共查询到20条相似文献,搜索用时 31 毫秒
1.
不同比例有机无机肥配施土壤腐殖质组分的光谱学特征 总被引:3,自引:0,他引:3
以16年长期定位试验为基础,探讨不同比例有机无机肥配施对土壤腐殖质特征的影响.通过分离纯化腐殖质中的胡敏酸(H A)和富里酸(FA)组分,并利用元素分析、红外光谱和核磁共振研究分析了F1(70% 化肥+30% 有机肥)、F2(50% 有机肥+50% 化肥)和F3(100% 有机肥)三种施肥方式下的HA和FA含量及结构变... 相似文献
2.
L. Trifonyuk W. Baranowski V. Ushenko O. Olar A. Dubolazov Yu. Ushenko B. Bodnar O. Vanchulyak L. Kushnerik M. Sakhnovskiy 《Opto-Electronics Review》2018,26(3):252-259
A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined. 相似文献
3.
水在生命体中是大量存在的,它是维持生命的必要物质.它能促进细胞的繁殖和血液的循环,促进和参与生物化学反应,为生物大分子的功能发挥提供适当条件.由于它是具有一定偶极矩的微观小分子,其转动频率是处在微波范围内,所以我们判定生物体中的液态水能吸收一定频率和强度的微波,并可以将所吸收的微波能量转化为水分子无规运动的热能,使水温升高.我们的实验结果应证了这个机制,从而可导致血液循环,细胞繁殖和一些生化反应的加快和增强DNA,蛋白质和酶的生物活性等生物功能.这就是毫米波的生物热效应的机理和特性. 相似文献
4.
Surface chemistry of nanodiamonds 总被引:2,自引:0,他引:2
I. I. Kulakova 《Physics of the Solid State》2004,46(4):636-643
The experimental data available in the literature and the results obtained by the author in research into the structure of nanodiamonds and the physicochemical and chemical properties of their surface are generalized. An account is given of the problems concerning the chemical state and modification of the nanodiamond surface in gaseous and liquid media and the infiuence of modification on the sorption and catalytic properties of nanodiamonds, their compactibility, and sintering. The similarity and difference in the behavior of nanodiamonds and diamond macrocrystals in oxidation processes are discussed. The activation energies of oxidation of nanodiamonds by different reagents are determined in the absence and presence of catalysts. 相似文献
5.
6.
惯导加速度计在精密离心机上的标校应用试验,涉及精密离心机动态半径和静态半径的精密测量、转速的精确测控以及被校加速度计信号的正确采集与实时传输等操作,需严格控制各类测控仪器的动作时序逻辑实现精密离心机精密测控与加速度计标校应用试验的自动化操作。介绍一种精密离心机测控与加速度计标校应用试验自动化系统设计,硬件上基于LAN总线组网集成精密离心机各类测控仪器,构建分布式测控系统,并应用外部光栅编码器脉冲信号作为触发信号控制测控仪器的硬件时序同步逻辑;软件上应用共享变量技术实现各类测控参数的有序传输,针对动态波形类大数据测试信号的共享变量传输可靠性差问题,提出一种基于文件动态拷贝的网络数据传输方案,设计严格的共享变量传输逻辑机制,实现了各类测控参数正确有序采集与传输。应用试验表明,设计的精密测控与加速度标校应用试验自动化系统满足加速度计在精密离心机上的标校自动化需求,显著提高了加速度计标校应用试验效率。 相似文献
7.
对我国华南地区六种棕榈藤的纤维和导管形态特征进行了观测,研究了应用近红外光谱分析技术预测棕榈藤纤维长度和导管长度的可行性.结果表明:六种棕榈藤的纤维平均长度在1229~1917μm,导管的平均长度在1035~2129μm;发现株榈藤纤维长度和导管长度模型的建立采用偏最小二乘法和完全交互验证法,在350~2454 nm谱... 相似文献
8.
