The impact of a paper’s new combinations and new components on its citation

Scientometrics - A paper’s novelty enhances its impact and citation. In this paper, we examine two dimensions of a paper’s novelty: new combinations and new components. We define new...     

A new active error compensatory method of machinery accuracy†

A new active error compensatory method for on-line cutting control has been developed for reduction of the form errors in machining. This approach is a combination of in-process gauging and model active compensatory control. In this approach, there are two features of substantial importance: stochastic modelling and optimum forecasting. Through stochastic modelling, the cutting tool error motions can be represented by a simple model without the necessity of obtaining the complex cause-and-effect relationships between various errors and error sources, and more importantly, it is possible to account for both repeatable and non-repeatable parts of errors. Optimum forecasting is an important prerequisite for a rational control strategy, considering the inevitable time delay associate with sensing, computation and actuation. The proposed control method was implemented for the control of cylindricity in boring operations. Through the controller simulation based on experimental measurements, the improvement in cylindricity accuracy confirms the effectiveness of this proposed strategy     

Effects of marketing–manufacturing integration across stages of new product development on performance

Our understanding on the benefits of marketing–manufacturing integration (MMI) across various stages of new product development (NPD) process is limited. Based on the resource-based view of a firm, this study empirically examines the direct and interactive effects of MMI in four stages of NPD process on three dimensions of new product performance. Survey data from 214 completed NPD projects in Chinese manufacturing firms are employed to test the developed hypotheses using hierarchical regression. The results indicate that greater MMI in each stage is, respectively, associated with faster NPD speed. Stronger MMI in business/market opportunity analysis (BMA), technical development (TD) and product testing (PT) stage is, respectively, associated with higher NPD cost efficiency. Higher MMI in BMA and PT stage is, respectively, associated with better market performance. In addition, the interactions of MMI in BMA and TD stages and MMI in PT and product commercialization (PC) stages have positive effects on NPD speed and NPD cost efficiency, while the interaction of MMI in BMA and PC stages has negative effects on NPD speed and NPD cost efficiency. The interaction of MMI in BMA, TD and PC stages is positively related to market performance; surprisingly, the interactions of MMI in BMA, TD and PT stages and MMI in BMA, PT and PC stages are negatively related to market performance. These findings have important implications for research and practice in both the cross-functional integration and NPD areas.     

Compressive properties of a new metal–polymer hybrid material

Compressive properties of a new hybrid material, fabricated through filling of an aluminum foam with a thermoplastic polymer, are investigated. Static (0.01 s⁻¹) and dynamic (100 s⁻¹) compression testing has been carried out to study the behavior of the hybrid material in comparison with its parent foam and polymer materials. Considering the behavior of metal foams, the point on a compressive stress–strain curve corresponding to the minimum cushion factor is defined as the “densification” point. The analysis of the stress–strain curves provides insight into the load carrying and energy absorption characteristics of the hybrid material. At both strain rates, the hybrid is found to carry higher stresses and absorb more energy at “densification” than the foam or polymer.     

The Anthropocene: a new epoch of geological time?

Anthropogenic changes to the Earth's climate, land, oceans and biosphere are now so great and so rapid that the concept of a new geological epoch defined by the action of humans, the Anthropocene, is widely and seriously debated. Questions of the scale, magnitude and significance of this environmental change, particularly in the context of the Earth's geological history, provide the basis for this Theme Issue. The Anthropocene, on current evidence, seems to show global change consistent with the suggestion that an epoch-scale boundary has been crossed within the last two centuries.     

The revolutionary creation of new advanced materials—carbon nanotube composites

Since the discovery of carbon nanotubes at the beginning of the last decade, extensive research related to the nanotubes in the fields of chemistry, physics, materials science and engineering, and electrical and electronic engineering has been found increasingly. The nanotubes, having an extreme small physical size (diameter ≈1 nm) and many unique mechanical and electrical properties depending on its hexagonal lattice arrangement and chiral vector have been appreciated as ideal fibres for nanocomposite structures. It has been reported that the nanotubes own a remarkable mechanical properties with theoretical Young's modulus and tensile strength as high as 1 TPa and 200 GPa, respectively. Since the nanotubes are highly chemical insert and able to sustain a high strain (10–30%) without breakage, it could be foreseen that nanotube-related structures could be designed for nanoinstrument to create ultra-small electronic circuits and used as strong, light and high toughness fibres for nanocomposite structures. In this paper, recent researches and applications on carbon nanotubes and nanotube composites are reviewed. The interfacial bonding properties, mechanical performance and reliability of nanotube/polymer composites will be discussed.     

