共查询到20条相似文献，搜索用时 296 毫秒
1.
目的:了解黎族中学生头面部特征,探讨其特点并积累形态学资料。方法:采用问卷调查法、活体观察法及人体测量法对689名黎族中学生进行头面部6项指标进行观察与测量。结果:黎族中学生主要以中头型(56.89%)较为常见,以椭圆型脸为主(27.42%),其次是卵圆型(19.94%);中鼻型最多(49.12%),其次是阔鼻型(30.94%)。结论:黎族中学生头面部特征与广西侗族、辽宁锡伯族以及满族中学生比较,有相近之处又有自己的特征。 相似文献
2.
恒河猴头骨非测量性状指标观察 总被引：1，自引：0，他引：1
观察了24例实验恒河猴(Macaca mulatta)完整头骨的近100项非测量性状.结果表明,颅形以楔形为主(41.67%),其次为盾形(29.17%);眶形多为圆形(58.33%);枕骨大孔形状较多,以五角形(29.17%)和菱形(20.83%)多见;翼区缝结构绝大多数为额颞型(79.17%).枕外隆凸显著(41.67%).＞12岁时颅顶缝趋向愈合,＜12岁猴矢状缝各段以深波形和锯齿形居多,冠状缝和人字缝各段主要为微波形.颧颞孔一般左右各一个(83.33%),颧面孔一般左右各一个(45.83%),两侧俱缺的较常见(33.33%),眶下孔以左右各3个最常见(41.67%). 相似文献
3.
目录:应用MSCT(多排螺旋CT,multi-slice computed tomography)测量正常新生儿的脑室结构和脑容积,为新生儿脑发育状况评价及颅脑疾病诊断提供CT解剖数据.方法:从进行颅脑CT扫描的新生儿中选取43例无异常发现者的CT图像进行测量,首先在CT机上选择测量距离值示标,分别测量侧脑室前角最大距离等7项指标,每个指标均测量三次,取其均值,并计算脑室指数;利用容积测量软件,用等灰度法均匀涂布所选区域,测量脑容积等9项指标.结果:获得正常新生儿脑室结构CT测量指标平均值和新生儿脑容积9项指标的平均值,且左右小脑半球容积及左右侧脑室容积差异无显著性(P均>0.05).结论:MSCT可准确可靠地测量正常活体新生儿脑室结构和脑容积,从影像学角度认识正常新生儿颅脑的CT解剖. 相似文献
4.
5.
根据林麝和马麝头骨的颅全长x_1,颅基长x_2,基长x_3,鼻骨长x_4,吻长x_5,眼眶直径x_6,眶间宽x_7,后颅宽x_8,颧长x_9,颧宽x_(10),上裂齿长x_(11),下裂齿长x_(12)共十二项指标进行判别分析,得出分类的判别函数为:y_1=-964.2218+8.8263x_1-0.3689x_7-0.4067x_(10)+12.4122x_(11)y_2=-740.5994+7.3648x_1+0.3894x_7+0.6138x_(10)+10.1241x_(11)将头骨质量x_1、x_7、x_(10)、x_(11)分别代入二方程计算,若y_1>y_2,则为马麝,若y_2>y_1,则为林麝. 相似文献
6.
采用相邻格子法取样的数据,应用方差/均值比的t检验法、负二项参数、扩散型指数、Cassie指标、丛生指标、平均拥挤指数和聚块性指数等方法,分析了天台山木荷种群在不同群落中的空间分布格局。结果表明:木荷种群在木荷纯林、常绿阔叶林中呈集群分布,而在针阔混交林中为集群趋向随机分布。其集群强度表现为常绿阔叶林最大,木荷纯林次之,针阔混交林最小。此外,还分大小级对木荷种群的分布格局进行了测定,从幼苗到中树,种群从集群分布到随机分布甚至均匀分布,集群强度逐渐降低,总体上种群呈扩散趋势。 相似文献
7.
