矿物溶解动力学与全球环境

硅酸盐矿物和碳酸盐矿物是构成地壳的主要造岩矿物,论述了两类矿物溶解动力学的研究现状与展望,指出两类矿物的溶解和沉积过程中CO2吸收和释放,对全球环境有重要影响。     

有机镍化合物催化烯烃聚合的研究进展

综述了有机镍化合物如烯丙基镍、乙酰丙酮镍、茂镍、二亚胺镍等催化烯烃聚合的研究进展。有机镍化合物可催化烯烃、α-烯烃(如乙烯、丙烯等)的齐聚及聚合、催化极性单体(如甲基丙烯酸甲酯、降冰片烯等)以及位阻较大的环烯烃、取代二烯烃、苯乙烯等的均聚和共聚。     

Surgery for primary hyperparathyroidism 1962-1996: indications and outcomes

Twenty-two cases of ameloblastoma and ten cases of adenomatoid odontogenic tumour (AOT) were analyzed comparatively by the AgNOR technique. Ameloblastomas were distributed into three groups according to their clinical behaviour: primary lesions without recurrences (PLWTR), 5 cases; primary lesions with recurrences (PLWR), 4 cases; and recurrences, 13 cases. The cases were also regrouped according to their histological pattern: follicular (9 cases), plexiform (7 cases), acanthomatous (4 cases) and unicystic (2 cases). Considering histological patterns, there was a significant statistical difference only between follicular and plexiform types. There were no significant differences between the group of ameloblastomas and the group of AOTs or between the three groups of ameloblastomas with different clinical behaviour. Our results strongly suggest that the distinct clinical behaviour of ameloblastomas and AOT is not correlated with their cellular proliferation ratio. Thus, the infiltrative ability of the ameloblastomas is probably not related to the cellular proliferation index of these tumours.     

Comparability of self-report of familial alcoholism among male and female college students

There is a general impression in the literature that women are more accurate reporters of familial psychiatric history. In this regard, this study presents data from a large cohort of young men (n = 427) and women (n = 607) who in answering a questionnaire self-reported alcohol abuse symptoms for various biological relatives. No significant gender differences emerged for any of the family history comparisons including reports for father, mother, either parent, any first- or second-degree relatives, or men or women relatives. The findings are discussed in the context of the existing literature.     

Relation between the level of E. coli gene expression and the structure of translation initiation region (TIR). III. Sites of complementary interaction of TIR with 16S rRNA

The addition of vertebral disc degeneration to the job-related disease register raises the question of vertebral disc degeneration patterns according to loading strain. The readings of the lumbar vertebra of construction workers and nurses were compared with those of a group without workload. In the groups examined, aged 35 to 50, monosegmental damage was found in only 17% of the patients with high workload, as opposed to 29% of those with no workload, mostly with monosegmental damage at level L5/S1. Damage to the upper segments of the lumbar spine with intact discs in between was found exclusively in patients with high workload. Multiple segment damage in the age range examined was found in subjects with activities that add to the load of the spinal column. The value of MRI in assessing and evaluating illness originating from the vertebral discs is currently being discussed.     

利用扫描电镜研究三维电极主电极表面腐蚀状况

借助扫描电镜（SEM）对不同实验条件下的三维电极主电极表面腐蚀状况进行研究。结果表明，三维电极主极阳极的内侧腐蚀程度远大于其外侧，水样性质、电极材料性质对电极的腐蚀程度有很大的影响，不锈钢做三维电极主电极优于铝、铁电极。为三维电极主电极的选材提供了一定的理论依据。     

Effect of feedback from peripheral movements on neuron activity in the aplysia abdominal ganglion

We have made reasonably comprehensive measurements of action potential activity in the Aplysia californica abdominal ganglion to determine the amount of feedback the central nervous system (CNS) receives from a movement which it initiates. Voltage-sensitive dye measurements of action potential activity of cells in the ganglion were made during the gill-withdrawal reflex elicited by siphon stimulation. We compared recordings in two situations which differed dramatically in the amount the gill moved. In the control sea water, the gill withdrawal was normal; in low-Ca2+, high-Mg2+ sea water, the gill movement was blocked. Both the timing and the number of spikes of the individual neurons were similar in the two situations. Histograms of the summed spike activity versus time and histograms of the number of active neurons versus time in the two conditions were also similar. Finally, two numerical measures of trial-to-trial differences, a paired t-test and a measure we named fractional similarity, did not indicate larger differences between two trials in the different sea waters than two trials in the same sea water. Feedback from sensory neurons activated by the gill movement itself does not make a large contribution to the spike activity in the abdominal ganglion. Apparently the Aplysia CNS issues the command for the withdrawal and does not make adjustments for the magnitude of the actual withdrawal. It may not even receive the information necessary for such adjustments to be made. A second motivation for these experiments was to test whether removing the feedback might simplify the neuronal activity that occurs during the gill-withdrawal reflex. This did not occur.     

FS-DDDP方法及其在水库群优化调度中的应用

可行搜索-离散微分动态规划(FS-DDDP)方法是在考虑水库运行的综合利用要求的前提下,利用正向搜索和逆向搜索相结合的方式寻找水库优化调度过程的大量可行轨迹,以目标函数较大的几个可行轨迹作为DDDP方法的初始轨迹分别进行再寻优计算的优化算法.该方法可进行单库优化计算,也可进行库群优化计算.黄河上游梯级水库数量较多,综合利用要求复杂.文中以该梯级为例,说明FS-DDDP方法可在满足该梯级水库群的河流生态用水、防凌用水、灌溉用水、发电用水等综合利用要求的前提下,以水库群发电效益最大为目标,求得水库群优化调度的较好解.