光纤传能的移动式激光诱导击穿光谱钢铁快速检测与分类

为了实现工业现场对特种钢材的快速检测与种类识别,采用基于光纤传能的移动式激光诱导击穿光谱(LIBS)样机对14种特种钢材进行光谱数据的采集与分析,采用预选谱线并遍历组合的降维方法与支持向量机(SVM)相结合的算法对特钢材料的光谱进行快速分类.分别将原始光谱数据、归一化处理后的光谱数据、归一化处理+遍历组合优选谱线数据作...     

半凸多目标优化ε-拟弱有效解的最优性条件及对偶定理

本文在相关文献考虑MP问题的基础上,增加了等式约束条件,即本文考虑了VP问题,并将已有文献中的凸性假设改为半凸性假设,得到VP问题的ε-拟弱有效解的相应最优性条件.接着,本文定义了VP问题的拉格朗日函数及其ε-拟弱鞍点,得到VP问题的ε-拟弱鞍点相应定理.最后,本文考虑了VP问题的对偶问题,获得了VP问题的弱对偶和强对偶定理.     

自组织生长InAs/GaAs量子点发光动力学研究

介绍了最新发展的粒子数混合超快光谱测量技术,以及采用该技术对自组织生长InAs/GaAs量子点发光动力学的研究结果.实验发现,自组织InAs/GaAs量子点结构的发光寿命大约为1ns,与InAs层厚度关系不大;激子寿命与温度有一定的关系,但没有明显的实验证据表明与量子点的δ态密度有关;用粒子数混合技术,实验上可直接观察到量子点中载流子在激发态能级的态填充过程. 关键词：     

CROSS SECTIONS OF ANTIHYDROGEN FORMATION IN COLLISIONS OF ANTIPROTONS WITH POSITRONIUM

New calculations of the cross sections for antihydrogen formation in collisions of antiprotons with positronium are reported in the present paper. A multiple-scattering expansion method has been used for getting reliable results. Discussion and comparison of the present results are made with other theoretical calculations.     

介入、腹腔热灌洗、微泵三途径治疗胃肠道癌

对157例胃肠道癌切除术后病人， 随机分成术中腹腔温热灌洗化疗联合术后置泵持续动脉灌注及静脉微泵化疗组72例(简称治疗组)、单纯静脉化疗组85例(简称对照组)， 并对其腹腔转移率、 肝转移率及3 a生存率进行对照研究， 取得了较满意的临床疗效。 术中腹腔温热灌洗化疗联合术后置泵持续动脉灌注及静脉微泵化疗三途径综合治疗对胃肠道癌病人术后腹腔转移及肝转移有良好的防治作用。 157 cases of gastrointestinal cancer patients after resection were randomly divided into treated group and control group. The treated group (intraperitoneal hyperthermic perfusion chemotherapy combined with postoperative continuous intraarterial infusion and intravenous micro pump chemotherapy) consisted of 72 cases， the control group (Intravenous chemotherapy)， 85 cases. The peritoneal and hepatic metastasis rates and 3 a survival rate were studied. The intraperitoneal hyperthermic perfusion chemotherapy combined with the postoperative continuous intraarterial infusion and intravenous micro pump chemotherapy is an effective way to control the recurrence on the peritoneal and hepatic metastasis of advanced gastrointestinal neoplasms after operation.     

切削用量对铝靶表面质量的影响

 采用单点金刚石切削技术，完成了对ICF实验用铝靶的切削加工，重点研究了切削用量对加工表面质量的影响。实验结果表明：采用较小的进给速度，较大的主轴转速能够获得较低的表面粗糙度，切削深度对表面质量影响较小。通过Form Talysurf 表面轮廓仪测量，结果表明表面粗糙度小于50 nm。     

A UNIFIED ISOSTATIC DATUM AND ITS APPLICATION IN SEA LEVEL CHANGE RESEARCH

The necessity of establishing a Unified Isostatic Datum (UID) for studying the sea levelchanges along the coast of China is discussed in this paper. A so-called Coastal Land Ver-tical Movement Isostatic Datum (CLVMID) is established based on precise releveling dataperformed from the 1950s to 1980s and some coniunction releveling data with tide stations.All the data consists of about 250,000 km releveling lines and covers the whole mainland ofChina. As examples, datum corrections for sea level changes derived from two tide stationsand recent crustal vertical movement in the Yangtse Delta area relative to the datum aregiven to explain the significance of the isostatic datum in the research of the sea levelchange trend.     

炭化过程对铁基费托合成催化剂强度和结构的影响

以模型费托合成Fe基催化剂为研究对象,在纯CO气氛中对催化剂进行不同时间的预处理,采用多种手段对预处理后催化剂的物理化学性质和抗磨损能力进行了表征。结果表明,在预处理初期,随着预处理时间的延长,催化剂的炭化程度显著提高,伴随着催化剂比表面积的降低和颗粒粒径的减小,而催化剂的抗磨损能力逐渐提高。当预处理时间超过72 h后,继续延长预处理时间,催化剂的炭化程度不再增加,而积炭程度逐渐增加,伴随着催化剂比表面积和颗粒粒径的增加,催化剂的质量也同时增加,并导致催化剂的抗磨损能力逐渐降低。     

Structure and magnetic properties of ScFe6Ga6-type RCo5Ga7 (R=Y, Tb, Dy, Ho and Er)

The structure and magnetic properties of the RCo₅Ga₇ (R=Y, Tb, Dy, Ho and Er) compounds with the ScFe₆Ga₆-type structure have been studied. The stability of RCo₅Ga₇ is closely related with the ratio of the metal radii R_RE/R_(Co,Ga). With R_RE/R_(Co,Ga)?1.36, the compounds can be stabilized in the ScFe₆Ga₆-type structure. The lattice of RCo₅Ga₇ shrinks as the atomic order of R increases, and it is consistent with the lanthanide contraction. The structure analysis based on X-ray diffraction patterns reveals that in the orthorhombic RCo₅Ga₇ (Immm), R occupies the 2a site, and Co enters into the 8k and the 4h sites, and Ga is at the 4e, 4f, 4g, 4h and 8k sites. The interatomic distances and the coordination numbers of RCo₅Ga₇ are provided from the refinement results. The short interatomic distance (less than 2.480 Å) between the Co ions results in the negative magnetic interaction, which does not favor ferromagnetic ordering. The magnetic moment of YCo₅Ga₇ is absent, and RCo₅Ga₇ (R=Tb, Dy, Ho and Er) may have long-range magnetic ordering with the paramagnetic Curie temperature lower than 5 K.     

低能轻离子输运的单参数描述

低能离子输运的一个重要特点是它有可能被一个简单的参数所确定，我们发现离子的标度输运截面即是具有这种重要性质的参数。这种单值对应关系反映了不同能量的不同靶一离子的组合在输运上的内在相似性。本文给出了标度输运截面的定义，讨论了此标度参数标定离子输运行为的理论依据。同时通过应用离子输运双群模型所作的大量计算检验了单参数标定离子输运行为这一结论。最后给出以标度输运截面为自变量的离子反射系数和平均投影射程的经验公式。 关键词：