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酶制品的稳定性及饲料中酶活性的测定

国外畜牧学（猪与禽） 1993年第3期13卷 12-13页

作者：李平化 m.r.bedford H.Graham 芬兰国际添加剂厂芬兰国际添加剂厂英国英国

引言加入配合饲料中的酶必须耐受饲料加工过程中所遇到的任何一种处理,因此,酶制品生产厂都必须设计出某种方法使酶具有热稳定性。根据酶在经受热处理后对其活性进行体外分析的结果并不能确定酶对热处理的耐受力。体外活性测定法存在两... 详细信息

引言加入配合饲料中的酶必须耐受饲料加工过程中所遇到的任何一种处理,因此,酶制品生产厂都必须设计出某种方法使酶具有热稳定性。根据酶在经受热处理后对其活性进行体外分析的结果并不能确定酶对热处理的耐受力。体外活性测定法存在两个主要问题: 1)现行标准分析法的条件常常远远偏离于动物消化道中的条件,所以其结果常会产生误导作用。下文的第一部分中将讨论这个问题。 2)即使有了管用的标准分析法,但要从经热处理的饲料中将酶提取出来也是很难的。

关键词：饲料添加剂酶制品稳定性测定

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酶可提高能量和蛋白质的利用率

国外畜牧学（猪与禽） 1999年第4期19卷 57-59页

作者：杨润生 F.G.Silversides m.r.bedford

Honeycomb-spiderweb-inspired self-similar hybrid cellular structures for impact applications

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Defence Technology(防务技术) 2025年第1期43卷 182-200页

作者： K.Tewari m.K.Pandit m.m.mahapatra P.r.Budarapu School of mechanical Sciences Indian Institute of Technology BhubaneswarBhubaneswar752050India

Inspired by nature's self-similar designs,novel honeycomb-spiderweb based self-similar hybrid cellular structures are proposed here for efficient energy absorption in impact *** energy absorption is enhanced by optimizing the geometry and topology for a given *** proposed hybrid cellular structure is arrived after a thorough analysis of topologically enhanced self-similar *** optimized cell designs are rigorously tested considering dynamic loads involving crush and high-velocity bullet ***,the influence of thickness,radial connectivity,and order of patterning at the unit cell level are also *** maximum crushing efficiency attained is found to be more than 95%,which is significantly higher than most existing traditional *** on,the first and second-order hierarchical self-similar unit cell designs developed during crush analysis are used to prepare the cores for sandwich *** tests are performed on the developed sandwich structures using the standard 9-mm *** influence of multistaging on impact resistance is also investigated by maintaining a constant total thickness and mass of the sandwich ***,in order to avoid layer-wise weak zones and hence,attain a uniform out-of-plane impact strength,off-setting the designs in each stage is *** sandwich structures with first and second-order self-similar hybrid cores are observed to withstand impact velocities as high as 170 m/s and 270 m/s,respectively.

关键词： Sandwich structures Honeycomb-spider web inspired Self-similar hierarchy Crush analysis High-velocity impact Strong and weak zones multistaging

ENSO-induced Latitudinal Variation of the Subtropical Jet modulates Extreme Winter Precipitation over the Western Himalaya

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ADVANCES IN ATmOSPHErIC SCIENCES 2025年第3期42卷 427-437页

作者： Bharati, Priya Deb, Pranab Hunt, Kieran m. r. Orr, Andrew Dash, mihir Kumar Indian Inst Technol Kharagpur Ctr Ocean River Atmosphere & Land Sci CORAL Kharagpur 721302 India Univ reading Dept Meteorol Reading RG6 6ET England Univ reading Natl Ctr Atmospher Sci Reading RG6 6ET England British Antarctic Survey Cambridge CB3 0ET England

In this study, we investigate the complex relationship between western disturbances (WDs), the El Ni & ntilde;o-Southern Oscillation (ENSO), and extreme precipitation events (EPEs) in the western Himalaya (WH) during the extended winter season (November-march). WDs west of WH coincide with 97% of recorded EPEs, contributing substantially (32% in winter, 11% annually) to total precipitation within WH. WDs are 6% less frequent and 4% more intense during El Ni & ntilde;o than La Ni & ntilde;a to the west of WH. During El Ni & ntilde;o (compared to La Ni & ntilde;a) years, WDs co-occurring with EPEs are significantly more intense and associated with 17% higher moisture transport over "WH box" (the selected region where most of the winter precipitation over WH occurs). This results in twice the EPE frequency during El Ni & ntilde;o periods than La Ni & ntilde;a periods. A substantial southward shift (similar to 180 km) of the subtropical jet (STJ) axis during El Ni & ntilde;o brings WD tracks further south towards their primary moisture sources, especially the Arabian Sea. We have shown that WDs that are both more intense and pass to the south of their typical latitudes have higher levels of vertically integrated moisture flux (VImF) within them. VImF convergence in the most intense pentile of WDs is 5.7 times higher than in the weakest, and is 3.4 times higher in the second lowest latitude pentile than in the highest. Overall, this study demonstrates a direct link between changes in the latitudinal position and intensity of WDs associated with the winter STJ, and moisture convergence, which leads to the occurrence of EPEs over WH during ENSO phases.

