982 resultados para 1.3-MU-M


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An efficient azidation of 1,3-dicarbonyl compounds led to tertiary azides in the presence of tetrabutylammonium iodide (TBAI). TBAI is used as a pre-catalyst along with aq. tert-butyl hydroperoxide (TBHP) as an oxidant in aqueous medium. This operationally simple, practical, mild and green method provides an opportunity to synthesize a variety of azidated -keto esters, amides, and ketones in good yields.

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El Código de Derecho Canónico tiene algunas normas que deben ser revisadas, porque son fruto de un momento histórico de la Iglesia. Después de citar algunos cambios que ya se han realizado en el Derecho Canónico en general y, en particular, en el Derecho Matrimonial Canónico, propongo revisar el canon 1095, 1º-3º, referido a las que yo llamo “causas psicopatológicas” de la incapacidad matrimonial, para una posible reforma del mismo que permita su mejor comprensión y aplicación...

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本文研究了以PMBP-苯萃取稀土和钍、铀、钛、锆的萃取行为。测定了La、Ce、Pr、Nd、Sm、Gd、Dy、Yb、Y、U(Ⅵ)、Ti、Th和Zr的pH_(1/2)值,计算了它们的萃取平衡常数。并介绍了近十年来作者将此萃取剂应用于铀、钍、稀土、鋰、钢铁合金及岩石中痕量稀土、钍和钙的分离和测定方面的工作。实践证明,PMOP合成简便、价格低廉、萃取能力较强,是比TTA更为优越的萃取剂。

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In 2006 the UK-based charity, Global Ocean, with local support from the Third Millennium Foundation, convened a Conversation among specialists about the problems facing the conservation of whales. Called "A consultation on whaling", this gathering was held in the ancient village of Paciano, in Umbria near the border with Tuscany, 15 – 17 October 2006. There were 15 participants from 11 countries. Dr Kees Lankester served as moderator. The outcome was an Aide Memoire which served to guide the participants in the run-up to the 2007 meeting of the International Whaling Commission (IWC), held in Anchorage, Alaska, in June. One point of agreement was that a second consultation should be held in the months following the Anchorage meeting, involving some but not necessarily all of the participants in the first, but concentrating this time on scientific issues – especially those encountered in the Scientific Committee of the IWC –with particular attention to informing a wider public about those scientific activities in relation to the problems confronting the IWC and the views of scientists about them. This document is the report of that Conversation, referred to as Paciano II. The moderator was Dr Giuseppe Notarbartolo di Sciara and the Report was written by Kieran Mulvaney in consultation with all participants, and with reference to an Aide Memoire prepared by the Rapporteur, Dr Russell Leaper. The sponsor and organisers have agreed with the general sentiment expressed by participants in Paciano II that further such conversations should be held at roughly yearly intervals and they will try to satisfy that desire. Although these future gatherings would be concerned with the living ocean they would not necessarily be restricted in future to consideration of whales and whaling. Discussions are on-going for selection of a theme which is of both scientific interest and practical concern for conservation of marine life and management of the uses of ocean space. (Document has 18 pages)

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In 2006 the UK-based charity, Global Ocean, with local support from the Third Millennium Foundation, convened a Conversation among specialists about the problems facing the conservation of whales. Called "A consultation on whaling", this gathering was held in the ancient village of Paciano, in Umbria near the border with Tuscany, 15 – 17 October 2006. There were 15 participants from 11 countries. Dr Kees Lankester served as moderator. The outcome was an Aide Memoire which served to guide the participants in the run-up to the 2007 meeting of the International Whaling Commission (IWC), held in Anchorage, Alaska, in June. One point of agreement was that a second consultation should be held in the months following the Anchorage meeting, involving some but not necessarily all of the participants in the first, but concentrating this time on scientific issues – especially those encountered in the Scientific Committee of the IWC –with particular attention to informing a wider public about those scientific activities in relation to the problems confronting the IWC and the views of scientists about them. This document is the report of that Conversation, referred to as Paciano II. The moderator was Dr Giuseppe Notarbartolo di Sciara and the Report was written by Kieran Mulvaney in consultation with all participants, and with reference to an Aide Memoire prepared by the Rapporteur, Dr Russell Leaper. The sponsor and organisers have agreed with the general sentiment expressed by participants in Paciano II that further such conversations should be held at roughly yearly intervals and they will try to satisfy that desire. Although these future gatherings would be concerned with the living ocean they would not necessarily be restricted in future to consideration of whales and whaling. Discussions are on-going for selection of a theme which is of both scientific interest and practical concern for conservation of marine life and management of the uses of ocean space. (19 page document)

