从造纸术摇篮到造纸工业现代化

众所周知，我国是造纸术的摇篮。造纸术的外传曾经一度起到促进世界文化发展的作用。然而，我国却经历了数百年的历程，机制纸才开始取代手工造纸，事实上，我国造纸工业是在中华人民共和国成立后，才开始阔步前进，并在1993年其纸和纸板总产量跃居世界主要产纸国家第三位。然而，人均消费量依然仅有36公斤，远远落后于世界平均水平的50公斤。为了促进我国造纸工业的现代化和健康发展，今后务必着眼于可持续纤维原料的开发和利用，认真执行清洁生产和质量第一的技术路线。这就意味着有必要在纤维原料中增加木材的份额。与此同时，又必须妥善处理工厂排污（特别是蒸煮废渣的处理），务使取得更好的环境保护效果。不言而喻，也就更有必要加强科研与开发工作，针对我国纤维原料的特点有所创新，并做到在实际生产中得到兑现。     

纤维编织网联合钢筋增强混凝土梁受弯性能解析理论

纤维编织网增强混凝土（TRC）是一种新型的高性能纤维增强水泥基复合材料，其不但有良好的耐腐蚀性，还可以有效限制混凝土的裂缝发展，使混凝土的裂缝宽度和间距变得更小．但由于纤维本身的脆性特征，使TRC结构达到极限荷载时没有明显的破坏预兆，而普通钢筋混凝土结构则由于特殊保护层厚度的限制，具有较大的自重，且不能有效限制结构的主裂缝发展．为克服二者的不足，本文创新性地提出纤维编织网联合钢筋增强混凝土结构，其充分利用了TRC和RC的优点．采用TRC替代其受拉区保护层的部分混凝土，同时减掉纤维编织网所替代钢筋用量，以发展一种自重小、使用安全、耐久性好的结构．分析了这种结构适筋梁的受弯发展过程，基于平截面假定按非线性分析理论给出了整个受力过程不同阶段梁的承载力，M-φ关系和跨中挠度的解析计算公式．最后通过与试验结果的对比，验证公式的合理性．     

玄武岩纤维布加固钢筋混凝土柱抗压对比试验研究

本文对玄武岩纤维布与碳纤维布加固钢筋混凝土柱进行了对比试验,研究了加固后其承载力、延性、应变发展、裂缝及破坏特征等变化。并对混凝土柱上黏贴一层纤维布和两层纤维布进行了对比试验,分析了各种参数对玄武岩纤维布加固柱承载力和变形的影响。对相应工程应用提出建议。     

应力、应力纤维、Rho三者关系的研究进展

应力影响细胞的形状和骨架结构并因此控制许多与组织发展有关的关键行为，因此应力作用下细胞的种种响应问题成为生物力学目前最热的研究领域，应力纤维、Rho在研究应力信号如何被细胞感受过程中占据核心地位并已成为研究者关注的重点。本文依据国内外近几年进行的细胞对应力响应的研究进展对应力、应力纤维、Rho三者的相互关系进行了综述。     

耐超高温连续Si-Al-C纤维的一步法制备与表征

采用先驱体转化技术，以聚铝碳硅烷（PACS）为先驱体，经过熔融纺丝、空气预氧化处理和超高温烧结处理，制备了近化学计量比的连续SiC纤维．研究结果表明：一步法所制备的连续Si-Al-C纤维的平均直径为11～12μm平均抗拉强度为1．8～2．0GPa；纤维的化学式为SiCl-0100040A10．024，主要由规整的β-SiC构成，此外含有少量的α-SiC和无定型的SiC；连续Si-Al-C纤维具有优良的耐超高温性能，在1500℃氩气中处理1h后，纤维的抗拉强度基本保持不变，在1800℃氩气中处理1h后，纤维的强度保留率为80％左右．     

面向21世纪加快现代农业建设

本文总结了我国农业和农村经济在“八五”期间所取得的成就，分析了其发展现状和存在总是，展望了“九五”的发展前景；针对世界农业发展的趋势，提出现代农业建设是加快农业增长方式转变的关键的观点，并探索了我国现代农业建设的途径；根据农业持续发展的需要和我国基本国情的要求，指出现代集约持续农业是我国现代农业建设的必由之路，并解释了现代集约持续农业的概念和内涵，探索了其区域发展战略，规划了其重点发展领域；在分析现代科学技术的新趋势、世界农业科技发展趋势与重点和科技进步对我国农业持续发展的重要作用的基础上，提出科学技术是推动农业持续发展的强大动力，探讨了我国农业科技发展的战略和主要任务；根据21世纪世界农业发展的主要特点和世纪之交我国农业发展的主要特点，提出了面向21世纪，树立推进现代农业建设的八个新观念。     

