PU微胶囊的合成、表征及降解性能研究

本文采用预聚-扩链-中和-分散溶解法，一步合成出聚氨酯（PU）水溶液，再用凝聚相分离法合成出Pu微胶囊。由傅立叶变换红外光谱（FT—IR）研究了PU微胶囊的化学结构；使用差示扫描量热仪（DSC），对PU微胶囊的玻璃化转变及微相分离结构进行了研究；通过扫描电子显微镜（SEM）的观测，对PU微胶囊的表面及剖面形态进行了研究，并测定出PU微胶囊直径约2．5mm，内腔直径50～600μm，膜孔直径为20～120nm；研究了PU微胶囊在磷酸缓冲液（PBS）中的降解行为，发现本实验合成的PU微胶囊基本上是不降解的。这种PU微胶囊有利于转基因CHO细胞的包覆，有利于临床应用中进行腹腔植入。     

聚醚型PU微胶囊的血液相容性研究

采用预聚-扩链-中和-分散溶解法,一步合成出聚氨酯（PU）水溶液,运用凝聚相分离法合成出PU微胶囊。以新鲜人血与3．8％的枸橼酸钠溶液配制成抗凝血,将PU材料与血液接触,测定其血小板消耗率;采集新鲜人血,与血液保存液（ACD）配制成ACD血液,使PU材料与ACD血液接触,动态地观察材料对凝血时间的影响,测定动态凝血时间;同样以新鲜人血与2％草酸钾溶液配制威抗凝血,用生理盐水稀释制得新鲜稀释抗凝血,测试PU材料与血液接触一定时间后,血液中红细胞释放出的血红蛋白量,得该种材料的溶血率,发现PU材料的血小板消耗率为17．99％,符合与血液接触材料使用的要求;所测PU材料的动态凝血时间为74min（接近阴性对照长的动态凝血时间78min）,说明材料引发的凝血少,具有较好的抗凝血性能;PU材料的溶血率为2．17％（小于规定值5％）,该材料对红细胞的破坏作用很小：由此说明PU微胶囊材料具有很好的血液相容性．可以作为与血液接触的植入材料.     

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．     

醇碱改性制备高凝胶强度κ-卡拉胶

为了提高κ-卡拉胶的产率和凝胶强度,研究了醇碱改性处理麒麟菜制备κ-卡枉胶工艺。通过正交实验确定了最佳工艺参数为：碱浓度3％、改性时间1．5h、改牲温度75℃。其凝胶强度达2567．9g／cm^2,产率39.15％,粘度、透明度、色泽等指标明显优于传统碱改性工艺。该工艺减少了原辅料投入和环境污架,适合工业化生产。     

不锈钢表面ZnO-尖晶石复合氧化膜的制备及其可见光光催化性能

通过电沉积锌及空气气氛下两步热氧化,在304不锈钢表面形成具有可见光光催化活性的ZnO复合氧化物薄膜。运用X-射线衍射（XRD）、拉曼光谱（Rarnan）、扫描电子显微镜（SEM）分析薄膜的结构及表面形貌,在可见光照射下测试了氧化膜催化降解罗丹明B的性能。结果显示：在0．05m0I／LZnSO4、2moL／LNH4Cl溶液中,以0．03A／cm^2的恒电流密度阴极极化120s,电沉积锌后于空气气氛中350℃下加热1h,然后升温至450℃下加热2h,在不锈钢表面形成了ZnO和尖晶石结构氧化物（AB2O4,A=Zn^2＋、Ni^2＋、Fe^2＋;B=Fe^3＋,Cr^3＋）的复合氧化膜,显示出良好的可见光光催化性能。     

超临界CO2在制备PCL/水杨酸甲酯控释体系中的应用研究

本文利用超临界二氧化碳（SCCO2）对生物可降解材料--聚己内酯（PCL）进行溶胀和塑化,进而将其作为携带剂,将水杨酸甲酯嵌入到PCL中,制备含有水杨酸甲酯的PCL多孔材料,即PCL/水杨酸甲酯控释体系,并研究超临界流体条件下水杨酸甲酯的插嵌规律.研究结果表明,PCL对水杨酸甲酯有很好的吸附能力,通过测定所制备的多孔材料PCL/水杨酸甲酯体系的缓释行为,表明其多孔结构对药物分子具有一定的缓释功能,药物分子释放时间最长可达18 h以上.     

