In view of the dearth of active components and the unsatisfactory dispersion of Cu-based catalysts,it is imperative to undertake a detailed investigation of catalysts with enhanced catalytic performance.In order to ac...In view of the dearth of active components and the unsatisfactory dispersion of Cu-based catalysts,it is imperative to undertake a detailed investigation of catalysts with enhanced catalytic performance.In order to achieve a balance between the catalytic activity and stability in the reaction process,a series of P-atom doped Cu^(0)/Cu^(δ+)binary Cu-based catalysts were prepared by means of heteroatom introduction and heat treatment.The introduction of P enhanced the stability of Cu during heat treatment,thereby inhibiting the excessive agglomeration of Cu.The structure of the Cu^(0)/Cu^(δ+)binary catalyst was modified through heat treatment and HCl activation,and the relationship between its structure and catalytic activity was subsequently investigated.The activation process of HCl facilitated the conversion of the Cu^(0)state to the Cu-Cl state and augmented the valence state of Cu.The valence modulation of the Cu site by HCl during the reaction prevented the over-reduction of the Cu site by acetylene and enhanced the stability of the catalyst.The 3Cu/5Cu P/AC-800 catalyst was operated for 50 h without significant deactivation under the reaction conditions of T=180°C,V(HCl)/V(C_(2)H_(2))=1.15 and GHSV(C_(2)H_(2))=180 h^(-1).This design strategy provides a novel reference point for further studies of Cu Cl_(2)based catalysts for acetylene hydrochlorination.展开更多
文章通过两步反应合成共轭超交联聚合物(TPP-CHCP)。TPP-CHCP有较宽的光吸收区间(400~900 nm),可作为光致原子转移自由基聚合(photocatalyzed atom transfer radical polymerization,P-ATRP)的光催化剂。TPP-CHCP可在940 nm近红外光照射...文章通过两步反应合成共轭超交联聚合物(TPP-CHCP)。TPP-CHCP有较宽的光吸收区间(400~900 nm),可作为光致原子转移自由基聚合(photocatalyzed atom transfer radical polymerization,P-ATRP)的光催化剂。TPP-CHCP可在940 nm近红外光照射下,驱动丙烯酸甲酯(MA)和甲基丙烯酸甲酯(MMA)的P-ATRP反应且单体转化率达到99%。所得聚合物的结构明确,分子量可控,分子量分布(D-_(s)<1.18)窄。在太阳光照射条件下,TPP-CHCP依然具有优异的光催化活性,可高效制备嵌段共聚物。展开更多
在实测数据较少的情况下,采用何种模型能对GPS Block IIR(M)卫星钟差进行最佳预报?经研究发现,采用GM(1,1)-AR(p)复合模型进行1天短期预报的精度在1 ns之内,进行10天长期预报的精度在10 ns之内,这不仅优于二次多项式和GM(1,1)等传统钟...在实测数据较少的情况下,采用何种模型能对GPS Block IIR(M)卫星钟差进行最佳预报?经研究发现,采用GM(1,1)-AR(p)复合模型进行1天短期预报的精度在1 ns之内,进行10天长期预报的精度在10 ns之内,这不仅优于二次多项式和GM(1,1)等传统钟差预报模型,而且好于IGS(the International GPS Service for Geodynamics)提供的预报钟差7 ns的精度。展开更多
设1<p2,0<α1,X是p一致可光滑空间的Banach空间,则对每个X值拟鞅f=(fn)n≥0∈pHασ(X)存在分解fn=sum form k∈Z to μkank(n≥0),并且‖f‖pHασ(X)+‖R(f)‖α～inf(sum form k∈Z to μkα)1/α,这里ak=(ank)n5≥0(k∈Z)是一...设1<p2,0<α1,X是p一致可光滑空间的Banach空间,则对每个X值拟鞅f=(fn)n≥0∈pHασ(X)存在分解fn=sum form k∈Z to μkank(n≥0),并且‖f‖pHασ(X)+‖R(f)‖α～inf(sum form k∈Z to μkα)1/α,这里ak=(ank)n5≥0(k∈Z)是一列(1,α,∞;p)拟鞅原子,并且在L1中收敛,supk∈Z‖ak*‖α<∞,(μk)k∈Z∈lα是非负实数列.对于拟鞅空间pHαS(X)和qKα(X)成立类似的结果.此外,利用拟鞅原子分解定理,证明了几个拟鞅不等式.展开更多
