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1.
To promote artificial rain in India and other such developing countries, in this article, we have proposed and analyzed a nonlinear mathematical model for cloud seeding by considering that aerosols are introduced proportional to the density of water vapors present in the atmosphere. The model is analyzed using Lyapunov's stability theory of differential equations. To reduce the cost of cloud seeding, an optimal control strategy is designed by incorporating four control parameters. We have shown the existence and uniqueness of solution of this optimal control problem, using Pontryagins Maximum Principle. To minimize the cost in making artificial rain, the optimal control problem provides the strategy for the rate of introduction of aerosols in the atmosphere. To capture the effects of environmental noise on control strategies, the model in deterministic framework is converted into stochastic framework. In this regard, the Hamilton-Jacobi-Bellman equation for stochastic control cost function has been formed. The stochastic analysis implies that the control strategy is effective in reducing the cost and increasing rainfall. 相似文献
2.
[目的]探讨河网严重污染后对环境的影响,尤其是对酸雨形成的影响。[方法]以广州市河网为例,通过测定河网受严重污染后水体沉积物中H2S、SO2、NH3的排放量,同时对当地的酸雨进行监测。[结果]实验表明,河网污染最严重的晚春、夏、初秋季节,H2S、SO2、NH3的排放量明显增高,且在这段时间,恰好是酸雨频发、严重的时期。[结论]河网污染与局部酸雨的形成有一定的相关性。 相似文献
3.
目的建立春雨烧伤凝胶剂中盐酸小檗碱含量测定的高效液相色谱法。方法色谱柱为Kromasil C18柱(4.6mm×250mm,5μm),流动相为乙腈-1%H3PO4-三乙胺(24∶76∶0.76),检测波长:345nm,流速:1.0mL/min,柱温:30℃。结果盐酸小檗碱在0.088~0.440μg(r=0.9997)之间具有良好的线性关系,平均回收率为98.13%,RSD=0.77%(n=6)。结论该法检测快速,精密度高,重现性好,可用于春雨烧伤凝胶剂的定量分析。 相似文献
4.
从伤寒的体质、病因、病理、诊法、辨证、治则、治法、方药及其临床等方面对《伤寒论》研究层面进行分析,对《伤寒论〗研究思路、方法及未来研究发展趋势进行了讨论。 相似文献
5.
S. Kato ‡ A. Hirano M. Kato† F. Herz† E. Ohama‡ 《Neuropathology and applied neurobiology》1993,19(5):436-442
This immunohistochemical study compares the expression of stress-response (heat-shock) protein (srp) 72, srp 27, αB-crystallin and ubiquitin in 86 primary human brain tumours and 21 carcinoma metastases to the central nervous system. Normal brain tissues were included for control purposes. Serial sections of formalin-fixed, paraffin-embedded tissues were used. Most meningiomas (17/23), glioblastomas (11/12) and breast carcinoma metastases (9/10) and some astrocytomas (7/13), pituitary tumours (4/9) and lung cancer metastases (5/11) had tumour cells that reacted with one or more of the antibodies used. Around 43% of the meningiomas and 25% of the glioblastomas expressed srp 72 only. Sole expression of srp 2 7, αB-crystallin or ubiquitin was seen in several tumours. Some meningiomas (3/23) and breast cancer metastases (4/10) co-expressed srp 72 and srp 27, and 1/3 of the glioblastomas co-expressed srp 27 and αB-crystallin. We conclude that primary and metastatic tumours of the brain produce stress-related proteins and that certain tumours concurrently express two or more srp's. 相似文献
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经筋刺法治疗难治性周围性面神经麻痹临床观察 总被引:1,自引:0,他引:1
目的 研究以石学敏教授"经筋、皮部"理论为指导的经筋刺法对难治性周围性面神经麻痹患者面部功能的改善作用.方法 将20例难治性周围性面神经麻痹的患者随机分为两组,治疗组与对照组各10例.对照组予普通针刺治疗,治疗组予经筋刺法治疗.治疗前及治疗后采用House-Brackmann分级量表进行评价分级,并比较两组患者临床疗效.结果 治疗组总有效率(90.0%)均优于对照组(80.0%),两组比较,差异有统计学意义(P<0.05).治疗组House-Brackmann分级量评分的改善优于对照组.结论 以石学敏教授"经筋、皮部"理论为指导的经筋刺法对难治性周围性面神经麻痹面部功能具有良好的改善作用. 相似文献
9.
疫情当前,为科学防护、有效应对,现我校转变传统的课堂教学为以“雨课堂”为授课平台的线上教学。针灸学属于西医院校中医学必修课内容,对于大多数西医院校的学生,针灸教学内容相对抽象、繁杂。本文将雨课堂这种新的教学模式应用于针灸课程中,通过“课前-课上-课后”的“3段式导学”,充分调动学生主动学习针灸的积极性,活跃课堂气氛,学生可以个性化调整学习节奏,同时为教师提供数据性的反馈结果,及时科学地调整教学内容。在保障学生可以足不出户、安全有效完成教学任务的同时,还可提升教学质量。本研究探讨了雨课堂线上授课在针灸教学中的优势,构建了一次传统文化与现代网络技术的火花碰撞,以期促进针灸教学的课程改革。 相似文献
10.
Episodic acidification resulting in increased acidity and inorganic aluminum (Ali) is known to interfere with the parr-smolt transformation of Atlantic salmon (Salmo salar), and has been implicated as a possible cause of population decline. To determine the extent and mechanism(s) by which short-term acid/Al exposure compromises smolt development, Atlantic salmon smolts were exposed to either control (pH 6.7–6.9) or acid/Al (pH 5.4–6.3, 28–64 μg l−1 Ali) conditions for 2 and 5 days, and impacts on freshwater (FW) ion regulation, seawater (SW) tolerance, plasma hormone levels and stress response were examined. Gill Al concentrations were elevated in all smolts exposed to acid/Al relative to controls confirming exposure to increased Ali. There was no effect of acid/Al on plasma ion concentrations in FW however, smolts exposed to acid/Al followed by a 24 h SW challenge exhibited greater plasma Cl− levels than controls, indicating reduced SW tolerance. Loss of SW tolerance was accompanied by reductions in gill Na+,K+-ATPase (NKA) activity and Na+,K+,2Cl− (NKCC) cotransporter protein abundance. Acid/Al exposure resulted in decreased plasma insulin-like growth factor (IGF-I) and 3,3′,5′-triiodo-l-thyronine (T3) levels, whereas no effect of treatment was seen on plasma cortisol, growth hormone (GH), or thyroxine (T4) levels. Acid/Al exposure resulted in increased hematocrit and plasma glucose levels in FW, but both returned to control levels after 24 h in SW. The results indicate that smolt development and SW tolerance are compromised by short-term exposure to acid/Al in the absence of detectable impacts on FW ion regulation. Loss of SW tolerance during short-term acid/Al exposure likely results from reductions in gill NKA and NKCC, possibly mediated by decreases in plasma IGF-I and T3. 相似文献