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Detailed un-standard experiments of fracture toughness in which SENB specimens of five different thicknesses were included, were carried out to investigate the size effect on the ductile and brittle fracture. It is found that the fracture toughness on the upper shelf increases with the size of the specimens, which have the similar geometry and then decreases gradually to the plane strain fracture toughness. The ductile fracture toughness increases with the size in the range of 4—16 mm for the increment of the plastic deformation zone size and plastic fracture strain under general yielding conditions, and then drops down from 16—22 mm for the increase of the high-stress triaxiality zone and the plastic deformation zone size not changing much which is less than the residual ligament width. While the fracture toughness of the lower shelf increases with the thickness in the range of 4—8 mm for the plastic deformation zone size increasing under small-scale yielding conditions, and then drops down from 8 to 22 mm for the increase of the high out-of-plane constraint. Theoretical analysis with the primary definition of the fracture toughness J integral, the constraint level and the plastic deformation volume was performed to investigate the different size effects for different temperatures. Finite Element Analysis simulations with continuum damage model to get the distribution and variety of the stress triaxiality as an important factor of fracture strain and fracture toughness.

Experiments of fracture toughness with non-standard SENB specimens of five different thicknesses were performed to investigate the size effect on the ductile and brittle fracture for different temperatures. From the experimental results it is found that size effects both brittle and ductile fracture with the same trend but for different mechanical reasons. The ductile fracture toughness increases firstly with increased plastic deformation zone size and plastic fracture strain under general yielding conditions, and then drops down due to the plastic deformation zone size not changing much which is less than the residual ligament width and the increase of the proportion of the high stress triaxiality zone to the whole specimen. The fracture toughness of the lower shelf increases with increasing thickness of the plastic deformation zone size under small scale yielding conditions, and then drops down due to the increase of the high out-of-plane constraint.

Small punch (SP) tests have been performed at room temperature on round specimens with six kinds of thicknesses. Experimental results show that the SP energy, the fracture strain and the fracture toughness increase with the thickness of the SP samples. Fracture surface displays typical ductile fracture, and the outer surface of the hemispherical bulk part punched off is full of little bowings around which there are many microcracks caused by the stretch stress under biaxial strain/stress state. From the view point of the energy dissipation, the fundamental theoretical model of fracture toughness is proposed, according to which the ductile fracture toughness is obtained from the SP energy, the plastic deformation and the experimental fractography. The fracture strain and the fracture energy density criteria are introduced into the local failure model. With the continuum damage model, the FEA simulations provide the results of the crack propagation process which agree with the experimental results and can verify the fracture model.

Three coordination polymers, [Cd3(BTC)2(m-bix)3]n·4nH2O (1), {[Cd(HBTC)(H2O)]·(p-bix)1/2(H2O)2}n (2) and [Zn3(BTC)2(p-bix)3(H2O)2]n·4nH2O (3) (H3BTC = 1,3,5-benzenetricarboxylic acid, bix = bis(imidazol-1-ylmethyl)-benzene), have been synthesized under hydrothermal conditions and structurally characterized. In 1, three Cd(II) ions are all in a highly distorted octahedral coordination environment, and m-bix plays a bidentate bridging ligand. In 2, Cd(II) ion is also in a highly distorted octahedral geometry, but p-bix is not coordinated with Cd(II) ions. p-Bix acts as a guest molecule filling in the Cd-HBTC rectangular channel. The structure of 3 contains two kinds of unique Zn(II) ions, one is in tetrahedral geometry and the other is in ideal octahedral environment. All the three compounds are three-dimensional metal-organic frameworks. Their TG, IR and fluorescent spectra are also reported. Additionally, a new parameter σ is proposed to quantify the distortion of an octahedral environment.

