信息化经济发展的新动力——写在石龙以宽带速度驶向E-TOWN之际

“我们在一个非常合适的时期,　在一个非常合适的地点,　召开了一个非常合适的会议。”在2003年的“中国城市信息技术应用高层论坛”上,中国市长协会副会长兼秘书长陶斯亮曾过这样一句话。这个“合适的地点”,就是石龙。 广东中心城镇——石龙　　　　美丽的东江蜿蜒而下的北干流与南支流交汇一处,形成一河三埠的风水宝地——石龙。石龙北靠广州,南临深圳,毗邻香港,距广州69公里,深圳78公里,历来都是东江水运的重要港口。　　　　石龙,已有800年的悠久历史,自宋代开始有人定居。由于东江穿境而过,航运极为便利,石龙在明末清…     

袖珍计算机放射性总量测量系统

本文介绍以PC-1500(A)型袖珍计算机为主体的地面放射性总量数据采集及处理系统的方案、硬件、软件及应用。     

秦山300MW核电机组全范围仿真机测试验收

介绍了秦山３００ＭＷ核电机组全范围仿真机的测试验收的整个过程，包括：验收测试规程的形成，工厂内部预测试和工厂用户测试。并分析了测试验收过程中存在的重大问题及解决的办法。     

EC与~（99m）Tc－GH之间的配体交换反应动力学研究

实验表明，ＥＣ浓度与配体交换反应速度常数无关，体系的ｐＨ值对速度常数和９９ｍＴｃ－ＥＣ的标记率影响较大。测定并计算了不同ｐＨ值的交换反应速度常数。结果表明，为保证用配体交换法制备９９ｍｃ－ＥＣ时９９ｍｃ－ＥＣ的标记率大于９０％，体系的ｐＨ值必须≥８。     

建立河南油田“全天候”电网的探讨

按照建立“全天候”电网的要求,分析了油田电网大气过电压保护设计标准偏低,方案选型不合理;内部过电压保护不完善;线路及设备污闪严重;抗自然灾害能力差;以及通讯系统、运行管理、综合治理等方面的问题。提出了完善大气过电压保护;加强内部过电压保护等5项适应“全天候”电网的措施。     

Influence of carbon concentration and reaction temperature upon bainite morphology in Fe-C-2 Pct Mn alloys

Isothermal transformation of austenite to bainite was studied by optical, replication, and thin foil transmission electron microscopy (TEM) in both hypo- and hypereutectoid Fe-C-2 wt pct Mn alloys (and a single 3 pct Mn alloy) containing from 0.1 to 1.37 wt pct C in order to characterize and explain the transitions which occur in bainite morphology as a function of carbon content and reaction temperature. A “morphology map” was constructed showing the temperaturecarbon composition(T-x) regions in which four different bainite morphologies predominate: upper bainite, lower bainite, nodular bainite, and inverse bainite. Calculations of the volume free energy changes associated with the nucleation of ferrite, ?G _v ^α , and cementite, ?G _v ^c , and the parabolic rate constant for growth of ferrite, α_α, and cementite, α_c, were performed in order to explain the observed morphological transitions. In hypoeutectoid alloys, where |?G _v ^α | ? |ΔG _v ^c | and α_α ? α _c , the Widmanstätten ferrite-dominated morphologies of upper and lower bainite predominate. The upper-to-lower bainite transition appears to be associated with the emergence of edge-to-face sympathetic nucleation at high values of |ΔG _v ^α |. In hypereutectoid alloys, the ratios ΔG _v ^α /ΔG _v ^c and α_α/α_c are considerably smaller; hence, cementite can compete much more readily with ferrite during both nucleation and growth, resulting in the formation of nodular bainite. With decreasing temperature in the hypereutectoid regime,ΔG _v ^α /ΔG _v ^c , and especially α_ga/α_c, increase, resulting in the replacement of nodular bainite by lower bainite at temperatures below about 250 °C to 275°C.     

电位滴定法研究~(99)Tc-HMDP和~(99)Tc-HEDP中Tc的氧化态

~(99)Tc-HMDP和~(99)Tc-HEDP溶液是在相应的螫合剂存在下,用过量SnCl_2还原~(99)TcO_4-制得。用标准I_2液对SnCl_2进行了剩余量电位滴定,确定了在pH～3的介质中,~(99)Tc-HMDP和~(99)Tc-HE-DP中~(99)Tc的氧化态均为+4。全部实验在N_2气流中进行。~(99)Tc-HMDP和~(99)Tc-HEDP的紫外光谱表明:在用I_2滴定的过程中,~(99)Tc只处于一种氧化态+4;将它们放置在空气中,一小时后仍较稳定。     

经食道心房调搏的放射性核素心血管造影

本文应用反符合电路剔除调搏脉冲干扰的方法,制成经食道心房调搏心电心音门电路触发装置,用于经食道心房调搏的核素心血管造影。参考Tzivoni标准,当逐级增加调搏心率至140次/min或亚极量心率后发现:冠心病人有调搏后EF降低;急性心肌梗塞病人EF减低更为明显,并呈室壁反向运动。因此,心房调搏核素心血管造影有助于冠心病,特别是心肌梗塞的诊断。     

FD—140型高灵敏测氡仪及其应用

FD—140型高灵敏测氡仪用于测量氡的浓度,测氡灵敏度可达15mBq/m~3 min。该仪器可用于普查与勘探铀矿床,也可用于找石油、煤、金、地下水和地震预报以及地质构造调查等方面。     

Parallel Algorithms for Image Template Matching on Hypercube SIMD Computers

This correspondence presents several parallel algorithms for image template matching on an SIMD array processor with a hypercube interconnection network. For an N by N image and an M by M window, the time complexity is reduced from O(N2M2) for the serial algorithm to O(M2/K2 + M * log2 N/K + log2 N * log2 K) for the N2K2-PE system (1 ? K ? M), or to O(N2M2/L2) for the L2-PE system (L ? N). With efficient use of the inter-PE communication network, each PE requires only a small local memory, many unnecessary data transmissions are eliminated, and the time complexity is greatly reduced.