65 research outputs found
Auto-Control Technology of Grinding Machine for the Manufacturing of Indexable Inserts
金属切削加工是机械制造业中使用最传统和最广泛的加工工艺方法。随着制造技术的发展,可转位刀具在现代金属加工中成为一种先进刀具,可转位刀片是可转位刀具的切削部分,对可转位刀具的加工精度和效率有直接和重要的影响。目前的先进制造业,高强度和高精度的可转位刀片使用量急剧增长,可转位刀片周边磨削是可转位刀片加工过程中的重要环节,但是在可转位刀片周边磨削技术研究方面,国内起步比较晚,国内高档可转位刀片周边磨床及高端可转位刀片均被国外产品所垄断。在此背景下,开展对高端国产可转位刀片周边磨床的研发具有重要的理论价值和现实意义。 本论文围绕“可转位刀片周边数控工具磨床全自动控制技术研究”这一课题,以实现高效、高...Metal cutting is the most traditional and comprehensive process in mechanical manufacturing industry. With the development of advanced manufacturing technology, the indexable tool becomes one advanced tool of modern tools in metal cutting, and the indexable insert is its key part. The indexable insert has significant influence on the accuracy and efficiency of indexable tool. Indexable insert peri...学位:工学硕士院系专业:物理与机电工程学院机电工程系_测试计量技术及仪器学号:1992009115245
Compare of cooperation modes in a supply chain based on the market equilibrium
以两阶段供应链为例,说明了供应链中供应商和零售商在生产与销售过程中存在的利益冲突,提出供应链的两种协作方式:核心企业协作方式及对等谈判协作方式.通过效用函数对比两种方式产生的供应链收益,阐述了在市场均衡条件下对等协作方式对供应链整体具有更好的激励作用.In supply chain,there are many conflicts of interest between the suppliers and the retailers during the production and selling of the products.In this paper,a two-stage supply chain sets to choose one of the two cooperation modes: the central cooperation mode and the coordinate cooperation mode.In order to harmonize the interest of each side and maximize the return of the supply chain,central cooperation mode suggests that the supply chain should have a central corporation which leads cooperation among all these suppliers and retailers.However,coordinate cooperation mode suggests that all the members in the supply chain should equally negotiate about the matter of cooperation and make decision together.We introduce utility functions and income functions to compare the outcome of the two modes in the chain.As a result,when the market comes to the equilibrium the coordinate mode gains more profits for the whole than the central one.We then explain the reasons by analyzing the rationality of the conclusions.And the applications and limitations of the paper's results for other domains are discussed
Experimental effects study of total flavonoids of Ajuga on nuclear transcriptional factor of kappa B in mesangial proliferative glomerulonephritis rats
目的探讨筋骨草总黄酮(TfA)治疗系膜增生性肾小球肾炎(MSPgn)大鼠后核转录因子-κb(nf-κb)及下游转化生长因子-β1(Tgf-β1)的变化。方法采用改良慢性血清病MSPgn大鼠模型,于造模第5周末检测尿蛋白,将尿蛋白阳性者随机分为模型组、雷公藤多甙(TWP)组、不同剂量TfA组。于造模第6周开始给药,6周后,测定各组大鼠的24 H尿蛋白定量、血生化和肾组织病理变化,MAXVISIOnTM即用型快速免疫组化一步法检测大鼠肾组织中nf-κb P65的表达,双抗体夹心法检测血清中Tgf-β1的变化。结果 TfA可显著降低尿蛋白,明显减小系膜区面积占毛细血管丛面积的百分比(P0.05)。模型对照组大鼠肾组织nf-κb P65、血清Tgf-β1的表达明显高于正常对照组[nf-κb P65:28.93±4.45 VS.4.51±0.96,P0.05).The renal tissue NF-κB(Integral optical density, IOD) and serum TGF-β1(pg/ml) in model control was significantly higher than that in normal control group, NF-κB p65 28.93±4.45 vs.4.51±0.96, P<0.01; TGF-β1:(247.63±51.55)pg/ml vs.