STRESS CONCENTRATIONS IN CYLINDRICAL SHELLS WITH LARGE OPENINGS

Based on Donnell's shallow shell equation, a new method is given in this paper to analyze theoretical solutions of stress concentrations about cylindrical shells with large openings. With the method of complex variable function, a series' of conformal mapping functions are obtained from different cutouts' boundary curves in the developed plane of a cylindrical shell to the unit circle. And, the general expressions for the equations of a cylindrical shell, including the solutions of stress concentrations meeting the boundary conditions of the large openings' edges, are given in the mapping plane. Furthermore, by applying the orthogonal function expansion technique, the problem can be summarized into the solution of infinite algebraic equation series. Finally, numerical results are obtained for stress concentration factors at the cutout's edge with various opening's ratios and different loading conditions. This new method, at the same time, gives a possibility to the research of cylindrical shells with large non-circular openings or with nozzles.

Calculation mode of side friction for large open caisson

To overcome the problems in design methodologies and construction control measures for the large open caisson, systematic research was conducted on the side friction calculation mode of the large open caisson. Based on the field monitoring data of lateral soil pressure on the side wall of the open caisson for the southern anchorage of the Maanshan Yangtze River Highway Bridge, the statistical result of the side friction under different buried depths of the cutting edge of the open caisson was back-analyzed; and the side friction distribution of the large open caisson was underlined. The analysis results indicate that when the buried depth of the cutting edge is smaller than a certain depth H0, the side friction linearly increases with the increase in the buffed depth. However, as the buffed depth of the cutting edge is larger than H0, the side friction shows a distribution with small at both ends and large in the middle. The top of the distribution can be regarded as a linear curve, while the bottom as a hyperbolic curve. As the buffed depth of cutting edge increases continuously, the peak value of the side friction linearly increases and the location of the peak value gradually moves down. Based on the aforementioned conclusions, a revised calculation mode of the large open caisson is presented. Then, the calculated results are compared with the field monitoring data, which verifies the feasibility of the proposed revised calculation mode.

AN APPLICATION OF THEORETICAL SOLUTIONS ABOUT CYLINDRICAL SHELLS WITH SMALL OPENINGS

Stress concentrations about thin cylindrical shells with small openings are reconsidered front a nerv angle. There is a sort of special internal relation between theoretical solutions about cylindrical shells,vith large openings and one,with small openings. Using this relation, the extent of applying the theory about small openings to engineering practice is estimated again, thus an idea of how to use this theory and a nerv appraisal of the application of theoretical solutions about cylindrical shells with small openings to engineering practice are given.

STUDY ON HIGH ACID LEACHING REACTIVE CALCINED KAOLIN

Leaching experiments on metakaolin show that the final Al extraction ratio reached in a batch reaction is strikingly influenced by the inferior pore structure geometry of the metakaolin pellets. By calcining kaolin particles adhered in low humidity state, a variety of metakaolin pellet, inside which a large openings structure developed, has been prepared. The structure remarkably benefits leachant ion transference, so, the variety has high acid leaching reactivity, even coarse as the pellets are, its aluminum extracted ratio still has a linear relationship with leaching time, and the leaching kinetics is maintained zero order up to a significant conversion degree. A revised Pellet-Particle Model has been developed to interpret the structure influence on Al extraction ratio. (Author abstract) 4 Refs.

Is right lobe liver graft without main right hepatic vein suitable for living donor liver transplantation?

BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not sufficient.Adequate hepatic venous outflow reconstruction in LDLT is essential to prevent graft congestion and its complications including graft loss.However,this can be complex and technically demanding especially in the presence of complex variations and congenital anomalies in the graft hepatic veins.CASE SUMMARY Herein,we aimed to present two cases who underwent successful right lobe LDLT using a right lobe liver graft with rudimentary or congenital absence of the right hepatic vein and describe the utility of a common large opening drainage model in such complex cases.CONCLUSION Thanks to this venous reconstruction model,none of the patients developed postoperative complications related to venous drainage.Our experience with venous drainage reconstruction models shows that congenital variations in the hepatic venous structure of living liver donors are not absolute contraindications for LDLT.

Large open-circuit voltage polymer solar cells by poly(3-hexylthiophene) with multi-adducts fullerenes

Polymer solar cells (PSCs) made by poly(3-hexylthiophene) (P3HT) with multi-adducts fullerenes, [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), PC61BM-bisadduct (bisPC61BM) and PC61BM-trisadduct (trisPC61BM), were reported. Electrochemistry studies indicated that PC61BM, bisPC61BM and trisPC61BM had step-up distributional lowest unoccupied molecular orbital (LUMO) energy. PSCs made by P3HT with above PC61BMs show a trend of enlarged open-circuit voltages, which is in good agreement with the energy difference between the LUMO of PC61BMs and the HOMO of P3HT. On the contrary, reduced short-circuit currents (Jsc) were observed. The investigation of photo responsibility, dynamics analysis based on photo-induced absorption of composite films, P3HT:PC61BMs and n-channel thin film field-effect transistors of PC61BMs suggested that the short polaron lifetimes and low carrier mobilities were response for reduced Jsc. All these results demonstrated that it was important to develop an electron acceptor which has both high carrier mobility, and good compatibility with the electron donor conjugated polymer for approaching high performance PSCs.

Open Air Concerts Draw Large Audiences

THE Waitan concert square is part of the new urban scene in Shanghai. With its unique location and fine performances, the concerts attract many people. Foreign merchants and ships pass Waitan (Outer Beach) as they enter the harbor on the Huangpu River at Shanghai. The scene at

Trilemma,RMB exchange rate regime reform,and policy orientation after August 2015

The discussions on RMB exchange rate could not depart from the ongoing reform of RMB exchange rate regime,which must be designed and promoted as an integral part of the large open economy macroeconomic policy framework.As a large open economy facing the trilemma,China should explicitly establish the principle of domestic monetary policy dominance in the impossible trinity,with the exchange rate policy and capital account management should both conform to this fundamental principle.Simplistically pegging RMB to the US dollar will result in lack of flexibility and violate this principle.Especially against the backdrop of unsynchronized economic cycles of major economies and the prospect of further Fed tighten up,that the real effective exchange rate of RMB moves passively along with the US dollar cannot reflect the relative changes in economic fundamentals in China and abroad,which will cause distortions,resulting in resource misallocations and loss of welfare.The reform of RMB exchange rate regime should be market-oriented,towards a direction with more flexibility.