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We study a coupled Schrödinger equation which is started from the Boussinesq equation of atmospheric gravity waves by using multiscale analysis and reduced perturbation method in this paper. For the coupled Schrödinger equation, we obtain the Manakov model of all-focusing, all-defocusing and mixed types by setting parameters value and apply the Hirota bilinear approach to provide the two-soliton and three-soliton solutions. Especially, we find the all-defocusing type Manakov model admits bright-bright soliton solutions, what’s more, we find the all-defocusing type Manakov model admits bright-bright-bright soliton solutions. Following that, we go over how the free parameters affect the Manakov model’s all-focusing type’s two-soliton and three-soliton solutions’ collision locations, propagation directions, and wave amplitudes. These findings are useful for setting a simulation scene in Rossby waves research. The answers we have found are helpful to study the equation’s physical properties in Rossby waves.

In this article, the relationship between the initial microvoids or cavities variations and lamellar structures evolutions of oriented β-PP cast films along different tensile directions was mainly investigated via In-situ small-angle X-ray (SAXS) and wide-angle X-ray diffraction (WAXD) measurements. The pore formation mechanism, initial cavities were directly originated from the lamellar separation and its specific positions were at the weak boundary between β lamellae and adjacent amorphous phase, was proposed. Although the pore formation mechanism of both different stretching directions was consistent, the separation process of β lamellae was greatly different during stretching. Lamellae on β-transcrystals (β-TCs) were preferred to be separated along machine direction, while twisted and inter-crosslinked β lamellae were more likely to separate along transverse direction. Both stretching directions mainly affected the stage of microvoids growth that could be promoted along transverse direction. Moreover, for the sample of stretching along transverse direction, microporous membranes with higher porosity and more homogeneous micropores distribution could be obtained through subsequent biaxial stretching. Therefore, the suitable stretching methods were optimized for β-TCs to prepare PP microporous membranes with excellent performance.

Intractable functional constipation (IFC) is the most severe form of constipation, but its etiology has long been unknown. We hypothesized that IFC is caused by refractory infection by a pathogenic bacterium. Here, we isolated from patients with IFC a Shigella species - peristaltic contraction-inhibiting bacterium (PIB) - that significantly inhibited peristaltic contraction of the colon by production of docosapentenoic acid (DPA). PIB colonized mice for at least 6 months. Oral administration of PIB was sufficient to induce constipation, which was reversed by PIB-specific phages. A mutated PIB with reduced DPA was incapable of inhibiting colonic function and inducing constipation, suggesting that DPA produced by PIB was the key mediator of the genesis of constipation. PIBs were detected in stools of 56% (38 of 68) of the IFC patients, but not in those of non-IFC or healthy individuals (0 of 180). DPA levels in stools were elevated in 44.12% (30 of 68) of the IFC patients but none of the healthy volunteers (0 of 97). Our results suggest that Shigella sp. PIB may be the critical causative pathogen for IFC, and detection of fecal PIB plus DPA may be a reliable method for IFC diagnosis and classification.

Poly(4-methyl-1-pentene) casting films with row-nucleated lamellar structure were extruded through a slit die followed by stretching using a chill roll. The influences of melt draw ratio, annealing temperature, annealing time and supplied strain level on the crystalline morphology and orientation of the poly(4-methyl-1-pentene) casting films were carefully investigated by means of scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectrometry and X-ray diffraction. It was found that the crystalline morphology and the degree of orientation were greatly influenced by the melt draw ratio. In addition, both the changes of crystallinity and orientation degree exhibited similar tendencies (firstly increasing and then decreasing) upon increasing the free annealing temperature and time. The use of an appropriate temperature and time meant that molecular chains of the amorphous region could rearrange into a crystal lattice and defects could be removed, while an excessive annealing temperature and time could lead to partial imperfect crystals melting and recrystallizing or even disorientation phenomena. In contrast to the free annealing method, it was surprisingly discovered that annealing under supplied strain was really helpful in improving the crystalline structure and orientation of casting films.

The soil macro-mechanical properties depend on soil microstructure. In order to build the quantitative relation between the macro porosity and pore microstructure, Zhejiang clay was taken as an example in the paper. The pore microstructure was observed by scanning electron microscope (SEM), and was quantitatively studied by Image Pro-Plus (IPP) software. The microcosmic indexes that describe the morphological feature and permutation characteristic were mainly measured. Especially, the pore grading curve was obtained to describe the permutation characteristic, and the nonuniformity coefficient of the pore grading curve was proposed, as well as the curvature coefficient. The regression analysis methods were used to build the quantitative relation. The results show that the structure and size of the clay pore are varied. The macro porosity is significantly related to the two microcosmic indexes of the roundness and the pore grading curve. Finally, the function relationship between macro porosity and pore microcosmic indexes was established.

In this study, alkylated graphene oxide (GO–ODA) was obtained successfully via electrostatic self-assembling of oppositely charged GO and ODA. Then, TPX/GO–ODA nanocomposites were obtained from the solution. All samples have the same crystal structure, Form I, as found by X-ray diffraction (XRD). It can be noted that poly(4-methyl-1-pentene) (TPX) has two types of lamellae at high crystallization temperatures, as found by differential scanning calorimetry (DSC). The higher the crystallization temperature, the slower crystallization occurs; however, the nanofiller GO–ODA has the great advantage of accelerating crystallization. At the same time, the added GO–ODA, as a nucleating agent, improves the appearance temperature of the Type II lamellae. Moreover, space for crystal growth is limited by the structure of GO–ODA. In rheological experiments, when the frequency was higher than a critical value, crystallization was no longer affected by the frequency. In this study, exploring such interplay between the crystallization behavior and rheology of crystallization could guide the choice of polymers in practical applications and processing.

Modified graphene oxide (GO) not only offers a wrinkled structure but may also transform the crystal structure, giving it a potential application in high performance polymer/filler composites. In this work, alkylated graphene oxide (GO–ODA) is obtained via mutual electrostatic interaction between the epoxide group of GO and the amine group of octadecylamine (ODA). Then nanocomposites are obtained via introducing different contents of GO–ODA to poly(4-methy-1-pentene) (PMP or TPX) using a solution approach. It is found that the obtained GO–ODA has no effect on the crystallinity of TPX. It is worth noting that GO–ODA changes the crystal structure. GO, as a kind of nanofiller, is used to change the crystal structure of polymer/filler composites for the first time, which is an important finding and obviously provides a good example to widen the application of GO.

The time domain direct simulation to the sound propagation has multiple advantages on adapting to complicated boundary conditions or applying on high performance computers, but it does not provide frequency information explicitly. However in the studies of ocean acoustics, underwater military applications and their numerical simulations, the frequency analysis of sound waves plays a much more significant role than the direct time domain results. For these reason we present a frequency analysis technique embedded to the direct finite volume method (FVM) simulation of the sound propagation using OpenFOAM. In this paper we also test the accuracy and efficiency of the embedded technique by solving the sound propagation in an ideal wedge-shaped wave guide. The results of the experiments validated the embedded technique and the improvements comparing with the post-processing frequency analysis.