192 research outputs found
Bis(2,2′-bipyridÂyl)bromidocopper(II) bromide bromoÂacetic acid hemihydrate
In the title compound, [CuBr(C10H8N2)2]Br·BrCH2COOH·0.5H2O, the CuII ion is coordinated by four N atoms [Cu—N = 1.985 (6)–2.125 (7) Å] from two 2,2′-bipyridine ligand molÂecules and a bromide anion [Cu—Br = 2.471 (2) Å] in a distorted trigonal-bipyramidal geometry. Short centroid–centroid distances [3.762 (5) and 3.867 (5) Å] between the aromatic rings of neighbouring cations suggest the existence of π–π interÂactions. InterÂmolecular O—H⋯Br hydrogen bonds and weak C—H⋯O and C—H⋯Br interÂactions consolidate the crystal packing
Bis(3,4-dimethoxyÂbenzoato-κ2 O,O′)(1,10-phenanthroline-κ2 N,N′)copper(II)
The asymmetric unit of the title compound, [Cu(C9H9O4)2(C12H8N2)], contains one half-molÂecule, the complete molÂecule being generated by a twofold rotation axis. The CuII atom exhibits a six-coordinated distorted octaÂhedral geometry with two N atoms from the phenanthroline ligand [Cu—N 2.007 (2) Å] and four O atoms from two 3,4-dimethoxyÂbenzoate ligands [Cu—O 1.950 (1) and 2.524 (1) Å]. The difference in Cu—O bond distances indicates a strong Jahn–Teller effect. In the crystal, C—H⋯π interÂactions result in chains of molÂecules along the c axis
Effects of nanosilica on early age stages of cement hydration
Effects of nanosilica on cement hydration have been broadly investigated in the literature and early age cement hydration, as awhole, has been mainly considered, disregarding the substages of the hydration. The hydration of cement is characterized by different substages and nanosilica effect on the hydration could be a result of diverse, even contradictory, behavior of nanosilica in individual stages of the hydration. In this study, effects of nanosilica on different substages of cement hydration are investigated. Isothermal calorimetry results show that at early ages (initial 72 hours) the effects of nanosilica depend on the phenomenon by which the hydration is governed:when the hydration is chemically controlled, that is, during initial reaction, dormant period, and acceleratory period, the hydration rate is accelerated by adding nanosilica; when the hydration is governed by diffusion process, that is, during postacceleratory period, the hydration rate is decelerated by adding nanosilica. The Thermal Gravimetric Analysis on the samples at the hardened state (after 28 days of curing) reveals that, after adding nanosilica, the hydration degree slightly increased compared to the plain paste
Prototypical Fine-tuning: Towards Robust Performance Under Varying Data Sizes
In this paper, we move towards combining large parametric models with
non-parametric prototypical networks. We propose prototypical fine-tuning, a
novel prototypical framework for fine-tuning pretrained language models (LM),
which automatically learns a bias to improve predictive performance for varying
data sizes, especially low-resource settings. Our prototypical fine-tuning
approach can automatically adjust the model capacity according to the number of
data points and the model's inherent attributes. Moreover, we propose four
principles for effective prototype fine-tuning towards the optimal solution.