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用共沉淀法合成LiNi1/3Co1/3Mn1/3O2正极材料。采用谢乐公式计算LiNi1/3Co1/3Mn1/3O2晶粒大小,与观察的SEM晶粒结果进行比较。结果发现,计算得到的LiNi1/3Co1/3Mn1/3O2II每个晶面的晶粒尺寸比LiNi1/3Co1/3Mn1/3O2I相应晶面的晶粒尺寸大,随温度升高LiNi1/3Co1/3Mn1/3O2平均晶粒度增大,和观察到的SEM晶粒大小基本一致。

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The STREAM Initiative set logframe indicators, at their Technical Advisory Committee meetings and this is a progress report based on given indicators. It further includes two articles: The Kandhkelgaon story: A bold bid by women in Kandhkelgaon Village, Saintala Block, Bolangir District, to break out of their poverty trap, by Graham Haylor, S.D. Tripathi, B.K. Satpathy and Dipti Behera. Networking for rural development: a closer look at the evolution of communications in the STREAM Initiative, by Graham Haylor, Kath Copley and William Savage. (PDF contains 27 Pages)

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he 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(S-a)-Binap.AuTFA](2). The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high enantiodiscrimination observed with maleimides and tert-butyl acrylate is analyzed using DFT computed at M06/Lanl2dz//ONIOM(b3lyp/Lanl2dz:UFF) level. Several applications of these cycloadducts in the synthesis of new proline derivatives with a 2,5-trans-arrangement and in the preparation of complex fused polycyclic molecules are described.

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Future coastal management practices require that a holistic, ecosystem management approach be adopted. Coastal ecosystems, however, present a variety of specific and unique challenges relative to open ocean systems. In particular, interactions with the seabed significantly influence the coastal ecosystem. Observing technologies must be developed and employed to incorporate seafloor interactions, processes and habitat diversity into research and management activities. An ACT Workshop on Seabed Sensor Technology was held February 1-3, 2006 in Savannah, Georgia, to summarize the current state of sensor technologies applicable to examining and monitoring the coastal seabed, including the near-bed benthic boundary layer and surface sediment layer. Workshop participants were specifically charged to identify current sensors in use, recommend improvements to these systems and to identify areas for future development and activities that would advance the use of sensor technology in the observation, monitoring and management of the coastal benthic environment. (pdf contains 23 pages)

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The International Collective in Support of Fishworkers (ICSF) organized a workshop titled “Enhancing Women’s Roles in Fisheries in India” during 1-3 February 2010 in Navi Mumbai, India. The workshop was meant to discuss and analyze the role of women in fisheries, and reflect on issues facing women in fishing communities and organizations in contemporary India. Not only did the workshop expose the participants to women’s issues, organizational strategies, policies, schemes and legislation relevant to fishing communities, but it also stimulated discussions and exchange of views, which helped them explore a vision of a fisheries that sustains both communities and livelihoods. The workshop strengthened the linkages between diverse groups, and helped them search for strategies to protect the spaces of women in fisheries and their sources of livelihood. (PDF contains 61 pages)

