Study on the Piezoresistive Effect in P type Diamond Films

The piezoresisitive effect of p type diamond films is analyzed by deformation potential theory and valence bands split off model.It is found that the great difference of the efficient mass between the heavy and light hole of diamond is one of the main factors which are responsible for the piezoresistive effect in the p type diamond films.The gauge factor calculation formula is obtained according to the strain induced heavy and light hole band splitting off model,and the calculation results are in accordance with the experimental results.     

定点屠宰场生猪的检疫技术

笔者根据定点屠宰场生猪检疫试述定点屠宰场生猪的检疫技术,供同行参考。1宰前检疫通过宰前检疫可以及早发现患病生猪,及时剔出处理,以避免混入正常屠宰加工过程,不致造成污染和引起疫病传播。1．1查证验物对受检的生猪,首先要查动物防疫机构签发的检疫证明、运载工具消毒证明和非疫区证明,然后核对生猪头数,了解运输途中及进场后有无病死,若发生及时处理。1．2检疫方法幸前检疫通常采用两种方法,一是群体观察;二是个体检查。1．2．1群体观察检疫时,对同一批待宰生猪按静态、动态、食欲状态的顺序,观察比较,把有病的剔出来。1…     

棘球蚴病的危害及防制

棘球蚴病又名包虫病,是由棘球绦虫和幼虫-棘球蚴寄生在动物和人的肝脏及其他器官中引起的一种人畜共患的寄生虫病。1包虫病的危害我区的绵羊、山羊、猪、骆驼以及人都有不同程度的发生和感染,其中以绵羊感染最严重,感染率平均在50％左右。感染无明显的季节变化,但感染率随羊只的年龄增长而加大,成年羊感染率高达602％以上,老龄羊只几乎无一幸免。从感染强度来看,在剖检的绵羊中,轻度感染时,在肝或肺上有1个一2个棘球蚴,中等感染时有7个～8个,严重时,一只羊肝脏上寄生的包虫囊数目可达百余个,甚至几百个,包囊大小不等,大的象…     

炭疽沉淀反应在牛皮检疫中的应用

广西桂平市地处亚热带,全年气候温和,雨温充沛,水草丰盛,极易发展养牛业。近几年年末存栏牛达16万多头,每年屠宰1万多头,每年都有大量牛皮出口。根据国家有关规定“皮张作炭疽沉淀反应,结果为阴性”,方可开具产地检疫证明。为此,我们每年对运出市外的牛皮,在实验室做了牛皮炭疽沉淀反应,从1992年2月24日至1999年3月31日,共检牛皮达51323张。现将做法介绍如下：1材料与方法1．1牛皮抗原液的制备1．1．1栋样用半自动栋皮器在每张牛皮腿部或腋下边缘部位,大的皮张取1g,小的取0．5g重样皮一块,放进容器内,样皮容器每100个为一盒…     

Hydrogen Sulfide and Odor Control in İzmir Bay

The city of ?zmir on the Aegean Sea shoreline is suffering from rotten odors emitted by anoxic river mouths. Anaerobic conditions in the shallowest portion of ?zmir Bay due to industrial and domestic wastewaters as well as eutrophication products in this very calm part of the Bay are responsible for this. The inner section of the Bay is becoming shallower with sediments rich in organic matter. Aerobic digestion of organic pollutants is limited by the oxygen input and the warm climate leads to an optimal medium for anaerobic processes when anoxic conditions take over. Anaerobic digestion products are odorous gases among which H₂S with a characteristic pungent odor is most effective in this case. Sulfur containing gases are formed from sulfides and sulfates in the sediment-water interface and are released into the air. Airborne H₂S concentrations are variable as they depend on factors such as high atmospheric diffusion coefficients under changing wind direction and speed, as well as variable such as water depths, organic loadings from rivers, air and water temperatures, sulfate concentrations in sediment and water phases, pH, and Eh. This study aimed to control noxious smells by inhibiting the anaerobic sulfate-reducing bacteria at the sediment surface. To achieve this aim, pH of the sediment-water interface was increased by spreading hydrated lime. Successful lime doses were investigated in laboratory models first and were then tested and applied in the estuary and downstream segment of one of the creeks. Rates of H₂S gas emissions and aqueous H₂S levels were measured. It was noted that waterborne H₂S levels at river mouths were reduced. Odor control efficiencies of 80–96% even after 10 days of lime addition in the field experiments were obtained. Therefore, the results of this study indicated that lime application to the sediment surface is a recommended method in odor control programs.     

