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991.
文章简述了主减速器总成结构振动与故障的关系,介绍了一种用于工业现场的在线故障监测系统的硬件组成、评价原理、评价指标以及诊断效果.它在生产线上能够科学有效地检测主减总成的早期故障,并对被测产品性能作出量化的评价,从而有针对性地采取检修措施,提高产品质量. 相似文献
992.
This paper investigates the set stability of probabilistic Boolean networks (PBNs) with switching topology. To deal with this problem, two novel concepts, set reachability and the largest invariant set family, are defined. By constructing an auxiliary system, the necessary and sufficient conditions for verifying set reachability are given and the calculation method for the largest invariant set family is obtained. Based on these two results, an equivalent condition of set stability is derived, which can be used to determine whether a PBN with switching topology can be stabilized to a given set. In addition, the design method of switching signal is proposed by combining the characteristic of the largest invariant set family, and a numerical example is reported to demonstrate the efficiency of presented approach. 相似文献
993.
讨论了一类具有正负系数的咏冲时滞差分方程(?)解的振动性,给出了所有解振动的充分条件,推广和改进了已有的结果 相似文献
994.
995.
设(X,d,f)为拓扑动力系统,其中X为局部紧第二可数Hausdorff空间,d为紧型度量,f为完备映射,用2^x和f分别表示由X的所有非空闭子集和所有闭子集构成的集族,(2^x,ρ,2^f)和(f,ρ,2^f)为由(X,d,f)诱导的赋予hit—or—miss拓扑的超空间动力系统.本文研究了h(X,d,f)和h(2^... 相似文献
996.
Let $
\mathfrak{S}
$
\mathfrak{S}
be a locally compact semigroup, ω be a weight function on $
\mathfrak{S}
$
\mathfrak{S}
, and M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω) be the weighted semigroup algebra of $
\mathfrak{S}
$
\mathfrak{S}
. Let L
0∞ ($
\mathfrak{S}
$
\mathfrak{S}
; M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω)) be the C*-algebra of all M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω)-measurable functions g on $
\mathfrak{S}
$
\mathfrak{S}
such that g/ω vanishes at infinity. We introduce and study a strict topology β
1($
\mathfrak{S}
$
\mathfrak{S}
, ω) on M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω) and show that the Banach space L
0∞ ($
\mathfrak{S}
$
\mathfrak{S}
; M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω)) can be identified with the dual of M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω) endowed with β
1($
\mathfrak{S}
$
\mathfrak{S}
, ω). We finally investigate some properties of the locally convex topology β
1($
\mathfrak{S}
$
\mathfrak{S}
, ω) on M
a
($
\mathfrak{S}
$
\mathfrak{S}
, ω). 相似文献
997.
In this paper, some properties of order topology and bi-Scott topology on a poset are obtained. Order-convergence in posets
is further studied. Especially, a sufficient and necessary condition for order-convergence to be topological is given for
some kind of posets. 相似文献
998.
Yanming Zhao Wenhao Dai Yunlei Peng Zheng Niu Qi Sun Chuan Shan Hui Yang Gaurav Verma Lukasz Wojtas Daqiang Yuan Zhenjie Zhang Haifeng Dong Xueji Zhang Bao Zhang Yaqing Feng Shengqian Ma 《Angewandte Chemie (International ed. in English)》2020,59(11):4354-4359
Herein, for the first time, we present the successful synthesis of a novel two‐dimensional corrole‐based covalent organic framework (COF) by reacting the unusual approximately T‐shaped 5,10,15‐tris(p‐aminophenyl)corrole H3TPAPC with terephthalaldehyde, which adopts desymmetrized hcb topology and consists of a staggered AB stacking structure with elliptical pores. The resultant corrole‐based COF, TPAPC‐COF , exhibits high crystallinity and excellent chemical stability. The combination of extended π‐conjugated backbone and interlayer noncovalent π–π interactions endows TPAPC‐COF with excellent absorption capability in the entire visible‐light and even near‐infrared regions. Moreover, this work suggests the promise of TPAPC‐COF as a new class of photoactive material for efficient singlet‐oxygen generation with potential photodynamic therapy application as demonstrated by in vitro anticancer studies. 相似文献
999.
Zhi-Xiang Wang Hai-Xin Tian Jian-Gang Ding Bao-Long Li Bing Wu 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(1):23-29
The Co‐MOF poly[[diaqua{μ4‐1,1,2,2‐tetrakis[4‐(1H‐1,2,4‐triazol‐1‐yl)phenyl]ethylene‐κ4N:N′:N′′:N′′′}cobalt(II)] benzene‐1,4‐dicarboxylic acid benzene‐1,4‐dicarboxylate], {[Co(C34H24N12)(H2O)2](C8H4O4)·C8H6O4}n or {[Co(ttpe)(H2O)2](bdc)·(1,4‐H2bdc)}n, (I), was synthesized by the hydrothermal method using 1,1,2,2‐tetrakis[4‐(1H‐1,2,4‐triazol‐1‐yl)phenyl]ethylene (ttpe), benzene‐1,4‐dicarboxylic acid (1,4‐H2bdc) and Co(NO3)2·6H2O, and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, powder X‐ray diffraction (PXRD), luminescence, optical band gap and valence band X‐ray photoelectron spectroscopy (VB XPS). Co‐MOF (I) shows a (4,4)‐connected binodal two‐dimensional topology with a point symbol of {44·62}{44·62}. The two‐dimensional networks capture free neutral 1,4‐H2bdc molecules and bdc2? anions, and construct a three‐dimensional supramolecular architecture via hydrogen‐bond interactions. MOF (I) is a good photocatalyst for the degradation of methylene blue and rhodamine B under visible‐light irradiation and can be reused at least five times. 相似文献
1000.
Crystal Engineering of an nbo Topology Metal–Organic Framework for Chemical Fixation of CO2 under Ambient Conditions
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Wen‐Yang Gao Yao Chen Youhong Niu Kia Williams Lindsay Cash Pastor J. Perez Lukasz Wojtas Prof. Jianfeng Cai Yu‐Sheng Chen Prof. Shengqian Ma 《Angewandte Chemie (International ed. in English)》2014,53(10):2615-2619
Crystal engineering of the nbo metal–organic framework (MOF) platform MOF‐505 with a custom‐designed azamacrocycle ligand (1,4,7,10‐tetrazazcyclododecane‐N,N′,N′′,N′′′‐tetra‐p‐methylbenzoic acid) leads to a high density of well‐oriented Lewis active sites within the cuboctahedral cage in MMCF‐2, [Cu2(Cu‐tactmb)(H2O)3(NO3)2]. This MOF demonstrates high catalytic activity for the chemical fixation of CO2 into cyclic carbonates at room temperature under 1 atm pressure. 相似文献