综合气象干旱指数(Ci指数)是以标准化降水指数、湿润度指数及近期降水量为基础,同时考虑了降水和潜在蒸散两项因子而设计的干旱指标。通过对衡阳市各区域1960—2012年逐日Ci指数统计,运用非参数Mann-Kendall检验(MK检验),分析了近53年来Ci指数的年代际、年及季节变化特点。结果表明:衡阳市干旱日、重旱日及特旱日出现频率分别为24.6%、3.1%和1.2%,其中有94.3%和77.4%年份出现了重、特旱日,进入21世纪以后,特旱日出现频率略有增大;Pd值在冬、夏季呈减少变化,而在春、秋季则有增大趋势,且在Pd值较高的季节,其倾向率增大(减小)更为明显;Pd值在8～9月达到高点,而Pz和Pt则在10～11月达到较高水平,9月份Pz、Pt偏低是由于8月降水较7月偏多所致。 相似文献
8.
联合国开发计划署(UNDP)提出的人类发展指数(HDI)仅用三个指标难以完整地表现人类发展的全部内涵,所以,本文在拓展的人类发展的概念的基础上,构建新人类发展指数.首先是指标的拓展,以我国所倡导的"四个文明"所涉及的论域为二级指标,下面又设置了23项三级指标;其次是计算方法的改变,用层次分析法确定权重、用线性加权和合成法进行指数的合成;然后从大连市新人类发展指数的测量中发现大连市经济社会发展的优势与不足,并寻找提升大连市新人类发展指数的对策. 相似文献
9.
农村寄宿制初中学生营养状况调查分析及改善营养途径的探讨 总被引：1，自引：0，他引：1
我在讲授到七年级生物学下册第8章第3节《合理膳食》内容时,让七(5)班的全体同学共同参与了《评价自身的营养状况》这个活动。每个同学根据测量出的身高和体重(为了精确,由专门培训过的小组长进行测量,且每项指标都要测量3次,取平均数作为自己的身高体重数值),按照公式:体重(kg)/身高的平方(m2)计算自己的体质指数,再对照评价指标(体质指数<18.5为营养不良,体质指数在18.5～25之间为正常,体质指数 相似文献
10.
本文对张家口地区出土具有完整鼻骨的150个成年颅骨进行了观测。未分性别。结果如下: 一、鼻骨形态:分三型、Ⅰ型:上、下宽,中部窄。81例,居首位;Ⅱ型:由上向下渐增宽。66例;Ⅲ型:整个宽度大致相等。4例。两侧鼻骨融合者为13例。二、额鼻缝:分三型,Ⅰ型:直线,49例;Ⅱ型:弧线,79例;Ⅲ型:曲线22例。三、鼻根点凹陷:分三度:0度42例;1度62例;2度46例。四、鼻骨孔数:具有一孔者左侧107例,右侧99例。二孔者左侧25例,右侧28例。右 相似文献
11.
Research on the protection effect of pioglitazone for non-alcoholic fatty liver disease （NAFLD） in rats 总被引：4，自引：0，他引：4
Objective： The prevalence of non-alcoholic fatty liver disease （NAFLD） has markedly increased. Insulin resistance has been implicated in the pathogenesis of NAFLD. This study was aimed at observing the relationship between insulin resistance and NAFLD, and evaluating the role of pioglitazone （PGZ） acting as insulin-sensitizing agents in the prevention and treatment of rat fatty liver induced by high fat feeding. Methods： The rats were separated randomly into 6 groups： model group Ⅰ were fed high fat diet for 8 weeks, PGZ prevention group were given PGZ 4 mg/（kg.d） simultaneously, while control group Ⅰ were fed normal food for 8 weeks; model group Ⅱ were fed high fat diet for 16 weeks, PGZ treatment group were given PGZ 4 mg/（kg.d） orally simultaneous with high fat diet for 8 weeks after high fat feeding for 8 weeks, control group Ⅱ were fed normal food for 16 weeks. The rats were sacrificed after 8 weeks and 16 weeks respectively. Liver weight, body weight, serum activities of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, alkaline phosphatase （ALP）, tumor necrosis factor alpha （TNF-α）, fasting blood glucose （FBG）, fasting plasma insulin （FINS）, HOMA （homeostasis model assessment） insulin resistance index （HOMA-IR）, and the liver histology of rats of all groups were assayed. Results： After 8 weeks, the liver in model group Ⅰ showed typical steatosis, accompanied with mild to moderate lobular inflammatory cell infiltration, liver indexes and serum levels of ALT, AST, ALP, TNF-α were significantly increased （P〈0.05） compared with control group Ⅰ. Whereas, the degree of hepatic injury was attenuated in PGZ prevention group, liver indexes and serum levels of ALT, ALP were significantly decreased （P〈0.05） compared with model group Ⅰ. After 16 weeks, notable steatosis, and lobular inflammation were observed in model group Ⅱ rat liver, while the degree of hepatic injury was attenuated in the PGZ treatment group. Liver index, serum levels ofALT, AST, ALP, FINS and HOMA-IR were significantly increased （P〈0.05） in model group Ⅱ compared with control group Ⅱ. Whereas, in PGZ treatment group, serum levels of AST and FINS showed decreasing tendency, liver indexes, serum levels of ALT, ALP, TNF-α and HOMA-IR were significantly decreased compared with model group Ⅱ. Conclusion： Insulin resistance plays a role in the pathogenesis of NAFLD in rats. Pioglitazone can attenuate insulin resistance and biochemical and histological injury in high fat-induced fatty liver in rats. 相似文献
