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41.
在中华倒刺鲃每千克基础饲料中分别添加免疫多糖2g、免疫多糖4g、维生素C(VC)700mg、VC1400nag、VC700mg+免疫多糖2g、VC700mg+免疫多糖4g、VC1400mg+免疫多糖2g、VC1400mg+免疫多糖4g,以基础饲料为对照组,连续投喂2周后,通过测定血液白细胞的数量,白细胞吞噬能力,血清、头肾和脾脏的溶菌酶活力,探讨不同浓度的免疫多糖和VC对中华倒刺鲃非特异性免疫功能的影响.结果表明:VC和免疫多糖都能提高中华倒刺鲃免疫机能,且免疫多糖和VC二者间在较低浓度组合时有协同作用,高浓度组合时反而产生拮抗作用.免疫多糖和VC的最适宜组合浓度为(VC700mg+免疫多糖2g)/kg基础饲料.  相似文献   
42.
The paper deals with the investigation of gender differences in performances in mathematics for Italian students at the end of lower secondary school. The study is based on a new large-scale assessment test developed and administered by the National Evaluation Institute for the School System. Given the evidence in the literature which favors males, performances of female and male students are compared using different approaches. Scores proposed by educational experts based on item subgroups were considered, while a model-based approach was used within item response theory. The results revealed a significant advantage to males in overall performance, while no meaningful differences were observed with respect to item domain and type. An interpretable item map was developed crossing expert opinions with IRT abilities, and plausible proficiency levels were defined. According to the map-based student classification, a relatively lower percentage of females fell into the highest proficiency groups with respect to males.  相似文献   
43.
Objective: To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines. Methods: BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA; splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro. Results: The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone, but there was not significantly different (P>0.05). Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05). Conclusion: The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant.  相似文献   
44.
本文建立涡轮流量计动态数学模型 ,并对涡轮流量变送器的运动微分方程和传递函数进行了分析 ;从理论上计算得出 LW-1 5型涡轮流量计的单位阶跃速度响应 ;证明了限制涡轮流量计动态响应速度的瓶颈是流量积算仪的动态响应 ;最后提出了用软件代替流量积算仪的实验方案  相似文献   
45.
乡镇政府及其工作人员能否对乡村社会和广大农民的需求作出积极、敏感、负责任的回应,直接关系到新农村建设的成效。提升乡镇政府回应能力的路径主要有合理划分各级政府的事权;把握好回应指向;转变乡镇政府职能;建立健全乡镇政府回应机制和注重对乡镇政府回应进行科学的绩效评估等。  相似文献   
46.
When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments. The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.  相似文献   
47.
The literature on teacher uncertainty suggests that it is a significant and perhaps inherent feature of teaching. Yet there is disagreement about the effects of these uncertainties on teachers as well as about the ways that teachers should regard them. Recognition of uncertainties can be viewed alternatively as a liability or an asset to effective teaching. Findings from the literature on uncertainties in teaching are summarized and analyzed, including explanations in the research about what accounts for and contributes to uncertainties. Recommendations for research and professional development are provided.  相似文献   
48.
对于具有圆形周边,质量对其中心有对称分布的刚体,本文从不同角度出发给出两种非常规解法,求解其沿斜面向下运动时的规律,得到相同的结果,进而讨论只滚不滑和边滚边滑的条件。  相似文献   
49.
本文论讨了在实验室里用单摆测重力加速度时,摆球的大小对测量结果的影响,指出摆长在一米左右,摆球直径在二厘米时,由摆球大小带来的误差,出现在重力加速度的第五位有效数字上。  相似文献   
50.
社会转型·社会治理·社会回应机制链   总被引:7,自引:1,他引:7  
在全球化多元共生、开放、回应与同构的趋势中,中国社会转型与西方社会转型因社会主义制度因素的嵌入而具有非同源性,但中国因工业化、现代化的使然,仍引发了社会结构的重构和具有现代性特质的社会分化开始,并凸显出我国传统的政府与社会高度合一管制模式的内生性冲突。因而在社会转型情境中建设和谐社会,不仅需要重设动力机制、社会机制,而且建设和谐社会的新制度安排还需要建立一套不断完善的社会机制链才能持续地转化为现实生产力,才能促进与实现社会的和谐。  相似文献   
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