5,810 research outputs found

    Tris(5,6-dimethyl-1H-benzimidazole-κN 3)(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)nickel(II)

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    The title mononuclear complex, [Ni(C7H3NO4)(C9H10N2)3], shows a central NiII atom which is coordinated by two carboxyl­ate O atoms and the N atom from a pyridine-2,6-dicarboxyl­ate ligand and by three N atoms from different 5,6-dimethyl-1H-­benzimidazole ligands in a distorted octa­hedral geometry. The crystal structure shows intermolecular N—H⋯O hydrogen bonds

    Tris(1H-benzimidazole-κN 3)(pyridine-2,6-dicarb­oxy­lato-κ3 O 2,N,O 6)nickel(II)

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    In the title complex, [Ni(C7H3NO4)(C7H6N2)3], the NiII ion is coordinated by two carboxyl­ate O atoms and the N atom from a pyridine-2,6-dicarboxyl­ate ligand and by three N atoms from three benzimidazole ligands to form a slightly distorted octa­hedral geometry. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds to form a three-dimensional network

    Significance of rice sheath photosynthesis: Yield determination by 14C radio-autography.

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    Using high-yielding hybrid rice Liangyopeijiu (LYP9), its male parent 9311 and hybrid rice Shanyou 63 (SY63) as the experimental materials, the photosynthesis of rice sheath was studied by 14C radio-autography. The results showed that rice sheath could trap sunlight and produce photosynthates, and these photosynthates were transported mainly to the spikes. The 14C-labeled photosynthates transported to the spikes of LYP9 and 9311 were significantly more than those of SY63 after 72 hr, which indicated that differences among genotypes existed for contribution rates of sheath photosynthesis to economical yield. Transport of the 14C-labeled photosynthates to the spikes was faster in the sheaths of LYP9 than in those of 9311and SY63 at 12 and 72 hr after treatment. Hybrid rice housed the heterosis and were influenced by the inheritable characters of its parents. Since photosynthesis of rice sheath is an important supplement to rice yield, inefficient photosynthesis in rice sheaths could cause serious yield reduction.Key Words: Hybrid rice, photosynthates, spike

    Bi- and tri-dentate imino-based iron and cobalt pre-catalysts for ethylene oligo-/polymerization

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    Recent progress on the use of iron and cobalt complex pre-catalysts for ethylene reactivity is reviewed. The review is organized in terms of the denticity of the chelate ligands employed, with particular reference to the influence of the ligand frameworks and their substituents on the catalytic performance for ethylene oligomerization/polymerization catalysis. The majority of the systems bear tri-dentate ligation at the iron/cobalt centre, though it is clear that bi-dentate iron/cobalt complex pre-catalysts have also attracted significant attention. Such systems produce in most cases highly linear products ranging from oligomeric α-olefins to high molecular weight polyethylene, and as such are promising candidates for both academic and industrial considerations

    What about the contribution from reggeons in hard process of strong interactions?

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    We discuss in this paper the possible contributions from R_\rho(\rho-reggeon associated with \rho meson) in DIS process on protons. Using results from phenomenological analysis of high energy \pi-N charge-exchanged scattering process, we get the expression of effective propagator of R_\rho and the coupling constant \beta_\rho between R_\rho and light quarks. As a simple and concrete example, we use them to evaluate the contributions of R_\rho to F_2(x,Q^2) from charge-exchanged photoproduction quark-pair process,\gamma^* + p-->n + q_u + \bar{q}_d (--> n + X), in HERA kinematical regions. For a comparison, we also evaluate contributions both from pomeron and partons in the same process. The ratio of contributions in F_2(x,Q^2) from R_\rho versus IP is larger than 1%, therefore, the former may be tested experimentaly.Comment: 13 page, LaTex, 4 figure in postscript. To appear in Commu. in Theor. Phy

    Diagnotic Value of the Combined Determination of Telomerase Activity in Induced Sputum, Pleural Effusion and Fiberobronchoscopic Biopsy Samples in Lung Cancer

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    Background and objective It has been proven that telomerase activation correlates with the carcinogenesis, aggressiveness and turnover of lung cancer. Telomerase is one of the improtant molecular biomarkers for diagnosis and targeting therapy in lung cancer. The aim of this study is to investigate the diagnostic value of the combined determination of telomerase activity in induced sputum, pleural effusion and fiberobronchoscopic biopsy in lung cancer patients. Methods The technique of TRAP (telomeric repeat amplification protocal)-PCR-ELISA was employed to detect telomease levels of induced sputum, pleural effusion and fiberobronchoscopic biopsy in 80 lung cancer patients with pleural effusion and 50 benign pulmonary disease patients with pleural effusion. Results Telomemse levels of induced sputum, pleural effusion and fiberobronchoscopic biopsy were all significantly higher in patients with lung cancer than those with benign pulmonary disease (P < 0.001). There was no significant difference in the level of telomerase activity between different pathologic types (P>0.05). The sensitivity of induced sputum, pleural effusion and fiberobronchoscopic biopsy were 62.5% (50/80), 46.3% (37/80) and 60.0% (48/80), respectively. The specificity were 72.0% (36/50), 66.0% (33/50) and 70.0% (35/50), respectively. The overall accuracy were 66.2% (86/130), 53.8% (70/130) and 63.8% (83/130), respectively. The sensitivity, specificity and overall accuracy of combined induced sputum, pleural effusion and fiberobronchoscopic biopsy were 85.0% (68/80), 78.0% (39/50) and 82.3% (107/130), respectively. The sensitivity of telomease level in combined detection for diagnosis of lung cancer was much higher than that in single sample detection (P < 0.01). Conclusion The sensitivity of telomease activity in combined three samples was the highest. It can further improve the accuracy for the diagnosis of lung cancer with pleural effusion

    Efficient Methods for Non-stationary Online Learning

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    Non-stationary online learning has drawn much attention in recent years. In particular, dynamic regret and adaptive regret are proposed as two principled performance measures for online convex optimization in non-stationary environments. To optimize them, a two-layer online ensemble is usually deployed due to the inherent uncertainty of the non-stationarity, in which a group of base-learners are maintained and a meta-algorithm is employed to track the best one on the fly. However, the two-layer structure raises the concern about the computational complexity -- those methods typically maintain O(logT)\mathcal{O}(\log T) base-learners simultaneously for a TT-round online game and thus perform multiple projections onto the feasible domain per round, which becomes the computational bottleneck when the domain is complicated. In this paper, we present efficient methods for optimizing dynamic regret and adaptive regret, which reduce the number of projections per round from O(logT)\mathcal{O}(\log T) to 11. Moreover, our obtained algorithms require only one gradient query and one function evaluation at each round. Our technique hinges on the reduction mechanism developed in parameter-free online learning and requires non-trivial twists on non-stationary online methods. Empirical studies verify our theoretical findings.Comment: preliminary conference version appeared at NeurIPS 2022; this extended version improves the paper presentation, further investigates the interval dynamic regret, and adds two applications (online non-stochastic control and online PCA
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