Narrow Results

Cellulose with at least one of its dimensions less than or equal to 100 nm is termed as nanocellulose. It is a unique and promising natural material extracted from native cellulose and produced by certain microbial cells and cell-free systems. Nanocellulose has received immense consideration in last couple of decades owing to its abundance, renewability, remarkable physical properties, special surface chemistry, and excellent biological features (biocompatibility, biodegradability, and non-toxicity). Taking advantage of the structure and properties of nanocellulose, the current science of biomaterials aims at developing new and formerly non-existing materials with novel and multifunctional properties, in an attempt to meet current requirements in different fields such as biomedicine, the environment, energy, pharmaceutics, agriculture, food, etc. This chapter provides an overview of different synthesis methods of nanocellulose: mechanical approaches by applying high-pressure, grinding, crushing, sonication, and milling; chemical synthesis involving alkaline, acidic, oxidation, and enzymatic treatment; as well as by using bacteria and cell-free systems. It further discusses different morphological forms of nanocellulose including cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs), bacterial nanocellulose (BNC), and cellulose produced by cell-free systems, in terms of their features such as chemical structure, macrostructural morphology, physico-mechanical properties, thermal and biological properties, rheology, optical behavior, and their interrelationships and applications.

During the INT-18-3 workshop, we presented an analysis of unpolarized Drell-Yan pair production in pion-nucleus scattering with a particular focus into the pion Transverse Momentum Distributions in view of the future Electron Ion Collider. The transverse distributions of the pion calculated in a Nambu–Jona-Lasinio framework, with Pauli-Villars regularization, were used. The pion Transverse Momentum Distributions evolved up to next-to-leading logarithmic accuracy is then tested against the transverse momentum spectrum of dilepton pairs up to a transverse momentum of 2 GeV. We found a fair agreement with available pion-nucleus data. This contribution joins common efforts from the TMD and the pion structure communities for the Electron Ion Collider.

With the rapid development of computer technology and Internet technology, the financial management of modern enterprises and companies is gradually developing in the direction of intelligent management. As a result, the traditional financial management model can no longer adapt to the current financial information management. This paper takes the application of J2EE technology in finance as the research object, analyzes the technical knowledge (including J2EE technology, J2EE structure and database, and Java database connection) used in J2EE in financial application in detail, and analyzes the application of J2EE technology in finance. The system design in the application and the main advantages are analyzed in detail. This technology not only saves a lot of manpower, time, and cost, but also plays an extremely important role in enhancing the competitiveness of enterprises, improving the level of enterprise management, and promoting financial management techniques and methods, theoretical innovation, and concept renewal.

Under the action of the geodynamics and a variety of geostresses, the global crust experienced eight structural styles in different geological periods. This chapter discusses tectonic deformation patterns of the crust, including the EW tectonic pattern, NS tectonic pattern, NE tectonic pattern, NNE tectonic pattern, NW tectonic pattern, epsilon tectonic pattern, S-shaped or reverse-S-shaped tectonic pattern, and twisted structure pattern. Finally, the evolutionary characteristics of tectonic patterns are introduced.

The polymer electrolyte which is firstly made by micro-wave inter-connect method and based on blended PVDF/PMMA and its conductivity is exceeding 10^-3S · cm at room temperature. The result of polymer electrolytes that is dispersed by sub-micron SiO₂ indicate that the mechanic intension is improved and the conductivity also improved. There is a new state with the test of the SEM and XRD and the non-crystal state of the polymer electrolytes have been improved after system adulteration which are favorable for the migration of Li⁺ and this is the expiation of the improvement of the conductivity of the polymer electrolytes.

We first discuss the concept of structure to differentiate between structural and systemic properties. Within this framework we discuss processes of establishing structures, such as phase transitions, organization and self-organization. The paper introduces concepts and insights about the process of Acquiring Properties (AP) in systems, not just possessing properties. The last point relates to establishing, sustaining and managing new properties in emergent and organizational systems. In the Appendix we briefly discuss this approach for the concept of mind possessed by living matter.

