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1.
方法是目的途径，锯割的技能训练也是这样。在掌握规范的操作姿势之后，再加上正确的操作方法锯割的质量就～定能得到保证。为了更好地帮助学生掌握运用和记忆，可将锯割的操作方法归纳为七个字《一夹二安三起锯》其内容如下：一、锯割的操作方法一夹央伸有界限，锯割就不颤。夹紧要牢靠，避免把形变。二安无条不成锯，安时齿朝前。松紧要适当，锯路才成线。二面保平行，锯缝就不偏。三起锯操作操作起锯不能放过。左大拇指逼右手银。行程短小慢角度记心间。远近起锯视料定。边棱卡齿断锯条。远近起锯要选好。二、几种材料的铅割方法1．薄板… 相似文献
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锯割是操作技能训练三部曲中的第三曲，它同样是技能训练重要部分主要课题。在这一课题中应当怎样进行呢？谈其具体作法如下：一、锯弓和锯条锯弓和锯条是银割的主要工具。因此，对其主要工具必须有个全面了解和掌握，为锯割的技能训练打下好的基础。为了便于学生掌握和记忆，用（锯弓和锯条歌）指导学生。1、锯弓锯条歌锯弓锯条构成锯，锯弓用来安锯条。锯弓种类分有二，固定可调易分辨。固安一长度锯条，调安见长度锯条。调用广来便用力，用它锯割质效高。2、锯条种类的正确选用锯条种类分有三，牙距大小粗中细。整数相同小数异，粗中细来… 相似文献
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通过对内圆锯切力进行计算分析,分析了内圆锯片锯切硅晶棒的锯切力特征以及进给速度、主轴转速和工件尺寸等锯切工艺参数对锯切力的影响。由计算分析可知,锯切力是连续变化的,变化特征与接触弧长的变化特征相同,法向锯切力比切向锯切力对锯切加工过程的影响更显著;锯切工艺参数对内圆锯切力的影响明显,对锯切工艺参数进行合理选择和优化改善接触弧长,可有效改善锯切力状态,保证锯切加工过程的平稳性。 相似文献
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长弓 《学生之友(小学版)》2005,(11)
锯凿、斧、钻,这些都是木匠师傅常用的工具。然而自然界里,有一些奇树异木,他们的木质比钢铁还要坚硬,如果木匠遇上了它们,那真是用锯锯不动,用斧砍不开,毫无一点办法,只能弃置不用。绿心木出产在南美洲的圭亚那,它因木质是黄绿色的而得名,绿心木质地十分坚硬,用普通的木工锯来锯,根本就锯不动,人们只好用锯钢铁的锯来锯它,因锯它的时候,竟能迸发出火星来,所以,当地的居民又称它为“迸火树”。绿心木不但坚硬结实,而且防腐、防蛀,不易起火,是制作坚固耐用器物的好材料。 相似文献
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[病例]有一根很粗的木料,锯成3段需要12分,如果每锯1段所需的时间都相等,锯成13段需要多少分? [病症]12÷3×13=52(分)。[诊断]这种解法混淆了锯的段数和锯的次数之间的关系。实际上,锯的段数不等于锯的次数,锯1次能锯 相似文献
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通过监测系列锯切试验的主轴功率,分析锯切过程空载功率、有效锯切功率的变化规律,并结合材料去除率进行分析。结果表明,空载功率随锯切线速度增大基本呈线性增大。有效锯切功率随材料去除率呈近似线性增大。能效系数随材料去除率增大而增大,去除单位体积材料总能耗系数随材料去除率增大呈先快速后缓慢的减小趋势。总体上讲,高线速度锯切工艺直接增加空载功率,并不节能,适当提高材料去除率有利于低能耗加工。 相似文献
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Effects of fish protein hydrolysate on growth performance and humoral immune response in large yellow croaker (Pseudosciaena crocea R.) 总被引：1，自引：0，他引：1
We investigated the effects of fish protein hydrolysate (FPH) on growth performance and humoral immune response of the large yellow croaker (Pseudosciaena crocea R.). One thousand and two hundred large yellow croakers [initial average weight: (162.75±23.85) g] were divided into four groups and reared in floating sea cages (3 m×3 m×3 m). The animals were fed with 4 diets: basal diet only (control) or diets supplemented with 5%, 10% and 15% (w/w) FPH. The results show that dietary FPH levels significantly influenced the growth and immunity of the large yellow croaker. Compared with the control group, total weight gain (TWG) in all treatment groups, relative weight gain (RWG) and specific growth rate (SGR) in fish fed with diets supplemerited with 10% and 15% FPH were significantly increased (P＜0.05). Similar results were observed in immune parameters [lysozyme activity, serum complements, immunoglobulin M (IgM)]. Lysozyme activity, complement C4 and IgM were also significantly increased (P＜0.05) in fish fed with diets supplemented with 10% and 15% FPH, while complement C3 level was significantly increased (P＜0.05) in all treatment groups. In general, with the supplementation of FPH, particularly at dose of 10%,the growth performance and immunity of the large yellow croaker can be improved effectively. 相似文献
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Hong-gang TANG Li-hong CHEN Chao-geng XIAO Tian-xing WU 《Journal of Zhejiang University. Science. B》2009,10(2)
We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age.One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis.Moisture,protein,lipid and ash contents were determined by methods of Association of Analytical Chemist (AOAC) International.Fatty acid profile was determined by gas chromatography.Crude protein,fat,moisture and ash contents showed no significant differences between the two age groups.The contents of total polyunsaturated fatty acids and docosahexaenoic acid (DHA) were significantly higher and eicosapentaenoic acid (EPA) content was significantly lower in the two-year-old large yellow croaker than in the one-year-old (P<0.05).No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty acids,or the ratio of n-3/n-6 fatty acids among the large yellow croakers of the two age groups.We conclude that large yellow croakers are good food sources of EPA and DHA. 相似文献
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Hong-gang Tang Li-hong Chen Chao-geng Xiao Tian-xing Wu 《Journal of Zhejiang University. Science. B》2009,10(2):154-158
We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis. Moisture,
protein, lipid and ash contents were determined by methods of Association of Analytical Chemist (AOAC) International. Fatty
acid profile was determined by gas chromatography. Crude protein, fat, moisture and ash contents showed no significant differences
between the two age groups. The contents of total polyunsaturated fatty acids and docosahexaenoic acid (DHA) were significantly
higher and eicosapentaenoic acid (EPA) content was significantly lower in the two-year-old large yellow croaker than in the
one-year-old (P<0.05). No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty
acids, or the ratio of n-3/n-6 fatty acids among the large yellow croakers of the two age groups. We conclude that large yellow croakers are good food
sources of EPA and DHA.
