桑叶配方颗粒物质基准研究

桑叶配方颗粒迄今尚没有统一的质量标准。为提升桑叶配方颗粒的内在质量,对其物质基准评价方法进行了研究。选取具有代表性产地的15批桑叶制备物质基准,采用高效液相色谱法,以芦丁、异槲皮苷、紫云英苷作为评价指标,确定桑叶物质基准的出膏率范围、标志性成分含量及转移率范围,采用超高效液相色谱法,建立物质基准UPLC特征图谱,并对其主要成分进行指认。结果表明:15批物质基准中,芦丁转移率为19.94%～34.05%,异槲皮苷转移率为11.67%～43.58%,紫云英苷转移率为10.73%～43.05%;物质基准特征图谱中,标定了14个共有峰,指认出7个色谱峰,分别为新绿原酸、绿原酸、咖啡酸、芦丁、异槲皮苷、槲皮素-3-O-(6″-O-丙二酰基)-β-D-葡萄糖苷、紫云英苷。所建立的基准评价方法为桑叶配方颗粒质量标准的制定及其后续大规模生产提供了数据基础。     

Regime switching rough Heston model

This model combines two important stylized features of volatility, the rough behavior consistent with a Hurst parameter less than , and the regime switching property consistent with more long-term economic considerations. It is nevertheless highly tractable in the sense of semianalytic formulae for European options, and permits a partial Monte Carlo method of similar computational speed as the semianalytic formula (at an appropriate number of Monte Carlo simulations). While option prices are relatively insensitive to the choice of Hurst parameter, introducing rough volatility allows for a better fit to the at-the-money skew.     

对国内外砂土地震液化评价介绍及比较

本文通过应用国内外不同的勘察规范对同一个工程场地的地震液化等级划分的计算及评价介绍,得出了一个采用不同规范,可取得比较一致的地震砂土液化等级的结论。     

Asymptotics for Autocovariances and Integrated Periodograms for Linear Processes Observed at Lower Frequencies

One of the most frequently used class of processes in time series analysis is the one of linear processes. For many statistical quantities, among them sample autocovariances and sample autocorrelations, central limit theorems are available in the literature. We investigate classical linear processes under a nonstandard observation pattern; namely, we assume that we are only able to observe the linear process at a lower frequency. It is shown that such observation pattern destroys the linear structure of the observations and leads to substantially different asymptotic results for standard statistical quantities. Central limit theorems are given for sample autocovariances and sample autocorrelations as well as more general integrated periodograms and ratio statistics. Moreover, for specific autoregressive processes, the possibilities to estimate the parameters of the underlying autoregression from lower frequency observations are addressed. Finally, we suggest for autoregressions of order 2 a valid bootstrap procedure. A small simulation study demonstrates the performance of the bootstrap proposal for finite sample size.     

中药方剂浸浴联合外用钙泊三醇倍他米松软膏治疗寻常性银屑病患者的临床效果

目的探讨中药方剂浸浴联合外用钙泊三醇倍他米松软膏治疗寻常性银屑病患者的临床效果。方法选取2018年2月至2019年4月于沈阳市第七人民医院就诊的寻常性银屑病患者114例作为研究对象,以随机数字表法将其分为观察组和对照组,每组57例。对照组患者外用钙泊三醇倍他米松软膏进行治疗,观察组患者通过中药方剂浸浴联合外用钙泊三醇倍他米松软膏治疗。比较两组患者临床疗效、银屑病面积严重程度指数(PASI)评分以及不良反应发生率。结果观察组患者治疗有效率为82.46%,显著高于对照组的63.16%(P<0.05)。两组患者治疗2周、4周后的PASI评分均显著低于治疗前(P<0.05);观察组患者治疗2周、4周后的PASI评分均显著低于对照组(P<0.05)。观察组患者的不良反应发生率为14.04%,低于对照组的21.05%,但差异无统计学意义(P>0.05)。结论中药方剂浸浴联合外用钙泊三醇倍他米松软膏治疗寻常性银屑病能有效改善患者的临床症状,效果显著,且不良反应少。     

