商业银行行业风险敞口与商业银行绩效

在无套利框架的基础上,讨论基于个体公平原则下的寿险产品定价问题,即运用倒向随机微分方程理论,将投保人和保险人置于同一系统中进行考虑：首先,根据双方的随机投资决策目标分别建立无套利寿险定价模型和动态资产份额定价模型,得出两个特殊线性倒向随机微分方程的显式解;然后,建立基于个体公平原则的寿险定价模型,从投保人和保险人双方的角度对寿险产品进行公平定价,得出了从供需双方考虑的投资回报定价公式;最后,利用所建立的模型进行案例分析,计算出基于个体公平原则的保费及保险公司的投资策略.该寿险产品定价模型不仅考虑了保险人的意愿,还同时考虑了投保人的实际情况,因此,按此定价理念开发出的保险产品,不仅可以提高产品研发的成功率,而且使得研发出的新产品更能在竞争激烈的保险市场中站稳脚步.     

Recruitment limitation in forests: Lessons from an unprecedented mountain pine beetle epidemic

Since the mid-1990s the forests of central British Columbia have undergone an unprecedented Mountain Pine Beetle (Dendroctonus ponderosae Hopkins) (MPB) epidemic that has resulted in extensive mortality of canopy lodgepole pine (Pinus contorta var. latifolia Engelm.). This study investigated how seed-source availability, seedbed substrate, overstory structure, and time since MPB attack interact to affect post-MPB seedling recruitment of the dominant tree species of these forests. In addition to post-MPB recruitment, these forests may be regenerated by trees established in the understory prior to MPB disturbance. Accordingly, we examined abundance and patterns of all regeneration less than 130 cm tall. We found post-MPB recruitment was sparse. Subalpine fir (Abies laciocarpa (Hook.) Nutt.) comprised the majority of the post-MPB recruitment. It increased with local parent tree basal area and increased strongly with proximity to a major seed source. This resulted in a patchy distribution for subalpine fir post-MPB regeneration. Lodgepole pine post-MPB recruitment was limited by overstory shading. Recruitment of pine decreased as the total overstory basal area increased. Interior spruce (Picea glauca × engelmannii) post-MPB recruitment was similarly limited by total overstory basal area. Seedbed substrates were uniform and dominated by moss. Substrate type distribution did not change as time since MPB disturbance increased. The overall low post-MPB recruitment observed was likely due to a lack of disturbance to the moss-dominated forest floor. Moss is known to be a poor substrate in northern forests. The distribution of all regeneration less than 130 cm tall showed the same trends as the post-MPB regeneration. We believe the post-MPB seedling recruitment dynamics of these forests was not substantially changed from conditions prior to MPB disturbance. There was no pulse of regeneration up to 10 years post-MPB disturbance. Unless this changes, future stand structure will be dominated by the seedling bank established prior to the MPB epidemic. Subalpine fir dominated the seedling bank (68%) and post-MPB recruitment (94%). This suggests that MPB-disturbed forests are undergoing a substantial shift in landscape-level species composition.     

模拟生物反应器填埋场产甲烷模型及应用研究

根据不同渗滤液回灌频率、渗滤液回灌前加热、加入厌氧污泥进行微生物接种等操作运行方式下模拟生物反应器填埋场产甲烷试验的结果,建立了反映环境温度影响的生物反应器填埋场产甲烷数学模型,并对其参数进行估计,在此基础上对模型进行了检验,提出了利用生物反应器填埋场甲烷气体的操作运行方案。     

水稻高产施肥数学模型研究及应用

[目的]探讨水稻高产施肥数学模型。[方法]采用3因素5水平二次通用旋转回归组合设计建立数学模型。[结果]水稻单产≥9750 kg/hm2的最优施肥组合为:氮(N)242.0~283.4 kg/hm2,磷(P2O5)117.2~149.4 kg/hm2,钾(K2O)183.9~237.6 kg/hm2,概率≥95%。[结论]采用最优施肥方案,水稻单产可达10159.5 kg/hm2,比当地习惯施肥增产895.5 kg/hm2,增产9.67%,增产效果十分明显。     

