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1.
在缺硼上壤上进行秦油2号移栽穴内底施硼肥(6.0—18.0kg·hm-2硼砂)和蕾苔期喷施硼肥(1.5—7.5kg·hm-2硼砂)试验。结果表明:移栽穴内底施硼肥以施用15kg·hm-2硼砂增产幅度最大,增产达487.5kg·hm-2,增幅20.1%;蕾苔期喷施以施用4.5kg·hm-2硼砂增产幅度最大,增产达265.5kg·hm-2,增幅11.0%;“花而不实”诛率、裂茎株率均随施硼砂量的增加而下降,菌核病发生率与硼肥用量无关。  相似文献   

2.
据美国国家科学基金会的统计显示,1998年,美国政府和民间投入科学研究和开发的经费比前年增长5.3%,增长到2206亿美元,仍居世界首位,其中344亿美元投入基础研究,498亿美元投入应用研究,其余1364亿美元则是投入开发。从美国投入研究的经费占国内生产总值的比重来看,去年达2.61%,高于前年的2.54%和1996年的2.57%。在美国历史上,科研经费占国内生产总值最高值是约翰逊任内的1964年,达2.87%;最低值是卡特总统任内的1978年,为2.12%。美国的科研经费虽居世界之首,但它所…  相似文献   

3.
我们对大连开发区 32所幼儿园 2 128名 3-6岁幼儿进行了龋病流行病学调查, 按照卫生部的标准,按年龄分为四组.调查结果显示:患龋率随年龄增长而上升,易感 牙位依次为第一乳磨牙、第二乳磨牙、上颌乳中切、乳侧切、乳磨牙下颌乳切牙.平均 患龋率为81.16. 乳牙早失不但给幼儿进食带来不便,而且直接影响恒牙发育.我们建议窝沟封闭不 但要对六龄齿,而且要从乳磨牙做起.  相似文献   

4.
中草药对奶牛隐性乳房炎的治疗效果观察   总被引:2,自引:0,他引:2  
选择皖南地区某奶牛场106头奶牛进行乳房炎流行病学调查。应用SMT诊断液对奶牛奶样进行检测,发现59头奶牛具有隐性乳房炎,其发病率达55.66%。应用中草药组方研制的中药超细散剂“消炎增乳散”对奶牛隐性乳房炎进行治疗。消炎增乳散混入饲料中喂服,每天200g,3天为一个疗程。对照组不使用药物预防和治疗。结果表明中药制剂“消炎增乳散”对奶牛隐性乳房炎的治疗愈为72.2%。  相似文献   

5.
计表2数学教师计算机知识的掌握、使用情况表1学校设备配置情况386计算机486计算机586以上的计算机校园网络31.1%42.9%26%元计算机知识掌握情况使用计算机的情况没有掌握能进行简单的文字处理能编写公式处理表格与数据能制作简单的课件几乎每天都用学计算机时用过偶然用过几次没用过17人26人2人3人2人16人16人14人35.4%54.1%4.2%6.3%4.2%33.3%33.3%29.2%算机辅助教学(CAI)开始在我们的中学教育中实施应用,并产生了巨大的影响。为了了解当前中学数学CAI…  相似文献   

6.
整式乘除运算和整式加减运算一样,是代数式运算的基础,也是初中阶段一项重要的基本计算技能.熟练、准确地进行整式的混合运算,可为进一步地学习其他知识打下扎实的基础.本文着重介绍一些典型的有关整式乘除的综合应用问题,希望能对学学习有所帮助.□江苏例1已知3x+1·2x-3x·2x+1=36,求x.分析:若两个幂相等,且它们的底相同,则指数一定相等.在这里,可考虑先将底化为相同,再比较其指数.解:∵3x·2x(3-2)=36,6x=36,6x=62,所以x=2.例2已知多项式A与(x-1)2的乘积为x3-3x2+kx…  相似文献   

7.
1.在图1所示的盛水容器中,A、B、C、D、E各点受到水的压强分别为ρA、ρB、ρC、ρD、ρE,将各点受到水的压强从大到小排列,应是2.在水平地面上放着一块底面积为S、高为h的长方体铁块,现把它锻打成一个高为h/2的圆柱体,竖放在水平面上,它对地面的压强是原来的倍。3.如图2,甲、乙、两三个容器中盛有三种不同的液体,它们的密度之比为1.8:1.2:1.质量之比为3:2:1.若三个容器底面积相同,且液体的深度相同,则容器底面积受到液体的压强之比为__,压力之比为_.4.履带式拖拉机的履带是用一块…  相似文献   