相似文献
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董云霞 《临沂师范学院学报》2014,36(5):107-110
宋代是中国绘画发展的高峰时期,在此期间花鸟画风格发生了转变,由承袭黄筌"富丽工巧"的宫廷花鸟画逐渐转向于"清新淡雅"的世俗化花鸟画。世俗化花鸟画造型严谨、生动逼真、极具生活气息,追求人性化的情境,是对自然生活的再创造,将情、景、理融为一体,使宋代花鸟画具有独特的艺术风格和魅力。 相似文献
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We examined the effects of conjugated linoleic acid (CLA) on growth, fatty acid composition and enzyme activity of fatty acid oxidation in the liver of large yellow croaker. We divided 1600 fish (average initial weight 150 g) into 4 groups and reared them in 8 cages. Four dietary treatments were formulated to contain 0%, 1%, 2% and 4% (w/w) CLA, respectively. The fish were fed for 10 weeks ad libitum twice daily. We found that the dietary CLA had no effect on growth, biometric parameters and whole body proximate (P>0.05), but showed some significant effects on the fatty acid composition in both muscle and the liver.The activities oflipogenic enzymes were slightly depressed in fish fed with increasing levels of CLA when compared with control (P>0.05). Dietary CLA supplementation had no effects on liver lipid content, but significantly increased the contents of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) (P＜0.05) and decreased monounsaturated fatty acid (MUFA) content in both muscle and the liver. Dietary CLA inclusion resulted in significant increases of the biologically active cis-9, trans-11 and trans-10, cis-12 isomers in both tissues (P＜0.05). The total accumulation of CLA was higher in the liver (3.83%, w/w) than in muscle (3.77%, w/w) when fed with 4% (w/w) CLA. This study demonstrates that large yellow croakers are capable of absorbing and depositing CLA and long-chain n-3 PUFA in the liver and muscle, showing that this species fed with CLA could be an important human food source for these healthful fatty acids. 相似文献
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对购买的一种黄茶进行SD大鼠胃损伤预防效果评价。通过动物模型分析,研究其胃损伤预防效果。研究结果表明,高浓度的黄茶比低浓度黄茶降低了IL-6和TNF-α炎症细胞因子水平。本实验中,1000mg/kg灌胃浓度的黄茶（74.6%）具有最强的胃损伤抑制效果。综合分析得出,一定浓度的黄茶具有良好的胃损伤预防效果。 相似文献
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李晓峰 《北京工业职业技术学院学报》2013,12(3):124-126
阐述了黄灯的产生与作用,指出黄灯使用中存在的系列问题,对取消黄灯的可行性和科学性进行了分析,提出了取消黄灯,实施绿灯3秒闪烁措施,可有效减少道路交叉路口事故隐患,保证路人及行车安全的建议. 相似文献
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聚氨酯清漆的耐黄变性与其组分的组成有着密切关系。为了确定各种组分对聚氨酯亚光清漆黄变性能的影响进行了对比实验。结果表明：影响漆膜黄变性的主要因素是固化剂,且固化剂HDI三聚物与TDI三聚物相比因其稳定性而不易变黄;树脂易受日光、温度、水分等作用产生黄变基团,椰子油改性醇酸树脂分解产生的黄变基团少,因而以其制备的PU亚光清漆耐黄变性好;紫线吸收剂会有效地抑制漆膜黄,而硝化棉的加入则会加重黄变。 相似文献
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黄酒高产优质技术初探 总被引：2，自引：0，他引：2
以正交试验法为主，对影响黄酒产量及质量的诸多因素进行了综合定量研究.研究结果表明影响黄酒产量的主要因素是用曲，其次是原料，而工艺的影响最小.生产黄酒的最佳条件为以糯米和小米为原料，选用大曲，淀粉酶和小曲为糖化发酵剂，发酵时开耙2～3次，在上述条件下出酒率达82.76%，黄酒品质的感官鉴定结果为优良，理化检验各项指标均达国家标准. 相似文献
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不同品种黄鳝怀卵量的比较 总被引：4，自引：0，他引：4
分别检查深黄大斑鳝和青黄斑鳝的怀卵量 ,结果发现深黄大斑鳝的怀卵率和怀卵强度均高于青黄斑鳝 ;深黄大斑鳝和青黄斑鳝各体长段间怀卵强度差异的不显著 ;深黄大斑鳝 2 5 .1～ 3 0 .0cm、3 5 .0～ 3 9.0cm段分别与青黄斑鳝 14 .0～ 2 0 .0cm、3 0 .1～ 3 5 .0cm和 2 5 .1～ 3 0 .0cm段黄鳝怀卵强度存在显著差异 . 相似文献