Detailed un-standard experiments of fracture toughness in which SENB specimens of five different thicknesses were included were carried out to investigate the size effect on the ductile and brittle fracture. It is found that the ductile fracture toughness parameter-the critical strain energy release rate increases with the size of the specimens which have the similar geometry shape and then decreases gradually to the plane strain fracture toughness. On the upper shelf the critical strain energy release rate increases with the size in the range of 4–16 mm for the increment of the plastic deformation zone size and plastic fracture strain under general yielding conditions, and then drops down from 16 mm to 22 mm for the plastic deformation zone size not changing much which is less than the residual ligament width and the increase of the proportional of the high stress triaxiality zone to the whole specimen. While on the lower shelf the critical strain energy release rate increases with the thickness in the range of 4–8 mm for the plastic deformation zone size increasing under small scale yielding conditions, and then drops down from 8 mm to 22 mm for the increase of the high out-of-plane constraint. Theoretical analysis with the primary definition of the strain energy release rate, the constraint level and the plastic deformation volume was performed to investigate the different size effects for different temperatures. FEA simulations with continuum damage model of GTN models to get the results of the stress triaxiality as an important factor of fracture toughness increasing with the reduction of the thickness.

Hydrothermal reaction of CuCN with 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) affords a wave-like infinite chain coordination polymer [Cu2(CN)2(3-bpo)]n (1). Replacement of 3-bpo by its isomer 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) could yields polymer [Cu(CN)(4-bpo)]n (2). In the complex 1, the bent 3-bpo ligand adopts bidentate chelating mode binds with the Cu(I)-cyanide chain to form 16-membered macrocyclic structure. The complex 2 exhibits a layered metal–organic framework, in which exo-bidentate 4-bpo ligand connects the Cu(I)-cyanide chains to form 2-D rectangle grid. Both of these Cu(I) complexes are thermal stable under 200 °C and release 3-bpo or 4-bpo ligand in 200–360 °C. Luminescent study reveals that 1 has green-light emission, while 2 has blue-light emission.

Hydrothermal reactions of Cu(NO3)2 with 2,6-bis(1,2,4-triazolyl)pyridine (btp) and 1,3,5-benzenetricarboxylic acid (H3btc) or 1,2,4,5-benzenetetracarboxylic acid (H4btec) in base aqueous solution afford two novel complexes [Cu2(btp)(btc)(H2O)(OH)]n (1) and [Cu2(btp)(Hbtec)]n · nH2O (2). Complex 1 is a coordination polymer where a carboxylate and a hydroxyl are bound to Cu(II) ions to form (μ-OH)(μ-O2CR)Cu2 core, which is ferromagnetic couple with 2 J = 21.30 cm−1. Complex 2 is a 3-D coordination polymer. Bond valence sum (BVS) analysis indicates it is a mixed-valence compound. Cu(I) is three-coordinated by triazole N-donors, while Cu(II) is four-coordinated by a triazole N and three carboxyl O-donors. Both complexes are quite thermal stable.

The low-cycle fatigue (LCF) behavior of a nickel-based single crystal superalloy with [001] orientation was studied at an intermediate temperature of T 0 °C and a higher temperature of T 0 + 250°C under a constant low strain rate of 10 −3 s −1 in ambient atmosphere. The superalloy exhibited cyclic tension-compression asymmetry which is dependent on the temperature and applied strain amplitude. Analysis on the fracture surfaces showed that the surface and subsurface casting micropores were the major crack initiation sites. Interior Ta-rich carbides were frequently observed in all specimens. Two distinct types of fracture were suggested by frac-togaphy. One type was characterized by Mode-I cracking with a microscopically rough surface at T 0 + 250°C. Whereas the other type at lower temperature T0C favored either one or several of the octahedral {111} planes, in contrast to the normal Mode-I growth mode typically observed at low loading frequencies (several Hz). The failure mechanisms for two cracking modes are shearing of γ′ precipitates together with the matrix at T 0 °C and cracking con ned in the matrix and the γ/γ′ interface at T 0 + 250°C.