关键词： western Himalaya extreme precipitation western disturbances ENSO moisture flux winter

The effect of adsorbent textural and functional properties on model naphthenic acid adsorption

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Journal of Environmental Sciences 2025年第2期148卷 27-37页

作者： Tyler m.roy Elmira Nazari Oliver K.L.Strong Paul r.Pede Andrew J.Vreugdenhil material Science Department of ChemistryTrent University1600 West BankPeterboroughOntario K9L 0G2Canada Carbonix 690 Mountain RdSuite 200Fort William First NationOntario P7J 1G8Canada

Naphthenic acids,NAs,are a major contaminant of concern and a focus of much research around remediation of oil sand process affected waters,*** activated carbon adsorbents are an attractive option given their low cost of fabrication and implementation.A deeper evaluation of the effect NA structural differences have on uptake affinity is *** we provide an in-depth exploration of NA adsorption including many more model NA species than have been assessed previously with evaluation of adsorption kinetics and isotherms at the relevant alkaline pH of OSPW using several different carbon adsorbents with pH buffering to simulate the behaviour of real *** for the NA varied considerably regardless of the activated carbon used,ranging from 350 mg/g to near zero highlighting recalcitrant *** equilibrium data was explored to identify structural features of these species and key physiochemical properties that influence *** found that certainNAwill be resistant to adsorptionwhen hydrophobic adsorbents are *** isotherm modelling helped explore interactions occurring at the interface between NA and adsorbent *** identified the importance of NA hydrophobicity for activated carbon *** is also presented that indicates favorable hydrogen bonding between certain NA and surface site hydroxyl groups,demonstrating the importance of adsorbent surface functionality for NA *** research highlights the challenges associated with removing NAs from OSPW through adsorption and also identifies howadsorbent surface chemistry modification can be used to increase the removal efficiency of recalcitrant NA species.

关键词： Adsorption Activated carbon model naphthenic acids Isotherm modelling

Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural regeneration research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam m.r.Groh moein Yaqubi Qiao-Ling Cui Jo Anne Stratton G.r.Wayne moore Jack P.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by robertson and río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus rNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

Effect of divalent cations(Co^(2+) and Ni^(2+)) on microstructure,physical properties and application of NdFeO_(3)

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Journal of rare Earths 2025年第1期43卷 89-97,I0004页

作者： m.m.Arman materials Science Lab(1) Physics DepartmentFaculty of ScienceCairo UniversityGiza12613Egypt

The nanocrystalline samples Nd_(1-x)m_(x)FeO_(3)(x=0.0 and 0.1;m:Co^(2+)and Ni^(2+))were prepared using the citrate combustion *** X-ray diffraction(XrD)pattern confirmed that the nanoparticles were synthesized in an orthorhombic *** particle size of Nd_(1-x)m_(x)FeO_(3) is in the range of 29-59 *** selected area electron diffraction(SAED)indicates the samples were prepared in a polycrystalline *** samples Nd_(1-x)m_(x)FeO_(3)(x=0.0 and 0.1;m:Co^(2+)and Ni^(2+))have anti ferromagnetic *** Fe^(3+)spins are aligned antiparallel,forming the antiferromagnetic(AFm)properties,which are affected by many factors such as the bond angle between the Fe^(3+)(Fe^(3+)-O_(2)--Fe^(3+))and the Dzyaloshinskii-moriya(D-m)*** doping of Co^(2+)and Ni^(2+)ions in NdFeO_(3) enhances the magnetic properties of the NdFeO_(3).The saturation magnetization(ms)of Nd_(0.90)Co_(0.10)FeO_(3) increases 1.8times more than that of NdFeO_(3).The exchange bias field(HEX)of the Co-doped sample is two times greater than that of NdFeO_(3).The magnetic anisotropy constant(K)of the 10%Co-doped sample increases by 11 factors compared to that of NdFeO_(3).The Tauc plot illustrates that the samples have a direct optical *** divalent cation substitution(Co^(2+)and Ni^(2+))decreases the optical band gap of NdFeO_(3),leading to the recommendation of using the samples Nd_(0.90)Co_(0.10)FeO_(3) and Nd_(0.90)Ni_(0.10)FeO_(3) in photocatalysis of dye degradation from *** removal efficiencies of Cr6+at pH=6 are 88.06%,85.54%,and 85.52%for the samples NdFeO_(3),Nd_(0.90)Co_(0.10)FeO_(3),and Nd_(0.90)Ni_(0.10)FeO_(3),*** Freundlich isotherm mode is the best-fit model for NdFeO_(3) to adsorb Cr6+ions from aqueous solutions.

