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植物生理生态学(续)

辽宁农业科学 1981年第2期 50-56页

作者： j.r.etherington 陈士平

三、物质源:大气与土壤1.大气我们已经知道太阳系的外层行星带有含水分、甲烷、二氧化碳的大气层。这是一个化学还原系统,游离氧在其中是无法存在的。据信地球的原始大气层也曾是这样,它形成了一种富碳的环境,生命就是从这个环境中起源... 详细信息

三、物质源:大气与土壤1.大气我们已经知道太阳系的外层行星带有含水分、甲烷、二氧化碳的大气层。这是一个化学还原系统,游离氧在其中是无法存在的。据信地球的原始大气层也曾是这样,它形成了一种富碳的环境,生命就是从这个环境中起源的,进化的第一步骤产生了微生物。微生物依靠就地的化学能源而生存(见前章图1),如果没有光合过程的生物化学进化,生物圈可能至今仍被一小撮碳素收支极低的化能营养微生物种所统治着。我们地球的表层和大气圈,对其中的有机体来讲,是一个并不宽敞的系统。这层富氧、穷碳的大气层,是光合作用所造成的。“宇宙

关键词：有机质灰壤铁磐森林土倍半氧化物三二氧化物腐殖酸肥料泥炭矿物基质残落物层枯枝落叶层阳离子交换母质矿质营养

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植物生理生态学

辽宁农业科学 1981年第1期 51-56页

作者： j.r.etherington 陈士平

生态系统平衡是当前农业现代化中的一个突出的重大问题。不少读者希望了解这方面的基本知识。本刊从本期开始连续刊载英国南威尔士大学高级讲师、哲学博士 *** 撰写的《植物生理生态学》一书。这是英国生物学协会主编的一系列生物科学... 详细信息

生态系统平衡是当前农业现代化中的一个突出的重大问题。不少读者希望了解这方面的基本知识。本刊从本期开始连续刊载英国南威尔士大学高级讲师、哲学博士 *** 撰写的《植物生理生态学》一书。这是英国生物学协会主编的一系列生物科学小丛书中的一本。作者对这门近来发展很快的边缘学科作了简明扼要、深入浅出的介绍。本书文笔生动,材料新颖,值得一读。全文计划分六期登完。

关键词：植物生理生态学辐射能地球表面地表生态系统分析电磁辐射生物圈能流密度

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植物生理生态学(续)

辽宁农业科学 1981年第3期 49-53页

作者： j.r.etherington 陈士平

四、物质循环1.植物和养分循环所谓“顶极生态系统”,一般认为是指那种在种类组成和现存生物量两方面都达到演替系列平衡的生态系而言。顶极生态系统的生物量虽然也稍微带点季节性循环,但是与那些不成熟的生态系统生物量逐年增加不一样... 详细信息

四、物质循环1.植物和养分循环所谓“顶极生态系统”,一般认为是指那种在种类组成和现存生物量两方面都达到演替系列平衡的生态系而言。顶极生态系统的生物量虽然也稍微带点季节性循环,但是与那些不成熟的生态系统生物量逐年增加不一样,它的年平均总量是稳定的。在这样一种平衡状态下,每年的粗第一性产量完全消耗于植物、动物和微生物的呼吸上。要防止这种生态系统缓慢退化,必须所有用于合成活体组织的物质资源,在活体死亡之后都最终归还到初级生产者。如果通过降雨、飞尘或新近风化地质物质

关键词：渍水土壤生态系统生物量现存量元素循环

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植物生理生态学(四)

辽宁农业科学 1981年第4期 52-55页

作者： j.r.etherington 陈士平

五、生长的限制1.限制因素关于生长限制的概念,在植物生理和群体生长等生物学研究中曾多次受到攻击。这个概念首次出现于十九世纪中叶李比西的“最小养分律”中。Blackman(1905)在他的一篇经典著作《最适因素与限制因素》中,把这个观点... 详细信息

五、生长的限制1.限制因素关于生长限制的概念,在植物生理和群体生长等生物学研究中曾多次受到攻击。这个概念首次出现于十九世纪中叶李比西的“最小养分律”中。Blackman(1905)在他的一篇经典著作《最适因素与限制因素》中,把这个观点加以发展,从最大与最小两方面来全面阐明了限制的概念。在他的“限制因素律”中,他指出:“如果一个过程是有条件的,比如说,其速度受各种不同因素的制约,则该过程的效率

关键词：限制因素概念思维形式结构元素植物分布地下水土壤水辐射能植物生长传导度植物组织叶片光合水分传导金属材料金属化学因素粘粒矿物硅酸盐矿物粘土矿物痕量元素微量元素

