availability ratio
1.By sampling survey method, from the aspects of bibliographical availability, the ratio of book forecasting, fields for description, description format, acquisition costs etc., the paper makes a comparative analysis among the main Chinese books acquisition bibliographies, including Xinhua Book News, CIP data, National New Books Information, and bibliographies compiled by publishers, and hope can provide useful experience information for the selecting of library acquisition bibliography.
2.2. The availability degree (AD, ratio of total content to available content) of Zn, As and F were affected by the contents of total elements, organic matter, free Fe and clay, as well as soil pH.
3.The results obtained were as follows:1)Uptake of Cd and Zn by the rice were affected by soil type, cultivars, and Cd spike, of which under a positive mutual interaction(high Cd affinity cultivars on the soil of high Cd availability)very high grain Cd and Cd/Zn ratio was observed due to strong uptake and high grain partitioning of Cd;
4.Dynamics of inorganic nitrogen in soils are similar to the pools of nitrogen, cultivation ratio of NO_3~- -N/(NH~4-N+ NO_3~- -N) is opposite, cultivation > abandonment > marsh meadow, showing that the availability of nitrogen is the highest in the Mire-wetlands and the lowest in the cultivation.