A serious of hydrotalcite-like compounds such as Mg-Al-LDHs, Mg-Al-Cu-LDHs, Mg-Al-Fe-LDHs and Mg-Al-Ni-LDHs were prepared by coprecipitation. The structures were characterized by X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). TGA and DTA were used to characterize their thermal stabilities. Results from XRD and FT-IR showed that the prepared hydrotalcites had a typical layered structures and the layer distances of hydrotalcites with Cu²⁺ and Ni²⁺ were increased and the weak coordination bonds existed in Mg-Al-Ni-LDH and Mg-Al-Fe-LDH. The results of TGA and DTA proved Mg-Al-Cu-LDH has a better thermal stability and there are decomposition reactions happened in Mg-Al-Ni-LDH and Mg-Al-Fe-LDH under 100℃.

There has been growing interest in exploring the topology structure of networks, especially multi-layer networks. However, with the rapid development of social media and technology, it has shown that modeling such multi-dimensional systems leads to a huge complexity in dealing with them. A fundamental open question is then how many layers are really needed to represent the systems, which has also attracted many scientists from various fields. Here we adopt the Von Neumann entropy theory to measure the information contained in network and through defining a distance based on it, we are able to reduce the number of network layers, as well as retaining the main characteristics of the whole system. Besides, in order to validate the method, we have built a benchmark networks which consists of three different kinds of networks to realize the aggregation process. Surprisingly, the method can not only reduce the redundancy but also distinguish the structure diversity, since it first merged the same kind of networks. Our results provide a better understanding of entropy theory and could also lead to interesting future research about how to reduce the structural reducibility of complex systems.

The equilibrium and stability of anisotropic strange stars is analyzed. For this purpose, we consider that the anisotropy factor follows the equation σ = k p_r(1 − e^−λ); being k a constant, p_r the radial pressure and e^−λ a metric function. We found that the anisotropy yields considerable changes in some macroscopic properties of strange stars. Despite this, such as is determined in isotropic strange stars, the onset of the instability is marked by the maximum mass point. This indicates that stable and unstable equilibrium configurations can be recognize through the conditions dM/d_ρc > 0 and dM/d_ρc < 0, respectively.

In this investigation, three routes, namely, uniaxial pressing, slip casting and H₂O₂ foaming, were used to fabricate porous hydroxyapatite (HA). Processing parameters in each route were studied, pore characteristics in sintered bodies assessed, and mechanical properties of porous HA evaluated. Scanning electron microscopy, gas pycnometry and mercury intrusion porosimetry were used to assess pore characteristics in terms of porosity, pore size and pore shape. Mechanical properties of porous HA were evaluated using a biaxial testing fixture. The 2³ factorial design method was used to determine the influence of pore characteristics on mechanical properties. It was shown that pore characteristics were dependent on the manufacturing route, processing parameters, porosifier and the amount of porosifier. In the uniaxial pressing and slip casting routes, porosity, pore size and pore shape could be controlled using different porosifiers. Porosifiers were able to pass their geometrical characteristics to the pores they formed. Although H₂O₂ foaming was the simplest route and large pores could be formed through this route, pore characteristics were not easily controllable. It was found that porosity, pore size and pore shape all had effects on mechanical properties of sintered products. The interaction of pore size and pore shape affected mechanical properties in that it caused mechanical properties to vary differently according to pore shape (or pore size) when pore size (or pore shape) was at different levels.

Hydroxyapatite (HA) reinforced high density polyethylene (HDPE) composites (HAPEX™) have been developed as a bone analogue for medical applications. Conventionally processed HAPEX^TM containing 40vol% of HA possesses a stiffness approaching the lower bound of human cortical bone and is now used in minor- or non- load bearing areas in patients. In order to improve the mechanical properties of HAPEX™ and hence extend its application into major load bearing areas, HAPEX™ with various amounts of HA was hydrostatically extruded at different extrusion ratios. The extruded rods were subsequently tested under tension or bending. Their structure as well as fracture surfaces were examined under an SEM. The molecular mass of the HDPE matrix was analyzed at each processing stage. DSC thermograms were also obtained to study the effects of hydrostatic extrusion. It was found that the uniform distribution of HA in the HDPE matrix achieved by compounding was not altered by hydrostatic extrusion, but the average molecular weight of HDPE was reduced. DSC results indicated polymer chain alignment along the extrusion direction. Mechanical properties of HDPE and HAPEX™ were substantially increased by hydrostatic extrusion. It was evident that the higher the extrusion ratio, the stronger and the stiffer the HAPEX™ rod. Hydrostatically extruded HAPEX™ containing 40vol% of HA possessed a Young’s modulus of 11.4GPa and fracture strength of 91.2MPa, which are within the bounds for mechanical properties of human cortical bone. This clearly shows the potential of HAPEX™ for major load bearing applications.

