查询词典 stability conditions

In this paper, through stability analysis based on a novel Lyapunov function and Lyapunov's direct method, the sufficient conditions of global asymptotical stability and the deductions are given.

文中引入一种新的 Lyapunov 预选函数，采用 Lyapunov 直接法研究系统的稳定性问题，得到了系统全局渐近稳定的充分条件及推论。

The structural and photocatalytic properties of TiO〓 as well as surface acidity were greatly improved by sulfation. SO〓〓/TiO〓 solid superacid with Hammett constant Ho less than -12.14 was prepared by treating the TiO〓 with 1.0mol. L〓 sulfuric acid solution and then calcining at 450℃ for 3h. When compared to unmodified TiO〓, the SO〓〓/TiO〓 superacid catalyst exhibited higher anatase content, smaller crystal size, higher specific surface area, centralized pore size distribution, and the blue-shifted band edge of uv-vis adsorption spectra. Furthermore, the SO〓〓/TiO〓 superacid also showed excellent reaction activity and stability for CH〓Br photocatalytic decomposition even under the moist reaction conditions. The apparent quantum efficiency of SO〓〓/TiO〓 was 10 times of that of TiO〓 catalyst for the photocatalytic degradation of bromomethane. Therefore, the SO〓〓/TiO〓 superacid catalyst is promising for practical application in environmental remediation.It was found that both L and B acid sites exist on SO〓〓/TiO〓 photocatalyst while only L acid sites on TiO〓 photocatalyst. On the basis of experimental results, the synergistic model of superacidic centers was proposed for SO〓〓/TiO〓 photocatalyst to explain the photocatalytic behavior and the mechanism of superacidifing effects, assuming that the adjacent L and B acid sites induced by SO〓〓 comprise cooperatively the superacidic center on superacid photocatalyst. The group cooperation of the superacidic center could strengthen the surface acidity, increase surface acid sites and the adsorbtion of O〓, promote separation of photogenerated electron-hole pair, enhance the interfacial transfer of charges and reversibility of water adsorption. Consequently the excellent photocatalytic activity, reaction stability and resistibility to humidity of SO〓〓/TiO〓 superacid photocatalyst may attributed to the group cooperated effect of the superacidic center on the photocatalyst.

研究结果表明：SO〓〓与TiO〓表面的结合为螯合式双配位结构；TiO〓光催化剂表面经H〓SO〓浸渍处理后，提高了表面酸性，改善了催化剂结构和光催化性能，当H〓SO〓浸渍浓度为1.0mol.L〓、烧结温度为450℃时，可制得SO〓〓/TiO〓超强酸催化剂(H〓＜-12.14)，其结构和光催化活性得到明显改善，与TiO〓相比，SO〓〓/TiO〓光催化剂的锐钛矿含量高、晶粒小、BET比表面积大、孔径分布集中、光谱吸收边蓝移，具有优异的光催化氧化活性、稳定性及抗湿性能，光催化降解溴代甲烷的表观量子效率比TiO〓催化剂提高了一个数量级，是一种有实际应用前景的高效光催化剂；由此提出了SO〓〓/TiO〓超强酸催化剂表面集团协同作用的超强酸中心模型，认为在SO〓〓/TiO〓超强酸催化剂表面，由SO〓〓诱导的相邻L酸中心和B酸中心组成了集团协同作用的超强酸中心，其集团协同作用显著地增强了催化剂表面酸性、增大了表面酸量及O〓吸附量、促进了光生电子和空穴的分离及界面电荷转移，具有可逆吸附水的性能，是SO〓〓/TiO〓超强酸催化剂具有优异的光催化氧化活性、很好的活性稳定性及抗湿性能的重要原因。

The results showed that expression plasmid pET22b-lysB was constructed successfully. Highly purified recombination protein was obtained 33.2 mg from 1 L LB culture medium. A screening for His-LysB activity on esterase and lipase substrates confirmed the lipolytic activity. With p-nitrophenyl butyrate as substrate, the thermal stability of the enzyme was poor when the temperature was above 30oC. The enzyme exhibited higher stability at pH 5.0–9.5. The optimum temperature and pH for the lipolytic activity of His-LysB were 23oC and 7.5 respectively. Under the optimum conditions, the specific activity of His-LysB was 1.3 U/mg. Zn2+, Cu2+, Mg2+, Mn2+and phenylmethane sulfonyl fruoride severely inhibited the lipolytic activity of His-LysB.

结果表明：成功构建了pET22b-lysB表达载体，并从1 L的LB培养物中获得了33.2 mg高纯度重组蛋白；His-LysB具有分解脂肪的能力，属于脂肪酶；生物化学特性分析表明：丁酸对硝基苯为水解底物，His-Lys热稳定性不佳，30℃以下比较稳定，随着温度的升高，稳定性逐渐降低；该蛋白具有较高的pH值适应性，pH 5.0~9.5范围内稳定性较高；在23℃和pH 7.5时酶活力最高，其比酶活为1.3 U/mg；金属离子Zn2+、Cu2+、Mg2+、Mn2+和苯甲基磺酰氟抑制剂对酶活具有强烈的抑制作用。

Using the concept of Quadratic Stability and the approaches of predictive control, such as finite horizon and horizon receding, memoryless robust control and sufficient conditions of its existence and closed-loop stability are presented.

