{'fraction_non_alphanumeric': 0.03017552296225054, 'fraction_numerical': 0.022962250540995433, 'mean_word_length': 4.173507462686567, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Surface Distribution and Sources of Pb content in the ocean current of Jiaozhou Bay

According to the data on the investigation of Jiaozhou Bay in May, August and October, 1992, the Pb content and the horizontal distribution in the surface of Jiaozhou Bay were studied. The results show that in May, in the waters of Jiaozhou Bay, there were three Pb high content sources - open ocean current, ships and wharf, and Licun River. The open ocean current entered Jiaozhou Bay from the bay outside into the bay inside through the bay mouth with a high content of Pb. The Pb content in the mouth of the bay was 20.79 μg/L. In the bay, the ocean current moved forward the shore of the northeast and reached southeast waters of the bay, transporting 5.54 μg/L Pb content. Then, the ocean current continued to move along the nearshore to the northeast and reached the eastern nearshore waters of Jiaozhou Bay. Here, Pb content was transported via ships and wharf and was 16.34 μg/L. After that, the ocean current continued to move along the nearshore to the northeast and reached the waters in the northeast of the bay, with the Pb content 7.09 μg/L. The ocean current continued to move along the nearshore to the northeast and got the coastal waters near the mouth of the Licun River. Here, Pb content was transported via the Licun River and the Pb content was 37.90 μg/L. Afterwards, the ocean current continued to move along the shore to the northeast and reached the waters in the northeast of the bay, carrying 18.27 μg/L Pb content. Then, the ocean current turned westward along the near-shore direction and got the northern waters of the bay, where the Pb content transported via ocean current was 13.72 μg/L. The ocean current continued to run along the shore to the west and got to the westernmost waters in the northwest of the bay. The Pb content transported via the ocean current was 12.84 μg/L. After that, the ocean current turned southward along the near-shore and reached the waters in the southwest of the bay transporting 8.62 μg/L Pb content. At this moment, a low Pb content area of 7.37 μg/L appeared in the central waters of Jiaozhou Bay.


Introduction
With the China's development, the heavy metal lead (Pb) has been widely used. However, through the production process of products containing Pb, people continuously emit Pb content forward to the land, ocean and atmosphere [1][2][3][4][5][6]. Therefore, the migration process and migration trajectory of Pb content have become the focus of research, which provides a scientific theoretical basis for the study on the sources, pollution degree and migration process of Pb in the water body of Jiaozhou Bay.  and Haibo River, Licun River and Loushan Rive, and so on flowed into the sea in Jiaozhou Bay, the estuaries of the rivers surrounded the Qingdao City. Moreover, These rivers presented the large runoff and sediment content with obvious seasonal change [7,8].

The waters and methods of investigation
2.2Materials and methods. The North Sea Monitoring Center of the State Oceanic Administration showed the Pb survey data used in this study, the investigation of the data contributed to the Jiaozhou Bay water body in May, August and October 1992. We would pick up the water samples at 13 stations in the Jiaozhou Bay waters in May, August and October 1992. The stations included the stations from station 52 to station 61, and from station 2014 to station 2016 ( Figure 1). We got the water samples by the water depth. If the water depth is more than 10 m, we would pick up the water samples from surface layer and bottom layer. If the water depth is less than 10 m, we would pick up them from only the surface layer. The method used during the investigation of Pb in Jiaozhou Bay water body abided by the national standard method included in the National Marine Monitoring Specification (1991) [9].   3.2 Sources. In May, a high Pb content area was formed in the coastal waters near the mouth of Licun River in Jiaozhou Bay where the Pb content was relatively high 37.90 μg/L, indicating that the Pb content was from Licun River. In the eastern coastal waters of Jiaozhou Bay, a high Pb content area with 16.34 μg/L Pb content was formed, which manifested that the Pb content here was from ships and wharf. In addition, a high Pb content zone was formed in the mouth of Jiaozhou Bay, which demonstrated that the Pb content came from the open ocean current. And the Pb content was 20.79 μg/L.
In August, a high Pb content zone was formed in the mouth of Jiaozhou Bay. So, we can know that the Pb content came from the ocean current. The Pb content was 37.53 μg/L, which was relatively high. In

3.3Migration Process and Direction in May.
At station 58 in the coastal waters near the mouth of Licun River in Jiaozhou Bay, Pb content reached the highest value of 37.90 μg/L, and the high Pb content zone was formed centered on the coastal waters. Along the nearshore to the northeast direction to station 2014,Pb content in the northeast bay waters was 18.27 μg/L. Then, turn along the shore to the west to station 57. Pb content in the northern waters of the bay was 13.72 μg/L. Continue to move along the shore westward to station 56, Pb content was 12.84 μg/L in the northwest waters of the bay. After that, turn southward along the nearshore to station 54 where Pb content was 8.62 μg/L in the waters southwest of the bay (Figure 2). Therefore, it is believed that the high-content Pb transported via Licun river migrated along the coastal waters of Jiaozhou Bay with the ocean current. First, it migrated along the coastal direction to the northeast. Then, it turned and moved along the coastal direction to the west. Afterwards, it turned and migrated along the coastal direction to the south. Finally, it reached the waters on the west side of the mouth of the bay. In addition, with the high content of Pb transported via ocean current in the bay, the Pb content was continuously decreasing.
At station 61 in the eastern coastal waters of Jiaozhou Bay, the Pb content was 16.34 μg/L, the highest value. Centered on the eastern coastal waters, the high Pb content zone was formed. Along the nearshore to the northeast to station 2016, the Pb content in the waters in the northeast of the bay was 7.09 μg/L ( Figure 2). Therefore, it is believed that the high-content Pb transported via the ships and wharf moves along the coastal waters of Jiaozhou Bay along with the ocean current. The direction of the ocean current is northeast, in which the ocean current migrates to the waters in the northeast of Jiaozhou Bay. In addition, with the high content of Pb transported via ocean current in the bay, the Pb content is continuously decreasing.
At station 52 at the mouth of Jiaozhou Bay, the Pb content was the highest value of 20.79 μg/L, forming the high Pb content zone centered on the waters at the bay mouth. Along the nearshore to the northeast to station 60 where the Pb content in the southeastern waters of the bay was 5.54 μg/L ( Figure 2). Therefore, it is believed that the high-content Pb transported via open ocean current migrates along the estuary of Jiaozhou Bay along with the ocean current. The direction of the ocean current which moves to the southeastern waters of Jiaozhou bay is northeast.What's more, the Pb content is continuously decreasing with the high content of Pb transported via ocean current in the bay.
At station 55 in the central waters of Jiaozhou Bay, the Pb content in the water body was 7.37 μg/L. The Pb content is relatively low (Figure 2), indicating that the central waters of Jiaozhou Bay have always been in the low Pb content area. At station 55 in the central waters of Jiaozhou Bay, the Pb content in the water body was relatively low 5.53 μg/L (Figure 3), showing that the central waters of Jiaozhou Bay were always in the low Pb content area.

Conclusion
In May, a high Pb content zone of 37.90 μg/L was formed in the coastal waters near the mouth of Licun River in In August, a high Pb content zone of 37.53 μg/L was formed in the Jiaozhou Bay mouth. And a high Pb content zone of 11.30 -27.44 μg/L was formed in a circle of coastal waters in the bay. But in the central waters of Jiaozhou Bay, a low Pb content area appeared. The Pb content here was 5.53 μg/L, which was relatively low. In