从鱿鱼墨中精制黑色素

介绍了以鱿鱼墨为原料从中提取，精制黑色素的工艺。具体路线为：原料鱿鱼墨经水洗，酸洗，浓酸水解去除绝大多数杂质后，添加二甲亚砜（DMSO）使黑色素完全溶解，然后，加入丙酮改变溶液极性，减小黑色素的溶解度，从而使黑色素再次析出，经三次重结晶，以达到精制目的。在此基础上，测定了鱿鱼墨黑色素的一些物理和化学性制，精制所得黑色素呈黑褐色，不溶于水及通常的有机溶剂，但可溶于碱，浓硫酸，二甲亚砜等，紫外－可见光谱和红外光谱初步表明鱿鱼墨黑色素是以吲哚结构为主体的异聚物。     

从鱿鱼墨中精制黑色素

介绍了以鱿鱼墨为原料从中提取，精制黑色素的工艺。具体路线为：原料鱿鱼墨经水洗，酸洗，浓酸水解去除绝大多数杂质后，添加二甲亚砜（DMSO）使黑色素完全溶解，然后，加入丙酮改变溶液极性，减小黑色素的溶解度，从而使黑色素再次析出，经三次重结晶，以达到精制目的。在此基础上，测定了鱿鱼墨黑色素的一些物理和化学性制，精制所得黑色素呈黑褐色，不溶于水及通常的有机溶剂，但可溶于碱，浓硫酸，二甲亚砜等，紫外－可见光谱和红外光谱初步表明鱿鱼墨黑色素是以吲哚结构为主体的异聚物。     

Fast axonal transport in extruded axoplasm from squid giant axon

Development of video-enhanced contrast-differential interference contrast for light microscopy has permitted study of both orthograde and retrograde fast axonal transport of membranous organelles in the squid giant axon. This process was found to continue normally for hours after the axoplasm was extruded from the giant axon and removed from the confines of the axonal plasma membrane. It is now possible to follow the movements of the full range of membranous organelles (30-nanometer vesicles to 5000-nanometer mitochondria) in a preparation that lacks a plasma membrane or other permeability barrier. This observation demonstrates that the plasma membrane is not required for fast axonal transport and suggests that action potentials are not involved in the regulation of fast transport. Furthermore, the absence of a permeability barrier surrounding the axoplasm makes this an important model for biochemical pharmacological, and physical manipulations of membranous organelle transport.     

中国远洋鱿钓渔业的可持续发展探讨

1　中国远洋鱿钓渔业的发展概况1 989年 ,上海水产大学受中国水产总公司委托 ,派“浦苓号”实习船赴日本海俄管水域进行太平洋褶柔鱼资源的开发 ,揭开了中国远洋鱿钓渔业的发展序幕。至 1 992年基本上完成了日本海太平洋褶柔鱼的渔场开发、钓捕技术掌握、技术装备的改制等技术工作 ,并初步形成了小规模的生产。这段时间 ,参与鱿钓生产的企业仅舟山海洋渔业公司一家 ,1 990年该公司首先改装了 2艘鱿钓船投入试生产 ,取得了收支保本的好成绩 ,随即有了迅速的发展 ,1 992年鱿钓船增至 1 6艘。 1 992年与 1 990年相比 ,在产量表 1　 1 990 - 1 9…     

中国远洋鱿钓渔业的可持续发展探讨

1　中国远洋鱿钓渔业的发展概况1 989年 ,上海水产大学受中国水产总公司委托 ,派“浦苓号”实习船赴日本海俄管水域进行太平洋褶柔鱼资源的开发 ,揭开了中国远洋鱿钓渔业的发展序幕。至 1 992年基本上完成了日本海太平洋褶柔鱼的渔场开发、钓捕技术掌握、技术装备的改制等技术工作 ,并初步形成了小规模的生产。这段时间 ,参与鱿钓生产的企业仅舟山海洋渔业公司一家 ,1 990年该公司首先改装了 2艘鱿钓船投入试生产 ,取得了收支保本的好成绩 ,随即有了迅速的发展 ,1 992年鱿钓船增至 1 6艘。 1 992年与 1 990年相比 ,在产量表 1　 1 990 - 1 9…     