BaMg（1-x）/3）ZrxNb2（1-x）/3）]O3微波介质陶瓷的红外光谱

利用传统固相陶瓷烧结工艺在1520℃下制备Ba[Mg（1-x）/3ZrxNb2（1-x）/3]O3（BMZN,x=0,0.10,0.15）微波介质陶瓷.通过远红外光谱（FIR）来分析研究B位Zr4＋取代对BMN陶瓷晶体结构和介电性能的影响.研究发现,随着Zr4＋取代的增加,红外光谱上在370 cm-1附近的振动模发生分裂而出现新的极化模式;410 cm-1附近的振动模消失;230,290和510 cm-1附近的振动模的频率向高波数偏移且强度明显降低.这些红外振动模的变化表明随着Ba Zr O3的增加,陶瓷的晶体结构发生转变,由六方晶系逐步转变为立方晶系.分析了陶瓷介电性能与红外模式的内在联系.     

二元量子码的截短码和扩展码的构造

本文提出了一类从包含其对偶码的经典线性码[n,k,d]2到纯量子码[In—i,2k—n＋i,d—i]]2（0≤i≤d-2）和[[n＋1,2k-n-1,d＋1]]2（或№＋1,2k-n-1,d]]2）的基于矩阵初等变换的构造方法．基于初等代数理论,设计了其构造体系;基于检验矩阵与线性码最小距离之间的关系,分析了其纠错性能：基于稳定子体系,构建了其编译码网络．该方法正确可行的构造性证明简单,易懂,易于计算机及各种硬件系统实现．理论结果显示出该方法对一类量子码的构造非常实用．     

用于稳定金属锂负极的FeF_2/PVDF复合保护层

通过在金属锂箔表面涂覆氟化亚铁(FeF_2)/聚偏氟乙烯(PVDF)的复合保护层,制备了FeF_2/PVDF保护层修饰的改性金属锂负极.采用扫描电子显微镜(SEM)对循环前后的电极形貌进行表征,并通过恒电流充放电、电化学交流阻抗谱和倍率等测试对改性金属锂负极的电化学性能进行分析.研究发现,与传统的金属锂箔负极相比,具有保护层的金属锂负极循环后表面无锂枝晶和"死锂"产生,因此表现出良好的循环稳定性,恒电流(1 mA/cm~2)充放电循环1300 h,充放电间的电压迟滞始终稳定保持在50 mV;该改性金属锂负极与磷酸铁锂正极匹配后的全电池也展现出优异的倍率性能,在3 C的电流密度下放电比容量依然可以达到110 mAh/g.     

铋层状化合物Na0.5Ho0.5-xYbxBi4Ti4O15陶瓷材料的上转换发光、铁电、介电性能研究

采用传统的固相烧结法,制备了Na0.5Ho0.5-xYbxBi4Ti4O15铋层状结构陶瓷.经X射线衍射（XRD）表征,新合成材料为单相结构,且扫描电子显微镜下的表面和断面图像均为层状,说明合成材料为新型铋层状材料.室温时,在可见光波长范围内,有2个峰,分别为546 nm处的绿光峰和656 nm处的红光峰,分别对应于Ho3＋离子的5F4＋5S2→5I8和5F5→5I8跃迁.为研究其机理,测试了变功率条件下的发光强度,经计算,绿光和红光发射均为双光子过程.研究陶瓷样品在变温（-130~270°C）条件下的发光性能时,发现红光与绿光的强度比值与温度呈线性关系,该材料有望应用于光学温度传感器领域.经介电性能测试发现当Ho：Yb=1：9时,样品的居里温度为686.4°C.研究铁电性能发现当Ho：Yb=3：2时,剩余极化Pr为9.3μC/cm2,矫顽场强为Ec=82 k V/cm,表明具有一定的铁电性能.以上研究结果表明,制得的新材料是一种具有优异光学性能的多功能材料.     

Inherent properties and statistics with individual particles in quantum mechanics

This paper puts forward the hypothesis that the distinctive features of quantum statistics are exclusively determined by the nature of the properties it describes. In particular, all statistically relevant properties of identical quantum particles in many-particle systems are conjectured to be irreducible, ‘inherent’ properties only belonging to the whole system. This allows one to explain quantum statistics without endorsing the ‘Received View’ that particles are non-individuals, or postulating that quantum systems obey peculiar probability distributions, or assuming that there are primitive restrictions on the range of states accessible to such systems. With this, the need for an unambiguously metaphysical explanation of certain physical facts is acknowledged and satisfied.     

Spasmin-like proteins in various ciliates revealed by antibody to purified spasmins ofCarchesium polypinum

Summary It was found that some ciliates,Stentor, Spirostomum andBlepharisma, which can contract rapidly like the stalks of Vorticellidae, have Ca²⁺-binding proteins that are very similar to spasmins, in the immunological sense. The presence of spasmins in other Protozoa and in some Metazoa was also investigated.     