先进材料科学与应用的展望

本文对材料的发展现状作了较为详尽的综述，对先进材料的开发使用和材料科学的发展前景作了展望。由于材料特别是高性能，多用途先进材料是人类社会发展的重要推动力，先进材料将继续成为科学和工程研究的重点。作者认为纤维增强树脂复合材料和硅基电子材料是当今工业中最重要的材料，而智能材料、纳米材料、光电材料、生物材料和高温陶瓷材料将是２１世纪的研究重点，并将发挥愈来愈大的作用。     

近代我国畜牧科技事业发展回顾与思考

1840年以来，尽管西方资本主义列强对我国进行长期搔扰以及国内战争频伐，我国畜牧科技现代化发展遭遇极大困难；但在全国广大人民的共同努力和畜牧科技工作者的辛勤工作下，通过克服重重困难，不仅建立了许多畜牧科技机构，还开展大量具有远见卓识的畜禽饲养和繁殖研究以及牧草引种栽培试验，为我国现代畜牧科技的发展奠定了基础；同时为我国畜牧科技今后的发展构筑了框架，指明了方向。总结我国畜牧科技这段艰难发展历程，看今天我国畜牧科技现代化发展道路，无疑将给我们许多重要启迪与借鉴。     

航空发动机发展简述与思考

本文简要回顾航空发动机发展的历程，对当前航空发动机发展的特点和展望进行简述，主要是从我国航空发动机发展的现状，思考和分析其落后的根本原因，为了我国航空事业的更快发展，提出了我国航空发动机发展的关键是管理的论点和建议。     

水热法制备氧化锌纤维及纳米粉体

介绍了一种新的水热合成技术－－水热盐溶液卸压技术，并由此技术制得了晶粒粒度仅为５ｎｍ的ＺｎＯ粉体和长径比为１６：１的ＺｎＯ纤维，着重研究了在水热条件下制得的ＺｎＯ粉体的晶粒粒度变化以及ＺｎＯ纤维形成的主要原因，提出了由水热法制备粉体时成核速度是影响晶粒度的主要原因，即成核速度越快，制得的粉体的晶粒粒度越小，纤维的形成与水热反应过程在卸压条件下进行有关；与卸压前粉体的结晶程度有关。     

Selectivity of alterations in skeletal fibers in chronic Chagas' disease of the mouse

Summary In mice chronically infected withTrypanosoma cruzi, the masseter muscle (rich in type II fibers) was devoid of inflammatory infiltrates and parasites. In contrast, other muscles, composed of type I and II fibers, showed a decrease of type I fibers, parasites and lesions, suggesting that inT. cruzi infection type I muscle fibers are selectively damaged.     

Interaction between bradykinin and voltage-sensitive sodium channels in myelinated nerve fibers

The effects of externally and internally applied bradykinin on the excitability of single myelinated nerve fibers were studied. External bradykinin (10 microM) slightly prolongs the action potential of a single myelinated nerve fiber; hence, when the fibers are stimulated by long-lasting pulses, this raises the frequency of repetitive firing in sensory fibers and evokes repetitive activity in motor fibers. Under voltage-clamp conditions, sodium channel inactivation is slowed, while sodium channel activation remains unaffected. Prolonged depolarization of the membrane leads to a maintained sodium current. The voltage dependence of the steady-state sodium current inactivation (h infinity) is shifted in the depolarized direction by approximately 10 mV. Internally applied bradykinin produces a frequency-dependent block of the sodium current. The phenomena described here imply that more than one site on the sodium channel is modified by bradykinin.     

Different intrafusal fiber composition of spindles in sheep and pig extraocular muscles

Summary Histochemical profiles of intrafusal fibers have been examined in muscle spindles of extraocular muscles of sheep and pig. Results show that in the sheep the intrafusal content presents, in addition to chain fibers, at least one bag₁ and one bag₂ fiber, whereas in the pig almost all the spindles are bag₁-fiber spindles.Acknowledgment. This study was supported by grants from C.N.R. and M.P.I.     

The conduction velocity,number and diameter of unmyelinated fibers in Remak's nerve

Summary Remak's nerve in the chicken was examined ultrastructurally and electrophysiologically to determine the characteristics of fibers in the nerve trunk. The ratio of unmyelinated fibers to myelinated ones was 1111. The mean number of unmyelinated fibers was 3555±232 (SEM, n=5) and they had a mean diameter of 0.502±0.034 (SEM) m. The compound action potential consisted almost entirely of a large diphasic waveform which had a mean peak conduction velocity of 0.62±0.031 (SEM, n=5) m·s^–1 at 37°C.     

