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Objective: A method based on high pressure digestion andinductively coupled plasma mass spectrometry (ICP-MS) detection was establishedfor determination of arsenic, mercury, lead, cadmium, chromium and thallium inbiological tissues. Method: The samplesof hair, nails, viscera, blood, urine were digested with HNO3 and H2O2in high pressure digestion tank ; Indium was used as internal standard element,The certified GBW07601a (CRM Human Hair) was adopted as the quality control forthe whole processes. Results: Theexcellent sensitivity and reliability were demonstrated by the method ofrecovery 82% ~ 110%, RSD (n = 5) less than 5% and the linear range of 0.020ng/mL to 100 ng/mL (r > 0.99). The prototype measurements are within thescope of the standard value. Standard addition recovery of the six elements is therange of 92% ~ 105%. Conclusion: Arapid, easy and accurate quantitative ICP-MS method was established fordetermination of toxic elements in the human body, which enrich the existing meansof forensic technology. At the same time, this work provide the most practicaland reliable core data for poisons metabolism and pathological study.

For the lack of adaptability about the existing concurrency control algorithms, adaptive decision concurrency control algorithm is proposed. ADCC algorithm divides concurrency control process into two phases in: execution authorizing phase and strategy selecting phase. In execution authorizing phase, algorithm compares statistics and effectiveness of transactions to determine the execution order of conflict transactions. In strategy selecting phase, according to transactions’ read/write status and current conflict rate, algorithm selects optimistic/pessimistic conflict resolution strategy adaptively. Such selection mechanism makes ADCC algorithm have high efficiency no matter database system is busy or idle. Simulation experiment proves that ADCC algorithm this paper proposed is superior to classical strict two phases locking algorithm and hybrid concurrency control. So ADCC algorithm performs well in the period of concurrency control.