TAKENO孤子的量子理论

研究蛋白质分子中能量远距离传输的机理,在Ｔａｋｅｎｏ提出的孤子理论的基础上,进上步考虑了氢键相互作用的非简谐性,并用量子力学对模型进行了处理,在连续近似下,得到的结果表明,能量可以通过以超声速运动的孤子来传输。     

车轮虫分类与系统发育研究进展

车轮虫属一大类寄生性纤毛虫原生动物，可不同程度地给宿主造成危害，故对其研究既具有理论意义，又具有经济价值。文中简单回顾了车轮虫的分类研究和系统发育研究的历史。在分类学研究领域方面，全面介绍了目前车轮虫科已发现属的寄生部位和地理分布等；而系统发育研究领域方面，则介绍了车轮虫研究在萌芽期、探索期和发展期这三个时期的进展，包括形态学和分子生物学两方面的研究内容。并对该领域今后应进行的研究提出了建议。     

一本质量较高的专著──《植物激素及其免疫检测技术》

我国植物激素研究早在对年代已经开始，解放后，研究队伍越来越大，研究成果也越来越多。近20年来，无论在国外还是国内，植物激素研究都是处于急剧发展时期，研究内容逐渐扩展深入。五大激素的研究层次已从细胞水平深入到分子水平，新的激素种类不断增加，新的生长调节剂也如雨后春笋那样增加种类、扩大应用范围。可以说，植物激素研究硕果累累，长盛不衰。然而，我国有关植物激素的专著则聊聊无几。关于植物生长调节剂应用的专著尚有三两本，而植物激素的理论著作则只有罗土韦等于1963年编的《植物激素》一书（上海科学技术出版社出版），…     

田野工作在食物消费研究中的应用

田野工作作为一种经典研究手段和科学学术范式，通过参与式观察和深度访谈获取事实，探寻现象背后的逻辑和意义，特别适合对繁杂琐碎、难以系统表述的日常生活和行为事件，或缺乏客观表达能力的人群进行研究。田野工作研究有助于再现日常生活和行为的丰富细节和真实性，并且挖掘行为背后的意义。将田野工作用于食物消费研究中，有助于解决当前食物消费研究中数据获取成本高、准确性差的问题，弥补食物消费研究“重统计数据，轻生活实践”的不足，充分呈现食物消费的丰富内容和复杂层面，并挖掘其中的深层结构和意义。探讨应用田野调查工作方法研究中国居民食物消费问题，对于促进我国食物消费研究方法的多样化和理论进步具有重要现实意义。     

基于Citespace知识网络图谱的霍山石斛国内外研究进展

目的：梳理霍山石斛国内外研究现状，预测未来研究趋势。方法：运用Citespace软件对中国知网（CNKI）和Web of Science核心数据库收录的有关霍山石斛中英文文献进行文献计量学研究。从论文的发文量、作者集群、合作机构、关键词等进行对比分析和可视化呈现。结果：经过筛选，获得霍山石斛中文文献345篇，英文文献113篇。中英文发文量均稳步递增，中文研究早于英文。罗建平等国内学者是中英文文献的主要研究者，霍山石斛拥有一批以高校为主的研究团队，但团队之间合作不紧密。中英文发文量排名第一的研究机构分别来自皖西学院和合肥工业大学，且有很强的地域特点。关键词分析显示，有关霍山石斛多糖、黄酮成分的抗炎、抗氧化、抗疲劳、抗脂质过氧化作用是中英文研究的热点，此外，中文研究还涉及种植栽培技术，英文更侧重作用机制研究。结论：未来霍山石斛有效成分的药理活性和作用机制仍是国内外研究的主要趋势，尤其是内生真菌及代谢产物的药效研究。另外，良种选育和保护、创新霍山石斛的鉴别技术也是值得关注的热点。     

研究者视角的中国卫生技术评估决策转化现状分析

目的 从研究人员视角描述中国卫生技术评估相关研究向决策转化的现状，并分析其中可能存在的影响因素，为促进我国卫生技术评估向决策转化提供建议。方法 采用问卷调查法和文献检索法，在全国范围内调查研究人员，收集研究人员对我国卫生技术评估现状，以及研究结果的政策转化和利用情况等观点。结果 研究共调查了382名研究人员。调查结果显示，尽管研究人员充分认可研究成果向政策转化的必要性，并且在进行选题时已经对决策转化有所考量，但多数卫生技术评估研究仍停滞在学术阶段，多数研究人员仅提交报告并在学术期刊上发表文章，仍缺乏决策转化的实际行动。此外，部分研究者未能获得充足的研究经费和研究时间，研究机构对卫生技术评估研究所给予的支持也仍显不足，这些也是影响卫生技术评估向决策转化的重要原因。结论 有必要建立卫生技术评估研究必要的规范，以统一并提高研究质量，为决策转化打下坚实的基础；并完善卫生技术评估的研究系统，以保障研究经费、高素质的研究人员，以及多样化的研究成果传播渠道。     

