南澳岛及其附近岛屿夏季鸟类的初步调查

作者一行于 2 0 0 1年夏季对南澳及其附近岛屿的鸟类资源状况进行了调查研究 .结果发现 ,南澳及其附近岛屿有鸟类 51种 ,隶属 1 3目 2 8科 ,其中雀形目 2 3种 ,占所发现种类的 45% ,非雀形目 2 8种 ,占 55% ;国家一、二级保护动物各一种 ,分别为 :白腹军舰鸟 (F regataandrewsi)和岩鹭 (Egretta sacra) .按鸟类的栖息和迁徙习惯划分 ,有海鸟 8种 ,湿地候鸟 2种 ,湿地留鸟 9种 ,陆地候鸟 4种 ,陆地留鸟 2 8种 .在所有鸟类中以褐翅燕鸥 (Sterna anae-thetus)为优势种 ,数量最大 ,分布最广 .     

国有大中型工业企业技术创新问题浅析

通过对天津市国有大中型工业企业的调查，揭示了国有大中型工业企业技术创新中存在的问题，并对提高国有企业技术创新能力提出了建议。     

豫西早二叠世掌蕨Chiropteris Kurr和髻籽羊齿Nystroemia Halle有机连接标本的发现

基于河南登封早二叠世肾掌蕨Chiropteris reniformis Kawasaki和髻籽羊齿Nystroemia pectiniformis Halle有机连接的标本, 确立了肾髻籽羊齿(新组合)Nystroemia reniformis (Kawasaki) comb.nov.营养叶具长柄, 肾形, 基部心形, 全缘或具细齿; 叶脉细, 多次二歧分叉并结为多边形或菱形细网.生殖枝在苞片腋部着生.苞片与营养叶同形.胚珠器官在叶性器官腋部着生或两者分别不规则地着生于生殖枝的轴上.极多的具翼双角籽倒圆锥形, 呈两列状排列, 珠孔朝上.该植物代表了一种新的已灭绝的裸子植物.     

三峡兴隆洞出土12~15万年前的古人类化石和象牙刻划

在重庆市奉节县兴隆洞发掘出土早期智人牙齿、石器、有人工刻划痕迹的象牙和丰富的哺乳动物化石. 这些材料的种类、特点和埋藏状况说明该洞穴是一处远古人类的居住遗址. 通过出土动物群推断和铀系年代测定, 古人类在该洞穴的生存行为发生在中更新世晚期, 距今12~15万年前. 这是在三峡地区首次发现的早期智人化石. 出现在剑齿象门齿上的刻划纹成组分布, 组成简单而抽象的图案, 是目前所知最早的人类有意识的刻划作品, 对原始艺术的起源和东亚地区现代人类的起源、演化和行为方式的研究具有重要的学术意义.     

Effect of hydrogen peroxide on the binding of Merocyanine 540 to human erythrocytes

The fluorescent dye Merocyanine 540 (MC540) is often used as a probe to monitor the molecular packing of phospholipids in the outer leaflet of biomembranes. In a previous study we showed that the increased staining of erythrocytes with a perturbed membrane structure was mainly due to an increase in the fluorescence yield of cell-bound MC540, rather than to an increase of the number of bound molecules. Erythrocytes and ghosts exposed to continuous fluxes of H₂O₂ exhibited pronounced lipid peroxidation. Further, red blood cells subjected to this form of oxidative stress also showed increased staining with MC540. It appeared that this was caused by a strong increase in binding of MC540, together with a slight red shift of the fluorescence emission maximum and a small increase in the fluorescence yield of bound MC540. The changed MC540 binding characteristics were not observed when lipid peroxidation was suppressed by the presence of the antioxidant BHT in the incubation medium. However, open ghosts exposed to H₂O₂ showed no increase of MC540 binding, excluding a direct involvement of lipid peroxidation. Measurement of fluorescence emission spectra and gel filtration studies showed that MC540 can bind to H₂O₂-exposed hemoglobin. Experiments with erythrocytes lysed in hypotonic medium after exposure to H₂O₂ revealed that peroxidation of lipids with H₂O₂ induced a non-specific permeabilization of the plasma membrane to MC540, thereby allowing MC540 to bind to the oxidatively denatured, more hydrophobic hemoglobin. These results indicate that conclusions about packing of phospholipids in the outer leaflet of the membrane based on increased MC540-staining should be drawn with care. Received 27 September 1996; received after revision 5 November 1996; accepted 27 November 1996     

Induction of autotomy in the American bird grasshopperSchistocerca americana (Drury) by the ecdysone agonist RH-5849 and investigation of its mode of action

The non-steroidal ecdysone agonist RH-5849 (1,2-dibenzoyl-l-tert-butylhydrazine) was found to be an effective neurotoxicant on injection into the American bird grasshopper,Schistocerca americana (Drury). Treated grasshoppers became immediately hyperactive, followed by loss of coordination, paralysis and eventually death. We also discovered that this compound induced bilateral autotomy of the metathoracic legs during the early stages of intoxication. However, no evidence of ecdysonergic or morphogenetic activities was observed. Synergism studies with neurotoxins of known mode of action suggested that RH-5849 has a mechanism of action similar to that of 4-amino pyridine, which blocks potassium channels.     

DeLuca－Termini混合熵的合理性分析及其推广

对ＤｅＬｕｃａ和Ｔｅｒｍｉｎｉ提出的混合熵的合理性进行了分析并加以推广，对其性质作了详细证明。并指出，本文混合熵的表达式具有更明确的数学及物理含义。     

蕴涵环交换性的某些多项恒等式

设ｍ＞１，ｎ，ｐ，ｑ，ｒ，ｓ均为正整数，Ｒ是一个具有单位元１的环．证明了：如果Ｒ中的任意ｘ，ｙ满足且Ｒ具有Ｑ（ｍ）性质，则Ｒ是一个交换环．此外，在适当的条件下确立了Ｒ的交换性．     

用子波变换分析方法实时监测视觉诱发电位的潜伏期

诱发电位的实时监测在临床中有重要意义。本文提出利用多分辨率子波分析技术来实时监测视觉诱发电位的潜伏期。为克服随机噪声的影响，我们引入相邻响应的相关系数来修正所检测得的潜伏期的偏移，并应用前一次响应的波峰位置来决定当前的搜寻范围。实验表明，本方法能实时监测视觉诱发电位的潜伏期。