Inorganic chemical composition and source signature of PM2.5 in Beijing during ACE-Asia period

Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 Ilg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 μg/m^3, respectively.These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.     

Analysis of cDNA sequence, protein structure and expression of parotid secretory protein in pig

Parotid secretory protein (PSP) secreted abundantly in saliva, whose function is related with the anti-bacterial effect. The PSP cDNA has been isolated from pig parotid glands by 3′ and 5′ rapid amplification of cDNA end (RACE), based on the conserved signal peptide region among the known mammalian PSP. The result of homologous comparison shows that pig PSP and human PSP shares the high identity at the level of the primary, secondary and tertiary protein structure. A search for functionally significant protein motifs revealed a unique amino acid sequence pattern consisting of the residues Leu-X(6)-Leu-X(6)-Leu-X(7)-Leu-X(6)-Leu-X(6)-Leu near the amino-terminal portion of the protein, which is important to its function. RT-PCR, Dot blot and Northern blot analysis demonstrated that PSP was strongly expressed in parotid glands, but not in other tissues.     

种植器官的“农场”

詹姆士·芬恩已被逼到了绝境。帕金森氏症正在吞噬他的运动和语言能力,而且所有常用药物都无济于事。因此当医生向他提出一种试验性治疗的建议时,他决定试试运气。1996年9月24日,医生在他的头骨上凿了一个洞,植人数百万个神经元,以取代其大脑已经停止制造的一种化学物质。但这些植入物的来源却非同寻常:它们来自一头猪。     

地转变慢与地磁倒向

地球自转变慢的事实，使刚性内核和地幔处于不同频幅的扭摆振荡状态。由地球温度分布和汤姆逊效应，知道地核带正电，地幔带负电。所以外棱正电荷的振荡是形成基本炀的原因。由此对地磁倒向规律作出物理说明。     

武器的仿生学起源

文化人类学的研究表明,战争在较为低级的文明阶段就已经开始了.社会生物主义的代表阿德勒认为,人类之所以是地球上处于独特地位的万物之灵,是由于人类用杀伤工具即武器武装了自己,武器成了人类生物装备的一部分,即延伸了肢体、牙齿等可用于进攻和搏斗的凶猛本能.     

环腺苷酸制剂对生长育肥猪生长性能和肉脂品质的影响

选用 2 0 kg左右的“杜长”元杂交猪 2 4头 ,随机分成 1个对照组、 3个试验组 ,试验组分别添加环腺苷酸制剂 (二丁酰 c AMP) 10 mg/kg(试验 1组 )、 2 0 mg/kg(试验 2组 )、 30 mg/kg(试验 3组 ) ,进行饲养试验、屠宰试验和肉的品质测定。结果表明 :添加二丁酰 c AMP,能提高生长育肥猪的生长性能和改善肉脂品质。以添加二丁酰 c AMP2 0 mg/kg效果最好 ,与对照组相比 ,日增重提高 11.80 % (P <0 .0 1) ,料重比降低 16 .4 % (P <0 .0 1) ,胴体瘦肉率提高 8.12 % (P <0 .0 5 ) ,眼肌面积增加 11.98% (P <0 .0 5 ) ,平均背膘厚下降 18.90 % (P <0 .0 1) ;大理石纹评分提高 11.6 6 % (P <0 .0 1) ;肌肉间脂肪含量提高 2 8.88% (P <0 .0 1)。     

断奶仔猪腹泻的病因及其综合防治

阐述了断奶仔猪腹泻主要包括仔猪生理发育不成熟，断奶应激，出生时母源抗体水平较高，以后逐渐降低，抵抗力差及肠道对饲料蛋白的过敏反应等方面病因，并讨论了其综合防治措施。     

论韩国发现的印本《无垢净光大陀罗尼经》

从历史、考古、宗教史、文献学、版本学、文字学、印刷史及中外文化交流史等诸多侧面对1966年韩国发现的印本《无垢净光大陀罗尼经》作初步的综合研究,证明它701年译出,702年刊于唐东都洛阳,同时说明它是中国佛教和印刷文化的必然产物.文内叙述了此本在韩发现的经过和近30年韩人的研究现状,证明韩学者因在韩发现此本而提出印刷起源韩国说是不能成立的.最后考证了此印本在日本和韩国的传播情况.文内以文献和实物资料论证了印刷术起源地是中国.     

试论中国栽培大豆起源问题

栽培大豆起源问题的最终解决要靠多学科的协作。而历史学的考证，就是解决栽培大豆起源问题最重要地途径之一。该文从文献学和考古学两上方面研究了探讨和栽培大豆的起源问题。     

三峡地区盐资源与巴族起源及社会流动的关系——三峡盐文化简论(三)

食盐是巴人活跃于三峡地区的物质基础,也是导致其向峡外迁徙的历史动因.最早行盐出峡的先民是崇蛇巴,而崇虎巴更是以盐立国,亦以盐卷入战争,终至覆灭.