Characteristics of black carbon aerosol in Jiaxing,China during autumn 2013

We conducted measurements of black carbon（BC） aerosol in Jiaxing,China during autumn from September 26 to November 30,2013.We investigated temporal and diurnal variations of BC,and its correlations with meteorological parameters and other major pollutants.Results showed that hourly mass concentrations of BC ranged from 0.2 to 22.0 μg/m³,with an average of 5.1 μg/m³.The diurnai variation of BC exhibited a bimodal distribution,with peaks at 07:00 and 18:00.The morning peak was larger than the evening peak.The mass percentages of BC in PM_2.5 and PM₁₀ were 7.1%and 4.8%,respectively.The absorption coefficient of BC was calculated to be 44.4 Mm^-1,which accounted for 11.1%of the total aerosol extinction.BC was mainly emitted from local sources in southwestern Jiaxing where BC concentrations were generally greater than 11 μg/m³ during the measurement period.Correlation analysis indicated that the main sources of BC were motor vehicle exhaust,and domestic and industrial combustion.     

Molybdenum(VI) Bis(imido) Complexes: From Frustrated Lewis Pairs to Weakly Coordinating Cations

Molybdenum(VI) bis(imido) complexes [Mo(NtBu)₂(L^R)₂] (R=H 1 a ; R=CF₃ 1 b ) combined with B(C₆F₅)₃ ( 1 a /B(C₆F₅)₃, 1 b /B(C₆F₅)₃) exhibit a frustrated Lewis pair (FLP) character that can heterolytically split H−H, Si−H and O−H bonds. Cleavage of H₂ and Et₃SiH affords ion pairs [Mo(NtBu)(NHtBu)(L^R)₂][HB(C₆F₅)₃] (R=H 2 a ; R=CF₃ 2 b ) composed of a Mo(VI) amido imido cation and a hydridoborate anion, while reaction with H₂O leads to [Mo(NtBu)(NHtBu)(L^R)₂][(HO)B(C₆F₅)₃] (R=H 3 a ; R=CF₃ 3 b ). Ion pairs 2 a and 2 b are catalysts for the hydrosilylation of aldehydes with triethylsilane, with 2 b being more active than 2 a . Mechanistic elucidation revealed insertion of the aldehyde into the B−H bond of [HB(C₆F₅)₃]⁻. We were able to isolate and fully characterize, including by single-crystal X-ray diffraction analysis, the inserted products Mo(NtBu)(NHtBu)(L^R)₂][{PhCH₂O}B(C₆F₅)₃] (R=H 4 a ; R=CF₃ 4 b ). Catalysis occurs at [HB(C₆F₅)₃]⁻ while [Mo(NtBu)(NHtBu)(L^R)₂]⁺ (R=H or CF₃) act as the cationic counterions. However, the striking difference in reactivity gives ample evidence that molybdenum cations behave as weakly coordinating cations (WCC).     

Die eingespannte Halbplatte mit verformbarem Randstück und sprunghaft veränderlichen Randlasten

Übersicht Der Verformungszustand isotroper Halbplatten mit sprunghaft veränderlichen Randbedingungen kann durch zwei stückweise analytische Funktionen (z) und (z) beschrieben werden. Setzt man geeignete Funktionenkombinationen aus (z) und (z), also Funktionen, welche die Randbedingungen beschreiben, über Randteilbereiche analytisch fort, so gelingt es, lineare Kopplungsprobleme (Hilbertprobleme) der genannten Lösungsfunktionen zu definieren. Die Lösungen dieser Kopplungsprobleme zeigen, daß im Bereich von Randpunkten mit sprunghaft veränderlichen Randbedingungen Querkraft und Momentensingularitäten auftreten, die sogar oszillierenden Charakter haben können.

---

Summary The displacement of isotropic half-plates with mixed boundary conditions can be described by two sectionally holomorphic functions (z) and (z). Continuing analytically suitable combinations of the functions (z) and (z), defined by the boundary conditions, linear Hubert problems for the solution functions can be obtained. The solutions of these problems show, that in points of abrupt changes of the boundary conditions singularities in torques and in shear forces may arise, which might even have oscillating character.

---

---

Auszug aus einer von der Fakultät für Bauwesen der Technischen Universität München angenommenen Habilitationsschrift. Referent: Prof. Dr.-Ing. G. Knittel, Korreferent: Wiss. Rat Dr.-Ing. H. Grundmann.     