A new analytical model of normal penetration of projectiles into the light-weight ceramic–metal targets

In this paper based on Zaera and Sanchez-Galvez [4] model, a new analytical model has been presented for penetration of deformable projectiles into ceramic–metal targets. By considering erosion and flattening of projectile tip, the one-dimensional equation of motion has been established. The momentum equation has been employed to describe the fragmented ceramic conoid. Considering work hardening material behavior, energy conservation equation has also been used for modeling the deformation of back-up metallic plate. Semi-angle of ceramic conoid is modified based on Wilson and Hetherington [8] experiments. The ballistic limit and residual velocity of projectile predicted by new analytical model have a good agreement with the experimental results.     

Thermal properties of new copper matrix composite reinforced by β-eucryptite particulates

Abstract

Cu matrix composites with different volume fraction of Ag coated β-eucryptite particulates were successfully fabricated by powder metallurgy method. Low thermal expansion coefficient and high thermal conductivity were attained simultaneously in the new Cu matrix composite. The microstructure of β-eucryptite–Cu composite was studied by scanning electron microscope and transmission electron microscope. The thermophysical properties of β-eucryptite–Cu composites were analysed by means of thermal dilatometer and diathermometer. No interfacial reaction products between β-eucryptite and Cu were found in the composite. The research indicates that β-eucryptite, which has a negative coefficient of thermal expansion, is a useful reinforcement, which can remarkably reduce the coefficient of thermal expansion of Cu matrix composite. The effects of volume fraction of β-eucryptite particulates on the thermal expansion coefficient and thermal conductivity of the composite were investigated.     

Authors’ sources of information: a new dimension in information scattering

The purpose of this study is to determine the usage patterns of core journals by scholars, and to address the differences among various academic disciplines. Thus, the references of 11,230 corresponding authors for the past 35?years from the world??s top five highly cited universities and institutions were analyzed. To build robust models of information scattering, we need a deeper understanding of this phenomenon. The results show that core journals usage is a social phenomenon, in exactly the same way as Bradford??s law, Zipf??s law and Lotka??s law. The analysis of author references shows that if core scientific journals are arranged in order of decreasing productivity, then they could be divided into a small group of highly cited periodicals and a large group of minimally cited ones. Scholars may do browsing and similar information-seeking activities to form their core journals, and the findings may support Bates??s hypothesis that Bradford??s core zone is best searched by browsing. Bradford??s law and relevant research may consequently help to solve many of the practical problems that practitioners of the profession face, particularly in collection development in libraries, and help users to gather highly scattered information.     

Preparation and characterization of NASICON with a new sol–gel process

NASICON powders with the composition of Na₃Zr₂Si₂PO₁₂ were synthesized by using a sol–gel method. In the course of synthesis, a different material of oxalic acid was used to modify the synthesis process. The resulted precursors were sintered at the temperatures ranging from 700 to 1000 °C to get NASIOCN powders. X-ray diffractometer (XRD), IR and Raman spectra were employed to characterize the sintered products. Also, the ionic conductivity measurement conducted in the temperatures of 150–300 °C was used to evaluate their electronic properties. Furthermore, CO₂ sensor was prepared based on the pressed NASICON bulk. The relationship between its EMF response and the target gas concentration was checked. The experiment results showed that the NASICON material sintered at 900 °C possessed better properties in comparison with those sintered at other temperatures.     

Influence of chromium on microstructure and etching behaviour of new Ni–Fe–Al based alloy

In the present study, the influence of chromium on the microstructure and etching behaviour of the polycrystalline alloy Ni–13Fe–8Al–4Ti (at-%) has been examined. The alloy was recently designed for nanomembrane fabrication, but although it showed the necessary γ/γ′ microstructure with cubic, well aligned γ′ precipitates, it proved to be unsuitable for nanomembrane fabrication as the γ matrix was dissolved during chemical etching. To obtain the passivation of the γ matrix, chromium has been added in further modifications containing 1, 2, 3 and 4 at-% chromium. Moreover, the influence of heat treatment and the different cooling rates of heat treatment in air/vacuum have been investigated. For chemical phase extraction, the application of the chemical etchants MoO₃ acid and ‘G’ etchant has been examined, the formability was characterised by Vickers hardness testing. The main purpose of the present study, namely the passivation of the γ matrix, could be achieved by the addition of 4 at-% chromium and etching with ‘G’ etchant.     