A variety of bioactive particle filled polymers have been developed for tissue replacement since the early 1980s. In this investigation, hydroxyapatite (HA) reinforced polysulfone (PSU) composites were produced and evaluated for potential medical applications. Composites containing up to 15vol% of HA were studied at the preliminary stage. The HA/PSU composites were made through a standardised procedure by incorporating a commercially available HA powder into a polysulfone resin of medium viscosity that is suitable for injection moulding. Compounded materials and injection moulded parts were assessed using a variety of techniques. It was found that HA particles were well dispersed in the PSU matrix after the compounding process. Defect-free composite samples could be obtained by injection moulding. Thermogravimetric analysis (TGA) verified volume percentages of HA in the composites. Differential scanning calorimetry (DSC) results indicated that the glass transition temperature (Tg) of the polymer matrix was not affected by the incorporation of HA. It was shown through dynamic mechanical analysis (DMA) that the storage modulus of the composite was increased with an increase in HA content below ~185°C which is Tg of the polymer, while tan δ was maintain at nearly the same level for all composites. It was established that water uptake reached an equilibrium after 7 days’ immersion in distilled water for all composites and unfilled PSU. It was found that after 7 days’ immersion in distilled water, the storage modulus of HA/PSU composite was decreased less than that of unfilled PSU.

Bioceramic composites were synthesized by sintering the powders of hydroxyapatite (HAp) mixed directly with additive of 5.0wt.%SiO₂ at different temperatures ranging from 800°C to 1200°C. X-ray diffraction analysis indicated that the phase transformation from HAp to tricalcium phosphate (TCP) began to take place as the sintering temperature is as high as 900°C, and the content of TCP phase increased notably with increasing temperature. Microstructural observations demonstrated that a distinctive microstructure featuring crystalline clusters with different sizes surrounded by glassy matrix formed in HAp-5.0wt.%SO₂ bio-composites, as the sintering temperature reached 1100°C. Soaking experiments in a stimulated body fluid revealed that the bio-composites showed a faster bone-like apatite layer growth, namely an enhanced in vitro bioactivity, as the sintering temperature increased, since the increase in sintering temperature promoted the phase transformation from HAp to TCP, which exhibits a higher solubility than HAp.

Antimicrobial peptides have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum, ranging from prokaryotes to humans. These molecules are small, relatively compact compounds, which are structurally and functionally rather diverse. This consideration is focussed on the structural and functional properties of the natural antimicrobial oligopeptides that are ribisomally synthesised without extensive posttranslational modifications. They are cationic molecules as the molecules are usually rich in lysine, and arginine. They are also amphipathic, containing hydrophobic and hydrophilic region. Natural antimicrobial oligopeptides have a broad spectrum of antimicrobial activity. They serve as an ancient defence mechanism against pathogenic microorganisms that easily come into contact with the host through the environment. These molecules are considered as part of the innate immune system of all species. Lastly, the review discusses the potential applications in health care products.

Structural homogeneity of type IV silica glass is an important parameter and decides its usability. To characterize this parameter easily and quickly is very important. This paper discussed ways to characterize structural homogeneity of type IV silica glass. Current optical homogeneity test by interferometer, fictive temperature and stress birefringence test were compared at first. Then a new optical homogeneity test based on birefringence and image processing was present and can characterize structural homogeneity of type IV silica glass effectively and easily with low costs.

Graphene as a new carbon material allotropism body has many unique properties. The material structure of graphene is a two-dimensional crystal structure with carbon atom superposition in monolayer mode. This special structures exhibit many unique physical and chemical properties, etc. This paper introduced the special physical and chemical properties of graphene, and reviewed the research progress and applications of graphene in the high-tech fields.

In this paper, Y-shaped straw chopper blade (Y-SCB), which is a critical part of the collecting mechanism of stalk baler, is designed. To solve the problem of easy to wear and break, the structure of Y-SCB is optimized and the structure parameter of the Y-SCB as well as the arrangement on straw chopper-axis is determined. The natural frequency of collecting component is analyzed by ANSYS Workbench, together with strained condition as well as structure strength. The results show that the maximum stress location is identical to the actual damage location. This research has certain guiding significance on the design, manufacture and maintenance of collecting mechanism of stalk baler.