中国远洋鱿钓渔业的发展与前景

介绍了中国远洋鱿钓渔业发展的３个阶段。从生产规模、生产效率、作业渔场３个方面介绍了中国远洋鱿钓渔业发展状况,对中国产鱿钓渔业目前的生产和发展提出一些建议,并对中国远洋鱿钓渔业的前景进行了展望。     

IPV4向IPV6网络体系的过渡与安全问题

伴随互联网用户数膨胀所出现的问题越来越严重,人们提出下一代互联网采用的核心协议IPv6.现行的IPv4向IPv6过渡势在必行,因此对IPv4向IPv6过渡过程中网络体系结构的更替进行研究具有重要的现实意义.另外,新的网络体系也面临诸多安全问题同样不可忽视.     

不同基质对几种花卉组培苗一次性过渡的影响

用腐殖土、红土、珍珠岩配成比例不同的 6种基质 ,探讨其对满天星、情人草、勿忘我组培苗一次性过渡的影响。结果表明 ,满天星在腐殖土 红土 珍珠岩 (1∶2∶1/4 ) ,情人草在腐殖土 红土 (1∶1/7) ,勿忘我在腐殖土 红土 珍珠岩 (1∶2∶1/6 )中成活率高、成苗快、幼苗健壮。     

互联网IPv4向IPv6的过渡技术

IPv6及相关协议已相对成熟,如何渐进的、无伤害的由IPv4过渡到IPv6是当前Internet发展所面临的重要问题。研究IPv4向IPv6的过渡技术,旨在使IPv6最终替代IPv4。     

Singlet diradicals: from transition states to crystalline compounds

Singlet diradicals are usually not energy minima. As observed by femtosecond spectroscopy, they readily couple to form final sigma bonds. Substituent effects allow lifetimes to increase into the microsecond range. Taking advantage of the properties of hetero-elements, a diradical has been prepared that is indefinitely stable at room temperature. The availability of diradicals that can be handled under standard laboratory conditions will lead to further insight into their chemical and physical properties, raising the likelihood of practical applications, especially in the field of molecular materials such as electrical conductors and ferromagnets.     

Heat generated by the dark-adapted squid retina in response to light pulses

A rapid increase in the temperature of the dark-adapted squid retina evoked by a brief light pulse was detected with a pyroelectric detector. The amount of heat generated by the retina in response to a pulse of blue light of moderate intensity was far greater than that produced by direct conversion of the stimulating light by the retinal pigments into thermal energy. D-Glucose in the medium was required to maintain the ability of the retina to produce light-evoked thermal responses.     

浅析IPV4向IPV6的过渡

IPv4地址资源的短缺决定了基于IPv6技术的网络时代的必然到来.本文主要分析了IPv4面临的问题.IPv6的定义、发展现状及优势,存在的问题以及IPv6发展趋势等,试着探讨下一代互联网协议IPV6发展.     

The microscopic basis of the glass transition in polymers from neutron scattering studies

Recent neutron scattering experiments on the microscopic dynamics of polymers below and above the glass transition temperature T(g) are reviewed. The results presented cover different dynamic processes appearing in glasses: local motions, vibrations, and different relaxation processes such as alpha- and beta-relaxation. For the alpha-relaxation, which occurs above T(g), it is possible to extend the time-temperature superposition principle, which is valid for polymers on a macroscopic scale, to the microscopic time scale. However, this principle is not applicable for temperatures approaching T(g). Below T(g), an inelastic excitation at a frequency of some hundred gigahertz (on the order of several wave numbers), the "boson peak," survives from a quasi-elastic overdamped scattering law at high temperatures. The connection between this boson peak and the fast dynamic process appearing near T(g) is discussed.     