土地产权稳定能促进农户绿色生产行为吗？——以广东省确权颁证与农户采纳测土配方施肥技术为例证

土地产权趋于稳定将强化农户的剩余控制权和剩余索取权，进而激励农户改进农业生产行为，但这种激励具有情景依赖性：由于农户进行农业生产经营的能力和目的不同，并不是所有的农户都会因此而改进农业生产行为。采用2018年广东省“千村调研”数据，分析确权颁证对农户采纳测土配方施肥技术的影响，结果表明：农地确权颁证虽然赋予农户实现农地价值的剩余权，但能否促进农户采纳测土配方施肥技术还取决于农户自身的获益能力和收益本身的效用。如果农户缺乏实现农业生产超额利润的能力（低收入农户），即使土地产权趋向稳定，也难以产生采纳测土配方施肥技术的动力；如果实现农地价值的最优方式是“他用”而非“自用”，即使采纳测土配方施肥技术会带来农业生产超额利润，农户也不会积极采纳；如果农户具有实现农业超额利润的能力（高收入农户）和预期（以农业为主业的农户），则确权颁证会促进其采纳测土配方施肥技术。农地确权颁证对农户绿色生产行为的促进有着情景依赖性，因而，在农地确权颁证的同时要完善农地流转制度，通过土地产权稳定和流转稳定的双重激励更有效地促进农业生产经营主体积极施行绿色生产行为。     

基于泰勒公式的交错级数审敛准则的改进

本文利用泰勒公式,对文献[2]中交错级数的一种收敛准则给出了新的证明,并将此准则进行了改进,使其可以应用于由复合函数构成的更复杂的级数形式。     

论历史逻辑

历史逻辑是以历史时间的历时性和共时性统一为基础的概念推论，研究关于叙述史中基本概念之间的意义关系和推论规则。过去、现在和未来是历史逻辑的基本范畴，“过去-现在-未来”三段式是历史逻辑的基本公式，它是概念逻辑推论三段式“正题-反题-合题”在历史逻辑中的具体形式。历史逻辑研究的目的，是根据特定历史时段的特殊性，建构以不同时段概念为逻辑变项的历史逻辑，预见未来的发展，规划现在的实践。     

古树名木文化价值货币化评估研究

从物质文化价值和非物质文化价值的角度,建立了古树名木文化价值评估指标体系。将古树名木的文化价值分为物质自身价值、历史文化价值、社会生态价值。运用基本价值×调整系数之和的公式法计算了物质自身价值及历史文化价值。运用条件价值评估法(CVM)基于人们的支付意愿评估社会生态价值。最后,以福州国家森林公园中的千年古榕为例评估其文化价值,得出其文化价值的评估值为1.901亿元。     

BLACK–SCHOLES REPRESENTATION FOR ASIAN OPTIONS

Asian options are securities with a payoff that depends on the average of the underlying stock price over a certain time interval. We identify three natural assets that appear in pricing of the Asian options, namely a stock S, a zero coupon bond B^T with maturity T, and an abstract asset A (an “average asset”) that pays off a weighted average of the stock price number of units of a dollar at time T. It turns out that each of these assets has its own martingale measure, allowing us to obtain Black–Scholes type formulas for the fixed strike and the floating strike Asian options. The model independent formulas are analogous to the Black–Scholes formula for the plain vanilla options; they are expressed in terms of probabilities under the corresponding martingale measures that the Asian option will end up in the money. Computation of these probabilities is relevant for hedging. In contrast to the plain vanilla options, the probabilities for the Asian options do not admit a simple closed form solution. However, we show that it is possible to obtain the numerical values in the geometric Brownian motion model efficiently, either by solving a partial differential equation numerically, or by computing the Laplace transform. Models with stochastic volatility or pure jump models can be also priced within the Black–Scholes framework for the Asian options.