8.
通过连续三年对新乡市耕土壤养分动态监测结果表明,土壤有机质、速效磷、速效钾含量逐年下降,其中东部四县分别下降0.03425%、2.5875和0.8875ppm,中西部五县市分别下降0.124%、2.01和3.39  相似文献   

9.
困惑与联想     
老师给我们讲过液体压强及其特点后,有一个问题引起了我的困惑.如图1所示,将底面积为S、高为h的圆桶装满密底为ρ的水,则水对桶底的压力是多少?如果将这些水装人底面积为S/2、高为2h的桶中,水对桶底的压力又是多少?这个问题我能解答.即两种情况水对桶底的压力均相等,且压力大小等于水的重力ρgSh.而且,我觉得似乎发现了一条规律,即装水容器水对桶底的压力等于水所受的重力.可是,这样的一个想法很快就被另一个问题的结论给推翻了.这个问题是:如果做一只尺寸如图2所示的桶,再用前面题中的那些水将其灌满,这时水…  相似文献   

10.
目前,我国高校毕业生的就业问题,成为全社会的关注焦点。据347所高职高专院校的人效数据统计,截止2003年月12月底高职高专毕业生就业率平均为87.6%,未就业率为11.7%,不就业率平均为0.7%。另外2003年12月底与6月底高职高专男女生的就业比,调查统计分别为:1.22:1与1.29:1。  相似文献   

11.
目的寻求一种能够有效地保存乳牙生活根髓,提高活髓切断术成功率的方法.方法:选择102只患牙用2%戊二醛固定根髓断面后用含戊二难之盖髓剂盖髓,然后充填并观察半年至1年疗效,结果术后半年成功率为97.1%,术后1年成功率为95.7%,结论2%戊二醛法活髓切断术可大量替代神剂失活干尸术.具有操作安全,疗程缩短为一次等优点。  相似文献   

12.
The aim of this study was to evaluate the predictive validity of a two-step admissions procedure that included a cognitive ability test followed by multiple mini-interviews (MMIs) used to assess non-cognitive skills, compared to grade-based admissions relative to subsequent drop-out rates and academic achievement after one and two years of study. The participants consisted of the entire population of 422 psychology students who were admitted to the University of Southern Denmark between 2010 and 2013. The results showed significantly lower drop-out rates after the first year of study, and non-significant lower drop-out rates after the second year of study for the admission procedure that included the assessment of non-cognitive skills though the MMI and the admissions test. Furthermore, this admission procedure resulted in a significant lower risk of failing the final exam after the first and second year of study, compared to the grade-based admissions procedure. Finally, students admitted through the MMI and the admissions test scored significantly higher on academic learning self-efficacy and critical thinking compared to students selected by grades. The implications for higher education admissions are discussed.  相似文献   

13.
分析建筑现浇板由混凝土收缩和温差共同作用引起上下贯穿裂缝的产生机理,通过微元体建立建筑外周粱与室内板间的静力平衡关系,导出以混凝土极限收缩应变值ε反映混凝土材料质量影响的外梁温差应力计算公式,提出建筑现浇板预控贯穿裂缝的强度计算式及施工过程与使用过程的预控措施.  相似文献   

14.
对42人47颗早期牙隐裂患牙,用作者提出的综合方法治疗后定期追踪2年以上,观察结果:总的牙齿保存率为95.74%,其中有26例患牙功能良好,临床检查和牙髓活力正常,结果提示:38.30%的早期牙隐裂患牙,其隐裂继续加深和开髓病变的发生均不易控制,宜及早做牙髓治疗和全冠修复。  相似文献   

15.
Child Abuse and Neglect (CAN) is an important problem both in Turkey and worldwide. Unfortunately, we still don’t have enough and reliable data on this important subject. In this study, we aimed to investigate the prevalence of childhood maltreatment in a population of first year medical students in a Turkish university using the retrospective version of the ISPCAN Child Abuse Screening Tool (ICAST-R). One hundred seventy three first year medical students, aged between 18 and 24 years, who agreed to complete the ICAST-R questionnaire, were recruited in our study. Of 173 students who completed the survey, 51.4% are found to be subjected to at least one type of child abuse (physical, emotional or sexual). The prevalence is higher in male gender and the difference is statistically significant. Physical, emotional and sexual abuse exposure rates are found to be 23.1%, 40.5% and 11% respectively. Physical and emotional abuse rates are higher in male gender and the difference is statistically significant. We did not find any statistically significant association between gender and sexual abuse. Efforts to prevent child abuse and neglect are growing in our country, as they are worldwide. However, child abuse is still common and a problematic issue. It is important to determine the prevalence of child abuse in order to raise awareness. We need further studies investigating not only prevalence but also risk factors to have reliable data for our country.  相似文献   

