Osteopromotion with a plasmatransglutaminase on a β-TCP ceramic

We investigated the osteopromotive properties of plasmatransglutaminase (F XIII), bone marrow and venous blood on a resorbable β-tricalcium phosphate (β-TCP) scaffold. A baseline binding and release study of F XIII from the scaffold showed a continuous release of 18% of the total dose after 48 h. The main study consisted of 18 adult sheep with cylindrical defects in both tibiae. The defects were filled with a β-TCP cylinder impregnated either with bone marrow, venous blood, F XIII or sheep were treated with 1250 IU F XIII intravenously over 14 days (n = 4 in each group). The defects were left open in two sheep. QCT and histology was performed after 6 and 12 weeks. The best bone ingrowth was seen after 6 weeks in the bone marrow group and after 12 weeks in the local F XIII group. The highest ingrowth on the inside of the cylinder proving the osteopromoting potential of F XIII was found in the local F XIII group. In our opinion F XIII is a good and readily available osteopromoting agent which can be used with β-TCP in cases of bone deficit to promote bone regeneration.     

Vortex Dynamics in a Superconducting Film with a Kagome and?a?Honeycomb Pinning Landscape

The vortex dynamics in a superconducting thin Al film with a periodic Honeycomb or Kagome array of antidots has been investigated by electrical transport measurements. The large values of the superconducting coherence length and penetration depth of the Al films guarantee a maximum of one flux quantum trapped per pinning site. This allows us to directly compare the experimental results with previous theoretical investigations based on molecular dynamics simulations. For the Kagome lattice, two submatching features not anticipated theoretically at H/H ₁=1/3 and 2/3, where H ₁ is the field at which the number of vortices coincides with the number of pinning sites, are observed. Possible corresponding stable vortex patterns are suggested. For the Honeycomb pinning landscape, the commensurability effects are in agreement with the theoretical expectations. A preliminary analysis of the vortex mobility in this lattice shows the presence of a weak vortex guidance.     

Research on a Diagnosis Method Based on a Correlation Integral

For the first fime,the diagnosis idea based on a correlation integral is proposed,which re-gards the correlation integral as a feature set.The correlation dimension is contained in the double-log curve of the correlation integral to scale,so extracting features directly from the correlation integral can avoid the bottleneck problem of determining the range of non-scale length.Several features extracted from the correlation integral are better than the single feature of the correlation dimension when descri-bing the signal.It is obvious that this method utilizes more information of the signal than does the cor-relation dimension.The diagnosis examples verify that this method is more accurate and more effective.     

Grey Problems of a Mechanical Transmission System in a Reliability Study

1 IntroductionReiability acted as an imPortant index that was aPPied to weigh the quality of a mechanicalProdct, and it has brOadiy been thought. Currently, an imPortant taSk of machine scope is to aimat the market's needs inside and outside the country and adust the strUcture of ProductS tooccuPy the Inarket in Products of high qualiy It is a key aspeCt of all tO sahsfy reiability needsof users in the new Products explored. The machine transAnssion system is an imPortantcomPosition of…     

Minimum cement content requirements: a must or a myth?

The objective of the present work was to systematically investigate the issue of minimum cement content requirements, by studying the behavior of concretes with different water to cement ratios ( w/c) in the range of 0.45–0.70, in which the cement content was varied, by controlling the water content, using water reducing admixtures. The effect of cement content was noted to be different for various properties: strength was a function of w/c and independent of cement content; total water absorption was proportional to the paste content at a given w/c, while capillary absorption and chloride ingress reduced with a reduction in the cement content for a given w/c, to an extent which was much greater than the reduction in total porosity. Carbonation and shrinkage were largely independent of cement content for a given w/c. The trends observed were discussed in terms of the effect of paste content on concrete properties, and the influence of admixtures on the paste properties. These results suggest that requirements for minimum cement content in standards should be revisited.     