12.
《教育实用测度》2013,26(4):265-288
Many of the currently available statistical indexes to detect answer copying lack sufficient power at small α levels or when the amount of copying is relatively small. Furthermore, there is no one index that is uniformly best. Depending on the type or amount of copying, certain indexes are better than others. The purpose of this article was to explore the utility of simultaneously using multiple copying indexes to detect different types and amounts of answer copying. This study compared eight copying indexes: S1 and S2 (Sotaridona & Meijer, 2003), K¯ 2 (Sotaridona & Meijer, 2002), ω (Wollack, 1997),B and H (Angoff, 1974), and new indexes Runs and MaxStrings, plus all possible pairs and triplets of the 8 indexes using multiple comparison procedures (Dunn, 1961) to adjust the critical α level for each index in a pair or triplet. Empirical Type-I error rates and power of all indexes, pairs, and triplets were examined in a real data simulation (i.e., where actual examinee responses to items [rather than generated item response vectors] were changed to match the actual responses for randomly selected source examinees) for 2 test lengths, 9 sample sizes, 3 types of copying, 4 α levels, and 4 percentages of items copied. This study found that using both ω and H* (i.e., H with empirically derived critical values) can help improve power in the most realistic types of copying situations (strings and mixed copying). The ω-H* paired index improved power most particularly for small percentages of items copied and small amounts of copying, two conditions for which copying indexes tend to be underpowered. 相似文献
13.
Paulette Rozencwajg 《European Journal of Psychology of Education - EJPE》2003,18(3):281-294
The aim of this study on 42 seventh graders (ages 12–13) was to determine whether and to what extent students’ metacognitive
level is linked to their conceptualization and performance in problem solving at school, especially science problems. This
hypothesis is supported by a number of studies showing that metacognition is a factor in learning. Two indexes were devised
for the study: an index of metaknowledge about classroom learning, and an index of metacognitive monitoring in relation to
task difficulty on a non-academic problem. These two indexes were related to the students’ intelligence test scores and solving
strategies on electricity problems. The results showed that (1) the metaknowledge level was more closely tied to crystallized
intelligence (Gc), and (2) metacognitive monitoring was more closely associated with fluid intelligence (Gf). Moreover, both
metacognitive indexes were strongly linked to scientific problem-solving strategies (correlations around .50). 相似文献
14.