16.
The current study investigated whether the quality of school anti-bullying policies allows the drawing of any conclusions about the extent of bullying problems in schools. That is, do schools with a more detailed anti-bullying policy have lower rates of bullying? A total of 2377 children in primary schools (six year olds/year two: 1072; eight year olds/year four: 1305) were individually interviewed using a standard interview about bullying experiences. A detailed content analysis scheme that closely followed the core whole-school intervention approach was carried out on a total of 34 schools: 24.5% of the children reported being directly victimised very frequently and 45.9% reported being relationally victimised frequently or very frequently. No correlation between the content and quality of anti-bullying policies and the prevalence of direct bullying behaviour was found. Conversely, an inverse relationship was found for relational bullying behaviour: schools with the most detailed and comprehensive anti-bullying policies had a higher incidence of relational bullying and victimisation behaviour. Inspection of school anti-bullying policies per se provides little guide to the actual amount of direct bullying behaviour in schools.  相似文献   

17.
This random assignment impact study of Big Brothers Big Sisters School-Based Mentoring involved 1,139 9- to 16-year-old students in 10 cities nationwide. Youth were randomly assigned to either a treatment group (receiving mentoring) or a control group (receiving no mentoring) and were followed for 1.5 school years. At the end of the first school year, relative to the control group, mentored youth performed better academically, had more positive perceptions of their own academic abilities, and were more likely to report having a "special adult" in their lives. However, they did not show improvements in classroom effort, global self-worth, relationships with parents, teachers or peers, or rates of problem behavior. Academic improvements were also not sustained into the second school year.  相似文献   

18.
OBJECTIVE: To examine trends by year in reports of victims of child maltreatment in the US Army Central Registry (ACR) during the period 1975-97. We report the rates/1,000 children of Army families of initial substantiated cases from 1988-97 and the number of cases of maltreatment as a percentage of total victims for each year from 1975-97. Army data are compared to published reports from military service child abuse registries. METHODS: Numbers of cases of child maltreatment for each year were obtained from the ACR for major, minor, and total physical abuse, sexual abuse, emotional abuse, and neglect. Population figures for numbers of children were obtained from the Defense Manpower Data Center. RESULTS: The rates/1,000 for neglect have decreased by 24% from 1991-97, although the decrease has not been steady. The rates/1,000 of minor physical abuse declined 28% from 1993-97. The rates/1,000 of major physical abuse were basically unchanged from 1988-96, although the highest rate was recorded in 1997. The rates/1,000 of sexual abuse were also basically unchanged with the exception of increases in 1992-94 after which time the rates/1,000 returned to the pre-1992 levels. The rates/1,000 of emotional abuse cases more than doubled from 1988-97. CONCLUSIONS: While minor physical abuse and neglect have shown decreases over the past decade, major physical abuse has remained virtually unchanged and sexual and emotional abuse have shown fluctuations. All these forms of maltreatment are challenges to the Army Family Advocacy Program.  相似文献   

19.
Maintaining academic integrity and preventing students from cheating and plagiarising academic work are challenges faced by higher education institutions. These areas have become even more problematic with the growth of the Internet and readily available information, which increase the temptation for students to copy and paste information directly into academic work. Institutions have turned to various strategies to mitigate these aspects. This retrospective research study examined a four-prong anti-plagiarism programme and its impact on the incidence of plagiarism in a Post-Professional Doctor of Physical Therapy programme. The results showed that, using a combination of a structured education module related to plagiarism, Turnitin plagiarism detection software, implementation of policies and procedures, and support from the institution’s writing centre resulted in significant differences in the rate of plagiarism (P < .001) over the five-year period. The rate of plagiarism in year 1 (0.96%) was 2.7 (95% CI, 1.4–5.3) times the rate in year 5 (0.35%, P = .004). The rates of plagiarism in years 2, 3, and 4 were 0.74, 0.35, and 0.30%, respectively. Using a combination of these strategies may help higher education institutions address episodes of plagiarism and improve academic integrity.  相似文献   

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