叶绿素a测定探讨

针对环境监测中叶绿素a测定的重要性及其意义,探讨了叶绿素a的分光光度法及荧光法的不同,对不同厂家、不同型号荧光法仪器测定叶绿素a进行了比较,并且指出在实际工作中,荧光法测定仪应经常与实验室测量方法进行比对。     

Developing a product–service system through a productisation strategy: a case from the 3PL industry

A Product–Service System (PSS) is created by combing a tangible product and an intangible service into one integrated offering. Thus, a PSS can be achieved by a production company adding intangible services to a product using a servitisation strategy or by a service company adding a tangible product to a service by means of a productisation strategy. The focus of this paper is on the latter. Our work demonstrates a significant gap in the literature in this area. To address this, we adapt an existing PSS conceptual framework as a means to identify the driving and restraining forces considered by a service company as it explored the possibility of pursuing a PSS productisation strategy. The conceptual framework is applied in an exploratory case study with a 3PL service provider. Application of the framework reveals new driving and restraining forces not previously discussed in the literature. Furthermore, it allows a preliminary quantification of the driving and restraining forces using a force field analysis approach. Our work contributes towards the expansion of the empirical knowledge base in the area of PSS.     

薄膜晶体管a－Si：H／a－SiN_x界面研究

对比ａ－Ｓｉ：Ｈ／ａ－ＳｉＮｘ界面附近ａ－Ｓｉ：Ｈ和体材料ａ－Ｓｉ：Ｈ的光致发光谱（ＰＬ）发现：随着ＳｉＮｘ中ｘ的增大，ＰＬ峰值向低能方向移动，相对发光强度减小。这是因为由于氮含量的增加，界面晶格不匹配加剧，导致悬挂键密度增多和深能级隙态密度增加。该观点得到Ｃ－Ｖ测试结果的证实。     

Dynamic emission of dislocations from a crack tip — a computer simulation

The behavior of dynamic emission of dislocations from the tip of a stationary crack under mode II or mode III loading is examined. A critical stress intensity factor, K _D is assumed for dislocation emission. After emission, the dislocation moves with a velocity which varies with the effective shear stress to the third power. The effective shear stress is due to the applied stress , modified by the presence of the crack and all other dislocations minus the lattice friction stress, ^F. The effects of K _D, , and ^F on the rate of emission, the plastic zone strain rate, the plastic zone size, the dislocation distribution, and the dislocation-free zone are reported.

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Résumé On a examiné le comportement d'une émission dynamique de dislocations depuis l'extrémité d'une fissure stationnaire. On suppose que l'émission de dislocations est caractérisée par un facteur critique d'intensité de constrainte K _D. Après son émission, la dislocation se meut avec une vitesse qui varie avec le cube de la constrainte effective de cisaillement. Celle-ci résulte de la constrainte appliquée , modifiée par la présence de la fissure et de toutes les autres dislocations, et sous déduction de la contrainte de friction du réseau, ^F.On étudie les effects de K _D, et ^F sur la vitesse d'émission des dislocations, la vitesse de déformation plastique, la taille de la zone plastique, la distribution des dislocations, et sur la zone qui en est dépourvue.

     

Optimization of a Flexible Rotor-Sliding Bearing System With a Squeeze Film Damper

A dynamic model of a flexible rotor-sliding bearing system (FRSBS) with a squeeze film damper (SFD) is established. Considered in the model are oil film inertia force, damping force,clearance excitation force, interference force of different frequencies and static load, as opposed to previous research. On the basis of this model, the optimal design of the system is deeply studied. Simulation shows that the system optimization design can effectively improve the system stability.     

