In detecting cluster targets in ports or near-shore waters, the echo amplitude is seriously disturbed by interface reverberation, which leads to the distortion of the traditional target intensity characteristics, and the appearance of multiple targets in the same or adjacent beam leads to fuzzy feature recognition. Studying and extracting spatial distribution scale and motion features that reflect the information on cluster targets physics can improve the representation accuracy of cluster target characteristics. Based on the highlight model of target acoustic scattering, the target azimuth tendency is accurately estimated by the splitting beam method to fit the spatial geometric scale formed by multiple highlights. The instantaneous frequencies of highlights are extracted from the time-frequency domain, the Doppler shift of the highlights is calculated, and the motion state of the highlights is estimated. Based on the above processing method, target highlights’ orientation, spatial scale and motion characteristics are fused, and the multiple moving highlights of typical formation distribution in the same beam are accurately identified. The features are applied to processing acoustic scattering data of multiple moving unmanned underwater vehicles (UUVs) on a lake. The results show that multiple small moving underwater targets can be effectively recognized according to the highlight scattering characteristics.

The paper presents the results of seven-year survey of Antarctic seals along the western shore of Admiralty Bay, King George Island, South Shetland Islands. Five species were monitored during seven of the eight years, between 1988-95, excluding 1993. Numbers of elephant seals and Antarctic fur seals showed strong annual cycles, fur seals with two seasonal peaks. These of the other three species were more irregular. Fewer Weddell seals were seen in 1994 and 1995 then during the period 1988-92; with this exception, no overall trend in numbers was apparent during the period 1988-95.

Annex VI Regulation for the Prevention of Air Pollutionfrom Ships to the International Convention for the Prevention of Pollution from Ships (MARPOL) provides for establishment of emission control area (ECA), in the areas of emission control of nitrogen oxides (NECA).The new rules apply to the requirement that ships built from 1 January 2016, reduced NOx emission by about 80%. Therefore, considering the early opportunity to take ECA status of the Baltic Sea as an area of NOx control, relevant activities in this field were undertaken by HELCOM. They consist incollecting the documentation and presentation of the International Maritime Organization for approval. According to the HELCOM the Baltic Sea upon entry status of NECA be possible to greatly reduce NOx emission from ships, which will have a positive impact on the marine environment and the health of people living in the Baltic Sea.

The Enlightenment occupied an important place in the oeuvre of Professor Józef Andrzej Gierowski. This piece presents his evolving views on the Enlightenment in three syntheses of the history of early modern Poland and the Polish‑Lithuanian Commonwealth: two university textbooks first published in 1967 and 1978 respectively, and a book addressed to a wider, non‑academic readership first published in 2001, much of which was presented to Anglophone readers in 1996. J. A. Gierowski’s views are presented against the background of the sardonic references to “the enlightened age” and “enlightened Europe” in the synthesis published by his supervisor, Władysław Konopczyński in 1936, as well as the Marxist‑Leninist scheme of the Enlightenment forced on historiography and the humanities in postwar Poland, especially by Celina Bobińska. J. A. Gierowski’s view of “the ideology of the Enlightenment” gradually shifted from the primacy of rationalist and materialist thinking to the aim of the pursuit of happi-ness within human society. While still emphasising economic and social factors, including the role of the bourgeoisie in the Dutch Republic, England and France, he increasingly distanced himself from the model of the Enlightenment as the ideology of the rising bourgeoisie, forced on him in the early stages of his academic career. After long reflection on the question of the reception and originality of the Enlightenment in the Commonwealth, he came to appreciate the contributions of Royal Prussian burghers, the Catholic clergy and the Polish‑Lithuanian nobility. He also jettisoned the postwar dogma that the beginning of the capitalist order in Poland should be dated to 1764.