J. Chamani A. Asoodeh M. Homayoni-Tabrizi Z. Amiri Tehranizadeh A. Baratian M.R. Saberi M. Gharanfoli 《Journal of luminescence》2010,130(12):2476-2486
Combination of several drugs is often necessary especially during long-term therapy. The competitive binding drugs can cause a decrease in the amount of drug bound to protein and increase the biological active fraction of the drug. The aim of this study is to analyze the interactions of Lomefloxacin (LMF) and Colchicine (COL) with human serum albumin (HSA) and to evaluate the mechanism of simultaneous binding of LMF and COL to protein. Fluorescence analysis was used to estimate the effect of drugs on the protein fluorescence and to define the binding and quenching properties of drugs-HSA complexes. The binding sites for LMF and COL were identified in tertiary structure of HSA with the use of spectrofluorescence analysis. The analysis of fluorescence quenching of HSA in the binary and ternary systems show that LMF does not affect the complex formed between COL and HSA. On the contrary, COL decreases the interaction between LMF and HSA. The results of synchronous fluorescence, resonance light scattering and circular dichroism spectra of binary and ternary systems show that binding of LMF and COL to HSA can induce micro-environmental and conformational changes in HSA. The simultaneous presence of LMF and COL in binding to HSA should be taken into account in the multi-drug therapy, and necessity of using a monitoring therapy owning to the possible increase of the uncontrolled toxic effects. Molecular modeling of the possible binding sites of LMF and COL in binary and ternary systems to HSA confirms the spectroscopic results. 相似文献
9.
Dr K. P. Zetie 《Contemporary Physics》2013,54(5):449-450
Soil has its origin in physical processes of comminution and abrasion of rock masses and in chemical processes of solution and recrystallization of rock minerals. After formation it is transported and distributed by a variety of agencies before subaerial or subaqueous deposition. Generally, soils experience a number of cycles of sedimentation, uplift, erosion and redeposition. Their mechanical behaviour under the stresses imposed by engineering structures varies with the type of soil. Both the deformation and failure of soils are of interest in the design of structures and these properties must be studied by special laboratory tests. The solution of a soil engineering problem therefore involves a field investigation and sampling programme to define the boundaries of the soil involved, laboratory testing of the soil, and analytical or computer calculations to determine the displacements and stresses which will occur in the soil and structure. Problems of particular interest include slope failures, the design of earth dams, retaining walls and piled structures, the displacement and failure of soil under buildings and the determination of soil properties on the surface of the moon and other planets. 相似文献
10.
In the age of the Internet and with the dramatic proliferation of mobile listening technologies, music has unprecedented global distribution and embeddedness in people's lives. It is a source of intense experiences of both the most intimate and solitary, and public and collective, kinds – from an individual with their smartphone and headphones, to large-scale live events and global simulcasts; and it increasingly brings together a huge range of cultures and histories, through developments in world music, sampling, the re-issue of historical recordings, and the explosion of informal and home music-making that circulates via YouTube. For many people, involvement with music can be among the most powerful and potentially transforming experiences in their lives. At the same time, there has been increasing interest in music's communicative and affective capacities, and its potential to act as an agent of social bonding and affiliation. This review critically discusses a considerable body of research and scholarship, across disciplines ranging from the neuroscience and psychology of music to cultural musicology and the sociology and anthropology of music, that provides evidence for music's capacity to promote empathy and social/cultural understanding through powerful affective, cognitive and social factors; and explores ways in which to connect and make sense of this disparate evidence (and counter-evidence). It reports the outcome of an empirical study that tests one aspect of those claims, demonstrating that ‘passive’ listening to the music of an unfamiliar culture can significantly change the cultural attitudes of listeners with high dispositional empathy; presents a model that brings together the primary components of the music and empathy research into a single framework; and considers both some of the applications, and some of the shortcomings and problems, of understanding music from the perspective of empathy. 相似文献
11.
This article reports the suggestion, realization and verification of the newly developed measuring means of the noiseless and locally shift-invariant modulation transfer function (MTF) of a digital video camera in a usual incoherent visible region of optical intensity, especially of its combined imaging, detection, sampling and digitizing steps which are influenced by the additive and spatially discrete photodetector, aliasing and quantization noises. Such means relates to the still camera automatic working regime and static two-dimensional spatially continuous light-reflection random target of white-noise property. The introduced theoretical reason for such a random-target method is also performed under exploitation of the proposed simulation model of the linear optical intensity response and possibility to express the resultant MTF by a normalized and smoothed rate of the ascertainable output and input power spectral densities. The random-target and resultant image-data were obtained and processed by means of a processing and evaluational PC with computation programs developed on the basis of MATLAB 6.5. The present examples of results and other obtained results of the performed measurements demonstrate the sufficient repeatability and acceptability of the described method for comparative evaluations of the performance of digital video cameras under various conditions. 相似文献
12.
The effect of high-power (high-voltage) nanosecond pulses on the phase composition and chemical state of atoms of surface layers of sulfide minerals with different semiconductor properties (galenite, molybdenite, and sphalerite) is investigated by means of XPES. Common patterns and characteristic features of the structural phase transformations of sulfide surfaces under the pulsed energetic effect are the formation and growth of a surface layer by the nonstoichiometric sulfur-enriched sulfide phase and Zn and Mo oxides and hydroxides; the staged character of the transformation of sulfur atoms in the composition of galenite and sphalerite surface layers; and the stability of the chemical state of sulfur in the molybdenite composition and lead atoms in the galenite composition. 相似文献
13.