Interaction between bradykinin and voltage-sensitive sodium channels in myelinated nerve fibers

Summary The effects of externally and internally applied bradykinin on the excitability of single myelinated nerve fibers were studied. External bradykinin (10 M) slightly prolongs the action potential of a single myelinated nerve fiber; hence, when the fibers are stimulated by long-lasting pulses, this raises the frequency of repetitive firing in sensory fibers and evokes repetitive activity in motor fibers. Under voltage-clamp conditions, sodium channel inactivation is slowed, while sodium channel activation remains unaffected. Prolonged depolarization of th membrane leads to a maintained sodium current. The voltage dependence of the steady-state sodium current inactivation (h ) is shifted in the depolarized direction by 10 mV. Internally applied bradykinin produces a frequency-dependent block of the sodium current. The phenomena described here imply that more than one site on the sodium channel is modified by bradykinin.     

Uptake and transport of exogenous peroxidase in the masticatory muscles of cats. Localization of ganglionic neurons]

Retrograde axonal transport of Horseradish peroxydase (HRP) has been used to trace the cells of origin of proprioceptive fibers in jaw-closing and jaw-opening muscles. After injection of HRP in young cats' masticatory muscles (masseteric, temporal, pterygoid, mylohyoid and digastric) labelled neurons were found in the ipsilateral semi-lunar ganglion and trigeminal mesencephalic nucleus. It is concluded that sensory endings are present in jaw-opening as in jaw-closing muscles; possibly the afferent fibers from muscle endings of the opener muscles have their somata in the mesencephalic nucleus, afferent fibers from tendinous receptors in the semi-lunar ganglion.     

Dynamics of increase in muscle fibers in fishes in relation to size and growth

Summary Dynamics of increase of white myotomal muscle fibers of four species of freshwater teleosts (Salmo gairdneri, Pimephales notatus, Esox masquinongy andE. americanus vermiculatus) from three families (Salmonidae, Cyprinidae, Esocidae) representing a variety of maximum attainable sizes and growth rates, have been investigated. There are at least three major differences in these dynamics, and there appears to be an association between the ability of a fish species to attain large size (and grow fast) and its ability to recruit new fibers into this predominant tissue of the myotomal mass.     

Mechanisms of glial-guided neuronal migration in vitro and in vivo

Summary Our laboratory has developed an in vitro model system in which glial-guided neuronal migration can be observed in real time. Cerebellar granule neurons migrate on astroglial fibers by apposing their cell soma against the glial arm, forming a specialized migration junction, and extending a motile leading process in the direction of migration. In vitro assays indicate that the neuronal antigen astrotactin functions as a neuron-glia ligand, and is likely to play a role in the movement of neurons along glial fibers. In heterotypic recombinations of neurons and glia from mouse cerebellum and rat hippocampus, neurons migrate on heterotypic glial processes with a cytology, speed and mode of movement identical to that of neuronal migration on homotypic glial fibers, suggesting that glial fibers provide a permissive pathway for neuronal migration in developing brain. In vivo analyses of developing cerebellum demonstrate a close coordination of afferent axon ingrowth relative to target cell migration. These studies indicate that climbing fibers contact immature Purkinje neurons during the migration and settling of Purkinje cells, implicating a role for afferents in the termination of migration.     

Expression of alpha-cardiac myosin heavy chain in mammalian skeletal muscle

We have investigated the reactivity of different human, rat and cat muscles to a monoclonal antibody directed against human -cardiac myosin heavy chain. We have found that special fiber subpopulations of human massetr and extraocular muscles, as well as the bag fibers of human, rat and cat muscle spindles, were reactive to this antibody, indicating that these fibers expressed -cardiac myosin heavy chain or a closely related isoform. This isomyosin was present in the spindle bag fibers at early fetal stages, whereas its expression in masseter and extraocular muscle fibers was not detected during the first 22 weeks of gestation. Our results add to the list of muscle proteins which are expressed in locations or at developmental stages other than those initially described, suggesting that a revision of the present nomenclature of the subgroups of myosin heavy chains might be considered in the future.     

有机/无机杂化材料与多功能纤维研究进展

有机/无机杂化材料能够实现有机高分子材料与无机材料在纳米或分子水平上的复合,在发挥各自组分特性的同时,体现出特有的协同效应,如新性能、多功能.该原理同样适用于有机/有机杂化体系.随着产业用纤维材料的不断发展,其应用领域也随之拓展,开发新型高分子材料,实现纤维的多功能化成为研究热点.根据纤维多功能化的发展需求,结合有机/无机杂化机理,在分子水平上设计构筑杂化功能材料,采用结构设计、界面构筑的方法建立杂化功能材料与成纤高聚物杂化体系.以成纤高分子的结构设计及凝聚态控制、纳米纤维和低维纳米材料的结构可控制备及其功能化复合为例,简要介绍了有机/无机杂化原理在纤维多功能化方面的研究进展,最后提出了多功能化有机/无机杂化纤维的展望.