本刊的宗旨、栏目和要求

本刊宗旨系面向应用和应用基础理论研究，以促进科研，加强我国的经济建设和国防建设。内设三个栏目：研究论文，报道与应用有关的生理学研究及对应用生理学有指导意义的基础理论研究的论文；技术方法，登载有关的新技术、新方法；研究简报，以短篇的形式报道最新的研究成果。     

稻田蜘蛛研究进展

稻田蜘蛛研究是稻虫生态管理的基础工作之一，从生态学的观点出发，介绍中国近年稻田蜘蛛研究的主要内容及进展，阐明蜘蛛的保护利用在可持续农业发展中的地位和作用，分析稻田蜘蛛生态研究的可行性，探讨蜘蛛群落研究方向，主要任务和应用前景。     

基于CiteSpace的地果（Ficus tikoua）知识图谱分析

目的：分析地果研究领域的现状和发展趋势，为其研究和应用提供参考。方法：以中国知网（CNKI）期刊全文数据库和Web of Science核心数据库为文献来源，基于CiteSpace对地果研究领域的发文量、发文机构、研究作者、关键词和高被引文献进行分析。结果：地果研究相关文献的数量处于波动状态，总量较少，质量还需提升；中国是研究地果的主要国家，且国内研究机构主要位于其自然分布区域内，国际上对地果的关注极少。国内核心作者源于机构内的合作，机构之间协作较少。总黄酮和化学成分等主题是当前地果的研究热点。结论：目前，对地果的研究少、开发利用程度低，未来应加强品种选育以发挥其在园林、药用、食用和生态修复等方面的优良特性，同时应加强对其系统发育和地果-榕小蜂协同进化等研究。     

论文写作要点——前言

简明介绍论文背景，相关领域研究历史与现状，同时与自己的研究工作进行比较，突出自己著文的意图与分析依据，包括：论文追求目标和创新性，研究范围和理论，技术方案选取与确定，研究结论等。     

Harmonic analysis of two-tone discharge patterns in cochlear nerve fibers

Discharges in cochlear nerve fibers evoked by low frequency phase-locked sinusoidal acoustic stimuli are synchronized to the stimulus waveform. Excitation and suppression regions of single units were explored using a stimulus composed of either a fixed intensity test tone at the characteristic frequency, a variable intensity interfering tone with a simple integer frequency relation to the characteristic frequency, or both. Compound period histograms were constructed from period histograms in response to normal and reversed polarity stimuli. Discharge patterns were characterized by Fourier components of the histogram envelopes. The two stimulus frequencies constituted the principal harmonics in the histogram envelopes and their combination accounted for observed rate changes. Suppression of the test tone harmonic as a function of interfering tone intensity was always seen; rate suppression was not. The harmonic was typically suppressed by 20–30 dB compared to the value for the test tone alone and often reached the 40–60 dB resolution limit of the experiment. Suppression plots were nearly linear on a power scale with an average slope of-0.8. The onset of suppression occurred for an interfering tone 9 dB greater on average than the test tone intensity. Information transfer through the peripheral system was described by the ratio of the principal harmonic amplitudes versus the ratio of the intensities of the two stimulus tones. These plots were nearly linear on a power scale with an average slope of 0.9. Neither the onset of suppression nor the slopes of the harmonic plots displayed strong dependence on characteristic frequency or interfering tone frequency. These features of harmonic behavior, however, are closely related to system nonlinearity. Comparison of measured harmonics to the predictions of two phenomenological models suggest the presence of complex nonlinear transformations in the peripheral auditory system.     

Perception of harmonics in the combination long call of cottontop tamarins, Saguinus oedipus

A number of nonhuman primates produce vocalizations with time-varying harmonic structure. Relatively little is known about whether such spectral information plays a role in call type classification. We address this problem by utilizing acoustic analyses and playback experiments on cottontop tamarins‘ combi nation long call, a species-typical vocalization with a characteristic harmonic structure. Specifically, we used habituation-discrimination experiments to test whether particular frequency components, as well as the relationship between components, have an effect on the perception and classification of long calls. In Condition 1, we show that tamarins classify natural and synthetic exemplars of the long call as perceptually similar, thereby allowing us to use synthetics to manipulate components of this signal precisely. In subsequent conditions, we tested the perceptual salience and discriminability of long calls in which we deleted (1) the second harmonic, (2) the fundamental frequency, or (3) all frequencies above the fundamental; we also examined the effects of frequency mistuning by shifting the second harmonic by 1000 Hz. Following habituation to unmanipulated long calls, tamarins did not respond (transferred habituation) to long calls with either a missing fundamental frequency or the second harmonic, but responded (discriminated) to long calls with the upper harmonics eliminated or with the second harmonic mistuned. These studies reveal the importance of harmonic structure in tamarin perception, and highlight the advantages of using synthetic signals for understanding how particular acoustic features drive perceptual classification in nonhuman primates. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Two-dimensional model of a double-well potential: Proton transfer upon hydrogen bond deformation

