非正规就业是扩大就业的重要渠道

非正规就业是扩大我国就业渠道的现实选择,能有效增加就业岗位,能提供了灵活、多样性的就业空间,为就业制度改革提供了必要保证。根据我国当前的非正规就业现状,笔者针对弱势群体的非正规就业提出了几点建议。     

How do beginners learn to read irregular words as sight words?

Learning irregular words involves mental marking of irregular letters in the spelling, a process not fully understood. In a within‐subjects experiment, we manipulated the type of scaffolding given to beginning readers to evoke mental marking. We pretested to sort 103 kindergarten and first‐grade participants into sequential decoders, who decode letter by letter, and hierarchical decoders, who recognise vowel patterns. In the control phase, children read irregular words in sentence contexts with minimal scaffolding. In the experimental phase, participants read additional irregular words in sentence contexts by ‘operating on the word’ to mark irregular letters. Results indicated that the experimental condition induced better untimed word reading, but it did not improve spelling or reading in a flash presentation. Hierarchical decoders were significantly more successful than sequential decoders in untimed word reading, spelling and reading in the flash presentation. These results suggest that learning hierarchical decoding predisposes readers to learn irregular words.     

Our experience with experimental<Emphasis Type="Italic">Wuchereria bancrofti</Emphasis> infection in Indian langur (<Emphasis Type="Italic">Presbytis entellus</Emphasis>)

Thyroid antibodies are commonly utilized in the assessment and diagnosis of autoimmune thyroid disorders. We compared the measurements of antithyroglobulin and antithyroidperoxidase antibodies by enzyme immunoassay with that of the conventional agglutination method. This fully automated enzyme immunoassay is more specific and cost effective than the agglutination method. Further this is a very quantitative and rapid method producing results in two hours as compared to at least twenty=four hours required by the conventional method. Antithyroidperoxidase antibodies determined by enzyme immunoassay are more specific and sensitive in the diagnosis of Hashimoto's thyroiditis than the antithyroglobulin antibodies.     

抛物线方程算法在不规则地形电波传播中的应用

文章对标准抛物线方程（SPE）的分裂步傅里叶变换（SSFT）方法进行了详细的分析,引入一种适合SPE的不规则地形建模方式,利用SSFT算法计算自由空间与不规则地形的电波传播问题,与经典理论计算所得的结果相当吻合。     

Comparative study and error analysis of digital elevation model interpolations

Researchers in P. R. China commonly create triangulate irregular networks （TINs） from contours and then convert TINs into digital elevation models （DEMs）. However, the DEM produced by this method can not precisely describe and simulate key hydrological features such as rivers and drainage borders. Taking a hilly region in southwestern China as a research area and using ArcGISTM software, we analyzed the errors of different interpolations to obtain distributions of the errors and precisions of different algorithms and to provide references for DEM productions. The results show that different interpolation errors satisfy normal distributions, and large error exists near the structure line of the terrain. Furthermore, the results also show that the precision of a DEM interpolated with the Australian National University digital elevation model （ANUDEM） is higher than that interpolated with TIN. The DEM interpolated with TIN is acceptable for generating DEMs in the hilly region of southwestern China.     

影响双醛化致敏血球检测霍乱肠毒素（CT）若干因素的探讨

报道了一些影响双醛化被动血凝法检测霍乱肠毒素（ＣＴ）的因素。通过试验认为红细胞的固定方法、致敏的ｐＨ、致敏物的浓度、以及致敏红细胞的浓度均对血凝有影响．用纯化抗ＣＴ－ＰｃＡｂ（ＭｃＡｂ）致敏双醛化羊红细胞作反向被动血凝，可以测出每毫升含２４ｎｇＣＴ．致敏红细胞于４Ｃ保存３个月其血凝滴度无明显变化，纯化抗体在４Ｃ保存４个月，致敏效果未见下降。对二种致敏方法进行比较，铬－免疫球蛋白－鞣酸法和Ｈｏｌｌｉｎｇｅｒ法检测ＣＴ敏感性一致，未经纯化的抗体致敏红细胞，效果较差，不直使用。抗ＣＴ－ＰｃＡｂ（ＭｃＡｂ）致敏羊血球对ＣＴ的检测具有较高的特异性和敏感性。     

交易信号对交易过程的动态影响模型研究

交易时间、交易量和交易价格是市场交易者最容易观察到的交易信号,这些信号所传递的信息必然对交易者的交易策略和交易过程产生影响。根据Manganelli基于不规则时间序列对交易时间、交易量和交易价格建立的动态系统模型,在考虑交易时间间隔的不规则性对价格波动性度量影响的基础上提出了改进模型,并利用中国股市的数据对改进前后的模型进行了实证比较。比较结果表明改进模型能更好地解释微观结构理论所揭示的交易时间、交易量和交易价格之间的动态关系及其对交易过程的影响。     

碰撞检测算法的探讨

在视景仿真和3d游戏设计中,碰撞检测是必不可少的一部分。通过对碰撞检测算法的现状的研究,在几种碰撞检测算法的基础上,提出了一种经过改进的用于判断三维空间中视点或运动物体与场景的碰撞检测算法。     

谈反例教学对数学思维品质的培养

在数学分析教学中,笔适时抓住教材中的“瑕点”,应用反例教学,对调动学生的积极思维－思维的敏捷性、灵活性、批判性,起到了较好的效果。同时还指出了几本高等数学参考书中关于不定积分、二重积分、曲线积分计算中出现的错误。     

Seroprevalence of SARS-CoV-2 infection among children in Children’s Hospital Zagreb during the initial and second wave of COVID-19 pandemic in Croatia

IntroductionThe study aimed to investigate the prevalence and titres of anti-SARS-CoV-2 antibodies in children treated at the Children’s Hospital Zagreb in the first and the second wave of the COVID-19 pandemic. Statistical significance of difference at two time points was done to determine how restrictive epidemiological measures and exposure of children to COVID-19 infection affect this prevalence in different age groups.Materials and methodsAt the first time point (13th to 29th May 2020), 240 samples and in second time point (24th October to 23rd November 2020), 308 serum samples were tested for anti-SARS-CoV-2 antibodies by enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence immunoassay (ECLIA). Confirmation of results and titre determination was done using virus micro-neutralization test. Subjects were divided according to gender, age and epidemiological history.ResultsSeroprevalence of anti-SARS-CoV-2 antibodies differs significantly in two time points (P = 0.010). In first time point 2.9% of seropositive children were determined and in second time point 8.4%. Statistically significant difference (P = 0.007) of seroprevalence between two time points was found only in a group of children aged 11-19 years. At the first time point, all seropositive children were asymptomatic with titre < 8. At the second time point, 69.2% seropositive children were asymptomatic with titre ≥ 8.ConclusionsThe prevalence of anti-SARS-CoV-2 antibodies was significantly lower at the first time point than at the second time point. Values of virus micro-neutralization test showed that low titre in asymptomatic children was not protective at the first time point but in second time point all seropositive children had protective titre of anti-SARS-CoV-2 antibodies.