Preparation of core–shell type nanoparticles of diblock copolymers of poly(L‐lactide)/poly(ethylene glycol) and their characterization in vitro

Core–shell type nanoparticles of poly(L ‐lactide)/poly(ethylene glycol) (LE) diblock copolymer were prepared by a dialysis technique. Their size was confirmed as 40–70 nm using photon correlation spectroscopy. The ¹H‐NMR analysis confirmed the formation of core–shell type nanoparticles and drug loading. The particle size, drug loading, and drug release rate of the LE nanoparticles were slightly changed by the initial solvents that were used. The drug release behavior of LE core–shell type nanoparticles showed an initial burst during the first 12 h and then a sustained release until 100 h. The degradation behavior of LE block copolymer nanoparticles was divided into three phases: the initial rapid degradation phase, the stationary phase, and the rapid degradation phase until complete degradation. It was suggested that lidocaine release kinetics were predominantly governed by the diffusion mechanism in the initial burst phase and after that by both of the diffusion and degradation mechanisms. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2625–2634, 2002     

圆杆弹性和弹—塑性扭转公式的探讨

对圆杆在线弹性阶段，弹－塑性阶段和全塑性阶段的扭转剪应力的计算公式作了分析，并推导了在材料的应力－应变关系（τ－γ关系）不服从虎克定律时，扭转真实剪应力的计算公式。文中对扭转强度计算公式的来源，物理含义及其都作了详细的说明。这对执行和理解国家ＧＢ１０１２８－８８《金属室温扭转试验方法》是有益的，而且对高校中材料力学的教学具有一定的参考价值。     

Prolonged poststrike elevation in tongue-flicking rate with rapid onset in gila monster,Heloderma suspectum: Relation to diet and foraging and implications for evolution of chemosensory searching

Experimental tests showed that poststrike elevation in tongue-flicking rate (PETF) and strike-induced chemosensory searching (SICS) in the gila monster last longer than reported for any other lizard. Based on analysis of numbers of tongue-flicks emitted in 5-min intervals, significant PETF was detected in all intervals up to and including minutes 41–45. Using 10-min intervals, PETF lasted though minutes 46–55. Two of eight individuals continued tongue-flicking throughout the 60 min after biting prey, whereas all individuals ceased tongue-flicking in a control condition after minute 35. The apparent presence of PETF lasting at least an hour in some individuals suggests that there may be important individual differences in duration of PETF. PETF and/or SICS are present in all families of autarchoglossan lizards studied except Cordylidae, the only family lacking linguallly mediated prey chemical discrimination. However, its duration is known to be greater than 2-min only in Helodermatidae and Varanidae, the living representatives of Varanoidea. That prolonged PETF and SICS are typical of snakes provides another character supporting a possible a varanoid ancestry for Serpentes. Analysis of 1-min intervals showed that PETF occurred in the first minute. A review of the literature suggests that a pause in tongue-flicking and delay of searching movements are absent in lizards and the few nonvenomous colubrid snakes tested. The delayed onset of SICS may be a specific adaptation of some viperid snakes to allow potentially dangerous prey to be rendered harmless by venom following voluntary release after envenomation and preceding further physical contact with the prey.     

一种低频 空间定向及高灵敏遥感方法研究

本文提出一种低频、空间定向及高灵敏的遥感方法。文中介绍了传感器及其二次仪表设计原理和关键技术。由作者研制的本检测系统,在空气中的定向接收灵敏度,离1米处高达120mV/μPa,比HP4905A型机的输出信噪比高8倍.     

测量不确定度在钢材检验中的应用

中国加入WTO后，与外界的交流频繁了，用测量不确定度描述各种报告的测试结果，越来越迫切。钢材的外型尺寸检验、化学成分元素含量分析、钢材的力学性能测试等等的检验报告，都需要应用不确定度的理论。本文主要介绍了在这些测量中的不确定度问题。     

The costs and benefits of tonal centers for chord processing.

Harmonic priming studies have shown that a musical context, with its established tonal center, influences target chord processing. This study investigated costs and benefits of priming tonal centers for target processing by adding a baseline condition (sequences without a specific tonal center). Results confirmed harmonic priming, with faster processing for related than for unrelated and less related targets (tonic chord, out-of-key chord, subdominant chord). Comparing targets in baseline contexts with targets in sequences with well-established tonal centers revealed a benefit of processing for related targets but a cost of processing for unrelated and less related targets. Findings are discussed in terms of tonal knowledge activation and suggest that an activated tonal center gives rise to strong expectations for the tonic. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term measurements of the concentrations of halocarbons in an urban area of Kraków, Poland

The results of the measurements of the concentrations of freons (F-11 and F-113), chloroform (CHCl₃), trichloroethane (CH₃CCl₃) and carbon tetrachloride (CCl₄) in air are presented. The data concern concentration measurements that have been conducted in Krakow since half way through 1997 to the end of 1999. The mean monthly values of these concentrations have been compared with the data from Mace Head, the station situated at a similar longitude as Krakow. It has been concluded that, in the observed period of time, the concentrations of the pollutants in Krakow are higher than in Mace Head. The mean monthly concentrations of F-11 and CCl₄ decrease in Krakow faster than in Mace Head (2.5 and 3.3 times, respectively). The concentrations of CHCl₃ and CH₃CCl₃ decrease at both locations, but the change is greater in Krakow. In Krakow, the observed increase of F-113 is 0.13 ppt/month and has an opposite trend than in the same period at Mace Head.     

一种直流力矩电机跑合防堵转控制电路

本文介绍了一种力矩电机跑合防堵转控制电路。作者对该电路的原理、使用和调试以及实验结果进行了描述。     

黄河下游滩区居民心理研究的设计及信息获取

特殊的自然环境，必将塑造滩区居民特有的心理状况，进而影响滩区社会经济的发展。黄河下游滩区居民心理研究从研究对象、技术路线与方法、数据来源等方面进行了调查设计；整群随机抽取河南、山东2个省6个县22个村作为调查对象，调查问卷分为“搬迁居民卷”和“未搬迁居民卷”，涉及题项分另？为82个和91个；采取入户调查填写问卷、座谈、个案访谈等方式，共获得相关资料1021份。