Three novel triazine-based charring-foaming agents (M2-CFA,M4-CFA,and M6-CFA) were synthesized successfully with only water as the solvent and were characterized by FT-IR and thermal gravimetric analysis (TGA).These three charring-foaming agents and the byproduct 944-by were employed to study the effectiveness of the novel intumescent flame retardant dopant on the fire retardancy of polypropylene (PP) investigated through UL-94 and limiting oxygen index (LOI) tests.TGA results showed that the M4-CFA presented good char formation ability (char residue: 26.8% at 700 ℃).It was found that the sample with a 2/1 mass ratio of APP to M4-CFA exhibited the best flame retardancy among all the PP composites: 35.5% LOI and a V-0 rating of UL-94.Additionally,the microstructure and morphology of char residues were further studied by XRD,Raman spectroscopy and SEM. 相似文献
15.
This study investigated the performance of fit indexes in selecting a covariance structure for longitudinal data. Data were simulated to follow a compound symmetry, first-order autoregressive, first-order moving average, or random-coefficients covariance structure. We examined the ability of the likelihood ratio test (LRT), root mean square error of approximation (RMSEA), comparative fit index (CFI), and Tucker–Lewis Index (TLI) to reject misspecified models with varying degrees of misspecification. With a sample size of 20, RMSEA, CFI, and TLI are high in both Type I and Type II error rates, whereas LRT has a high Type II error rate. With a sample size of 100, these indexes generally have satisfactory performance, but CFI and TLI are affected by a confounding effect of their baseline model. Akaike's Information Criterion (AIC) and Bayesian Information Criterion (BIC) have high success rates in identifying the true model when sample size is 100. A comparison with the mixed model approach indicates that separately modeling the means and covariance structures in structural equation modeling dramatically improves the success rate of AIC and BIC. 相似文献
16.
采用聚氧化丙烯二醇（PPG）、异佛尔酮二异氰酸酯（IPDI）,甲苯二异氰酸酯（TDI）、二羟甲基丙酸（DMPA）等分别合成了IPDI型和TDI型水性聚氨酯（WPU）乳液,用共混的方法将阻燃剂FR-600引入到水性聚氨酯中,从而得到一系列阻燃水性聚氨酯。采用红外光谱对合成产物进行表征,并用氧指数仪、Zeta电位测试仪等对其性能进行研究。结果表明,阻燃剂FR-600能显著提高水性聚氨酯的阻燃性能,随着阻燃剂用量的增加,水性聚氨酯的极限氧指数不断增大,对于IPDI型水性聚氨酯,当阻燃剂FR-600的添加量为水性聚氨酯的8%时,其氧指数可达37%,使水性聚氨酯由可燃降低为不燃。对于TDI型水性聚氨酯,在阻燃剂添加量为10%时,其极限氧指数达到36%,达到了不燃级。粒径和Zeta电位测试表明,阻燃剂的加入对两种水性聚氨酯的粒径及稳定性影响不大。 相似文献
17.
Min Han Rong-yang Wang Hong Liu Xiu-juan Zhu Fu-lan Wei Tao Lv Na-na Wang Li-hua Hu Guo-ju Li Dong-xu Liu Chun-ling Wang 《Journal of Zhejiang University. Science. B》2013,14(1):25-32
Objective:To investigate the relationship between growth patterns and mandibular posterior tooth-alveolar bone complex morphology in a Chinese population with normal occlusion.Methods:Forty-five patients with normal occlusion(23 males,22 females) were included in this study.Among these patients,20 displayed the vertical growth pattern,and 20 had the horizontal growth pattern,while the remaining patients displayed the average growth pattern.All of the patients underwent dental cone beam computed tomography(CBCT),which included the region of the mandibular posterior teeth and the alveolar.A linear regression analysis and a correlation analysis between the facial height index(FHI) and the alveolar bone morphology were performed.Results:The inclination of the molars,the thickness of the cortical bone,and the height of the mandibular bone differed significantly between patients with the horizontal growth pattern and those with the vertical growth pattern(P<0.05).Significant positive correlations were found between:the FHI and the inclination of the molars;the FHI and the thickness of the cortical bone;and the FHI and the height of the mandibular bone.Conclusions:The mandibular posterior tooth-alveolar bone complex morphology may be affected by growth patterns. 相似文献
18.