Partial sequence of the gene for a serine protease from a halophilic archaeumhaloferax mediterranei R4, and nucleotide sequences of 16S rRNA encoding genes from several halophilic archaea

A part of the gene coding for a halophilic serine protease from a halophilic archaeumHaloferax mediterranei R4 was amplified by PCR and its 672 nucleotide sequence was determined. Tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172P1. Nucleotide sequences of 16S rRNA encoding genes from 9 halophilic archaea were determined. Alignment of 19 sequences known so far showed that there are more than 20 positions carrying bases or deletions specific for each halobacterial genus:Halobacterium, Haloarcula, Haloferax, andHalococcus.     

Anthelmintic activity of a benzimidazoline compound in sheep by abomasal infusion

Summary In vitro and in vivo data on the benzimidazoline compound indicate anthelmintic potential when introduced directly into the abomasum.     

Cognition wars

In what kinds of physical systems can cognition be realized? There are currently competing answers among scientists and theorists of cognition. There are many plant scientists who maintain that cognition can be realized in plants. There are biological scientists who maintain that cognition is materially realized in bacteria. In this paper, I will present the basis for such claims and evaluate them and discuss the future for theories of the metaphysical basis of cognition in the cognitive sciences.     

Mating attempts between the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L. (Lepidoptera: Arctiidae), involve a common sex pheromone composition

It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.     

Phenology of fruit and leaf production by ‘strangler’ figs on Barro Colorado Island,Panamá

Summary Fruit and leaf initiation by 26 trees representing five stranglerFicus species in the subgenusUrostigma were monitored for 5–8 years in a seasonal lowland forest of central Panamá. Individual trees of each species initiated fruit in synchronized crops. High variation in the number of crops, intervals between crops and dates of crop initiation indicate that these species, like species in the subgenusPharmacosycea, initiate fruit crops the year around. Nevertheless, mean crop initiation dates for four of five species fell within the four-month dry season. Similarly, all species produced new leaf flushes throughout the year, however, mean leaf flush dates of all species fell within the first three months of the dry season.     

Recruitment communication and pheromone trails in the neotropical ants,Leptothorax (Nesomyrmex) spininodis andL. (N.) echinatinodis

Leptothorax (Nesomyrmex) spininodis andL. (N.) echinatinodis workers lay pheromone trails when returning from food sources to their nests. Workers from within the nest begin following the trail almost immediately upon the successful forager's return and do not require a leader. The trail remains effective for about four minutes under our laboratory conditions but it is unclear whether the trail alone is sufficient to induce recruitment or whether additional signals, perhaps emitted within the nest, are involved. Pheromone trails of this type have not previously been documented for leptothoracine ants.     

Inter-specific avoidance of egg-associated semiochemicals in four tortricids

Oviposition of four tortricid pests of vineyards (the European grapevine moth and the grape berry moth) and fruit orchards (the codling moth and the oriental fruit moth) is deterred by a blend of straight chain fatty acids and esters of fatty acids that have been identified in the eggs of one of them: the European grapevine moth (EGVM)Lobesia botrana. This is the first evidence of inter-specific recognition of an egg-like signal in moths. We demonstrate that oviposition site selection is influenced by population density, avoidance of deterrent being most important when females are isolated. Inter-specific egg recognition might be an important phenomenon, especially in species competing for a common food resource. We propose the term oviposition regulating synomone for molecules and blends that affect the inter-specific spacing of eggs.     

Biochemical and environmental perspectives on nitrogen metabolism in fishes

Catabolism of nitrogen-containing substances makes a major contribution to the oxidative metabolism in teleostean fishes. In this review, we focus on aspects of the formation, transport, detoxification and excretion of the two most important nitrogenous products of fishes: ammonia (NH₃ plus NH ₄ ⁺ ) and urea. While NH ₄ ⁺ makes up the bulk of nitrogenous waste, it is in equilibrium with the highly toxic NH₃. Ammonia is generated in the liver and excreted through branchial, surface and renal routes. Innocuous urea is derived through hepatic uricolysis or argininolysis and voided through kidney, gill, skin or faeces. Under conditions hampering the release of ammonia, such as exposure to exogenous ammonia, water limitation, or alkaline conditions, some teleosts detoxify ammonia through synthesis of urea by the ornithine-urea cycle in liver. Ammonia and possibly alanine are the prevalent vehicles of internal nitrogen transport. Glutamine is immaterial to interorgan nitrogen transport in fishes, but plays a transient role in the detoxification of ammonia by brain glutamine synthetase.