In the Ductile–Brittle Transition Temperature (DBTT) region, it is not realistic to take unique fracture stress or fracture strain as the fracture criterion to investigate the fracture properties. In this paper, an updated continuum damage model was proposed, in which the fracture energy density, a function of the stress triaxiality, temperature and strain rate in the transition region was taken as the critical damage factor. Uniaxial tension tests were carried out to get the basic material properties at different temperatures, to calibrate the fracture model constants and verify the validity of the damage model. The fracture behaviour of pipes with penetrating cracks under the internal pressure was experimentally investigated with the load–deflection curves and the crack propagation length captured from tests. The J–R curves were obtained from the testing results for different temperatures. Based on the Finite Element Analyses (FEA) with the proposed fracture criterion of the updated continuum damage model, the loading level of pipes with penetrating cracks were estimated and compared with the experimental results. Meanwhile the fracture processes of the pipeline structures in the transition region were reproduced. The experimental and numerical results agreed very well in present calculations. It has been shown that the fracture process in the transition region strongly depends on both the stress and strain states, and could be effectively predicted using the continuum damage model.

Detailed experiments of fracture toughness in which SENB specimens of five different thicknesses were included were carried out to investigate the size effect in the ductile to brittle transition temperature region. It is found that the fracture toughness of the upper shelf increases with the thickness of the specimens with the similar geometry. While the fracture toughness of the lower shelf decreases with the thickness in the range of 4mm to 12mm and then drops up from 12mm to 16mm with the appearance of shear lips which present the shearing fracture under the plane stress state. The tearing modulus dJ/da which determines the resistance to stable crack growth increases with the increment of thickness and the reduction of the temperature. The results of the stress triaxiality increasing with the reduction of the thickness explain well the experimental results.

The syntheses, X-ray structures, and magnetic properties of two 3D cyano-bridged assemblies, CsI2CuII3[WIV(CN)8]2·4NH3·4H2O (1) and CuII2[MoIV(CN)8]·8NH3 (2), are presented. Both complexes 1 and 2 were synthesized in aqueous ammonia solution, and the crystal growth was dynamically controlled by introducing the competition mechanism between precipitation and coordination reactions. Complexes 1 and 2 crystallize in the monoclinic system and have space group P21/c, but complex 1 has unit cell constants a = 15.0213(17) A, b = 7.4222(7) A, c = 15.3083(14) A, and Z = 2, while complex 2 has a = 13.1877(14) A, b = 9.1381(10) A, c = 17.3340(18) A, and Z = 2. The structure of complex 1 consists of [CuII(NH3)4] and [CuII(H2O)] units bridged by [WIV(CN)8] to form a 3D network, where CsI ions balance the electrovalence to complete the neutral structure with the residual water molecules in the lattice. The structure of complex 2 shows that three CuII(NH3)4 sites are axially connected by [MoIV(CN)8]4- weakly coordinatin...

A cyano-bridged mixed-valence CuII Cu 2 I assembly, {CuII(NH3)3CuI(CN)[CuI(CN)3]}n (1), was directly synthesized in diluted ammonia aqueous solution by Cu(NO3)2·3H2O reacting with KCN. The X-ray crystallography displays that complex 1 is crystallized in Monoclinic, P2(1)/n space group with a=9.4680(19), b=12.626(3), c=9.4960(19) A and β=99.83(3)°. The single crystal structure of complex 1 exhibits 2D network formed by cyanide bridges connecting the ladder chains containing CuII–NC–CuI–NC–CuI–CN–CuII linkage. The magnetic investigation reveals the weak antiferromagnetic interactions between CuII ions in the ladder chain with g=2.138, J∥=−3.39 cm−1 (along the chain) and J⊥=−2.92 cm−1 (perpendicular to the chain) although eight diamagnetic atoms bridging between magnetic center ions. It is suggested due to the largest ionic radius of CuI ion in the first row transition metal ions leading to the diffusion of 3d orbitals of CuI ion, furthermore, the ability of [CuI(CN)3] mediating magnetic interaction is strengthened.