A. A. Bush K. E. Kamentsev V. F. Meshcheryakov Y. K. Fetisov D. V. Chashin L. Y. Fetisov 《Technical Physics》2009,54(9):1314-1320
The forward and inverse magnetoelectric (ME) effects are experimentally studied in a two-layer planar structure containing
mechanically coupled Galfenol and PZT plates. The process of production of polycrystalline Galfenol plates and their magnetic
and magnetostriction characteristics are described. For the forward ME conversion, the dependences of the amplitude of the
voltage generated by the structure on the magnitude and orientation of a dc magnetic field and the frequency and amplitude
of a modulating magnetic field are measured. For the inverse ME conversion, the dependences of the amplitude of the change
in the magnetic induction of the structure on the dc magnetic field and the frequency of an ac electric field applied to the
structure are measured. The efficiencies of the forward and inverse ME conversion are estimated for the case of low-frequency
field modulation and under conditions of the resonance excitation of bending and longitudinal mechanical vibrations in the
structure. 相似文献
14.
《声学学报:英文版》2016,(3)
This paper studies the controllability and observability measures of structural vi?bration and acoustic radiation and proposes a measure of modal observability based on acoustic pressure outputs and measures of controllability and observability of acoustic radiation by combining the measures of modal controllability and observability of vibration modes with corresponding modal acoustic radiation efficiencies. A plate with control force inputs and vibrational response outputs and acoustic pressure outputs is involved to show the modal controllability and observability measures of vibration modes and measures of controllability and observabil?ity of structural vibration and acoustic radiation. Observability measures based on vibrational response outputs and acoustic pressure outputs are compared and the emphasis is on the mea?sures based on the acoustic pressure outputs. Finally the application and usefulness of the controllability and observability measures to active control of structural vibration and acous?tic radiation are illustrated and compared. It shows that the controllability and observability measures provide useful guidance for active control design especially in optimal actuator and sensor placement. 相似文献
15.
针对颗粒介质力学特性的颗粒尺度效应研究,选用土矿物颗粒制备不同颗粒尺度的抗剪试样,进行一系列直剪快剪和三轴抗剪试验,测得了不同颗粒粒径和体分比试样的变形曲线及剪应力强度;基于颗粒间微观作用力与重力比值和胞元体模型,首次从微观和细观角度解释颗粒尺度效应的物理机理.结果表明,随着介质中粗颗粒的比例增加和粒径减小,介质变形特性增强,剪应力强度也随之提高;体分比对变形和强度特性的影响比粒径的影响更加显著.基于介质特性尺度效应物理机理分析,提出衡量介质颗粒聚集和摩擦效应的微重比判别参数以及应变梯度和变形协调微裂纹引起颗粒尺度效应的细观机理解释;文中提出的胞元体模型大大减少了颗粒物质体系的计算自由度,为工业和工程设计的计算建模提供一种可行途径. 相似文献
16.
侏罗纪优质煤炭资源为煤制油、制气等清洁高效利用提供了丰富的物质基础,其显微组分以富集惰质组为特征,而镜质组与惰质组大分子结构在很大程度上决定了煤的物理化学性质和工艺性能,进而决定了煤炭资源的综合利用效率及附加值。采集并制备了陕北侏罗纪煤田小保当煤矿和柠条塔煤矿的原煤(XR)、富镜质组煤(XV、NV)和富惰质组煤(XI、NI)样品,利用傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、固体13C核磁共振谱(13C NMR)等手段,结合煤质分析结果,定量表征了不同显微组分富集物分子结构的差异。研究结果表明:XI和NI煤中芳烃结构芳环取代程度低,主要以3个相邻、4~5个相邻的氢原子形式存在,苯环上氢原子较少被其他官能团取代,同时其结构中芳烃C═C骨架振动明显,脂肪结构中亚甲基伸缩振动强度较低,并且甲基含量略高于富镜煤,C═O基团相对含量略高,表明富惰煤有较多含氧桥键相连的芳香结构,其结构中脂族链、脂环基团脱落、断裂以及芳烃富集,支链相对较少且长度较短,芳碳率、芳香度、芳环缩合程度及成熟度较高。XV和NV煤中表面结构中碳的赋存形态“C—C,C—H”,“C—O”的相对含量高于富惰煤,反映其结构中应含较多的芳环取代的脂肪族侧链,XI和NI煤表面结构中氧的赋存形态以“C—O”为主,“C═O”和“COO—”明显高于富镜煤。XV和XI煤的芳碳率分别为57.91%和66.02%,脂甲基碳分别为10.02%和7.84%,质子化芳碳为非质子化芳碳的两倍,XV煤的羰基和羧基碳相对含量较高,两者桥碳和周碳之比分别为0.25和0.40,芳香核结构平均缩合环数分别为2.68和3.03,平均尺寸分别为0.448和0.676 nm,XI煤结构中芳香核以萘和蒽为主,支链化度Lγ分别为0.22和0.19,表明XV比XI存在较多脂肪侧链、饱和环结构,生烃(油)潜力大。 相似文献
17.
