Numerical Investigations on Transient Behaviours of Two 3-D Freely Floating Structures by Using a Fully Nonlinear Method

Two floating structures in close proximity are very commonly seen in offshore engineering. They are often subjected to steep waves and, therefore, the transient effects on their hydrodynamic features are of great concem. This paper uses the quasi arbitrary Lagrangian Eulerian finite element method （QALE-FEM）, based on the fully nonlinear potential theory （FNPT）, to numerically investigate the interaction between two 3-D floating structures, which undergo motions with 6 degrees of freedom （DOFs）, and are subjected to waves with different incident angles. The transient behaviours of floating structures, the effect of the accompanied structures, and the nonlinearity on the motion of and the wave loads on the structures are the main focuses of the study. The investigation reveals an important transient effects causing considerably larger structure motion than that in steady state. The results also indicate that the accompanied structure in close proximity enhances the interaction between different motion modes and results in stronger nonlinearity causing 2hal-order component to be of similar significance to the fundamental one.

A New Interface Identification Technique Based on Absolute Density Gradient for Violent Flows

An identification technique for sharp interface and penetrated isolated particles is developed for simulating two-dimensional,incompressible and immiscible two-phase flows using meshless particle methods in this paper.This technique is based on the numerically computed density gradient of fluid particles and is suitable for capturing large interface deformation and even topological changes such as merging and breaking up of phases.A number of assumed particle configurations will be examined using the technique,including these with different level of randomness of particle distribution.The tests will show that the new technique can correctly identify almost all the interface and isolated particles,and also show that it is better than other existing popular methods tested.

Effect of synthetic fibers on the mechanical performance of asphalt mixture:A review

Numerous studies showed that synthetic fibers are effective for reinforcing the mechanical performance of the asphalt mixture due to their high strength properties,ductility,and durability characteristics.In this paper,the objective is to present a review of the reinforcement effect of synthetic fiber on the mechanical performance of the asphalt mixture.This paper reviews the relevant literature on the characterizations and applications of synthetic fibers to improve different mechanical properties of asphalt mixes,which can provide a reference for the applications and development of synthetic fibers in asphalt pavement.The characteristics of common synthetic fibers are introduced and the utilization of synthetic fibers in asphalt mixture is discussed.Different surface treatment methods for fiber are reviewed and it is found that surface treatment can improve the performance of the synthetic fibers in asphalt mixtures,especially the chemical surface treatment method.The influence of synthetic fiber addition on the mechanical properties of the asphalt concrete such as rutting resistance,tensile strength,water stability performance,and cracking resistance are then discussed.The research results show that aramid,glass,and polyester fibers improve the fatigue cracking resistance of asphalt mixture.Polyester fibers,polyamide fibers,and carbon fibers are used to improve resistance to the permanent deformation of asphalt pavement.

Exponential isothermal amplification coupled MALDI-TOF MS for microRNAs detection

Micro RNAs(mi RNAs) have attracted significant attention in biomedical research and clinical diagnosis.However, due to their inherent characteristics of low abundance and the high complexity of corresponding biological matrices, simultaneous detection of multiple mi RNAs at low abundance is still a challenge.In this work, a method coupling exponential amplification reaction(EXPAR) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS) is developed for label-free and simultaneous detection of multiple mi RNAs. The assay can be performed under isothermal conditions in a single reaction tube, and finished in less than 30 min. It exhibits good quantification ability and with attomolar-level sensitivity for mi RNAs detection. It also shows high specificity to distinguish mi RNAs at single-nucleotide resolution. We used the method to detect the mi RNA-21, let-7a, mi RNA-100, and mi RNA-125b in samples of spiked human serum and breast cancer cells(i.e., MCF-7, MDA-MB-231 and SK-BR-3). The quantification results were well consistent with the standard real-time fluorescence EXPAR.Consequently, the label-free mass-spectrometric platform could be a potential tool for mi RNAs analysis in complex biological samples, and may be used for clinical diagnosis.

长序三宝木枝叶中一个新的异戊烯基异黄酮类化合物

综合运用多种现代色谱分离技术对大戟科三宝木属植物长序三宝木Trigonostemon howii枝叶中的化学成分进行了系统研究,从其枝叶的90%乙醇提取物中分离得到了8个异戊烯基异黄酮类化合物.采用多种现代波谱鉴定技术确定了这些化合物的化学结构.其中化合物1为一个新的异戊烯基异黄酮类化合物,化合物2~8为首次从三宝木属植物中分离得到的化合物.化合物1~8的体外抗肿瘤活性评价结果表明,它们对5种肿瘤细胞株(HL-60、A549、SMMC-7721、MCF-7和SW480)均显示出了较为明显的体外生长抑制活性,抗肿瘤活性与抗肿瘤阳性对照药阿霉素的抗肿瘤活性相当.

A comprehensive analysis of immunoglobulin heavy chain genes in the Bactrian camel(Camelus bactrianus)

Heavy chain only antibodies(HCAbs)represent a rare type of antibody that is devoid of light chains and the CH1 domain that have been reported in cartilaginous fish and camelids.By analyzing transcript data and genome sequences,we conducted a comprehensive analysis of Bactrian camel immunoglobulin heavy chain genes.Based on the transcript data,oneμgene,fiveγgenes,oneαgene and oneεgene were found.Additionally,the variable region of HCAbs(VHH)and the conventional antibodies(VH)sequences associated with theγ3,γ1a/b andμgenes were amplified.Based on these genome sequences,seven DH,six JH,μ,γ2a,γ2c,α,andεgenes and a portion of aγ3 gene were observed.Different Kozak sequences within different VH families were found in our analysis,and the variability index differed between the VHH3 and VH3 families.Phylogenetic analysis of the constant regions of the camelid immunoglobulin genes indicates that these genes appeared before the evolutionary divergence of Bactrian camels and dromedaries.