FY-3A/MERSI热红外通道在轨辐射定标精度评估

卫星资料辐射定标精度是其定量应用的关键因素。以METOP-A/IASI的高光谱探测资料为传递基准,利用同时星下点观测的交叉定标方法,对 FY-3A/MERSI热红外通道的在轨辐射定标精度进行了客观评估,并给出了亮温系统偏差的订正因子。从观测时间差异、卫星观测天顶角和方位角差异、以及目标均匀性四个方面,分析了交叉定标中所用主要匹配近似因子的不确定性。分析结果表明,目标均匀性是匹配误差的主要来源,偏差不确定性小于2%(当亮温偏差约为1 K时,不确定性<0.02 K),其他因素的影响可以忽略。一年多的样本统计及偏差分析结果显示,MERSI的观测亮温明显高于IASI,年平均亮温偏差约(3.18±0.34) K,月平均亮温偏差呈现季节波动特征,波动幅度约0.8 K。与相近时期敦煌场和青海湖地同步观测评价结果有非常好的一致性。初步原因分析推断,造成MERSI亮温偏高的原因主要有两个,一是星上黑体发射率被高估,二是光谱响应函数向大气窗区漂移,后者可能为主导因素。     

Mass and energy flow management in the sector of surface treatment

Vehicle refinishing body shops are concerned by the environmental policy against photochemical air pollution caused by VOC emissions. For supporting these small enterprises the mass and energy flow model IMPROVE has been developed. Based on an LCA-approach, the process steps of vehicle refinishing are modelled. The model IMPROVE helps to disseminate the consequences of product substitution in comparison to so far used products and techniques in the body shop. For the dissemination of experiences practical guidelines have been developed. Moreover, a comprehensible tool for the Solvent Balance is being offered. Thus, various means are available for consulting and also for strategic production planning for the SME in the sector.     

关于带重力项一维渗流方程解的自由边界的C^k正则性的一点注记

本文研究带重力项的一维渗流方程 u_t=(u~m)_(xx)+(u~n)_x,m>1,n>1Cauchy问题解的自由边界的正则性.正如我们所知,此退化方程解的显著特征是满足有限传播速度:当初值u_0(x)具有紧支集时,自由边界x=ζ_i(t),(i=1,2)是两条Lipschitz连续曲线.本文进一步研究指出:当n≥m对压力v=m/(m-1)u~(m-1)有ζ'_1(t)=-limv_x(x,t),t∈(0,∞),且对ζ_1(t)的任何移动部份Γ是C~1正则的;当n-1/m-1≥k,k为正整数,则微商(1≤2l+j≤k)在Γ的每一侧附近是有界的;特别当n-1/m-1=k,则任意阶微商(l≥0,j≥0)在Γ的每一侧附近有界,从而v在Γ的每一侧是C~∞的。 本文只考虑i=1的情形,至于i=2可类似地加以考虑。     

Influence of intersite modes on the exchange interaction in electron transfer at large distances

We consider the dependence of the exchange interaction in electron transfer processes on the intersite vibrational modes. We assume, in particular, that high-frequency intramolecular modes of proteins may play this role in biological processes. We compare our model with that for tunneling through a time dependent barrier and with other works which considered the dependence of the exchange interaction on the nuclear coordinates.Work partially supported by the Brazilian Agency CNPq and by the NSF (Grant PCM-8406049)On leave of absence from Institute de Física e Química de São Carlos, Universidade de São Paulo, 13560, São Carlos, SP, BrazilOn leave of absence from Departamento de Física, Universidade Federal de Pernambuco, 50000, Recife, Pe, BrazilContribution No. 7325     

Growth mode and interface structure of Ag on the HF-treated Si(111):H surface

A growth mode and interface structure analysis has been performed for Ag deposited at a high temperature of 300°C on the HF-treated Si(111):H surface by means of medium-energy ion scattering and elastic recoil detection analysis of hydrogen. The measurements show that Ag grows in the Volmer-Weber mode and that the Ag islands on the surface are epitaxial with respect to the substrate. The preferential azimuthal orientation is A-type only when Ag is deposited slowly. The interface does not reconstruct to the √3 × √3-Ag structure, which is normally observed for Ag deposition above 200°C on the Si(111)7 × 7 surface, but retain bulk-like structure. The presence of hydrogen at the interface is demonstrated after deposition of thick (1100 Å) Ag films. However, the amount of hydrogen at the interface is not a full monolayer. This partial desorption of hydrogen from the interface explains why the Schottky barrier heights of Ag/Si(111):H diodes are close to those of Ag/Si(111)7 × 7 and Ag/Si(111)2 × 1.     

Medium effects on the ionization constants of some pyridinecarboxylic acid derivatives

Summary The dissociation constants of 3-hydroxy-2-carboxypyridine (3H2CP), 2-hydroxy-3-carboxypyridine (2H3CP), and 2-mercapto-3-carboxypyridine (2M3CP) were determined by potentiometric titration in 20 mole% ethanol/water, dimethylsulfoxide/water, N,N-dimethylformamide/water, and dioxane/water mixtures at 25±0.1°C applying an empiricalpH correction for mixed aqueous solvents. ThepK _n values obtained are discussed with respect to the nature of the solvent and the ionic strength of the medium as well as the molecular structure. Linearization of the titrimetric data for the second equivalence point of3H2CP,2H3CP, and2M3CP was carried out using theGran method.