关键词： Optical properties Nanoparticles magnetic properties Perovskites removal efficiency rareearths

First Search for Pulsed CH maser Emission Stimulated by a Pulsar

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research in Astronomy and Astrophysics 2025年第2期25卷 62-71页

作者： mengting Liu Di Li J.r.Dawson Joel m.Weisberg George Hobbs Ningyu Tang Gan Luo Duo Xu Donghui Quan research Center for Astronomical Computing Zhejiang Laboratory Department of Astronomy Tsinghua University National Astronomical Observatories Chinese Academy of Sciences CSIrO Astronomy & Space Science Australia Telescope National Facility School of mathematical and Physical Sciences and Astrophysics and Space Technologies research Centre Macquarie University Department of Physics and Astronomy Carleton College Department of Physics Anhui Normal University Institut de radioastronomie millimetrique 300 Rue de la Piscine Canadian Institute for Theoretical Astrophysics University of Toronto 60 St.George Street

We present the first search for pulsed CH maser emission potentially stimulated by PSr J1644-4559,conducted using the ultra-wide-bandwidth low-frequency receiver on murriyang,CSIrO's Parkes radio *** targeted three CHΛ-doublet transitions at 3264,3335,and 3349 mHz,with a variability timescale of78 *** detected ten CH emission features at 3335 and 3349 mHz,and seven features at 3264 mHz,during both pulsar-ON and pulsar-OFF *** observed velocities align with the OH emission and absorption reported by a previous study,suggesting a close spatial association between CH and OH *** derived column densities for CH clouds within the Parkes beam range from 0.05 to 9.8×1013cm-2,indicating that these clouds are likely in diffuse and translucent *** limits for CH column densities within the pulsar beam ranged from 0.3 to 9.8×*** of these column densities suggests that CH clouds may exhibit clumpiness and *** significant stimulated emission feature was detected in the optical depth ***,as part of our search for pulsed stimulated emission,we investigated the potential CH absorption of the pulsar signal and found none,in agreement with astrophysical *** upper limits for the potential maser amplification factors towards PSr J1644-4559 at 3264,3335,and 3349 mHz are 1.014,1.009,and 1.009,*** study demonstrates the feasibility of detecting pulsed CH maser emission in the interstellar medium stimulated by pulsar photons.

关键词： (stars:) pulsars: general ISm: molecules masers

reduced-particle size wheat bran and endoxylanase supplementation in broiler feed affect arabinoxylan hydrolysis and fermentation with broiler age differently

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Animal Nutrition 2023年第1期12卷 308-320页

作者： An Bautil michael r.bedford Johan Buyse Christophe m.Courtin Laboratory of Food Chemistry and Biochemistry Department of Microbial and Molecular Systems(M2S)KU LeuvenLeuven3001Belgium AB Vista MarlboroughWiltshire SN84ANUnited Kingdom Laboratory of Livestock Physiology Department of BiosystemsKU LeuvenLeuven3001Belgium

Since the caecal microbiota of young broilers are not yet able to ferment the dietary fibre(DF)fraction of the feed to a large extent,increasing the accessibility of DF substrates along the gastrointestinal tract is crucial to benefit from the health stimulating metabolic end-products(*** acid)generated upon microbial DF ***,the present study aimed to evaluate the potential of reduced-particle size wheat bran(rPS-WB)and endoxylanases as feed additives to stimulate arabinoxylan(AX)hydrolysis and fermentation along the hindgut of young *** this end,rPS-WB and endoxylanase supplementation were evaluated in a 2×2 factorial design using a total of 256 male 1-d-old chicks(ross 308).Broilers were assigned to 4 dietary treatments:a basal wheat-based diet with(1)no feed additives(control,CTrL),(2)an endoxylanase(XYL;Econase XT 25 at 0.10 g/kg diet),(3)1%wheat bran with an average reduced particle size of 297μm(rPS-WB)and(4)an endoxylanase and 1%rPS-WB(rPS-WB+XYL).Each dietary treatment was replicated 8 times and on d 10 and 28,respectively,24 and 16 broilers per treatment group were euthanised to analyse AX degradation,short-chain fatty acid production and digesta viscosity in the ileum and *** receiving XYL in their diet showed increased AX solubilisation and fermentation at both d 10 and 28 compared to the CTrL group(PrPS-WB to the diet stimulated wheat AX utilisation by the primary AX degraders in the caecum at 10 d of age compared to the CTrL group,as observed by the high AX digestibility coefficient for the rPS-WB supplemented group at this young age(PrPS-WB supplementation lowered body-weight gains but increased butyric acid concentrations compared to the XYL and CTrL group(Prgistic effect for rPS-WB+XYL broilers was observed for AX hydrolysis and fermentation,these findings suggest that both additives can raise a dual benefit to the broiler as a butyrogenic effect and im

关键词： Broiler chicken Wheat bran Particle size reduction Xylanase Arabinoxylan fermentation