用FPGA实现高效分组处理

最近,我参加了斯坦福大学举办的一个非常有吸引力的Clean Slate因特网技术研讨会.研讨会的主题是重新创建因特网基础设施,以解决现有因特网的一些缺点,同时可以支持新的应用和服务.     

Silicon photodiode as a detector of exposure rate

The paper describes the utilization of a silicon photodiode as a detector of exposure dose rate. Theoretical considerations deal with the magnitude of the photocurrent as a function of minority carrier diffusion length and silicon thickness. Experimental results compare the sensitivity and radiation damage of photodiodes manufactured from various silicon materials. The photodiode energy dependence for photons in the range 7.6 keV to 1.25 MeV is also presented.     

Hybrid modelling of yeast production processes – combination of a priori knowledge on different levels of sophistication

Process models are used to formulate knowledge about process behaviour. They are applied, e.g., to predict the process' future behaviour and for state estimation when reliable on-line measuring techniques to monitor the key variables of the process are not available. There are different sources of information available for modelling, which provide process knowledge in different representations. Some elements or aspects may be described by physically based mathematical models and others by heuristically obtained rules of thumb, while some information may still be hidden in the process data recorded during previous runs of the process. Heuristic rules are conveniently processed with fuzzy expert systems, while artificial neural networks present themselves as a powerful tool for uncovering the information within the process data without the need to transform the information into one of the other representations. Artificial neural networks and fuzzy technology are increasingly being employed for modelling biotechnological processes, thus extending the traditional way of process modelling by mathematical equations. However, a sufficiently comprehensive combination of all these techniques has not yet been put forward. Here, we present a simple way of combining all the available knowledge relating to a given process. In a case study, we demonstrate the development of a hybrid model for state estimation and prediction on the example of a yeast production process. The model was validated during a cultivation performed in a standard pilot-scale fermenter.     

Chromium and selenium levels in commercially available enteral nutrition

Summary Chromium and selenium contents of thirty-five commercially available enteral feed were determined by atomic-absorption spectrometry after previous wet ashing. Daily chromium intake, based on a 2,000 kcal (8,368 kJ) diet, was below the proposed safe and adequate intake for 78% of the feedings. Hypocaloric diets especially provided extremely low doses of this element. For selenium nearly 80% of the diets provided intakes below the recommended 50 g/day. Selenium concentration was positively correlated with the protein content (p=0.007), whilst fat content and selenium concentrations showed a significant negative correlation (p=0.002). No definite correlation could be found between the selenium and chromium content of the food (p>0.1).

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Chrom- und Selen-Werte in handelsüblich erhältlicher Enteral-Nahrung

Zusammenfassung Der Chrom- und Selenium-Gehalt von 35 handelsüblich erhältlichen Enteral-Präparaten wurde nach vorausgegangener Veraschung durch Atomabsorptionsspektrometrie bestimmt. Die tägliche Cr-Aufnahme bei einer 2000-kcal-Diät lag unter der vorgeschlagenen Sicherheitsgrenze und der entsprechenden Aufnahme von 78% der Nahrung. Speziell niedrigcalorische Diät sichert extrem niedrige Dosen dieser Elemente. Bei Se lag nur bei 80% der Diät die Aufnahme unter dem empfohlenen Wert von 50 g/Tag. Die Se-Konzentration ist positiv korreliert mit dem Proteingehalt (p=0.007), während der Fettgehalt und die Se-Konzentration eine signifitent negative Korrelation zeigte (p=0.002). Es konnte jedoch keine definierte Korrelation zwischen dem Se- und Cr-Gehalt der Lebensmittel gefunden werden (p > 0.1).

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Darunter fällt die sogenannteFormula-Diät und die bilanzierte synthetische Diät, unter anderem adaptierte Milchpräparate (Der Herausgeber)     

Tuning the gas separation performance of fluorinated and sulfonated PEEK membranes by incorporation of zeolite 4A