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The preparation and direct observation of triplet 2,4-dimethylene-1,3- cyclobutanediyl (1), the non-Kekule isomer of benzene, is described. The biradical was generated by photolysis of 5,6-dimethylene-2,3- diazabicyclo[2.1.1]hex-2-ene (2) (which was synthesized in several steps from benzvalene) under cryogenic, matrix-isolation conditions. Biradical 1 was characterized by EPR spectroscopy (‌‌‌‌‌│D/hc│ =0.0204 cm^(-1), │E/hc│ =0.0028 cm^(-1)) and found to have a triplet ground state. The Δm_s= 2 transition displays hyperfine splitting attributed to a 7.3-G coupling to the ring methine and a 5.9-G coupling to the exocyclic methylene protons. Several experiments, including application of the magnetophotoselection (mps) technique in the generation of biradical 1, have allowed a determination of the zero-field triplet sublevels as x = -0.0040, y = +0.0136, and z = -0.0096 cm^(-1), where x and y are respectively the long and short in-plane axes and z the out-of-plane axis of 1.

Triplet 1 is yellow-orange and displays highly structured absorption (λ_(max)= 506 nm) and fluorescence (λ_(max) = 510 nm) spectra, with vibronic spacings of 1520 and 620 cm^(-1) for absorption and 1570 and 620 cm^(-1) for emission. The spectra were unequivocally assigned to triplet 1 by the use of a novel technique that takes advantage of the biradical's photolability. The absorption є = 7200 M^(-1) cm^(-1) and f = 0.022, establishing that the transition is spin-allowed. Further use of the mps technique has demonstrated that the transition is x-polarized, and the excited state 1s therefore of B_(1g) symmetry, in accord with theoretical predictions.

Thermolysis or direct photolysis of diazene 2 in fluid solution produces 2,4- dimethylenebicyclo[l.l.0]butane (3), whose ^(l)H NMR spectrum (-80°C, CD_(2)Cl_(2)) consists of singlets at δ 4.22 and 3.18 in a 2:1 ratio. Compound 3 is thermally unstable and dimerizes with second-order kinetics between -80 and -25°C (∆H^(‡) = 6.8 kcal mol^(-1), (∆s^(‡) = -28 eu) by a mechanism involving direct combination of two molecules of 3 in the rate-determining step. This singlet-manifold reaction ultimately produces a mixture of two dimers, 3,8,9- trimethylenetricyclo[5.1.1.0^(2,5)]non-4-ene (75) and trans-3,10-dimethylenetricyclo[6.2.0.0^(2,5)]deca-4,8-diene (76t), with the former predominating. In contrast, triplet-sensitized photolysis of 2, which leads to triplet 1, provides, in addition to 75 and 76t, a substantial amount of trans-5,10- dimethylenetricyclo[6.2.0.0^(3,6)]deca-3,8-diene (77t) and small amounts of two unidentified dimers.

In addition, triplet biradical 1 ring-closes to 3 in rigid media both thermally (77-140 K) and photochemically. In solution 3 forms triplet 1 upon energy transfer from sensitizers having relatively low triplet energies. The implications of the thermal chemistry for the energy surfaces of the system are discussed.

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We measured spectroscopic and laser action properties of a novel 8-position substituted pyrromethene-BF2, namely 1,3,5,7-tetramethyl-2,6-diethyl-8-n-propyl pyrromethene-BF2 complex. The laser action was performed with the corresponding dye solution in ethanol, which was placed in a Littman-type laser cavity pumped by the second harmonic of a Q-switched Nd:YAG laser. The spectroscopic measurements clearly indicated that the corresponding dye solution in ethanol exhibited intense absorption in the visible spectral region with large fluorescence quantum yield. It possesses rather low triplet-triplet absorption in the spectral region 460-550 nm and almost negligible triplet-triplet absorption in the lasing spectral region. As a consequence, it lases nearly as efficiently as commercially available benchmark laser dyes such as Rhodamine-6G and outperformed them in wavelength tunability in our laser cavity and pump geometry. (C) 2002 Optical Society of America.