南海鸢乌贼肌原纤维蛋白加热过程中理化性质的变化

为研究南海鸢乌贼Symplectoteuthis oualaniensis肌原纤维蛋白在加热过程中理化性质的变化,以南海鸢乌贼胴体肌肉为原料,对其肌原纤维蛋白在加热过程中浊度、溶解度、Ca~(2+)-ATPase活性和总巯基(-SH)含量进行了测定,并对该蛋白质在整个加热过程中SDS-PAGE电泳图的变化进行了研究。结果表明:在25~35℃时,鸢乌贼肌原纤维蛋白的浊度、溶解度、Ca~(2+)-ATPase活性、总巯基含量的变化均比较缓慢;在35℃后继续升温,浊度、Ca~(2+)-ATPase活性、总巯基含量均发生明显变化;总巯基含量在40~50℃时出现短暂升高现象后又急剧降低,溶解度在50℃时开始明显降低;在25~35℃时,随着温度的逐渐升高,鸢乌贼肌原纤维蛋白的肌球蛋白重链(MHC)略有减少,副肌球蛋白(PM)和肌动球蛋白(Actin)基本上未发生变化,但在35℃后,鸢乌贼肌原纤维蛋白开始产生大分子物质,逐渐发生变性。     

南海鸢乌贼肌原纤维蛋白加热过程中理化性质的变化

为研究南海鸢乌贼Symplectoteuthis oualaniensis肌原纤维蛋白在加热过程中理化性质的变化,以南海鸢乌贼胴体肌肉为原料,对其肌原纤维蛋白在加热过程中浊度、溶解度、Ca⁽²⁺⁾-ATPase活性和总巯基(-SH)含量进行了测定,并对该蛋白质在整个加热过程中SDS-PAGE电泳图的变化进行了研究。结果表明:在25(2+)-ATPase活性和总巯基(-SH)含量进行了测定,并对该蛋白质在整个加热过程中SDS-PAGE电泳图的变化进行了研究。结果表明:在25³5℃时,鸢乌贼肌原纤维蛋白的浊度、溶解度、Ca35℃时,鸢乌贼肌原纤维蛋白的浊度、溶解度、Ca⁽²⁺⁾-ATPase活性、总巯基含量的变化均比较缓慢;在35℃后继续升温,浊度、Ca(2+)-ATPase活性、总巯基含量的变化均比较缓慢;在35℃后继续升温,浊度、Ca⁽²⁺⁾-ATPase活性、总巯基含量均发生明显变化;总巯基含量在40(2+)-ATPase活性、总巯基含量均发生明显变化;总巯基含量在40⁵0℃时出现短暂升高现象后又急剧降低,溶解度在50℃时开始明显降低;在2550℃时出现短暂升高现象后又急剧降低,溶解度在50℃时开始明显降低;在25³5℃时,随着温度的逐渐升高,鸢乌贼肌原纤维蛋白的肌球蛋白重链(MHC)略有减少,副肌球蛋白(PM)和肌动球蛋白(Actin)基本上未发生变化,但在35℃后,鸢乌贼肌原纤维蛋白开始产生大分子物质,逐渐发生变性。     

Alpha-decay--induced fracturing in zircon: the transition from the crystalline to the metamict state

A natural single crystal of zircon, ZrSiO(4,) from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 10(16) and 0.8 x 10(16) alpha-events per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 10(16) alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.     

食品包装材料中邻苯二甲酸酯向食品模拟物中的迁移规律

采用超高效液相-串联质谱法(UPLC-MS/MS)对不同温度、时间条件下的16种邻苯二甲酸酯(PAEs)从食品包装材料中向水性、酸性、酒性与脂肪性食品模拟物中的迁移律进行研究。结果表明:在食品模拟物富集浓度30μg/m L,富集时间6 h条件下,PAEs富集最佳。其中PAEs在不同食品模拟物中迁移率为:脂肪性酒性酸性水性;在同一种食品模拟物条件下,随着迁移时间增长和温度增加都有助于PAEs迁移速率提高;同时,同一性质食品模拟液在同一温度条件下,随着分子链长逐步增长,相对分子质量依次增大,迁移率基本呈逐渐降低趋势。     

Band-gap engineering: from physics and materials to new semiconductor devices

Band-gap engineering is a powerful technique for the design of new semiconductor materials and devices. Heterojunctions and modern growth techniques, such as molecular beam epitaxy, allow band diagrams with nearly arbitrary and continuous band-gap variations to be made. The transport properties of electrons and holes can be independently and continuously tuned for a given application. A new generation of devices with unique capabilities, ranging from solid-state photomultipliers to resonant tunneling transistors, is emerging from this approach.