基金supported by the National Natural Science Foundation of China(No.22062021)the Science and Technology Project of Xinjiang supported by Central Government(No.2022BC001)+3 种基金Science and Technology Planning Project(No.2024AB048)Tianshan Talents Training Program of Xinjiang(Science and Technology Innovation Team,No.CZ002701)the Start-Up Foundation for high-level professionals of Shihezi University(No.RCZK201932)2024 Talent Development Fund-Tianchi Young Doctor of Excellence(No.CZ002744)。
文摘In view of the dearth of active components and the unsatisfactory dispersion of Cu-based catalysts,it is imperative to undertake a detailed investigation of catalysts with enhanced catalytic performance.In order to achieve a balance between the catalytic activity and stability in the reaction process,a series of P-atom doped Cu^(0)/Cu^(δ+)binary Cu-based catalysts were prepared by means of heteroatom introduction and heat treatment.The introduction of P enhanced the stability of Cu during heat treatment,thereby inhibiting the excessive agglomeration of Cu.The structure of the Cu^(0)/Cu^(δ+)binary catalyst was modified through heat treatment and HCl activation,and the relationship between its structure and catalytic activity was subsequently investigated.The activation process of HCl facilitated the conversion of the Cu^(0)state to the Cu-Cl state and augmented the valence state of Cu.The valence modulation of the Cu site by HCl during the reaction prevented the over-reduction of the Cu site by acetylene and enhanced the stability of the catalyst.The 3Cu/5Cu P/AC-800 catalyst was operated for 50 h without significant deactivation under the reaction conditions of T=180°C,V(HCl)/V(C_(2)H_(2))=1.15 and GHSV(C_(2)H_(2))=180 h^(-1).This design strategy provides a novel reference point for further studies of Cu Cl_(2)based catalysts for acetylene hydrochlorination.
文摘文章通过两步反应合成共轭超交联聚合物(TPP-CHCP)。TPP-CHCP有较宽的光吸收区间(400~900 nm),可作为光致原子转移自由基聚合(photocatalyzed atom transfer radical polymerization,P-ATRP)的光催化剂。TPP-CHCP可在940 nm近红外光照射下,驱动丙烯酸甲酯(MA)和甲基丙烯酸甲酯(MMA)的P-ATRP反应且单体转化率达到99%。所得聚合物的结构明确,分子量可控,分子量分布(D-_(s)<1.18)窄。在太阳光照射条件下,TPP-CHCP依然具有优异的光催化活性,可高效制备嵌段共聚物。
文摘在实测数据较少的情况下,采用何种模型能对GPS Block IIR(M)卫星钟差进行最佳预报?经研究发现,采用GM(1,1)-AR(p)复合模型进行1天短期预报的精度在1 ns之内,进行10天长期预报的精度在10 ns之内,这不仅优于二次多项式和GM(1,1)等传统钟差预报模型,而且好于IGS(the International GPS Service for Geodynamics)提供的预报钟差7 ns的精度。
文摘设1<p2,0<α1,X是p一致可光滑空间的Banach空间,则对每个X值拟鞅f=(fn)n≥0∈pHασ(X)存在分解fn=sum form k∈Z to μkank(n≥0),并且‖f‖pHασ(X)+‖R(f)‖α～inf(sum form k∈Z to μkα)1/α,这里ak=(ank)n5≥0(k∈Z)是一列(1,α,∞;p)拟鞅原子,并且在L1中收敛,supk∈Z‖ak*‖α<∞,(μk)k∈Z∈lα是非负实数列.对于拟鞅空间pHαS(X)和qKα(X)成立类似的结果.此外,利用拟鞅原子分解定理,证明了几个拟鞅不等式.