Dietary fibre effects and the interplay with exogenous carbohydrases in poultry nutrition

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Animal Nutrition 2024年第1期16卷 231-240页

作者： Michael r.Bedford Birger Svihus Aaron j.Cowieson AB Vista Feed Ingredients Ltd Norwegian University of Life Sciences DSM Nutritional Products

A comprehensive understanding of the role of dietary fibre in non-ruminant animal production is elusive. Equivocal and conflated definitions of fibre coupled with significant analytical complexity,interact with poorly defined host and microbiome relationships. Dietary fibre is known to influence gut development, feed intake and passage rate, nutrient absorption, microbiome taxonomy and function, gut p H, endogenous nutrient loss, environmental sustainability, animal welfare and more. Whilst significant gaps persist in our understanding of fibre in non-ruminant animal production, there is substantial interest in optimizing the fibre fraction of feed to induce high value phenotypes such as improved welfare,live performance and to reduce the environmental footprint of animal production systems. In order to achieve these aspirational goals, it is important to tackle dietary fibre with the same level of scrutiny as is currently done for other critical nutrient classes such as protein, minerals and vitamins. The chemical,mechanical and nutritional role of fibre must be explored at the level of monomeric sugars, oligosaccharides and polysaccharides of varying molecular weight and decoration, and this must be in parallel to standardisation of analytical tools and definitions for speciation. To further complicate subject, exogenous carbohydrases recognise dietary fibre as a focal substrate and have varying capacity to generate lower molecular weight carbohydrates that interact differentially with the host and the enteric microbiome. This short review article will explore the interactive space between dietary fibre and exogenous carbohydrases and will include their nutritional and health effects with emphasis on functional development of the gut, microbiome modulation and host metabolism.

关键词： Fibre Carbohydrase Nutrition Microbiome Gastro-intestinal development Feed

Stable diffusion gradients in microfluidic conduits bounded by fluid walls

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Microsystems & Nanoengineering 2024年第3期10卷 357-367页

作者： Federico Nebuloni Cyril Deroy Peter r.Cook Edmond j.Walsh Department of Engineering Science Osney Thermo-Fluids InstituteUniversity of OxfordOxford OX20ESUK Sir William Dunn School of Pathology University of OxfordOxford OX13REUK

Assays mimicking in vitro the concentration gradients triggering biological responses like those involved in fighting infections and blood clotting are essential for biomedical *** assays prove especially attractive as they allow precise control of gradient shape allied to a reduction in *** microfluidic devices are fabricated using solid plastics that prevent direct access to responding ***-walled microfluidics allows the manufacture of circuits on standard Petri dishes in seconds,coupled to simple operating methods;cell-culture medium sitting in a standard dish is confined to circuits by fluid walls made of an immiscible *** develop and experimentally validate an analytical model of diffusion between two or more aqueous streams flowing at different rates into a fluid-walled conduit with the cross-section of a circular *** solid walls,fluid walls morph during flows as pressures fall,with wall shape changing down the *** model is validated experimentally for Fourier numbersrescein diffusing between laminar *** enables a priori prediction of concentration gradients throughout a conduit,so allowing rapid circuit design as well as providing bioscientists with an accurate way of predicting local concentrations of bioactive molecules around responsive and nonresponsive cells.

关键词： walls diffusion attractive

Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony r.j.Kucernak David Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOr).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the *** electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the *** single-atom samples showed higher HOr activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating *** selective activity toward HOr arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

Mathematical modelling of ball and plate system with experimental and correlation function-based model validation

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Control Theory and Technology 2024年第2期22卷 326-341页

作者： T.r.Dil Kumar S.j.Mija Department of Electrical Engineering National Institute of Technology CalicutKozhikode673601KeralaIndia

The ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. The system comprises a ball and plate mechanism and a rotary servo unit. The ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. The nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. The simplified nonlinear model of the system is obtained with suitable assumptions. The model is linearized around the operating point using the jacobian. The validity of the developed models is investigated through correlation function analysis. The open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MATLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSO (particle swarm optimization) PID control scheme.

关键词： Ball and plate system Correlation function Model validation Particle swarm optimization(PSO) PSO PID controller

Analysis of mid-spatial frequency wavefront distortions from a liquid-cooled flash-lamp pumped Nd:phosphate laser amplifier

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High Power Laser Science and Engineering 2024年第1期12卷 24-29页

作者： Pierre-Marie Dalbies Sandy Cavaro Edouard Bordenave Nathalie Blanchot julien G.Moreau jérôme Neauport CEA CESTA Le BarpFrance

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition-rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90 mm × 90 mm aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash-lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.

关键词： flash-lamp pumping high-power laser laser cooling neodymium glass wavefront error

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