Yin-gang Zhang Zheng-ming Sun Jiang-tao Liu Shi-jie Wang Feng-ling Ren Xiong Guo 《Journal of Zhejiang University. Science. B》2009,10(7):522-527
Objective: The age-related change is important part of degenerative disc disease. However, no appropriate animal model or objective evaluation index is available. This study aimed to investigate the features of intervertebral disc degeneration in aging process of rats. Methods: 22-month-old Sprague-Dawley (SD) rats were used as spontaneously occurring intervertebral disc degeneration models and 6-month-old rats as young controls. Expression of collagen types Ⅱ and Ⅹ was measured by immunohistochemistry. Degenerations of intervertebral discs were scored according to Miyamoto's method. Numbers and areas of afferent vascular buds were measured. The thicknesses of non-calcified and calcified layers were measured and statistically analyzed.Results: There were less collagen type Ⅱ expression and more collagen type Ⅹ expression in the calcified layer of the cartilage endplates and nucleus pulposus in the rats of the aged group than in the young control. There were fewer and smaller afferent vascular buds in the rats of the aged group than in the young control group. The ratio of the non-calcified to the calcified layers in the rats of the aged group significantly decreased, compared with that of the young control group (P＜0.01). Conclusion: Rats can spontaneously establish intervertebral disc age-related degeneration. The expression of collagen types Ⅱ and Ⅹ, numbers and areas of afferent vascular buds, the ratio of the non-calcified to the calcified layers, and water and glycosaminoglycan contents in the nucleus pulposus are sensitive indexes of intervertebral disc degeneration. 相似文献
19.
用凝胶溶胶（sol—gel）法在普通截玻片和si上生长了稀土La掺杂ZnO薄膜,稀土La^3＋离子和Zn^2＋浓度摩尔比分别为1％,2％,3％．通过X射线衍射仪（XRD）、紫外可见分光光度计（UVS）、原子力显微镜（AFM）、光致发光（PL）等对薄膜的结构、光学特性、形貌进行表征,结果显示不同浓度La掺杂的ZnO薄膜均为六角纤锌矿结构,薄膜表面颗粒均匀平整,随着掺杂浓度的提高,La掺杂ZnO薄膜的紫外发光峰出现蓝移现象． 相似文献
20.
Chen L Tian H Chen J He ZG Tao SF Lokesh G Peng SY 《Journal of Zhejiang University. Science. B》2005,6(1):38-42
Objective: To observe the clinicopathological characteristics of gastric stump cancer (GSC) and evaluate the benefits of radical surgery of GSC. Methods: The clinicopathological characteristics and postoperative survival time of 37 GSC patients who underwent surgery were investigated retrospectively. The survival time was compared according to the type of surgical pTMN stage. Survival curves were traced by using Kaplan-Meier methods. Results: Most GSC (32/37) was detected in patients who had received Billroth Ⅱ reconstruction after partial gastrectomy for benign gastric disease. The lesser curvature side and the suture line of anastomosis were the most frequent sites where GSC occurred (27/37). Differentiated adenocarcinoma was the dominant histopathological type (24/37). The postoperative 5-year survival rate of early stage GSC patients (n=9) was significantly higher than advanced stage GSC (n=12) (55.6% vs 16.5%, xL2=1 1.48, P＜0.01). Five-year survival rate of 21 GSC patients with radical resection were 75% (3/4) for stage Ⅰ, 60% (3/5) for stage Ⅱ, 14.2% (1/7) for stage Ⅲ, and 0% (0/5) for stage Ⅳ respectively.The median survival time of 21 GSC patients who underwent radical resection was longer than those undergoing palliative operation (43.0m vs 13.0m, xL2=36.31, P＜0.01), the median survival time of stage Ⅳ patients with radical resection was 23.8months. Conclusions: Without remote metastasis, radical resection for GSC is possible, and is an effective way to improve the prognosis of GSC. Even in stage Ⅳ GSC, radical resection can still prolong the survival time. It is necessary for the patients with benign gastric diseases who received partial gastrectomy to carry out the endoscopy follow-up, especially in patients with Billroth Ⅱ reconstruction procedure at 15-20 years. 相似文献