抗相变耐硫变换催化剂的表征及性能研究

以特殊工艺制得镁铝尖晶石为载体,采用浸渍法制备出新型XB-2耐硫变换催化剂,通过原粒度反应装置对其进行活性评价和300 h的稳定性试验,对反应前后的催化剂进行了XRD、BET、SEM表征,并且与某工业催化剂A进行对比。结果表明,XB-2型催化剂机械强度高、活性好,在高压、高汽气比条件下,其抗相变性能强、结构稳定。

抗凝冰相变沥青材料的性能分析

抗凝冰相变沥青属于轻塑施工材料,相较于普通沥青,其物体性能更好,尤其在寒冷地区应用时效果更明显,本文将于此材料进行性能分析。

STUDIES ON CULTIVAR-INDUCED CHANGES IN INSECTICIDE SUSCEPTIBILITY AND ITS RELATED ENZYME ACTIVITIES OF THE WHITE BACKED PLANTHOPPER, SOGATELLA FURCIFERA (HORVTH) (HOMOPTERA:DELPHACIDAE)

The susceptibility of Sogatella furcifera female adults on N22 to malathion increased as feeding time prolonged, while the day change of susceptibility to isoprocarb showed a inverse tendency. The activities of esterase and carboxylesterase were induced significantly after on N22 for one day, and then declined. The non susceptible level of adults to insecticides and enzyme activities seemed to be heightened after feeding on ASD7, a variety resistant to Nilaparvata lugens. The total phenol content in rice leaf sheath was the highest in N22, and could be regarded as one of the factors, which caused chages in susceptibility of S. furcifera to insecticide after feeding different rice varieties. It was recommended that suitable insecticides and planthopper resistant varieties should be coordinately used in practice so that they contribute more effects respectively.

Enhanced mechanical properties in oxide-dispersion-strengthened alloys achieved via interface segregation of cation dopants

With significantly enhanced irradiation resistance,high-temperature strength,and creep resistance,oxide-dispersion-strengthened tungsten(ODS-W)alloys present tremendous potential for high-temperature applications.However,the oxide particles tend to segregate at W grain boundary and grow up(even to micron),greatly suppressing their strengthening effect.It is always a great challenge to effectively refine and disperse the oxide particles at W grain boundary.Here,we successfully developed a new type of cation-doped W-Y2O3 alloy via a wet chemical method and subsequent low-temperature sintering.It was found that proper cation doping could not only significantly refine the intergranular Y2O3 second phase particles but also dramatically improve the sinterability of W matrix.These doping effects,as a result,simultaneously enhance the strength and ductility of the W-Y2O3 alloy.It was confirmed that the segregation of cation dopants at the W/Y2O3 interface is the origin of these doping effects.Furthermore,X-ray photoemission spectra(XPS)analyses confirmed that cation dopant segregation also obviously affects the chemical bonding(i.e.,W–O bond)along the W/Y2O3 interface.As a result,the ratelimiting mechanism for W grain growth is influenced remarkably,explaining well the difference of W grain size in various cation-doped W-Y2O3 alloys.For the refinement of intergranular Y2O3 particles,it can be understood well from both thermodynamic and kinetic views.Detailedly,W/Y2O3 interfacial energy and atom mobility for Y2O3 coarsening are all limited by cation dopant segregation.More importantly,this cation-doping approach can also be applicable to other ODS alloys for enhancing their comprehensive mechanical properties.

Analysis of the effect of HCV resistance-associated substitutions on the short-term efficacy of DAA after single administration in three phase Ib clinical trials

As crucial factors in hepatitis C virus(HCV)management,resistance-associated substitutions(RASs)are associated with the treatment outcome of some direct-acting antiviral(DAA)-based regimens.In this study,we mainly analyzed the impact of baseline Y93 H or Y93 Y/H on the short-term efficacy after single administration of NS5 A inhibitors in three phaseⅠb clinical trials(yimitasvir phosphate,KW-136 and fopitasvir),and analyzed the prevalence of baseline RASs and treatment-emergent RASs.A total of 94 treatment-naive HCV genotype(GT)-1 b(n=63)and GT-2 a(n=31)Chinese patients were enrolled in three phase lb clinical trials.We investigated RASs in 77 patients with next generation or Sanger sequencing.In the 7-day trial of yimitasvir phosphate,the mean maximum HCV RNA decrease of patients with baseline Y93 H or Y93 Y/H was lower than that of patients without the mutation in the 30 mg and 200 mg cohorts(0.83 vs.2.45 log10 IU/mL and 1.92 vs.2.63 log10 IU/mL).In the3-day trial of KW-136,the mean maximum HCV RNA decrease in patients with baseline Y93 H or Y93 Y/H was lower than that of patients without the mutation in the 30,60 and 120 mg cohorts(1.58 vs.2.89 log10 IU/mL,3.16 vs.4.09 log10 IU/mL and3.00 vs.5.04 log10 IU/mL,respectively).In the 3-day trial of fopitasvir,only 30 mg group had baseline Y93 H or Y93 Y/H,and the average maximum HCV RNA decrease of patients with baseline Y93 H or Y93 Y/H was lower than that of patients without the mutation(1.45 vs.3.59 log10 IU/mL).In the three trials,baseline RASs were observed in 54 patients(70.1%;54/77).The most prevalent baseline RASs were Y93 H and Y93 Y/H(18.2%;14/77),followed by L3 IM(16.9%;13/77).The most common RASs after single administration of DAA were Y93 H and Y93 Y/H.Our data could provide reference for future clinical treatment and clinical trial.