ZL305A alloy in Al\|Mg\|Zn system with high strength, good marine corrosion resistance and age stability has made success in side scuttle, underwater weapon case and other casting parts subjected to marine corrosion.

Methods 12 animals were divided into 4 groups (Group Ⅰ, injured by regular weapon; Group Ⅱ,Ⅲ,Ⅳ injured by imitative kinetic weapons with different energy respectively).

Time system equipments are important in modern spaceflight test shooting range and normal weapon test shooting range, which send standard time signal and standard frequency signal to test equipments such as missiles, secondary planets and airships.

Dual 2×46 CCD IR signal processors are mainly used to preprocess the signal of 8×2 element HgCdTe IR detectors. In theory, they can make the signal to noise ratio increase 2 1/2 times so as to attain a new stage for weapon capability.

An example of determining the working points for a chemical weapon destruction plant was presented.

Impact of chemical weapon destruction on the structure of lake zoohydrobiont community

Community structure of zoohydrobionts in the lake affected by chemical weapon destruction was studied for the first time.

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery.

Suicide bombing attacks have emerged as a lethal weapon in the hands of terrorist groups.

This paper attempts to answer the following two questions: (1) Is it possible to derive the law of distribution of hydrological frequency theoretically(2) What type of distribution curve should be adopted as the model of hydrological frequency curve and how to determine their parameters? The results obtained may be summarized as follows: 1. Hydrological phenomena are time series with concealed periodic fluctuations. The results from statistical analysis based upon the current assumption that hydrological phenomena...

This paper attempts to answer the following two questions: (1) Is it possible to derive the law of distribution of hydrological frequency theoretically(2) What type of distribution curve should be adopted as the model of hydrological frequency curve and how to determine their parameters? The results obtained may be summarized as follows: 1. Hydrological phenomena are time series with concealed periodic fluctuations. The results from statistical analysis based upon the current assumption that hydrological phenomena are independent stochastic variables should be accepted with due considerations. 2. In view of the regional nature of hydrological phenomena, the current parctice of analyzing samples taking from a single station only is, in effect, to narrow the sampling field arbitrarily from a larger area to a point, thus reducing the accuracy of the statistical results. Hence, the synthetic utilization of the data of all stations within the hydrologically homo- geneous region is an important measure to increase the accuracy of statistical analysis. 3. The belief that the flood frequency obeys the binomial theorem or Poisson's theorem is but to mix up the priori with the empirical probability problem. The binomial theorem, being a powerful weapon to deal with the problems of priori probability, has not been adquately and properly utilized in the hydrologieal frequency analysis. 4. Analyses have been made of the nature of distribution of shydrologieal series on the basis of Kaptyen's derivation of the skew distribution, which indicate: (1) That the theoretical interpretation of the log-probability law of the hydrologic phenomena by V. T. Chow is not sound; (2) that hydrologic phenomena being results of very complicated meteorological and hydrological processes, it is impossible to derive theoretically the law of distribution for the hydrological series. 5. The view that the flood frequency obeys the Gumbel's distribution is theoretically not sound and also not verified by actual data. 6. According to the nature of the mathematical treatments applied, the method of description of the empirical probability can be classified into three systems: (1) The methods of the generalization of the characteristic factors of the distributions, such as Pearson's curves, Goodrich's curves, etc.; (2) The methods of the modification of a fundamental distribution by series and polynomials, such as Gram-Charlier curves. curves, etc.; (3) The methods of transformed functions, such as the log-probability law, curves, etc. It should be remarked that not only Pearson's and Goodrich's curves are frequency curves of empirical nature, but even the theoretical laws, such as the normal law and the log-probability law, will be aceepted as curves of empirical nature, when used as models for empirical probability problem. 7. Hydrological frequency analysis should not be mystified and made absolute. Instead of free selections, the models of hydrological frequency curve should be uniquely selected and specified. Statistical parameters should be determined not solely by the short period data of single station, but also by the synthetic utilization of the data of possible more stations. 8. It is recommended that one of the two types of distribution, i.e. the log-normal frequency curve with both sides limited and the Pearson's type Ⅲ curve, may be selected as unified models. The author suggests that the K-value corresponding to recurrence intervals of say 10~4, 10~5, or 10~6 years may be selected as the upper and lower limits for the log-normal curve. For Pearson's type III curves, C_s should be treated not as independent but as dependent variables of C_v. 9. The proper way to select and determine the model frequency curve is to see whether it fits well with the actual data of grouped stations (stations to be grouped by regions for rainfall data and by C_v for runoff data) and the reasonableness of the extrapolating part. 10. Suggestions on the method of determination of x and C_v: For point rainfall, iso-x map may be utilized, and the mean C_v for each hydrologicregion may be adopted in order to minimize the errors from single stations and to avoid the discrepancies in results obtained from the same region. With regard to flood frequency analysis, flood mark reconnaissance must be utilized to determine the magnitude and the recurrence interval of the unusual flood. The x and C_v values of the floods and runoffs of hydrologically similiar river basins may be compared. Besides, the reasonableness of the results of frequency calculations as well as of the statistical parameters adopted therein may be checked by comparing runoffs and point-rainfall values of the same frequency.

Studying the Introduction to Dialectics of Nature written by F. Engels one hundred years ago, deenpens our cognition of the struggle between the two oppos-ing worldoutlooks in the field of astronomy both at home and abroad. Engel’s In-troduction is an effective weapon in carrying out criticisms of the decadent idealistic-metaphysical viewpoints in contemporary cosmogonical researeh.

Fluxgate magnetometers, introduced in the 1930's, have been continually developedand improved. They have been applied to different fields of technology, such as mag-netic airborne detection, portable and fixed weapon detectors, nondestructive testing ofmaterials, space field measurements and space magnetic exploration etc. The design andcalculation of fluxgate magnetometers have been presented in many papers. Generallyspeaking, they are complicated in nature. Recent surveys of fluxgate magnetometer mayrefer...

Fluxgate magnetometers, introduced in the 1930's, have been continually developedand improved. They have been applied to different fields of technology, such as mag-netic airborne detection, portable and fixed weapon detectors, nondestructive testing ofmaterials, space field measurements and space magnetic exploration etc. The design andcalculation of fluxgate magnetometers have been presented in many papers. Generallyspeaking, they are complicated in nature. Recent surveys of fluxgate magnetometer mayrefer to [1]. This paper discusses the calculation of fluxgate magnetometers withsingle-core, double-core, rectangular-core and ring-core. These formulas only consist of thedimension of core, the number of turns of exciting and sense coils, and the frequency ofthe source. By using these formulas, the calculation of the exciting voltage, current andpower and the sensitivity of the sensor is much simplified, and with engineering accuracy.