Proton tunneling in a hydrogen bond can only take place if the potential energy surface has two minima; this is known as a double-well potential. The aim of this work was (i) to present a simple enough 2D model of H-bond double-well potential in harmonic approximation and (ii) to assess how proton transfer therein is affected by H-bond deformations (shifts and turns such as result from conformational motion of molecular structures carrying the donor and the acceptor). It is shown that even small stretching of the H-bond and reorientation of its covalent part (‘bending’) increase the characteristic time of proton tunneling by orders of magnitude. On the other hand, the model, being two-dimensional, demonstrates that different types of deformation not only can aggravate each other but in some cases can be mutually compensatory in terms of proton transfer efficiency. The properties of the model and some implications of the results are discussed.     

Application of the Fourier Method to Differentiate Biological Rhythms from Stochastic Processes in the Growth of <Emphasis Type="Italic">Selenastrum capricornutum</Emphasis> Printz: Implications for Model Development

The biological rhythms of microalgal growth within a hydraulically integrated serial turbidostat algal reactor (HISTAR) were examined after comparison of a simple mechanistic productivity model with actual data yielded a standard error of prediction (SEP) of 62%. The data used for this study were taken on cultures of Selenastrum capricornutum grown under continuous 400-watt metal halide lighting. Fourier series analysis (up to five harmonics) was used to model the biorhythms and differentiate them from stochastic processes. Regression analyses revealed that the best Fourier series fit for the data was a three harmonic summation. Regression analyses on additional harmonic summations did not increase r ² by more than 1%. The three harmonics were summed and incorporated into the growth term of the simple model, and the resultant full model was calibrated. The mechanistic HISTAR productivity model was greatly enhanced by the addition of the biological rhythm component, resulting in a SEP of <24.8 %. The period of the first harmonic was 13.4 days, which is very close to a circasemilunar rhythm (14.8 days). In summary, the predictive power of productivity models for continuous microalgal cultures can be dramatically improved with the inclusion of a biorhythm analysis.     

Acoustic studies on the mechanism of sound production in the mating songs of the melon fly,Dacus cucurbitae Coquillett (Diptera: Tephritidae)

The sound production mechanism in the male mating songs for the melon flyDacus cucurbitae Coquillett was acoustically investigated to determine whether sounds resulted from free wing-fanning or stridulation produced by contact between wing and abdominal pecten. Waveforms in the songs of normal (pecten-present) males showed more complex vibrations than those of pecten-removed males. The total harmonic distortion in normal songs was greater than that of the pecten-removed songs. Female (pecten-absent) songs showed different sound signatures on the oscillogram and frequency spectrum from normal male songs. The female songs had more harmonic components than the normal male songs. These results suggest that wing/pecten stridulation of normal male songs produces complicated wing oscillations with a small number of harmonics of near-periodic waveforms and a high harmonic distortion. They also suggest that the free wing-fanning observed during female and pecten-removed male songs produces simple and uniform wing oscillations with many harmonic contents of complex-periodic waveforms and low harmonic distortion. Despite the occurrence of some acoustic differences, pecten-removal did not positively influence the rate of copulation.     

A MORPHOMETRIC STUDY ON THE THICKNESS OF THE PULMONARY AIR-BLOOD BARRIER

A reliable knowledge of the thickness of the alveolo-capillary "membrane" or air-blood barrier is of physiologic interest since it is intimately related to a quantitative estimation of such functional events as gas diffusion or tissue metabolism in the lung. The characteristic thickness of the air-blood barrier with respect to gas diffusion is its harmonic mean thickness, while the arithmetic mean thickness is related to the mass of tissue building the barrier and consuming oxygen in the lung. Two morphometric methods are proposed by which these two dimensions can be estimated from random measurements in the electron microscope in a reliable, simple, and efficient manner. By applying these methods to three rat lungs the arithmetic mean thickness of the barrier was found to measure 1.25 µ, the harmonic mean thickness, 0.57 µ. On the basis of these measurements a geometric model of the barrier in the form of a corrugated membrane was derived. Its dimensions showed close similarity to those of the natural barrier. This analysis suggested furthermore that the gas conductance of the barrier is nearly optimal if one considers the mass of tissue and the minimal barrier thickness as fixed properties which are determined by other functional requirements on the alveolo-capillary membrane.     

