郑开大道顶进箱涵临时支撑结构设计

下穿京港澳高速公路顶推箱涵是郑开大道的关键控制性工程,顶进过程中箱涵的裂缝控制是该顶推工程成功与否的重要因素。经实践结果表明,临时支撑结构达到了预期的目的,值得应用推广。     

Phytochemical and Biological Activity Studies on Nasturtium officinale (Watercress) Microshoot Cultures Grown in RITA® Temporary Immersion Systems

The main compounds in both extracts were gluconasturtiin, 4-methoxyglucobrassicin and rutoside, the amounts of which were, respectively, determined as 182.93, 58.86 and 23.24 mg/100 g dry weight (DW) in biomass extracts and 640.94, 23.47 and 7.20 mg/100 g DW in plant herb extracts. The antioxidant potential of all the studied extracts evaluated using CUPRAC (CUPric Reducing Antioxidant Activity), FRAP (Ferric Reducing Ability of Plasma), and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays was comparable. The anti-inflammatory activity of the extracts was tested based on the inhibition of 15-lipoxygenase, cyclooxygenase-1, cyclooxygenase-2 (COX-2), and phospholipase A₂. The results demonstrate significantly higher inhibition of COX-2 for in vitro cultured biomass compared with the herb extracts (75.4 and 41.1%, respectively). Moreover, all the studied extracts showed almost similar antibacterial and antifungal potential. Based on these findings, and due to the fact that the growth of in vitro microshoots is independent of environmental conditions and unaffected by environmental pollution, we propose that biomass that can be rapidly grown in RITA^® bioreactors can serve as an alternative source of bioactive compounds with valuable biological properties.     

Rheological properties of liver actin solutions

G-actin prepared from pork liver and purified to give a product of 95–98% purity was polymerized to F-actin in a rotational dynamic viscometer. The rheological properties were investigated during the course of polymerisation and after polymerisation. G andG measured at frequencies around 0.1 Hz increased strongly during the first 3 hours of the reaction and then slowly approached a constant value in the range of 10–50 mPa. The rise during polymerisation was more than two orders of magnitude. When a solution of F-actin was subjected to steady shear at a high shear rate for a short period of time and subsequently dynamic measurements were performed, then a considerably smallerG (about 70% smaller) was observed immediately after cessation of the steady shear.G then increased with time and approached its initial value.When measuring the viscosity of F-actin solutions as a function of shear rate, a strong shear thinning effect was seen which did not vanish even at shear rates as low as 0.001 s^–1. Even at this low shear rates, a pronounced yield maximum was observed before reaching the steady state. Oscillatory experiments showed a remarkably weak frequency dependence ofG. The results imply that F-actin solutions are largely structured forming a weak temporary network which can be easily destroyed by application of high shear rates. It seems most likely that the destruction occurs by a reversible, shear induced depolymerisation process.     

机构投资者的最优持仓策略研究

讨论了机构投资者的最优持仓策略问题,假设证券价格服从几何布朗运动,以均值方差效用为目标函数,得到了最优持仓策略所满足的二阶微分方程,并由差分法得到其数值解.最后,由参数的敏感性分析知:最优持仓策略与瞬时冲击、市场波动率及风险厌恶系数等参数有关,并分析了参数变化对最优持仓策略的影响.     

新型暂堵酸化用自降解暂堵剂的制备及现场应用

针对传统暂堵酸化用暂堵剂颗粒耐酸性差、降解性差和除堵工艺复杂等问题，本研究通过水溶液自由基聚合法制备了一种新型的自降解暂堵剂CQZDJ。考察了单体加量、交联剂加量、引发剂加量对CQZDJ凝胶强度和降解性的影响；通过FT-IR、TGA、SEM对其结构进行表征；并对其降解机理进行了探讨；最后在长8区块的环平81-8实验井进行了现场实践。结果表明：CQZDJ凝胶强度及降解时间与单体加量、交联剂加量、引发剂加量成正比关系，且降解时间可控；降解性实验表明CQZDJ在(1%~10%)HCl溶液、水、（2%~10%）NaCl溶液中均可在4 d内完全降解，具备良好的降解性能，对地层伤害小；SEM照片显示CQZDJ的降解过程是从初始三维网状结构逐渐崩解为层状结构，最终降解为无规则线性小分子链的过程；暂堵后现场流压上升6.3 MPa，日产油由3.87 t/d增产至5.22 t/d，实现了储层的有效改造，增产效果显著。      

多元方差分析在蚕桑方面的应用

本文应用多元方差分析对不同的桑品种、蚕品种的养蚕成绩（全茧量、茧层量）及制种成绩（造卵数、产卵数）进行分析,得到多倍体桑的制种成绩极显著地高于二倍体桑;三倍体桑饲养的苏５蚕品种的养蚕成绩为最佳的结论,为养蚕、制种生产提供了一定的理论依据     

一类CKF模型稳态解的存在唯一性及其性质

在非强可加的Cobb-Douglas型效用函数下建立了含内生生育率的C-K模型,即CKF模型．证明模型至少存在的一个非零的稳态解,当参数满足一定条件时,稳态解是唯一的．稳态解处人口生育率与子女抚养时间成反比．与人口生育率界限成正比．讨论家庭消费、人口生育偏好和技术水下对经济发展最终状况的影响．     

日本医蛭(Hirudo Nipponica)耗氧量的研究

本文测定了 5 种温度条件下日本医蛭的耗氧量和耗氧率.结果表明: 各种温度条件下, 日本医蛭耗氧 量与体重均呈极显著的线性回归关系. 20℃和 25℃时日本医蛭耗氧率与体重均呈倒数回归关系,相关性 也极为显著.求出了耗氧量 X0(μ l ·h-1) 、耗氧率 Q0(μ l ·mg-1·h-1)与体重 W(mg)、温度 T 的二元回归方 程,方程为: X0=-10. 6274+0. 0500W+0. 6135T ,Q0 =0. 0325-0. 00014W +0. 0031T .由此建议, 人工 饲养时,在溶解氧较少( 1～ 2mg·h-1)的水体中,每 m3 养殖 0. 5g～ 1. 0g 的成蛭 5000～ 10000 条.     

利用集成光学技术的新型时间脉冲整形系统

通过对时间脉冲整形技术的探索，发展了一套准备应用于未来高功率激光装置的激光脉冲整形系统。在这套整形系统中，使用了通光波长1．053μm的质子交换型波导调制器。通过这套利用集成光学调制技术的整形系统，得到了脉冲起伏小于10％的整形方波光脉冲。     

Experimental study of polyacrylamide gel in close‐in well operation

An optimized polymer gel, known as temporary gel, based on polyacrylamide sulfonated copolymer, and a chromium acetate hydroxide were synthesized to close‐in the wells during applying well servicing work. Based on bottle tests, polymer gel with 28 000 ppm of polymer concentration, and 0.105 ratio of crosslinker to polymer, was selected. The pressure effect within the range of 1000 to 4000 psi indicated not impressive effect of pressure on the gel properties. As the results of creep test clarified, yield strength of the gel was measured at temperature of 90°C, and 2000 Pa. Moreover, the results of an experiment under simulated well condition showed a linear correlation between the height of polymer gel column, and the strength and persistence of gel against fluid pressure. At last, process of degelling with 40 g of optimum gel was performed using 14 g of 30 wt% solution of citric acid during 4 hours.