Application of near infrared diode laser spectroscopy for enhanced investigation of neutral closed shell molecular complexes is reported. The capabilities of high-frequency wavelength modulation with second derivative absorption detection using a cw supersonic slit jet expansion are demonstrated by an investigation of the previously unrecorded ν 1 K=2←1 P 1 ( J ) and P 2 ( J ) transitions of OC:Ar with transitions having signal-to-noise ratios up to 10 3 :1. Subsequently, rovibrational analyses are reported for the hydrogen-bonded interactions: (i) ν 1 O 13 C–H 35 Cl and O 13 C–H 37 Cl in natural abundance; (ii) analysis of a Coriolis perturbation in J ′=19 of ν 1 excited state in 14 N 2 –HBr; (iii) ν 1 , ν 2 + ν 5 1 , ν 2 + ν 5 1 − ν 5 1 in OC–H 79 Br and OC–H 81 Br, and generation of rovibrational parameters for the ground-state low frequency intermolecular vibrational ν 5 1 .

This study was undertaken to investigate the distribution and variation of microcystins (MC) from a water resource to a water plant in China including long distance transportation, ClO2 preoxidation, coagulation/precipitation, filtration, and disinfection. Advanced treatment methods including ozonation and granular activated carbon (GAC) adsorption were tested to remove microcystins from drinking water. The results indicated that, when containing high level of algae in raw water, preoxidation at 2 mg/L of ClO2 was not enough to stop algae growth in long distance transportation. In the water plant studied, both coagulation and filtration caused significant increase instead of removal of microcystins in drinking water. Chlorine disinfection removed part of microcystins. However, both ozonation and GAC adsorption were able to remove microcystins completely, thereby improving the quality of drinking water in terms of microcystins.

On the basis of triangular-shaped secondary building units, a hexanuclear manganese(III) complex, [MnIII6O2(sao)6(N3)2(H2O)8]·2.5H2O (1) (H2sao = salicylaldoxime), was synthesized and structurally characterized. The structure of 1 consists of two triangular-shaped [Mn3O] connected with end-to-end (EE) azide group. Magnetic data analysis shows that antiferromagnetic couplings dominated in the complex.

The self-assembly of organic TCNQF˙⁻ radicals (2-fluoro-7,7,8,8-tetracyano-p-quinodimethane) and the anisotropic [Tb(valpn)Cu](3+) dinuclear cations produced a single-chain magnet (SCM) involving stacking interactions of TCNQF˙⁻ radicals (H2valpn is the Schiff base from the condensation of o-vanillin with 1,3-diaminopropane). Static and dynamic magnetic characterizations reveal that the effective energy barrier for the reversal of the magnetization in this hetero-tri-spin SCM is significantly larger than the barrier of the isolated single-molecule magnet based on the {TbCu} dinuclear core.

© 2014 AMDA - The Society for Post-Acute and Long-Term Care Medicine. Objectives: To describe Chinese nursing home residents' knowledge of advance directive (AD) and end-of-life care preferences and to explore the predictors of their preference for AD. Design: Population-based cross-sectional survey. Settings: Nursing homes (n= 31) in Wuhan, Mainland Southern China. Participants: Cognitively intact nursing home residents (n= 467) older than 60 years. Measures: Face-to-face questionnaire interviews were used to collect information on demographics, chronic diseases, life-sustaining treatment, AD, and other end-of-life care preferences. Results: Most (95.3%) had never heard of AD, and fewer than one-third (31.5%) preferred to make an AD. More than half (52.5%) would receive life-sustaining treatment if they sustained a life-threatening condition. Fewer than one-half (43.3%) chose doctors as the surrogate decision maker about life-sustaining treatment, whereas most (78.8%) nominated their eldest son or daughter as their proxy. More than half (58.2%) wanted to live and die in their present nursing homes. The significant independent predictors of AD preference included having heard of AD before (odds ratio [OR] 9.323), having definite answers of receiving (OR 3.433) or rejecting (OR 2.530) life-sustaining treatment, and higher Cumulative Illness Rating Scale score (OR 1.098). Conclusions: Most nursing home residents did not know about AD, and nearly one-third showed positive attitudes toward it. AD should be promoted in mainland China. Education of residents, the proxy decision maker, and nursing home staff on AD is very important. Necessary policy support, legislation, or practice guidelines about AD should be made with flexibility to respect nursing home residents' rights in mainland China.