采用二次型稳定的概念，并借用预测控制中的时域有限及时域滚动的方法，给出了无记忆鲁棒控制律，并给出了其存在和使闭环系统渐近稳定的充分条件。

It was investigated how to increase the yield and purity of tannin, flavone and oligoprocyanidms from the root and stalk of sanguisorba, and the stability of polyphenols from sanguisorba was studied, too. The chemical constitutes of sanguisorba were analyzed, the conditions on extracting tannin, flavone and oligoprocyanidins from sanguisorba by general lixiviating process and ultrasonic wave were optimize. The flavone and oligoprocyanidins were separated from sanguisorba and purified. The stability of polyphenol from sanguisorba was studied and the chemical structure of the products was analyzed.

本论文以地榆根茎为原料，对如何提高其主要活性成分鞣质、黄酮类物质以及低聚原花青素得率和纯度以及地榆多酚的稳定性进行了探讨；主要分析了地榆中化学成分，常规浸提和超声波浸提对地榆根茎中鞣质、黄酮类以及低聚原花青素提取条件的优化，地榆根中黄酮类和低聚原花青素的分离纯化，地榆多酚稳定性能以及产品的初步化学结构分析。

Through the study of the engineering geology conditions and properties of the landslide about the left bank of Xiao Dong River Electric Station in the Lei River, through the analysis of the causes of landslide, and by using STAB procedure about limit balance method and famous Finite elements ANSYS software to analyze the landslide stability, a conclusion is made that when the water level of reservoir is 150 metres, the safe coefficient of landslide body stability under the statured status is 0.97, and the slope may be wriggled or slid, which is consistent with the result of the author using fuzzy analysis.

根据滑坡体稳定分析计算结果，从安全可靠、技术可行、经济合理多方面综合比较分析。

In this paper, based on BPA, a software of power system analysis, through the calculations of power flow and transient stability for Zhejiang power system under some typical underexcited operating conditions, the results are revealed that underexcited operation reduces the margin of transient stability of the system.

本文基于BPA系统分析软件对浙江电网若干典型进相运行方式进行潮流分析和暂态稳定计算，结果表明发电机进相运行使系统暂态稳定性下降，但在系统内选择适当的大型发电厂在一定范围内作进相运行，对缓解系统低谷负荷时电压偏高问题是可行而有效的。

Finally, based on the geological structure underlain by gravel sand, it calculates the stability factors of Xixipu landslide with the remained slip force method under several water conditions. The results show that the variation of water level in Three Gorge Reservoir has significant influence on the stability of Xixipu landslide. Therefore, great attention should be taken to Xixipu landslide in the prevention design.

根据下伏卵石砂土层的地质结构，对西溪铺滑坡的稳定性进行了评价，评价结果表明库水位的变化对西溪铺滑坡的稳定性有巨大的影响，在滑坡的防治设计中必须引起高度的重视。

In the second chapter, the stabilities of periodic regular gaits for six-legged robots walking longitudinally and laterally were systematically studied respectively, employing a hexpod's geometric model with outward extension of middle legs. Major progress and achievements reached are: a Both the necessary and the sufficient conditions for static walking of hexapods were established theoretically. b A generalized optimization method of gait stability was investigated. c For all feasible duty factor, stability-optimal gaits were obtained, with the expressions being of wide adaptation.

第二章系统分析研究了轴对称六足步行机器人在&中腿行程外置模型&下沿两个运动主方向运动时周期规则步态的稳定性及步态规划问题，主要取得以下三方面新的进展：（1）从理论上建立了六足步行机静态稳定的必要性定理和充分性定理；（2）探索了步态稳定性计算机择优的一般方法；（3）对于所有可能的有荷因数取值，从理论上证明静态稳定性最优步态的存在，并得到具有相当普遍意义的统一表达式。

This paper reviewed the developments in 2-D numerical model of the water flow. By means of the latest observation data of the prototype, the detailed analysis was made on the major thalweg, section, island and bottomland, the erosion and deposition of the river bed and the scour hole near the dock and the law of the fluvial process was obtained. Based on the related references, the evolution trend of the channel after the Three Gorges was finished was predicted. The 2-D mathematical model of the water flow was set up and validated using the latest data. With the model, the flow and velocity of several cases were calculated. The stability computation of the bank at the typical section under difference conditions was carried out by adopting the world widely used Geo-Slope slope stability analysis program. Finally, the synthetical evaluation on the influence of the project on the flood level, velocity, river circumstances, bank protection and flood prevention was made and the conclusion that the construction of the dock had little effect on the flood discharge was obtained.

本文介绍了平面二维水流二维模型研究进展，对河道历史演变概述，通过最新原型观测资料对河道近期主泓线、断面、洲滩、河床冲淤、码头附近冲刷坑等进行详细分析，总结近期河道演变规律，并参考有关文献，对三峡建成后河道演变趋势进行预测；建立了平面二维水流模型，并根据最新资料对模型进行率定和验证，采用模型对几种工况组合进行壅水和流速计算；采用国际上广泛应用的Geo-Slope滑坡稳定分析程序对几种工况条件下工程断典型断面岸坡进行稳定性计算；最后总结工程建设对洪水位、流速、河势、堤防及防洪抢险等方面进行综合评价，得出码头建设对行洪影响较小的结论。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。