组合时间序列ARMA模型在经济预测中的应用——内蒙古十一五期间GDP预测

2006—2010年是内蒙古"十一五"规划的重要时期.利用组合ARMA时间序列模型,对内蒙古2006—2010年GDP进行预测,得出的结果能够帮助我们把握"十一五"期间经济运行的变动趋势,并寻求最佳的调控办法.     

Effect of dry density on 125I diffusion in GMZ bentonite

Gaomiaozi(GMZ) bentonite is regarded as the favorable candidate backfilling material for a potential repository in China.It is important to understand the diffusion behavior of 125 I in GMZ bentonite and compare the diffusion behavior in GMZ and other types of bentonite like MX-80,Avonlea,etc.Therefore,through-and out-diffusion experiments were conducted to obtain the effective diffusion coefficient(D e) and distribution coefficient(K d).A computer code named Fitting for diffusion coefficient(FDP) was used for the experimental data processing and theoretical modeling.At the dry density of GMZ bentonite from 1600-2000 kg/m 3,the D e values of 125 I were(2.4-20.4) × 10-12 m 2 /s and K d values were constants.At dry density above 1800 kg/m 3,the diffusion behaviors were almost the same,indicating that the anion exclusion was ineffective.Out-diffusion results showed that the species of 125 I may be changed during the diffusion processing.It was probably caused by some organic matters or reducing substances in GMZ bentonite.Since the main composition of bentonite is montmorillonite,similar diffusion parameters were obtained in GMZ and other types of bentonite.The relationship of D e and accessible porosity(acc) could be described by Archie’s law with exponent n = 1.2-2.8 for 125 I diffusion in bentonite,whereas n = 2.0 in GMZ bentonite.Furthermore,bentonite with the dry density of 1800 kg/m 3 was proposed as the backfilling materials used in the construction of high level radioactivity waste repository.     

酚二磺酸光度法测定水中总氮

在酚二磺酸光度法测定水中总氮量的方法中,用高压反应釜代替比色管,改进了样品的碱性过硫酸钾消解效果,避免了样品消解不彻底,氧化剂分解不完全及样品中铵氮以氨气形式逸出等.标准曲线的线性范围在0.02～1.90 mg·L-1之间,检出限(3σ)为0.02 mg·L-1.按此方法测定了6种水样中的总氮量,测定值的相对标准偏差(n=6)均小于3.5%.用标准加入法对方法的回收率作了试验,测得结果在98%～102%之间.     

First Isolation and Confirmation of Sterol Based on β-sitosterol Skeleton from the Leaves of Podocarpusnagi Planted in Fujian,Preliminary in vitro Anticancer Activity and the Crystal Structure

The crystal of(24R)-3β,5α-dihydroxy-24-ethyl-5α-cholestan-6-one(1)was isolated from the leaves of P.nagi planted in Fujian for the first time with the same skel...     

Erratum to: Turnpike Properties for Stochastic LinearQuadratic Optimal Control Problems*

Erratum to: https://doi.org/10.1007/s11401-022-0374-x