The numerical simulation of three-dimensional large amplitude liquid sloshing under low gravity environment is discussed in this paper. The ALE (Arbitary Lagrange-Euler) kinematics description is introduced into the finite element fractional step method. The corresponding discrete numerical equations are developed by Galerkin weighted residual method afterwards. The formulations to calculate the free-surface tension are derived. Three-dimensional large amplitude fuel sloshing under low gravity environment in a cylindrical tank is simulated and some important nonlinear characteristics of three-dimensional nonlinear liquid sloshing are obtained. The numerical results are compared with experimental results and the effectiveness of the method conducted in this paper is demonstrated.

An octacyanotungstate(V)-manganese(II) bimetallic assembly [Mn(Me2-bipy)2]3[W(CN)8]2·9H2O (1) (Me2-bipy = 4,4′-dimethyl-2,2′-bipyridine) was synthesized in methanol and characterized by X-ray crystallography. X-ray analysis shows that complex 1 is a neutral, one-dimensional (1D) infinite chain polymer. Magnetic data analysis demonstrates a long-range magnetic interaction and two different antiferromagnetic coupling constants obtained by fitting between Mn and W ions in 1.

The objective of this paper is to investigate the transient processes of deep‐bed filtration with fiberball as medium. The study was conducted with a laboratory filtration column. The experimental results unveiled that the porosity of fiberball beds was reasonably distributed. Suspended solids in water flow were collected layer by layer along the whole bed depth. The filtration curve was of “S”; pattern moving along bed depth. The pressure drop peaked at deep layer instead of at upper layer as usually occurred in sand filtration. Backwashing was carried out with water and air simultaneously. The remnant deposit of concern within fiberball was kept at about 10% of fiberball weight. It was demonstrated that the fiberball is an innovative filtration medium combing the advantages of granular medium and fibrous medium and has high potential in application to water and wastewater treatment.

Organic contaminants present in drinking water sources can change the water electrodynamic characteristics significantly. Such change may complicate the coagulation processes. Zeta potential analysis based on coagulation tests indicated that the trend of zeta potential changes in the coagulation of organic‐contaminated water sources is different from the classic coagulation process. In this case, the conformation of organic molecules may play an important role. The effect of biological treatment on the zeta potential was also investigated within a biofilter in the scale of 10,000 m3/day. The results showed that the biological process can change the zeta potential of turbidity particles, reducing the stability of the turbidity particles probably through biodegradation and bioflocculation, leading to the improvement of the coagulation process.

Creep-fatigue interaction is a principal cause of failures of many engineering components under high temperature and cyclic loading. In this work, stress controlled creep-fatigue interaction tests are carried out for modified 9Cr-1Mo (P91) steel. In order to study the damage mechanism of P91 steel under creep-fatigue interaction, Scanning Electron Microscopy (SEM) of specimen fracture morphology and in-situ observation experiments were conducted. Based on the ductility exhaustion theory and creep-fatigue interaction tests data, the modified ductility exhaustion life prediction model was developed. The predicted results are in a good agreement with the experiment. By comparison with frequency separation model, the life predicted by ductility exhaustion model is better than frequency separation model obviously. The results show that different stress amplitude and mean stress have great effect on the fracture damage mechanism when the hold time is invariable. By the SEM analysis of fracture morphology, the damage characters of creep, creep-fatigue interaction and fatigue can be partitioned. The specimen crack initiation source is the modified 9Cr-1Mo steel inclusion. Therefore, this work can provide a reference of life prediction and design for high temperature materials and components.

