（MAA）3） is increased by gadolinium contents and is far better than PMMA.

TdIF1:a putative oncogene in NSCLC tumor progression

TdT-interacting factor 1(TdIF1)is a ubiquitously expressed DNA-and protein-binding protein that directly binds to terminal deoxynucleotidyl transferase(TdT)polymerase.Little is known about the functional role of TdIF1 in cancer cellular signaling,nor has it previously been identified as aberrant in any type of cancer.We report here for the first time that TdIF1 is abundantly expressed in clinical lung cancer patients and that high expression of TdIF1 is associated with poor patient prognosis.We further established that TdIF1 is highly expressed in human non-small cell lung cancer(NSCLC)cell lines compared to a normal lung cell line.shRNA-mediated gene silencing of TdIF1 resulted in the suppression of proliferation and anchorage-independent colony formation of the A549 adenocarcinoma cell line.Moreover,when these TdIF1-silenced cells were used to establish a mouse xenograft model of human NSCLC,tumor size was greatly reduced.These data suggest that TdIF1 is a potent regulator of lung tumor development.Several cell cycle-related and tumor growth signaling pathways,including the p53 and HDAC1/2 pathways,were identified as participating in the TdIF1 signaling network by in silico analysis.Microarray,transcriptome and protein-level analyses validated p53 and HDAC1/2 modulation upon TdIF1 downregulation in an NSCLC cellular model.Moreover,several other cell cycle regulators were affected at the transcript level by TdIF1 silencing,including an increase in CDKN1A/p21 transcripts.Taken together,these results indicate that TdIF1 is a bona fide tumor-promoting factor in NSCLC and a potential target for therapy.