R152a／R134a的汽液相平衡分析

本文用ＭＨ８１方程计算了Ｒ１５２ａ／Ｒ１３４ａ在２４３．１５Ｋ￣３１３．１５Ｋ范围内的等温汽液相平衡。计算表明：Ｒ１５２ａ／Ｒ１３４ａ是共沸混合物，有一最低共沸点。     

Expert Diagnosing system for a Rotation Mechanism Based on a Neural Network

By combining the artificial neural network with the rule reasoning expert system,an expert diagnosing system for a rotation mechanism was established.This expert system takes advantage of both a neural network and a rule reasoning expert system;it can also make use of all kinds of knowledge in the repository to diagnose the fault with the positive and negative mixing reasoning mode.The binary system was adopted to denote all kinds of fault in a rotation mechanism.The neural networks were trained with a random parallel algorithm (Alopex).The expert system overcomes the self-learning difficulty of the rule reasoning expert system and the shortcoming of poor system control of the neural network.The expert system developed in this paper has power ful diagnosing ability.     

Enhanced π-π interactions between a C60 fullerene and a buckle bend on a double-walled carbon nanotube

In situ low-voltage aberration corrected transmission electron microscopy (TEM) observations of the dynamic entrapment of a C₆₀ molecule in the saddle of a bent double-walled carbon nanotube is presented. The fullerene interaction is non-covalent, suggesting that enhanced π-π interactions (van der Waals forces) are responsible. Classical molecular dynamics calculations confirm that the increased interaction area associated with a buckle is sufficient to trap a fullerene. Moreover, they show hopping behavior in agreement with our experimental observations. Our findings further our understanding of carbon nanostructure interactions, which are important in the rapidly developing field of low-voltage aberration corrected TEM and nano-carbon device fabrication.      

Behavior of a single nitrogen molecule on the pentagon at a carbon nanotube tip: a first-principles study

Density functional theory (DFT) is used to investigate the adsorption properties of nitrogen on the pentagon at the tip of a capped (5, 5) single-walled carbon nanotube. The adsorption of N(2) outside the carbon nanotube with a parallel orientation with respect to the plane of the pentagon is found to be the most stable state of adsorption. Its binding energy of -0.318?eV is very small, with a large C-N equilibrium distance of 2.94??. We have also investigated the number and the position of adsorption sites in the pentagon for the parallel configuration. This knowledge can lead to the precise control of adsorption states, and consequently may bring about a novel multistate monomolecular device. We find two stable configurations of the molecule that have only a small difference in energy, while the other configurations are energetically unfavorable. Our results support previous experimental predictions that the nitrogen molecule transits between two states with a small current pulse. The predicted position sites for the transient states are in reasonable agreement with experimental observations.     

Interaction between a vortex and an edge dislocation nested in a cos‐Gaussian beam passing through a tilted lens

The interaction between a vortex and an edge dislocation nested in a cos‐Gaussian beam passing through a tilted lens was studied analytically and numerically. It is shown that in the presence of the tilted lens, by varying the cos‐part parameter of the beam, the slope of the edge dislocation, or the tilt coefficient of the lens, the topological charge is conserved for the case of the off‐axis edge dislocation, while charge conservation does not hold true for the case of an on‐axis edge dislocation, irrespective of the on‐axis or off‐axis vortex. The relation between the transverse positions (x, y) of vortices and the tilt coefficient is linear, and is interpreted.     

Failure Analysis of a Cam–Follower System Affected by a Crack

The dynamic behavior of a cam–follower system can be altered by several errors. Errors occurring during working operation are induced by excessive load and inappropriate operating condition. In this article, an investigation on the dynamic behavior of a cam–follower system caused by the cam crack failure was carried out. The crack causes a stiffness reduction of the system. An analytical formulation of this time varying stiffness was derived. A quantification of the influence of this crack on the stiffness is carried out. The response showed amplitude modulation resulting from the presence of the crack.     

Critical Outflow of a Vapor–Liquid Flow through a Grain Layer

High Temperature - Based on previous experimental studies, we carried out a numerical simulation of the process of the critical outflow of a vapor–liquid flow in cylindrical channels filled...     

Thermal Conductivity of a Three‐Dimensional Body with a Rough Inclusion

Thermal conductivity of a threedimensional body with a rough inclusion is studied. The problem is reduced to the problem of conjugation of harmonic functions and its exact solution is constructed. Distributions of temperature and heatflux density near distinctions of the interface between media are found. Results are illustrated by a numerical example.