Two new mixed-ligand complexes of formula [Cu(mal)(abpt)(H 2 O)].3/2H 2 O ( 1 ) and [Cu 2 (sq)(abpt) 2 ].2H 2 O ( 2 ) [mal = malonate, abpt = 4-amino-3,5-di-2-pyridyl-4H-1,2,4 triazole and sq = squarate], have been prepared and characterized by X-ray crystal structure determination and magnetic studies. Complex 1 crystallizes in the monoclinic system, space group C2/c, with a = 14.0086(2) A, b = 10.0980(2) A, c = 25.630(4) A; β = 97.5900(10) o , and Z = 8. Complex 2 crystallizes in the triclinic system, space group P-1 with a = 7.5696(15) A, b = 8.4697(17) A, c = 11.049(2) A; β = 93.00(3) o , α = 96.98(3), γ = 90.111(3) and Z = 1. Complex 1 consist of a neutral mononuclear [Cu(mal)(abpt)(H 2 O)] unit and water molecule of crystallization in a distorted square pyramidal coordination sphere, while complex 2 is viewed as being made up of [Cu(sq)(abpt) 2 ] units with the squarato ligand bridging the two copper(II) cations. Variable temperature magnetic behaviour of the complexes reveals the existence of weak antiferromagnetic interaction for complex 1 and weak ferromagnetic intrachain interaction for complex 2 . KEY WORDS : Copper(II) complexes, Mixed-ligand, Magnetic properties, Malonate, Squarate, 4-Amino-3,5-di-2-pyridyl-4H-1,2,4 triazole Bull. Chem. Soc. Ethiop. 2011 , 25(1), 53-60.

A new manganese(II) complex [Mn3(bidc)2(C2O4)(H2O)10]n (1) (bidc = benzimidazole-5,6-dicarboxylate) was synthesized and characterized by X-ray crystallography. X-ray diffraction shows that complex 1 has a neutral, one-dimensional (1D) brick wall chain structure. With the intramolecular and intermolecular hydrogen bonding interactions, the adjacent chains are joined into a 3D suparmolecular architecture. IR spectroscopy and variable temperature magnetic susceptibility measurements were made, which indicated weak antiferromagnetic coupling between the MnII ions in complex 1.

With the investigation of influence of the stress triaxiality on the fracture properties, an updated continuum damage model is proposed and realized by FEA to evaluate the temperature effect and the strain rate effect on the fracture properties in the ductile and brittle transition temperature (DBTT) region. The updated continuum damage model based on the fracture energy density per unit crack propagation area in Fracture Process Zone (FPZ) is proposed, in which the fracture energy density as the function of the stress triaxiality, temperature and strain rate is taken as the indicator of the critical damage factor, considering the unique fracture stress or the fracture strain as fracture criterions are not effective to describe the fracture properties for both the ductile fracture and the brittle fracture co‐exist and compete. With the user subroutine in ABAQUS, Finite Element Simulations are performed with the realization of the updated continuum damage model. From the simulation results, it is found tha...

A set of screening and classification method is proposed in this paper to manage the Systems, Structures and Components (SSCs) of the Pressurized Water Reactor (PWR) for the aging management. The method proposed and carried out in China Nuclear Power Plants (NPP) is based on the systematic aging evaluation method and the management method for the license renewal from International Atomic Energy Agency (IAEA) and U.S. Nuclear Regulatory Commission (NRC), whose successful management methods are discussed in this paper. Considering the importance of the classification management of the SSCs, the classification method is investigated from the aspects of the safety, reliability and replacement of the SSCs with the Nuclear Power Plant operation experience feed-back. With the classification management method, the SSCs are managed economically and effectively for the Nuclear Power Plants in China. The method also makes great foundation for the aging management and residual life evaluation of the PWR in China.