Mixed matrix membranes (MMMs) containing fluorinated‐sulfonated poly(ether ether ketone) (F‐SPEEK) and zeolite 4A filler, were prepared by solution casting. F‐SPEEK with a fixed degree of sulfonation (40%) was used for membrane synthesis. The SEM pictures showed good interfacial adhesion between filler particles and polymer, which was also confirmed by the increase in glass transition temperature of MMMs with increase in filler particles. Pure and mixed gas permeation experiments were carried out to investigate the potential of this membrane material. The results revealed that addition of zeolite 4A fillers enhanced both permeability and selectivity owing to the intrinsic nature of polymer and modified membrane morphology due to filler. The highest permeability obtained for CO₂ at 30% filler loading was 49.2 Barrer, while highest selectivities obtained for CO₂/CH₄ and CO₂/N₂ were 55 and 58 compared to 47 and 51 for the unfilled polymer, respectively. Intrinsic CO₂ solubility of F‐SPEEK was observed to be decreased from 10.7 to 1.9 (10^?2) cm³ (STP)/cm³ cmHg with the addition of Zeolite 4A. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45952.     

Mechanical properties of individual fiber segments of electrospun lignocellulose‐reinforced poly(vinyl alcohol)

The influence of lignocellulosic nanofibers (LCNF) additive on the inherent mechanical properties of submicron electrospun poly(vinyl alcohol) (PVA) fibers is reported. LCNF with a diameter of 25 ± 15 nm and a length of 220 ± 90 nm obtained from hemp shives were dispersed in aqueous PVA solutions to produce homogeneous nanocomposite fibers with 0, 5, and 10 w/w % LCNF loads in solid PVA. Tensile tests on mats show that LCNF additive causes up to sevenfold increase in stiffness and significant decrease in elongation at yield. AFM‐based 3‐point bending tests on single LCNF‐doped fibers reveal up to 11.4 GPa Young's modulus in the diameter range of 300 to 500 nm, indicating a 2.4 times increase compared to neat PVA fibers. Mechanical properties of both neat and LCNF‐doped PVA fibers are found to be strongly size‐dependent at lower fiber diameters, with Young's modulus values exceeding 100 GPa at below 100 nm diameters. The results can be explained by extensive restructuration of hydrogen bonding network due to the LCNF additive. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44361.     

Аntimicrobial and anticancer activity of new poly(propyleneamine) metallodendrimers

The synthesis, EPR characterisation and biological evaluation of two new metallodendrimers, i.e. a poly(propyleneamine) dendrimer functionalized at the external surface with 4-bromo-1,8-naphthalimide and conjugated with Cu(II) and Zn(II), was performed with the aim to evaluate their antimicrobial and anticancer activity. The antimicrobial activity was investigated in meat-peptone broth against bacteria B. subtilis and P. aeruginosa, and the yeast C. lipolytica. The results showed that the compounds inhibited effectively the tested pathogens even after their deposition on a textile fabric. Anticancer activity was investigated against three human permanent cell lines from non-small cell lung cancer (A549), triple negative breast cancer (MDA-MB-231) and carcinoma of the uterine cervix (HeLa) in the c?=?0.01–30 μM concentration range. The results suggest that these compounds are promising for application in biomedicine as anticancer drugs in the design of new effective preparations. The antimicrobial and anticancer activity may be related to the peculiar structural and dynamical properties revealed for the Cu(II) complexes, by a computer aided analysis of the electron paramagnetic resonance (EPR) spectra. This analysis indicated the formation, at the lowest Cu(II) concentrations, of a flexible rhombic Cu-N4 coordination with the internal amino groups of the dendrimer, which transformed into a Cu2-N4 coordination already at 0.25 equiv. of Cu(II).     

Modelling of reactive stripping in monolith reactors

In this work, (reactive) stripping carried out in film flow monolith reactors developed for counter-current operation is investigated. Usually mass transfer in reactive separation has to be determined experimentally due to the complex flow patterns. However, monoliths have a simple geometry; only laminar flow is present throughout the column. This allows the calculation of the thickness of the liquid layer directly using Navier–Stokes equations. With this thickness known, the mass transfer can be calculated based on the convection in axial direction, diffusion in radial direction and vapour–liquid equilibrium. A model has been developed and implemented in Fortran^® based on the concept of a direct solution of convective diffusion equations, using the Thomas algorithm for solving the counter-current operation mode. Experimental data from literature have been used to validate the model for a binary and a multi-component system. The stripping of oxygen from saturated water by nitrogen was modelled assuming Fickian diffusion and vapour–liquid transfer based on the Henry constants. In a second step, multi-component diffusion and complex mass transfer at the interface were taken into account to describe the stripping of water by nitrogen from a mixture of hexyl-octanoate and cumene (solvent) under reactive stripping conditions.