Trace Metals in Marine Algae and Sediment Samples from the Bosphorus

Concentration of As, Cr, Fe, Zn, Co, Sb, Pb, Cd and Cu weredetermined in sediment and algae samples collected from theBosphorus in Turkey. Certain algae species were chosen among thegreen, brown and red algae species at three sampling stations.Element analyses were carried out by atomic absorptionspectrophotometry and instrumental neutron activation analysis. The locations having the highest metal concentrations insediments were as follows: As at Poyraz; Cr, Zn, Sb at RumeliFeneri and Fe, Co at Garipçe. In genral, the accumulation ofmost of the metals showed no direct correlation with algaespecies. On the other hand, C. verticillatus and C. barbataspecies of brown algae showed ability to accumulate arsenic.     

Adsorption of Methylene Blue from Aqueous Solution onto Perlite

Adsorption of methylene blue from aqueous solutionsonto unexpanded and expanded perlite samples activatedby H₂SO₄ and NaCl solutions has beeninvestigated, to assess the possibility of usingperlite for removing cationic dyes from aqueoussolutions. The effects of pH and temperature of dyesolution on the adsorption capacities have beenevaluated. The experimental data were correlatedreasonably well by the Langmuir adsorption isothermand the isotherm parameters (Q _m and K) have beencalculated. The removal efficiency (P) anddimensionless separation factor (R) have shown thatperlite can be used for removal of methylene blue fromaqueous solutions, but unexpanded perlite is more effective.     

新型水产养殖消毒剂的制备、性能及其临床应用Ⅰ．碘伏

研究了新型水产养殖消毒剂——碘伏的制备、稳定性、毒性和消毒效果 .通过产品的理化性能、毒理、定量杀菌效果等试验了解产品性能 .结果表明 :该产品稳定 ,定温下有效期至少 1a;在使用体积分数范围内 ,对鳗鱼、甲鱼无刺激性 ;对家畜 L D50 >50 0 0 mg· kg-1,对欧洲鳗、日本鳗、甲鱼的 L D50 分别为 144 5、1750、3975mg· kg-1;2 2℃下 ,对嗜水性单胞菌最低杀菌体积分数为 1.0× 10 -6,杀菌率达 10 0 % ,在 3.0× 10 -6的体积分数下作用 4 h;对日本鳗爱德华氏病治疗有效率达 80 % ,对欧洲鳗赤鳍病治疗有效率达 85% .适当提高温度和酸度可提高消毒杀菌效果     

基于树枝状嵌段共聚物的载药微球的制备及其药物释放表征

为建立一种树枝状共聚物载药微球的制备方法及其药物释放行为的体外评价机制,研究采用实验室自制的4代树枝状大分子引发剂PEG-G4-(OH)32引发己内酯开环聚合,合成了一系列树枝状三嵌段共聚物,并对其结构进行了表征;采用乳液-溶剂挥发法制备了共聚物-紫杉醇载药微球。研究结果显示,以树枝状嵌段共聚物为壁材的载药微球形貌规整,表面平滑,粒径范围为1.92～2.54μm,载药量为15.7%～20.6%;在0～3d的时间里载药微球释药明显,在随后的3～15d的时间里基本呈现线性的零级释放效果。该研究首次采用树枝化聚己内酯的嵌段共聚物制备载药微球,与以线性聚己内酯为壁材制备的载药微球进行了对比,结果表明,前者药物缓释效果更好,具有一定的临床应用前景。     

喜树幽斑螟自然种群生命表的研究

1996～ 2 0 0 1年在福建省南平、沙县对喜树幽斑螟自然种群进行系统调查 ,组建和分析了 5个世代的自然种群平均生命表 ,结果表明 :喜树幽斑螟各世代自然种群存活曲线均属 Price A型 ,第 1～ 5代平均种群趋势指数 I值分别为 6.40、 4.66、 4.5 3、 4.88、 3.1 8. 5个世代中 ,影响喜树幽斑螟种群生命过程的关键因子均为成虫死亡和生殖力下降 .第 1～ 3代中 ,自然消亡的控制作用均大于寄生和捕食 .第 4代中 ,寄生的控制作用更大 ,第 5代则捕食的控制作用大 .年周期中 ,天敌对种群系统的控制作用随着时间的延续逐渐加强 .成虫期是各个世代的关键虫态 ,除成虫期外 ,第 1代的关键虫态为 3～ 4龄幼虫 ,第 2～ 4代的关键虫态为 1～ 2龄幼虫 ,第 5代的关键虫态为蛹期