大直径铵油炸药包的起爆技术

这个讨论试图对围绕着铵油炸药大直径炮孔装药的起爆药包选择上存在的某些含混问题作一澄清,其要点如下:1.总的思想倾向是认为爆速和爆压对于岩石破碎过程的重要性不象曾经相信的那么大,某些感觉是它们的重要性很小或者不重要。2.铵油炸药柱被起爆后展示出一个由起爆药包算起达几倍炮孔直径的瞬变速度区。3.一磅重熔铸起爆药包比组合起爆药包所产生的瞬变速度低,只要低瞬变速度不靠近破坏点它就不会严重影响爆破过程。4.在冲击和热的(铝化的)组合起爆药包所产生的瞬变速度之间无明显的区别。5.铵油炸药中的终极稳定状态速度不受起爆药包类型和尺寸的影响。6.高能组合起爆药包是保证铵油炸药在不利条件下起爆的良好的起爆物,对难爆地区能提供补充能量。7.起爆药包必须放在难爆破的地带,它可能位于台阶的根部亦可能位于爆破料物的坚硬区段,在超钻内放置起爆药包可能加强地震效应。8.铵油炸药一旦达到稳定状态速度,就以该速度可靠的传播,所以为保证传播而设置补充起爆药包是不必要的。9.轴向起爆虽然是一种目前存在的起爆技术,但是它没有显著的优点足以平衡它所需用的较高爆破费用。10.孔内导爆索依条件不同可能使铵油炸药产生钝感效应,或者能产生轴向起爆。     

Influence of small dozes ultra-violet radiation on motion of dislocation in alkali-halide crystals

The purpose of this work was research into influence of ultra-violet radiation on size of run of regional and screw dislocations in beams of dislocation sockets, formed at indentation surface of alkali-halide crystals. In experiments it was used crystals NaCl, with the quantitative maintenance of impurity 10-2 -10-3weight,, the wave length of UV-radiation λ=250 nanometers, the sizes of samples 10mm× 20mm× 2mm,temperature of samples was constant T=290 K.It is established that indentation and the simultaneous irradiation of samples a ultraviolet is increases size of run of head dispositions in dislocation sockets..It is marked, that influence UV-radiation nonequivalence for various times of an exposition. At small times (till 5 minutes) the size of run grows. The length of beams increases on ～ 50 ,. At the further increase in time of influence of a ultraviolet the length of beams is reduced till the sizes corresponding stressing without an irradiation (Figs. 1, 2, 3). The effect is observed on dislocation beams of regional and screw orientations and most expressed at small loadings (in our experiments-10 grams) (Fig. 3).Observable effects are explained from positions dislocation-exciton interactions. At UV-radiation exciton cooperates with the charged step on a disposition, causing movement of a step along a disposition on one internuclear distance. Due to this interaction overcoming by a disposition of a grid of stoppers is facilitated.Big times of endurance cause a relaxation of pressure directly in a print that provides convertible movement of dispositions in area of a print and as consequence, reduction of length of beams of dislocation sockets.     

数据库管理的软件工程观点

本文从软件工程的角度来考察数据库管理领域。软件工程中的关键问题同数据库的设计和实现中的专门活动密切相关。证明了数据库系统的产生步骤和其它种类的软件系统的产生步骤存在着许多相似之处。论证了为了建立高质量的系统需要统一考虑数据库系统以及其它种类的软件系统和工具。为了完备程序设计语言,数据库管理,和软件工程的概念,本文引进了程序设计语言PLAIN及其程序设计环境作为工具。     

耕耘部件的磨损

前言以土壤为加工对象的耕耘部件是通过对土壤切割、破碎、翻转、移动或其他的加工方式把力施于土壤,其本身是机具的一部分,它的工作性能及效率取决于与之相接触的土壤特性。当耕耘部件的几何参数改变较大时,土壤、部件、机械装置间的机械特性自然地被抵消和损害。例如,由于磨损改变了犁铧的形状,结果使牵引力     

Comparison of EEG and ECoG for detecting cerebrocortical activity during slaughter of calves

Parallel electrocorticograms (ECoG) and electroencephalograms (EEG) were recorded during stun-recovery and stun-slaughter of eight calves 4-6 weeks old. Epochs of 8·2 s duration, derived from the ECoG and EEG signals pre-stun, during recovery and during exsanguination, were compared for differences in power content and frequency distribution using Fast Fourier Transform analysis. ECoG signals recorded during the quiescent phase post-stun had a markedly lower power content compared with pre-stun, whereas the EEG signal showed no such reduction in power content. During exsanguination, the mean rate of decline in the ECoG power content was 0·025 log units/s, three times faster than the mean rate of decline of the EEG at 0·008 log units/s. The duration of the electroplectic fit post-stun was detected equally well by the two techniques. The differences between EEG and ECoG traces in this study are thought to arise from differences in the signal-noise ratio of the two techniques and by artefacts in the EEG signal, caused by microscopic movement between EEG electrodes and the surrounding tissue. The slower rate of decline in the power content of the EEG during slaughter means that the time to onset of isoelectric cortical electrical activity will be longer if determined by EEG measurements than by ECoG recording.     

Comparison of some components of pigs kept in natural (free-range) and large-scale conditions

A new pig genotype of Hungarian Large White (75%) × Mangalica (pig with curly bristles, 25%) was used in the experiments. The experimental group was kept in a farming system under strictly natural circumstances until a body weight of 120 kg was attained. Neither antibiotics nor yield-increasing hormones were given to this group. The control group was kept in the usual large-scale farming conditions until body weight of 120 kg was attained. In most cases, protein, zinc, and copper levels and, in some cases, iron levels were significantly higher in some major cuts (neck-end (Boston-butt), loin, ham) of the 'free-range' pigs (n = 12) in comparison with the control animals kept in large-scale farming conditions. There was, on average, 15% less cholesterol in the muscles and 30% less cholesterol in the liver and less linoleic acid in all tissues of 'free-range' pigs than in the control group. There was less fat, but the amount of thiamin and riboflavin in the liver of the naturally kept pigs was twice that in the controls. In respect of TBA-reactive compounds, there were no significant differences between the two groups, but superoxide dismutase (SOD) showed significantly higher activities in all cuts from pigs kept in a large-scale farming system. This may be the effect of a higher level of linoleic acid in the fat.     

Sensory evaluation of beef patties and sausages containing lipids with various component fatty acids

Sensory scores of beef patties and emulsion-type sausages containing varying levels of lipids with various component fatty acids were investigated. Sensory scores of beef patties containing solid fat were relatively constant at every fat level examined. However, scores of beef patties containing liquid oil decreased with increasing level of added oil. In the case of sausages, on the other hand, sensory evaluation scores markedly decreased with increasing the level of solid fat, while no significant change was observed in panel scores when liquid oil was mixed into sausages. Even 10% level of added lipids satisfactorily gave preferable acceptability to beef patties and sausages.