密植石榴综合施肥措施的数学模型研究

[目的]为密植石榴的规范化栽培、规模化生产和科学研究提供一定的参考。[方法]采用五元二次正交旋转组合设计方案,在影响石榴产量的施肥因素中,选取纯氮、纯磷、纯钾、硼肥和有机肥施用量5个因素作为决策变量,以石榴产量为目标函数,建立石榴产量与5个因素的数学模型。[结果]通过计算机摸拟、筛选,获得了密植石榴单株产量为15 kg以上的施肥配套方案为:氮肥98.88~128.76g/株,磷肥1.372~1.500 kg/株,钾肥263.52~285.84 g/株,硼肥5.550~6.068 g/株,有机肥64.90~67.22 kg/株。[结论]要提高密植石榴的单株产量,首先应当注意氮肥和钾肥的施用。     

家蚕晚期胚胎原代细胞分化和转分化的研究

对家蚕晚期胚胎组织进行原代培养,记录了培养过程中出现的多种分化和转分化现象。发现已分化的晚期胚胎组织、细胞尚可继续分化和转分化形成各种不同类型的组织与细胞,而且这些细胞多有一定的增殖能力,暗示了家蚕晚期胚胎组织可能有多种内部器官组织的多能干细胞存在。     

直榫榫眼形状的数学描述

将包络加工法和开榫工艺结合起来,使传统工艺方法数学化,提出了圆头直榫榫眼和斜面直榫榫槽的数学模型,为直榫形状的视频再现提供了数学方法。     

鹤大公路(鸡西-牡丹江段)的绿化工程设计

针针鹤冬公路鸡西至牡丹江段高等级公路立地条件的特殊性,强调选用乡土树种,并分路段、分立地类型,对道路、互通区进行绿化设计。     

半干法石膏纤维板工艺研究：Ⅰ.原料配比,密度等对板材性能的影响

本研究是建立在我国资源和工业技术基础之上,探讨利用木纤维以半干法制造石膏纤维板（ＧＦＢ）的生产工艺;提出了半干法石膏纤维板的工艺方案,并建立了密度、木膏比、水膏比与板材性能的数学模型。结果表明：密度（Ｄ）增加,板材力学性能显著提高,木膏比（Ｗ／Ｇ）、水膏比（Ｈ／Ｇ）有效强的交互影响。木膏比增大,板材反弹率和吸水厚度膨胀率（ＴＳ）增加,纤维形态,蒸煮工艺对板材静曲性能无显著影响,纤维形态对内结合强度     

Advanced glycation end products induce rat chondrocyte injury by modulating oxidative stress

ATM: To explore the possibility that advanced glycation end products (AGEs) induces rat chondrocyte injury by modulating oxidative stress. METHODS: Primarily cultured rat chondrocytes were identified. The viability of the chondrocytes was measured by CCK-8 assay. The intracellular levels of reactive oxygen species (ROS) were detected by DCFH-DA staining. The number of apoptotic cells was determined by Hoechst 33342 nuclear staining and flow cytometry. RT-PCR was performed to measure the mRNA levels of Bax, Bcl-2, caspase-3, MMP3, MMP13 and COL2 in the chondrocytes. Western blotting was used to evaluate the protein levels of cleaved caspase-3, MMP3, MMP13 and COL2. RESULTS: Compared with control group, the intracellular levels of ROS in the chondrocytes treated with AGEs were significantly increased (P<0.05), and pretreatment with N-acetyl-L-cysteine (NAC) suppressed the formation of ROS (P<0.05). Besides, NAC inhibited AGEs-induced apoptosis of the chondrocytes, as indicated by reduceing the levels of Bax/Bcl-2 and caspase-3, decreased the expression of MMP3 and MMP13, and reduced the loss of COL2.CONCLUSION: AGEs induce chondrocyte injury by activating oxidative stress.