Experimental results across various datasets show that our work achieves
significant performance improvements under various low-resource settings, as
well as comparable and usually better performances in high-resource scenarios.Comment: Published as a conference paper at AAAI 202
TriaquaÂchlorido(1,10-phenanthroline-κ2 N,N′)cobalt(II) chloride monohydrate
In the title compound, [CoCl(C12H8N2)(H2O)3]Cl·H2O, the CoII ion is coordinated by two N atoms from the 1,10-phenanthroline ligand [Co—N = 2.125 (6) and 2.146 (6) Å], one chloride ligand [Co—Cl = 2.459 (2)Ã…] and three water molÂecules [Co—O = 2.070 (5)–2.105 (5)Ã…] in a distorted octaÂhedral geometry. InterÂmolecular O—H⋯Cl and O—H⋯O hydrogen bonds form an extensive three-dimensional hydrogen-bonding network, which consolidates the crystal packing
Household Livelihood Strategy Changes and Agricultural Diversification: A Correlation and Mechanism Analysis Based on Data from the China Family Panel
Social and economic transformations have a profound impact on farmers’ livelihood strategies, and changes in these strategies, in turn, deeply impact the agricultural system. Based on four waves of China Family Panel Studies (CFPS) tracking data, this paper uses a Markov transfer probability matrix to explore changes in farmers’ livelihood strategies and builds multiple logit and fixed-effect models to empirically analyze the impact and lag effect of these changes on agricultural diversification. The results show that (1) farmers who choose not to shift away from an agricultural livelihood show no significant change in agricultural diversification. Compared with households showing an increase in the agricultural diversification index, households showing a decrease in this index are more inclined to diversify if they choose to maintain an agricultural livelihood either part-time or full-time. For households with an unchanged agricultural diversification index, their index value is more likely to remain unchanged if they choose to maintain a part-time or full-time agriculture-oriented livelihood. Moreover, (2) the impact of livelihood strategy changes on agricultural diversification displays regional heterogeneity. The index value of farmers in the central region shows no statistically significant change over the sample period, while the index value of farmers in the eastern region increases. Farmers in the eastern and central regions with unchanged index values are more inclined to show persistent index values. (3) Changes in farmers’ livelihood strategies have a lag effect on agricultural diversification that becomes significant at two lag periods
AquaÂbis(dichloroÂacetato-κO)(1,10-phenanthroline-κ2 N,N′)copper(II)
In the title complex, [Cu(C2HCl2O2)2(C12H8N2)(H2O)], the CuII ion has a distorted square-pyramidal coordination geometry. The equatorial positions are occupied by two N atoms from a 1,10-phenanthroline ligand [Cu—N = 1.994 (3) and 2.027 (3) Å] and two O atoms from dichloroÂacetate ligands and a water molÂecule [Cu—O = 1.971 (2) and 1.939 (2) Å]. One O atom from another dichloroÂacetate ligand occupies the apical positon [Cu—O = 2.152 (3) Å]. InterÂmolecular O—H⋯O hydrogen bonds link the molÂecules into centrosymmetric dimers. The crystal packing also exhibits weak interÂmolecular C—H⋯O hydrogen bonds, π–π interÂactions [centroid–centroid distance = 3.734 (2) Å] and short interÂmolecular Cl⋯Cl contacts [3.306 (2) and 3.278 (2) Å]
The Central Domain of MCPH1 Controls Development of the Cerebral Cortex and Gonads in Mice
MCPH1 is the first gene identified to be responsible for the human autosomal recessive disorder primary microcephaly (MCPH). Mutations in the N-terminal and central domains of MCPH1 are strongly associated with microcephaly in human patients. A recent study showed that the central domain of MCPH1, which is mainly encoded by exon 8, interacts with E3 ligase βTrCP2 and regulates the G2/M transition of the cell cycle. In order to investigate the biological functions of MCPH1’s central domain, we constructed a mouse model that lacked the central domain of MCPH1 by deleting its exon 8 (designated as Mcph1 -Δe8). Mcph1 -Δe8 mice exhibited a reduced brain size and thinner cortex, likely caused by a compromised self-renewal capacity and premature differentiation of Mcph1 -Δe8 neuroprogenitors during corticogenesis. Furthermore, Mcph1 -Δe8 mice were sterile because of a loss of germ cells in the testis and ovary. The embryonic fibroblasts of Mcph1 -Δe8 mice exhibited premature chromosome condensation (PCC). All of these findings indicate that Mcph1 -Δe8 mice are reminiscent of MCPH1 complete knockout mice and Mcph1 -ΔBR1 mice. Our study demonstrates that the central domain of MCPH1 represses microcephaly, and is essential for gonad development in mammals
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