气缸垫对机体受力和缸套变形影响的实验研究

某四缸柴油机在试制中出现机体裂纹现象，为保证内燃机正常工作，机体裂纹问题急待处理．应用力学理论对此进行分析，得出机体裂纹是由机体受力不均匀引起的结论．同时采用实验应力分析方法，对两种四缸柴油机机体进行了对比实验研究，在实验中发现了缸垫对机体受力和缸套变形的影响，从而提出了一种有效的改进方法，使机体的应力有明显下降，并不再出现裂纹，也未出现漏油、漏气和活塞拉缸等不良现象，大大提高了产品可靠性．     

任意外型薄板非线性后屈曲问题的边界元解

本文就薄板后屈曲问题建立一组新型的边界元计算公式，用这组公式求解能方便处理各种边界问题，另外文中将面内应力分解成基本部份和附加部份，并利用微分算子分解理论导得了挠度的一个不同形式的基本解，由于计算公式中，实现了面内位移和挠度的解耦，从而使迭代过程得到简化，文末还对圆板后屈曲路径进行了计算，得到了满意的结果。     

General solution of the two-dimensional heat equation for two concentric domains of different material

The general solution of the two-dimensional heat equation is given for two concentric domains consisting of different materials; it is represented as integrals over the given source and boundary distribution multiplied by a Green's function. The Green's function in this problem is given for any (linear) boundary condition of Sturm-Liouville type with constant coefficients. Examples are evaluated for source free problems with uniform initial temperature distribution and a boundary condition which corresponds to constant external temperature. Numeric evaluations show the development of the temperature distribution with time in compounds heated from outside and also for an isolated electric conductor which is cooled from outside after it has been heated by a short circuit.

---

Allgemeine Lösung der zweidimensionalen Wärmeleitgleichung für zwei konzentrische Kreisbereiche verschiedener Materialien

Zusammenfassung In dieser Arbeit wird die allgemeine Lösung der zweidimensionalen Wärmeleitungsgleichung für zwei konzentrische Kreisbereiche mit unterschiedlichen Materialeigenschaften angegeben. Diese ist als quellenmäßige Darstellung gegeben, d.h. als Integral über die Wärmequellen im Inneren und am Rand und über die Anfangsverteilung, wobei alle mit der zugehörigen Greenschen Funktion multipliziert werden. Die angegebene Greensche Funktion gilt für alle beliebigen (linearen) Randbedingungen vom Sturm-Liouvilleschen Typ mit konstanten Koeffizienten. Es werden für quellenfreie Probleme mit homogener Anfangstemperatur und konstanter Außentemperatur Beispiele berechnet. Numerische Berechnungen zeigen die zeitliche Entwicklung der Temperaturverteilung für Zweischichtenanordnungen, welche von außen erwärmt werden, und für einen isolierten elektrischen Leiter, welcher nach einer Erhitzung durch Kurzschluß von außen gekühlt wird.

---

Nomenclature a diffusion constant, m²/s - c specific heat for constant pressure, W_s/kgK - d₁ inner diameter, m - d₂ outer diameter, m - l length of the construction element, m - J_m, Y_m Bessel functions of m-th order - r, polar coordinates; m, rad - t time, s - T₀ initial temperature, K - T_e external temperature of the medium surrounding the compound, K - T(r, , t) temperature field - _n n-th eigenvalue of the characteristic equation - thermal conductivity, W/mK - (r, , t) heat source density, Ws/m⁵ - mass density, kg/m³     

板壳塑性屈曲中的佯谬及其研究进展

本文详细论述了板壳塑性屈曲中的佯谬及其研究进展。并对现有的各种观点作了分析讨论。     

Electromechanical cracking in ferroelectrics driven by large scale domain switching

Experimental results indicate three regimes for cracking in a ferroelectric double cantilever beam (DCB) under combined electromechanical loading. In the loading, the maximum amplitude of the applied electric field reaches almost twice the coercive field of ferroelectrics. Thus, the model of small scale domain switching is not applicable any more, which is dictated only by the singular term of the crack tip field. In the DCB test, a large or global scale domain switching takes place instead, which is driven...     

A new analytical edge spread function fitting model for modulation transfer function measurement

We propose a new analytical edge spread function (ESF) fitting model to measure the modulation transfer function (MTF).The ESF data obtained from a slanted-edge image are fitted to our model through the non-linear least squares (NLLSQ) method.The differentiation of the ESF yields the line spread function (LSF),the Fourier transform of which gives the profile of two-dimensional MTF.Compared with the previous methods,the MTF estimate determined by our method conforms more closely to the reference.A practical application of our MTF measurement in degraded image restoration also validates the accuracy of our model.     

THE INTERIOR LAYER SOLUTION TO NONLOCAL REACTION DIFFUSION EQUATIONS

An initial boundary value problem of semilinear nonlocal reaction diffusion equations is considered.Under some suitable conditions,using the asymptotic theory,the existence and asymptotic behavior of the interior layer solution to the initial boundary value problem are studied.