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Einfluß des Mediums auf die Ionisationskonstanten einiger Pyridincarbonsäurederivate

Zusammenfassung Die Dissoziationskonstanten von 3-Hydroxy-2-carboxypyridine (3H2CP), 2-Hydroxy-3-carboxypyridin (2H3CP) und 2-Mercapto-3-carboxypyridin (2M3CP) wurden mittels potentiometrischer Titration in 20 mol% Ethanol/Wasser, Dimethylsulfoxid/Wasser, N,N-Dimethylformamid/Wasser und Dioxan/Wasser bei 25±0.1°C unter Verwendung einer empirischenpH-Korrektur für wässrige Lösungsmittelgemische bestimmt. Die erhaltenenpK _n-Werte werden im Zusammenhang mit Lösungsmitteleigenschaften, Ionenstärken und Molekülstruktur diskutiert. Die titrimetrischen Daten für die zweiten Äquivalenzpunkte von3H2CP,2H3CP und2M3CP wurden mit Hilfe derGranschen Methode linearisiert.

     

液态Al80Fe20在快速冷却中的MD模拟

通过Tight binding (TB)势的分子动力学模拟分析了Al80Fe20合金熔体的中程有序结构以及快速凝固过程中体系微观结构的演变规律，发现在倒空间，其结构因子的小角部分都出现了一个预峰.在平衡态（1450 K），模拟结果得到了X射线衍射实验的进一步印证，这被认为是体系中存在中程有序的标志.随着温度的降低，预峰的高度逐渐增大，说明体系中原子团簇尺寸越来越大.通过运用键对分析技术和键取向序参数，发现体系中存在着大量的二十面体短程有序单元.在对平衡态化学短程序参数α的计算过程中，得到了负值的α，证实了熔体中存在着较强的化学序.在FZ偏结构因子中， SAl Fe(Q)在400 K的第二峰较之SAl Al(Q)和SFe Fe(Q)发生了更为明显的劈裂，表明在非晶形成能力方面， Al、Fe元素之间的轨道杂化作用比Al元素或Fe元素单独作用要强.从BT偏结构因子中我们也发现，表征化学序的SCC(Q)在17.5 nm－1左右处出现了第一峰，而这个峰位恰是总结构因子中出现预峰的峰位.因此可推断，正是体系中的化学序导致了中程有序结构的产生.     

Antimycobacterial and anticancer activity of newly designed cinnamic acid hydrazides with favorable toxicity profile

A series of twelve novel hybrids of cinnamic acid and thiocarbohydrazones were designed, synthesized in high yield using a simple coupling strategy via acid chlorides, and evaluated for their impact against Mycobacterium tuberculosis (Mtb) and cancer cells survival. Among them, compound 3 demonstrated strong anti-Mtb activity by reducing bacilli survival for>90 % in all three treated Mtb isolates, whereas isoniazid and rifampicin did not. Moreover, compound 3 didn’t affect vitality of HepG-2 cells, implying on advantageous hepatotoxicity profile compared to current therapeutic options for tuberculosis. Compounds 2a and 3b displayed as strong inducers of apoptosis in A549 cells, both activating intrinsic caspase pathway and cell cycle arrest at the G0/G1 phase. Subsequent analyses disclosed differences in their activities, where 3b has ability to induce production of mitochondrial superoxide anions, while 2a significantly inhibited cellular mobility. More importantly, 3b considerably affected viability of HepG-2 and HaCaT cells, whereas 2a had moderate impact only on the later. Molecular modeling studies indicated high permeability and good absorption through the human intestine, and moderate aqueous solubility with poor blood–brain barrier permeability. In summary, our results reveal that novel compounds 3 and 2a represent promising agents for tuberculosis and cancer treatment, respectively, indicating that further investigation needs to be performed to clarify the mechanisms of their anti-Mtb and anticancer activity.     

Immobilization of manganese peroxidase fromLentinula edodes on alkylaminated emphazeTM AB 1 polymer for generation of Mn3+ as an oxidizing agent

Manganese peroxidase (MnP) is secreted by white-rot fungi and participates in the degradation of lignin by these organisms. MnP uses H₂O₂ as an oxidant to oxidize Mn^II to Mn^III as the manganic ion Mn³⁺. The Mn³⁺ stabilized by chelation, is a highly reactive nonspecific oxidant capable of oxidizing a variety of toxic organic compounds. Previous attempts at immobilization of MnP, purified fromLentinula edodes through reactive amino groups, have been hindered by the protein’s low lysine content of only 1% and its instability above pH 6.0. As an alternative to amine coupling, the enzyme has now been covalently immobilized through its carboxyl groups, using an azlactonefunctional copolymer derivatized with ethylenediamine and 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) as a coupling reagent. The immobilization reaction was performed under acidic (pH 5.25) conditions, and 90% coupling efficiency was achieved within 2 h. Net immobilization efficiencies, expressed as the product of protein coupling efficiency and enzyme activity, have been measured at > 95% within 4 h. The MnP-NH-polymer and the free soluble protein were characterized and compared for their pH, temperature, and storage stabilities, as well as their H₂O₂ dependence and kinetics. The tethered MnP, employed in an immobilized enzyme bioreactor for generation of chelated Mn₃₊ may have industrial applications as a nonspecific oxidant of organopollutants.