Structural characterizations and optical properties of new Li–Sr–Nb-phosphate glasses

A new Li₂O–SrO–Nb₂O₅–P₂O₅ glass system was prepared by a high-temperature alumina crucible, and structural characterization and optical properties were investigated. Proper content of Li₂O and Nb₂O₅ was employed to replace partial SrO and P₂O₅ to improve the optical properties. It was observed that the enhancement of the refractive index from 1.75 to 1.85 is mainly due to the Nb₂O₅ content. An addition of Li₂O significantly increases the optical transmittance; optical transparency can be enhanced from 60% to higher than 85% in the UV–visible region with addition of 20–40 mol% Li₂O species. However, optical transmittance is monotonically decreased from about 90% to 80% under 10–30 mol% Nb₂O₅ addition. The 40P₂O₅–20Nb₂O₅–20SrO–20Li₂O glasses demonstrate the optimum refractive index (n > 1.75) and high optical transparency (>80%) in the UV–visible region.     

Optical solitons in a new type of coupled nonlinear Schrödinger equations

Abstract

We consider a new type of integrable coupled nonlinear Schrödinger (CNLS) equations proposed by Park and Shin [1999, Phys. Rev. E, 59, 2372]. Using the Ablowitz-Kaup-Newell-Segur method, we construct the Lax pair for simultaneous propagation of four fields in the new type of CNLS equations. The explicit form of soliton solutions are derived using the Hirota bilinear method.     

Microwave dielectric properties of new SrLa4−xNdxTi5O17 ceramics

New microwave dielectric ceramics in the SrLa_4?xNd_xTi₅O₁₇ (0 ≤ x ≤ 4) composition series were prepared through a solid state mixed oxide route. All the compositions formed highly dense (～95%) single phase ceramics upon sintering at 1500–1580 °C. The molar volume and theoretical density decreased due to the substitution of small (1.27 Å) Nd ions for large (1.36 Å) La ions. This decrease was associated with a decrease in the dielectric constant (?_r), temperature coefficient of resonant frequency (τ_f) and quality factor (Q_uf_o). An analysis of properties achieved in the present study indicated that ceramics exhibiting nearly zero τ_f corresponding to ?_r ～ 54 could be fabricated in the SrLa_4?xNd_xTi₅O₁₇ composition series at x ～ 1.6; however, further work is required to improve Q_uf_o (～6000 GHz) for possible practical applications.     

Synthesis of partial stabilized cement–gypsum as new dental retrograde filling material

The study describes the sol–gel synthesis of a new dental retrograde filling material partial stabilized cement (PSC)–gypsum by adding different weight percentage of gypsum (25% PSC + 75% gypsum, 50% PSC + 50% gypsum and 75% PSC + 25% gypsum) to the PSC. The crystalline phase and hydration products of PSC–gypsum were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The handling properties such as setting time, viscosity, tensile strength, porosity and pH, were also studied. The XRD and microstructure analysis demonstrated the formation of hydroxyapatite and removal of calcium dihydrate during its immersion in simulated body fluid (SBF) on day 10 for 75% PSC + 25% gypsum. The developed PSC–gypsum not only improved the setting time but also greatly reduced the viscosity, which is very essential for endodontic surgery. The cytotoxic and cell proliferation studies indicated that the synthesized material is highly biocompatible. The increased alkaline pH of the PSC–gypsum also had a remarkable antibacterial activity.     

Nanostructured SiC ceramics prepared by a new process—Crystallization of interfacial glass

Large bulk and fully dense SiC based nanoceramics with average grain size of 50 nm and 20–30 wt.% nanometer sized α-Sialon, Al_xSi_{3 − x}O₆ and α-SiO₂ interfacial phases were prepared by a new process, crystallization of interfacial glass, using LMAS glass-coated SiC powder as starting material. The process involves two major steps: densification by hot pressing, and crystallization of interfacial glass by annealing treatment. The densification was controlled by interfacial glass content, hot pressing temperature, and hot pressing pressure; density 99.8% theoretical being reached for SiC/30 wt. % glass nanoceramics hot-pressed at 1520 °C and 22 MPa for 30 min. The crystallization was complete and nearly all the interfacial glass was transformed into nanocrystalline phases after 800 °C and 900 °C for 5 h annealing treatments. Plastic flow and rearrangement of particles and interfacial glass infiltration are densification mechanisms. A large number of nanometer sized SiC powder particles serve as nucleating agents, e.g. hetero-nucleation, and are responsible for interfacial glass crystallization. A characteristic of the present process is that there is no SiC grain growth during densification and interfacial glass crystallization.