QuEChERS结合GC-MS/MS测定41种农残及方法耐用性探究

QuEChERS前处理方法结合气相色谱串联质谱(GC-MS/MS)检测是目前果蔬中多农残分析的主流方法.QuEChERS方法净化效果对GC-MS/MS检测结果影响显著,特别是净化管中石墨化碳黑(GCB)的含量,对上述多农残检测方法耐用性至关重要.本文选取甘薯叶、辣椒、甘蓝以及葡萄作为试验对象,通过研究不同GCB含量的Q...     

高校领导决断力探微

决断力就是指高校领导或高校领导团队在高校管理实践中坚决果断地做出决策的能力,是高校领导力体系中的一个重要的组成部分,由高校领导决策能力和勇敢果断的性格品质两大核心内涵构成,并蕴藏其特殊的决断过程——“黑匣效应”。然而,在高校管理实践中,存在高校领导决断力的缺失现象。高校领导可以通过弄清决断过程,优化决策引力;提高分析判...     

超微红茶粉的理化性质和抗氧化活性的研究

本文采用超微粉碎技术制备超微红茶粉,研究超微粉碎时间对红茶粉末的显微结构、功能特性、流动性及抗氧化活性的影响。结果表明,超微粉碎改善了红茶的理化性质,增加了功效成分溶出率,提高了其抗氧化活性,其中20 min粉碎时间制得的超微红茶粉理化性质变化显著,30 min粉碎时间制得的超微红茶粉抗氧化活性较强。     

超声波辅助提取黑豆油及其脂肪酸组成分析

采用超声波辅助法,以石油醚为溶剂提取黑豆油。考察了提取时间、提取温度、料液比和超声波功率对黑豆油提取效果的影响。结果表明,提取黑豆油的优化工艺条件为：提取时间9rain,提取温度58℃,料液比1：9,超声功率110W,在此条件下,黑豆油得率达到83．83％。对黑豆油进行GC—MS分析可知,黑豆油的主要脂肪酸有棕榈酸19．24％、亚油酸46．28％、油酸18．62％和硬脂酸7．3％等,其不饱和脂肪酸含量达68．98％。     

黑土生态系统脆弱性成因与修复

黑土生态系统脆弱性成因自然因素和人为因素共同作用的结果;自然因素是水土流失发生发展的潜在条件,人为因素对水土流失的发生发展起了促进和加速作用;遵循生物种群与环境相适应原则,对不同地貌类型导致生物生态分异,生物种群必须与地貌格局相一致;将黑土脆弱区分为3个生态系统进行生态修复。     

“红与黑”:论精神旅游产品的开发向度

红色旅游作为我国精神旅游的主导产品,其主题大多为爱国主义和革命传统教育,存在着主题概念僵化、客源以公费旅游群体为主等问题;而黑色旅游主题则以爱与和平为主,呈现负面事件“正面宣传化”、多元化深度开发不足等问题.鉴于此,文章提出创新我国精神旅游主题的思路,即从阐释美、正义、人性、自由和理性等多维视角重构旅游产品,更好地发挥其对国民的伦理教化作用.     

Geography, insolation, and vitamin D in nineteenth century US African-American and white statures

Using a new source of nineteenth century US state prison records I contrast the biological living conditions of comparable African-Americans and whites. Although blacks and whites today in the US reach similar terminal statures, nineteenth century African-American statures were consistently shorter than those of whites. Greater insolation (vitamin D production) is shown to be associated with taller black and white statures and a considerable share of the stature difference between US blacks and whites was attributable to insolation and vitamin D production. Black statures increased during the antebellum period, while white statures declined. Black and white statures both decreased after the Civil War. Farmers were taller than workers in other occupations, and an alternative explanation for stature variation by social class is considered.     

How broad-based is broad-based black economic empowerment?

Common perceptions about broad-based black economic empowerment (BBBEE) have been that it is nothing more than a tool for the already affluent to access further wealth and has limited potential to address the economic exclusion of the most marginalised. An analysis was conducted of data on black economic empowerment (BEE) deals between 2004 and 2009. The findings demonstrate that although the elite continue to benefit from deals, broad-based beneficiaries, particularly employees and women, are also beginning to benefit to some extent. This suggests that empowerment policies have some potential to promote private sector involvement in addressing the state's social transformation agenda. However, a closer analysis of the BEE transactions shows that the BEE landscape is far more complex and nuanced than commonly thought. Further research is necessary to understand the real impacts of BEE on the ground.     

企业竞争中的“黑洞现象”及其对策探讨

文章针对国际企业竞争中出现的新趋势,即随着全球化进程的加快,资源和市场份额愈来愈集中在少数几个跨国巨头手中,而无论从资金、技术还是管理和人力资源都不是很强的国内企业如何应对,尤其是中国按照加入WTO时所作的承诺将在2005年全面开放市场,国内企业失去了政策保护,将和跨国巨头直接展开厮杀的关头,我们如何提高胜算,本文将对此作一简要分析.     

旧水泥混凝土路面“白加黑”前压浆处治技术

旧水泥混凝土路面加铺沥青层(简称"白加黑")以其良好的使用性能在国内外得到广泛应用,反射裂缝是"白加黑"的主要病害,旧水泥混凝土路面良好的结构强度是控制或延缓反射裂缝发生的基础。对旧水泥混凝土路面采用压浆处治解决板下脱空问题,结合梅河高速公路加铺沥青混凝土工程,对板底脱空原因、压浆加固机理、压浆处治方案、压浆施工工艺及质量控制做了介绍。