The structure integrity of the primary pipe from the Pressure Water Reactor (PWR) will be one of the most serous problems for the life extension of the reactor for that the toughness of the Duplex Stainless Steel will reduce sharply for thermal aging effect for a long time service at 350°C high temperature. To evaluate the structure integrity of the primary pipe, the material properties, such as the basic mechanical properties, the Charpy impact energy and the fracture properties for different aging times are investigated by macro mechanical tests. The stress analysis of the primary pipe for internal pressure, thermal stress and static stress for weight are performed. With the damage tolerance method, the residual toughness of the material and primary pipe structures are investigated according to the stress analysis of the material and the damage mechanics. From the experimental results, it is found that the strength increases while the toughness decreases with the increment of the accelerated aging time. The safety factor of the structure strength increases while that of the toughness decreases.Copyright © 2010 by ASME

The fracture behavior of pipes with penetrating cracks was experimentally investigated with the results of the load-deflection curves and crack length. J-R curves were obtained from the testing results for different temperatures. With the decrement in temperature, the critical J integral decreases and the tearing modulus increases. An updated continuum damage model was proposed, in which the fracture energy density as a function of the stress triaxiality, temperature and strain rate in the transition region was taken as the critical damage factor. The uni-axial tension experiments at different temperatures were carried out to obtain the basic material properties and the critical fracture energy density, to verify the validity of the damage model. Based on detailed finite element analyses with the proposed updated continuum damage model, the loading level of pipes with penetrating cracks was estimated and compared with the experimental results, meanwhile the fracture processes of the pipeline structure in the ductile-brittle-transition-temperature region were reproduced. It has been shown that the fracture process in the transition region strongly depends on both the stress and strain state, and can be effectively predicted using the continuum damage models incorporating with the stress state effect.

This paper presents a fast and accurate solution for crack interaction problems in infinite- and half- plane solids. The new solution is based on the method of complex potentials developed by Muskhelishvili for the analysis of plane linear elasticity, and it is formulated through three steps. First, the problem is decomposed into a set of basic problems, and for each sub-problem, there is only one crack in the solid. Next, after a crack-dependent conformal mapping, the modified complex potentials associated with the sub-problems are expanded into Laurent’s series with unknown coefficients, which in turn provides a mechanism to exactly implement in the form of Fourier series the boundary condition in each sub-problem. Finally, taking into account the crack interaction via a perturbation approach, an iterative algorithm based on fast Fourier transforms (FFT) is developed to solve the unknown Fourier coefficients, and the solution of the whole problem is readily obtained with the superposition of the complex potentials in each sub-problem. The performance of the proposed method is fully investigated by comparing with benchmark results in the literatures, and superb accuracy and efficiency is observed in all situations including patterns where cracks are closely spaced. Also, the new method is able to cope with interactions among a large number of cracks, and this capability is demonstrated by a calculation of effective moduli of an elastic solid with thousands of randomly-spaced cracks.

A novel zero-dimensional (0D) octacyanotungstate(V)-manganese(II) bimetallic assembly, {[MnII(bipy)2]2(ox)}.{[MnII(bipy)2W(CN)8]2}.4H2O (1) (bipy = 2,2'-bipyridine, ox = C2O42-), was synthesized in methanol solution containing oxalic acid. X-ray analysis shows 1 is crystallized in monoclinic crystal system with C2/c space group and composed of two components of a dimeric Mn2 cation and a quadrate tetrameric Mn2W2 anion. The Mn2 and Mn2W2 moieties are connected by their respective pi-pi stacking to yield the alternative 2D layers, and the 2D layers are linked by hydrogen bonding to form a 3D network. The investigation of the magnetostructural correlation reveals that cyanide and oxalate bridges mediate weak intracluster antiferromagnetic coupling between Mn and W ions and between Mn ions, respectively. Further magnetic measurements and analysis show the spin glasses and intercluster ferromagnetic interaction exist in complex 1.

Two homochiral coordination polymers [Mn2(D-cam)2(2-Hpao)4]n (1) and [Co2(D-cam)2(3-abpt)2(H2O)3]n·5nH2O (2) were prepared with D-(+)-camphoric acid, and 1-D complex 1 featured good temperature-independent piezoelectric (6.9 pC N−1) and dielectric properties.

Magnetic Cu4 clusters with S = 2 are bridged by octacyanometaltate(IV) to form two 3D cluster arrays of metal-organic frameworks. Magnetic investigation shows the ferromagnetic coupling between Cu(II) ions and very weak antiferromagnetic interaction between clusters.