首先对微晶粒尺寸增长速率的表征进行总结.从微晶核和粒—高分子链组网络结构特点(高分子链组是微晶核和微晶粒同连接链段的复合体)同增长速率间的三个相关性的特征: ①晶核和晶粒加大同连接链段缩短的并存性; ②微晶核和粒表面上连接链段的缩短机制存有简并性; ③微晶粒内和粒表面上stem的反顺式构象共存性出发.建议了一种评估和计算微晶粒尺寸增长速率的新方法和原则,基于该种计算方法和原则用统计力学和动力学相结合法推导出了高分子熔体内几种不同结晶生长机制(近邻折叠、近邻伸直分凝和近邻折叠同近邻伸直分凝并存等生长方式)下微晶粒—高分子链组中微晶粒数增长速率和微晶粒尺寸增长速率动力学方程. 相似文献
18.
D.Q. Cao M.T. Song W.D. Zhu R.W. Tucker C.H.-T. Wang 《Journal of sound and vibration》2012,331(26):5685-5714
The in-plane vibration of a complex cable-stayed bridge that consists of a simply-supported four-cable-stayed deck beam and two rigid towers is studied. The nonlinear and linear partial differential equations that govern transverse and longitudinal vibrations of the cables and transverse vibrations of segments of the deck beam, respectively, are derived, along with their boundary and matching conditions. The undamped natural frequencies and mode shapes of the linearized model of the cable-stayed bridge are determined, and orthogonality relations of the mode shapes are established. Numerical analysis of the natural frequencies and mode shapes of the cable-stayed bridge is conducted for various symmetrical and non-symmetrical bridge cases with regards to the sizes of the components of the bridge and the initial sags of the cables. The results show that there are very close natural frequencies when the bridge model is symmetrical and/or partially symmetrical, and the mode shapes tend to be more localized when the bridge model is less symmetrical. The relationships between the natural frequencies and mode shapes of the cable-stayed bridge and those of a single fixed–fixed cable and the single simply-supported deck beam are analyzed. The results, which are validated by commercial finite element software, demonstrate some complex classical resonance behavior of the cable-stayed bridge. 相似文献
19.
CAO Zeng CUI Chenghe CAI Xiao GAO Xiaoyan DUAN Xuru PAN Yudong LI Quang 《核工业西南物理研究院年报(英文版)》2005,(1):43-44
The sputtering of impurities is caused by the interactions between plasma and the first wall, and the recycling of the gas affects the particle and energy transport of plasmas with a complicated mechanism in plasma operation. It is important for present tokarnaks to achieve a good confinement and high performance plasmas by means of controls of the vacuum condition, usage of low Z materials, control of the recycling of neutral particles and suppressions of the appearances and yield of impurities. For higher plasma parameters, some of the first wall of HL-2A is covered with graphite materials and carbon fiber tiles. Hence the studies on the in-situ coating application and development, and the interactions between the coating film and plasma are needed to effectively control the impurity, improve plasma confinement and achieve high performance plasma. 相似文献
20.
胆酸与硫酸加热产生脱水反应,形成共轭双键,在紫外区产生特征吸收峰。用紫外-分光光度法测定了牛胆粉与羊胆粉中胆酸的含量。测定线性范围为0·0033~0·0167mg·mL-1(r=0·9997),加样回收率及RSD分别为98·48%,1·79%,96·46%,2·50%。5批次样品测定表明:牛胆粉中胆酸的含量在40·85%~43·03%之间,羊胆粉在30·88%~32·64%之间。牛胆粉精密度RSD为2·41%,羊胆粉精密度RSD为2·92%。稳定性试验在8h之内测定牛胆粉RSD为0·55%,羊胆粉RSD为0·59%。重复性试验牛胆粉RSD为2·11%,羊胆粉RSD为2·68%。方法简便、快速、便于推广应用,且可有效地控制牛胆粉与羊胆粉的内在质量。 相似文献