(127.52±27.84)pg/ml, P<0.01; With the intervention trerapy of high-dosage TFA, middle-dosage TFA and TWP, the expression of NF-κB in renal tissue and TGF-β1 in serum was significantly decreased compared with model control group, NF-κB p65: 10.35±2.81, 15.21±4.71,11.70±3.97, P<0.01; TGF-β1:(181.96±52.93)pg/ml,(204.33±38.30)pg/ml,(188.07±42.92)pg/ml, P<0.05.Conclusion Reducing the expression of NF-κB and successive TGF-β1 may be one of the mechanisms of total flavonoids of Ajuga treatment on MsPGN rats.福建省卫生厅中医药科研重点课题(wzzsb0906); 陈可冀中西医结合发展基金·福建省中西医结合老年性疾病重点实验室开放课题资助项目(CKJ2008088); 福建中医药大学校管课题(X2009069
樟树籽仁油的遗传毒性评价
为评价樟树籽仁油的食用安全性,通过细菌回复突变试验、体外哺乳类细胞TK基因突变试验及哺乳动物红细胞微核试验探究樟树籽仁油的致突变和潜在致癌作用。结果表明:樟树籽仁油对组氨酸缺陷型鼠伤寒沙门氏菌TA1535、TA97、TA98、TA100、TA102均无致突变作用;樟树籽仁油未抑制L5178Y小鼠淋巴瘤细胞的生长,对体外哺乳类细胞TK基因无致突变作用;樟树籽仁油未导致小鼠细胞微核率上升,对哺乳动物红细胞无致突变作用,无遗传毒性。综上,樟树籽仁油无细胞致突变和潜在致癌作用,没有遗传毒性,具有一定的食用安全性。To evaluate the edible safety of Cinnamomum camphora seed kernel oil (CCSKO), the mutagenicity and potential carcinogenic effects of CCSKO were investigated by bacterial reverse mutation tests, in vitro mammalian cell TK gene mutation tests, and mammalian erythrocyte micronucleus tests. The results showed that CCSKO had no mutagenic effect on Salmonella typhimurium strains TA1535, TA97, TA98, TA100 and TA102 with histidine deficiency. CCSKO did not inhibit the growth of L5178Y mouse lymphoma cells, and had no mutagenic effect on TK gene in mammalian cells in vitro. CCSKO did not increase the micronucleus rate of cell in mice, had no mutagenic effect on mammalian erythrocytes and had no genotoxicity. To sum up, CCSKO has no mutagenicity and potential carcinogenic effect, no genotoxicity, and has certain edible safety
感知父母不偏爱对儿童攻击性行为的影响:一个链式中介模型
目的:探讨非独生子女家庭中,儿童感知父母不偏爱与攻击性行为之间的关系,以及父母情感温暖和同胞冲突在其中的中介作用。方法:采用父母差别对待量表、同胞关系量表、父母情感温暖量表、儿童攻击性行为量表,对257名3-6年级的非独生子女学生进行调查。结果:(1)儿童感知父母偏爱指数、父母情感温暖、同胞冲突和攻击性行为两两之间存在显著相关;(2)父母情感温暖在父母偏爱指数和攻击性行为之间的中介作用显著;父母情感温暖、同胞冲突在父母偏爱指数和攻击性行为之间的链式中介效应也显著。结论:儿童感知父母不偏爱可以通过父母情感温暖的单一中介效应和父母情感温暖→同胞冲突的链式中介效应间接影响攻击性行为
Perceived Parental Disfavoritism and Children’s Aggressive Behavior: A Chain Mediating Effect Analysis
目的:探讨非独生子女家庭中,儿童感知父母不偏爱与攻击性行为之间的关系,以及父母情感温暖和同胞冲突在其中的中介作用。方法:采用父母差别对待量表、同胞关系量表、父母情感温暖量表、儿童攻击性行为量表,对257名3-6年级的非独生子女学生进行调查。结果:(1)儿童感知父母偏爱指数、父母情感温暖、同胞冲突和攻击性行为两两之间存在显著相关;(2)父母情感温暖在父母偏爱指数和攻击性行为之间的中介作用显著;父母情感温暖、同胞冲突在父母偏爱指数和攻击性行为之间的链式中介效应也显著。结论:儿童感知父母不偏爱可以通过父母情感温暖的单一中介效应和父母情感温暖→同胞冲突的链式中介效应间接影响攻击性行为。</p
宫腔镜和经阴道 B超在子宫内膜息肉诊断中的价值对比
目的 对比宫腔镜和经阴道B超在子宫内膜息肉诊断中的价值。方法 选取2019年7月至2020年7月我院就诊的疑似子宫内膜息肉患者141例,均行宫腔镜检查 及 经 阴 道B 超 检 查,以 手 术 后 取 内 膜 组 织 活 检 的 组 织 病 理 学 诊 断 结 果 为 金 标准,比较两种方式的诊断价值。结果 经过 宫 腔 镜 检 查 及 经 阴 道B 超 检 查,宫 腔 镜 检 查 的 特 异 度 及 阴 性 预 测 值(73.91%,23.94%)高于经阴道B超检查(8.7%,5.71%)(P</jats:p
基于贵州劳动力充分就业估算的石漠化地区粮食安全研究
为探求贵州农业经济系统的运行规律,提供区域粮食安全战略和农业产业结构调整的决策依据,从贵州劳动力充分就业估算着手,对石漠化地区粮食安全进行研究。结果表明:2007年,贵州省实际负担人口3 315.34万人,为统计人口的83.6%。按现有的消费水平,贵州粮食有效需求为900~1 000万t,与粮食"有效生产"能力950~1 000万t相适应,区域"耕地—劳动力—人口—粮食"生态经济系统已达到相对均衡状态,属于粮食安全区域
西南喀斯特地区农业规模化发展存在的问题与对策
喀斯特地区存在生态系统脆弱,地表土壤少、土壤自然侵蚀量大,对植被有强烈的依赖性;气候条件复杂多样,干旱和洪涝灾害频繁;耕地资源缺乏,农田水利基础设施、农产品商品化率低,市场交易成本高等问题,制约了喀斯特地区农业规模化的发展。根据这些特点及存在的问题,对喀斯特地区农业可持续科学发展的途径进行了探讨,提出了发展规模化-市场型农业、多样化-混合型农业和适度规模-混合型农业的发展对策
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