印度理工学院孟买分校

文摘:黑碳气溶胶在地球气候系统中起着独特而重要的作用。黑碳是一种具有独特物理特性组合的碳质材料。这一评估提供了黑碳气候强迫的评估，它综合了所有已知的和相关的过程，定量地提供了主要强迫术语的最佳估计和不确定性:太阳直接吸收;对液体、混合相和冰云的影响;和沉积在冰雪上。这些影响是用气候模型计算的，但在可能的情况下，也用微物理测量和现场观测进行评估。主要来源是与燃烧有关的，即用于运输的化石燃料、工业和住宅用途的固体燃料以及生物质的露天燃烧。采用自下而上的库存方法，2000年全球黑碳排放总量为7500克yr−1，不确定范围为2000 ~ 29000。然而，在许多模式中，可归因于黑碳的全球大气吸收太低，应该增加近3倍。在此缩放之后，工业时代(1750年至2005年)大气黑碳的直接辐射强迫的最佳估定值为+0.71 W m−2,90%的不确定边界为(+0.08，+1.27)W m−2。 Total direct forcing by all black carbon sources, without subtracting the preindustrial background, is estimated as +0.88 (+0.17, +1.48) W m−2. Direct radiative forcing alone does not capture important rapid adjustment mechanisms. A framework is described and used for quantifying climate forcings, including rapid adjustments. The best estimate of industrial-era climate forcing of black carbon through all forcing mechanisms, including clouds and cryosphere forcing, is +1.1 W m−2 with 90% uncertainty bounds of +0.17 to +2.1 W m−2. Thus, there is a very high probability that black carbon emissions, independent of co-emitted species, have a positive forcing and warm the climate. We estimate that black carbon, with a total climate forcing of +1.1 W m−2, is the second most important human emission in terms of its climate forcing in the present-day atmosphere; only carbon dioxide is estimated to have a greater forcing. Sources that emit black carbon also emit other short-lived species that may either cool or warm climate. Climate forcings from co-emitted species are estimated and used in the framework described herein. When the principal effects of short-lived co-emissions, including cooling agents such as sulfur dioxide, are included in net forcing, energy-related sources (fossil fuel and biofuel) have an industrial-era climate forcing of +0.22 (−0.50 to +1.08) W m−2 during the first year after emission. For a few of these sources, such as diesel engines and possibly residential biofuels, warming is strong enough that eliminating all short-lived emissions from these sources would reduce net climate forcing (i.e., produce cooling). When open burning emissions, which emit high levels of organic matter, are included in the total, the best estimate of net industrial-era climate forcing by all short-lived species from black-carbon-rich sources becomes slightly negative (−0.06 W m−2 with 90% uncertainty bounds of −1.45 to +1.29 W m−2). The uncertainties in net climate forcing from black-carbon-rich sources are substantial, largely due to lack of knowledge about cloud interactions with both black carbon and co-emitted organic carbon. In prioritizing potential black-carbon mitigation actions, non-science factors, such as technical feasibility, costs, policy design, and implementation feasibility play important roles. The major sources of black carbon are presently in different stages with regard to the feasibility for near-term mitigation. This assessment, by evaluating the large number and complexity of the associated physical and radiative processes in black-carbon climate forcing, sets a baseline from which to improve future climate forcing estimates.

文摘:我们报道了玉米2.3千兆酶基因组核苷酸序列的改进草稿，玉米是一种重要的作物植物，也是生物学研究的模型。betway亚洲预测的基因超过3.2万个，其中99.8%位于参考染色体上。近85%的基因组由数百个转座因子家族组成，它们不均匀地分布在基因组中。它们负责大量基因片段的捕获和扩增，并影响着着丝粒的组成、大小和位置。我们还报告了甲基化贫乏区域与Mu转座子插入和重组的相关性，以及插入和/或缺失的拷贝数变异，以及复制区域之间不均匀的基因损失是如何参与将一个古老的异源四倍体返回到遗传二倍体状态的。这些分析为进一步的研究奠定了基础，以提高我们对玉米驯化和农业改良的理解。

文摘:定义了连续非lipschitzian自治系统平衡的有限时间稳定性。研究了沉降时间函数的连续性、Lipschitz连续性和Holder连续性，并举例说明。给出了涉及标量微分不等式的有限时间稳定性的Lyapunov和逆Lyapunov结果。结果表明，Lyapunov函数的正则性与沉降时间函数的正则性是相关的。因此，逆李雅普诺夫结果只能保证连续李雅普诺夫函数的存在。最后，研究了有限时间稳定系统对扰动的敏感性。

文摘:我们回顾了RHIC前三年核-核碰撞研究中最重要的实验结果，重点是STAR实验的结果，并评估了它们的解释和与理论的比较。理论和实验的比较表明，在RHIC中心Au + Au碰撞产生稠密的快速热化物质，其特征是:(1)初始能量密度高于晶格QCD预测的建立夸克胶子等离子体(QGP)的临界值;(2)极有可能在强子形成之前的阶段建立的以极短平均自由程组成相互作用为标志的近似理想流体流动;(3)射流不透明度。许多观测结果与在碰撞早期阶段包含QGP形成的模型一致，并没有在强子框架中找到现成的解释。然而，测量本身还没有为物质向这种新形式的转变建立明确的证据。尽管碰撞演化的理论处理取得了令人印象深刻的成功，但仍需要一系列不同的模型、自由度和未知定量结果的假设。我们提出了一系列重要的开放问题，并建议进行更多的测量，为了建立一个令人信服的基础，确定在RHIC中已经产生了热化的、解定义的夸克胶子物质，至少应该解决其中的一些测量。

文摘:自成立以来，在理解增材制造(AM)工艺和金属构件的结构和性能方面取得了重大进展。由于该领域正在迅速发展，对我们的理解进行周期性的批判性评估是有用的，本文旨在解决这一需求。它涵盖了金属材料AM的新兴研究，并提供了物理过betway亚洲程和沉积零件的冶金结构和性能的基础科学的全面概述。这篇综述的独特性包括对耐火合金、贵金属和成分梯度合金的实质性讨论，AM与焊接的简明比较，以及基于实验和理论对各种工程合金的可印刷性的严格检查。对该领域的现状、科学认识上的差距以及金属构件扩模的研究需求进行了评价。betway亚洲