Light absorption, electron paramagnetic resonance and resonance Raman characteristics of nitridochromium(V) protoporphyrin-IX and its reconstituted hemoproteins.

A surprisingly stable complex of the photolyzed product of azidochromium(III)protoporphyrin-IX was prepared and examined by light absorption, electron paramagnetic resonance (EPR) and resonance Raman spectroscopies. The characteristic EPR spectrum for this complex was consistent with a nitridochromium(V)-porphyrin complex which was two oxidation equivalents above the resting Cr(III) complex. The Cr(V)-N stretching mode was observed at 1010 cm-1 by resonance Raman spectroscopy. A simple diatomic harmonic oscillation model gave a force constant of 6.7 mdyn/A for the Cr(V)-N bond, in the region characteristic for the metal-nitrogen triple bond. Nitridochromium(V) protoporphyrin-IX reconstituted myoglobin and cytochrome c peroxidase were prepared for the first time. The nitridochromium(V)-porphyrins in these apo-proteins were unstable in contrast with the protein-free chromium(V)porphyrin. Upon irradiation of the azide complexes of the chromium(III) protoporphyrin-IX reconstituted myoglobin and cytochrome c peroxidase with ultraviolet light aerobically at room temperature, the characteristic optical and EPR spectra for nitridochromium(V) derivatives were observed. The optical spectra of these photo-induced products were different from those of the nitridochromium(V) protoporphyrin-IX reconstituted hemoproteins. The electrochemical structures of the unusual metalloporphyrin seemed to be modulated by the heme surrounding amino acid residues.     

The graph theoretical analysis of the SSVEP harmonic response networks

Steady-state visually evoked potentials (SSVEP) have been widely used in the neural engineering and cognitive neuroscience researches. Previous studies have indicated that the SSVEP fundamental frequency responses are correlated with the topological properties of the functional networks entrained by the periodic stimuli. Given the different spatial and functional roles of the fundamental frequency and harmonic responses, in this study we further investigated the relation between the harmonic responses and the corresponding functional networks, using the graph theoretical analysis. We found that the second harmonic responses were positively correlated to the mean functional connectivity, clustering coefficient, and global and local efficiencies, while negatively correlated with the characteristic path lengths of the corresponding networks. In addition, similar pattern occurred with the lowest stimulus frequency (6.25 Hz) at the third harmonic responses. These findings demonstrate that more efficient brain networks are related to larger SSVEP responses. Furthermore, we showed that the main connection pattern of the SSVEP harmonic response networks originates from the interactions between the frontal and parietal–occipital regions. Overall, this study may bring new insights into the understanding of the brain mechanisms underlying SSVEP.     

Variations on a theme by Debye and Waller: From simple crystals to proteins

Debye and Waller showed how to adjust scattering intensities in diffraction experiments for harmonic motions of atoms about an average, static reference configuration. However, many motions, particularly in biological molecules as compared to simple crystals, are far from harmonic. We show how, using a variety of simple anharmonic, multiconformational models, it is possible to construct a variety of Generalized Debye-Waller Factors, and understand their meaning. A central result for these cases is that, in principle, intensity factors cannot be obtained from true total mean square displacements of the atoms. We make the distinction between the intensity factors for unimodal quasiharmonic motions and those for the anharmonic, multimodal (valley hopping) motions. Only the former affect the conventional B factors. Proteins 29:153–160, 1997. Published 1997 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Higher harmonic generation microscopy for developmental biology

Optical higher harmonic generation, including second harmonic generation and third harmonic generation, leaves no energy deposition to its interacted matters due to an energy-conservation characteristic, providing the "noninvasiveness" nature desirable for biological studies. Combined with its nonlinearity, higher harmonic generation microscopy provides excellent three-dimensional (3D) sectioning capability, offering new insights into the studies of embryonic morphological changes and complex developmental processes. By choosing a laser working in the biological penetration window, here we present a noninvasive in vivo light microscopy with sub-micron 3D resolution and millimeter penetration, utilizing endogenous higher harmonic generation signals in live specimens. Noninvasive imaging was performed in live zebrafish (Danio rerio) embryos. The complex developmental processes within > 1-mm-thick zebrafish embryos can be observed in vivo without any treatment. No optical damage was found even with high illumination after long-term observations and the examined embryos all developed normally at least to the larval stage. The excellent 3D resolution of the demonstrated technology allows us to capture the subtle developmental information on the cellular or sub-cellular levels occurring deep inside the live embryos and larvae. This technique can not only provide in vivo observation of the cytoarchitecture dynamics during embryogenesis with submicron resolution and millimeter penetration depth, but would also make strong impact in developmental and structural biology studies.