新教材实验过程“得”“失”探讨

当前,二期课改的新教材陆续进入课堂,如何理解新理念,接受新观点,用好新教材,是我们中学师生共同面临的问题.本文提出的问题值得大家思考和讨论。     

重力图形匹配技术在水下导航中的应用

以国外有关文献为依据,对重力图形匹配技术的基本原理和关键技术进行了分析,介绍了重力图形匹配技术应用于水下导航的研究现状,探讨了未来的发展方向,为国内相关领域的研究人员提供参考。     

膜载体酶标记渗透式快速检测痕量西维因残留方法的研究

建立了一种快速检测氨基甲酸酯类农药西维因痕量残留的新方法,即膜载体酶标记渗透式快速检测技术。以带正电尼龙膜(M illipore)为固相载体,辣根过氧化酶标记的西维因半抗原为检测标记物,采用直接竞争酶联免疫吸附方式对农产品中的痕量西维因残留进行快速检测。该方法完成整个检测过程只需5m in,对西维因的检出限为10μg/L,通过高效液相色谱法(HPLC)验证了该检测方法的有效性,并经试验证明了方法的稳定性。     

Quantum correlation switches for dipole arrays

We investigate the characteristics of three kinds of quantum correlations, measured by pairwise quantum discord （QD）, geometric measure of quantum discord （GMQD）, and measurement-induced disturbance （MID）, in the systems of three- and four-dipole arrays. The influence of the temperature on the three quantum correlations and entanglement of the systems is also analyzed numerically. It is found that novel quantum correlation switches called QD, GMQD, and MID respectively can be constructed with the qubits consisting of electric dipoles coupled by the dipole-dipole interaction and oriented along or against the external electric field. Moreover, with the increase of temperature, QD, GMQD, and MID are more robust than entanglement against the thermal environment. It is also found that for each dipole pair of the three- and four-dipole arrangements, the MID is always the largest and the GMQD the smallest.     

基于可变航速的支线集装箱船舶调度优化模型与算法

随着航运市场的竞争不断加剧和集装箱船舶大型化的发展,越来越多的航运企业选择轴-辐式航运网络模式。支线船舶调度问题作为轴-辐式航运网络的重要组成部分受到研究者的高度关注。本文研究了可变航速和经济航速两种情境下的支线船舶调度问题,同时考虑枢纽港和喂给港的取送箱时间窗限制,以航运企业运营成本最小化为目标函数建立非线性混合整数规划模型。首先使用专业的规划求解器进行小规模算例的求解,验证了模型的准确性。同时运用改进的遗传算法对大规模支线船舶优化调度模型进行求解。为了提高求解效果,进一步设计了多智能体进化算法进行求解。数值结果表明,可变航速的运营成本低于经济航速的运营成本;在算法效率方面,改进遗传算法收敛速度较快,多智能体进化算法则可以提高求解精度。     

The polar ionosphere at Zhongshan Station on May 11, 1999, the day the solar wind almost disappeared

The solar wind almost disappeared on May 11,1999: the solar wind plasma density and dynamic pressure were less than 1cm-3 and 0.1 nPa respectively, while the interplanetary magnetic field was northward. The polar ionospheric data observed by the multi-instruments at Zhongshan Station in Antarctica on such special event day was compared with those of the control day (May 14). It was shown that geomagnetic activity was very quiet on May 11 at Zhongshan. The magnetic pulsation, which usually occurred at about magnetic noon, did not appear. The ionosphere was steady and stratified, and the F2 layer spread very little. The critical frequency of dayside F2 layer, foF2, was larger than that of control day, and the peak of foF2 appeared 2 hours earlier. The ionospheric drift velocity was less than usual. There were intensive auroral Es appearing at magnetic noon. All this indicates that the polar ionosphere was extremely quiet and geomagnetic field was much more dipolar on May 11. There were some signatures of auroral substorm before midnight, such as the negative deviation of the geomagnetic H component, accompanied with auroral Es and weak Pc3 pulsation.     

固定设计下半参函数关系模型参数估计的相合性

对于固定设计下的半参数函数关系模型,利用广义最小二乘法和一般的非参数权估计方法,得出了未知参数和未知函数的估计.在一定条件下,证明了它们的强相合性及其p(≥2)阶平均相合性.     

阈红利边界下Erlang(2)风险过程的罚金折现期望函数(英文)

本文研究了阙红利边界TErlang(2)风险过程的罚金折现期望函数.利用算子变换及复合几何分布函数得到了罚金折现期望函数满足的微分积分方程,并给出了罚金折现期望函数解析表达式.     

电位滴定法测定氯化钠试剂

氯化钠试剂为白色无臭结晶粉末.主要用作分析试剂、微量分析测定氟和硅酸盐及生物培养基的制备.我国国家标准(GB1266—86)用沉淀滴定法直接滴定氯化钠,以荧光素吸附指示剂确定终点.考虑到氯化银沉淀的生成会影响终点的观察.本文提出硝酸银电位滴定法测定氯化钠试剂含量,用二阶微商法确定滴定终点.通过多次试验结果证明,本法结果正确可靠,电位突跃范围宽,重现性好,与国家标准方法测得的结果一致,准确度和精密度能够满足常规分析的要求.1 仪器与试剂     

核酸定点切割试剂研究进展

近十年来,核酸定点切割试剂的研究引起了化学、生物化学和分子生物学等领域的广泛关注,并已成为研究的热点。本文综述了定点切割试剂及其两个组成部分——切割系统和识别系统的研究现状,讨论了影响其切割活性和位置专一性的因素,并提出了今后研究的方向。