It is well-known that such non-conventional digital control schemes,such as generalized sampled-data hold functions,have clear advantages over the conventional single-rate digital control ***,they have theoretical neg...
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It is well-known that such non-conventional digital control schemes,such as generalized sampled-data hold functions,have clear advantages over the conventional single-rate digital control ***,they have theoretical negative aspects that deviation of the input can lead to intersample oscillations or intersample *** paper investigates the zero dynamics of sampleddata models,as the sampling period tends to zero,composed of a new generalized hold polynomial function,a nonlinear continuous-time plant and a sampler in *** a new design of generalized hold circuit,the authors give the approximate expression of the resulting sampled-data systems as power series with respect to a sampling period up to the some order term on the basis of the normal form representation for the nonlinear continuous-time systems,and remarkable improvements in the stability properties of discrete system zero dynamics may be achieved by using proper adj us *** particular interest are the stability conditions of sampling zero dynamics in the case of a new hold ***,an insightful interpretation of the obtained sampled-data models can be made in terms of minimal intersample ripple by design,where the ordinary multirate sampled systems have a poor intersample *** has shown that the intersample behavior arising from the multirate input polynomial function can be localised by appropriately selecting the design parameters based on the stability condition of the sampling zero *** results presen ted here generalize the well-known notion of sampling zero dynamics from the linear case to nonlinear systems.
目的分析2015年四川省上消化道恶性肿瘤(胃癌和食管癌)发病、死亡和潜在减寿情况。方法收集四川省24个肿瘤登记处上报的2015年恶性肿瘤发病、死亡及人口资料。提取ICD-10编码C15-C16选择食管癌、胃癌的发病和死亡数据,用SAS 9.3软件分别计算性别、年龄别发病和死亡的粗率、标化率、构成比、累积率(0~74岁)、潜在减寿年数(potential years of life lost,PYLL)、潜在减寿率(potential years of life lost rate,PYLLR)和平均减寿年(average years of life lost,AYLL)。标准人口采用2000年全国普查人口年龄构成和Segi’s世界人口年龄构成。结果2015年四川省肿瘤登记地区食管癌和胃癌发病率分别为29.29/10万和28.60/10万,分别居发病第3位和第4位;胃癌和食管癌死亡率分别为23.90/10万和22.20/10万,分别居死亡第3位和第4位;根据上消化道恶性肿瘤发病率和死亡率的年龄性别分布,男女性45岁后发病率和50岁后死亡率均显著升高;无论城乡,男性食管癌和胃癌各项发病和死亡指标均高于女性。农村地区人群食管癌和胃癌疾病负担高于城市。食管癌潜在减寿年数为23399人年,平均减寿年数为15.41年,减寿率为1.92‰;胃癌潜在减寿年数为25390人年,平均减寿年数为16.74年,减寿率为2.09‰。结论四川省食管癌和胃癌发病与死亡水平相对较高,男性为食管癌和胃癌的高发人群,45岁以上的中老人群是上消化道恶性肿瘤高风险人群,农村地区人群的上消化道肿瘤疾病负担高于城市。
目的:分析垂体瘤经鼻蝶手术后恶心呕吐(postoperative nausea and vomiting,PONV)的发生情况,并探讨相关危险因素,为改善患者预后及术后生活质量提供参考。方法:采用前瞻性队列研究,收集2015年2月至2017年12月期间在成都市第五人民医院...
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目的:分析垂体瘤经鼻蝶手术后恶心呕吐(postoperative nausea and vomiting,PONV)的发生情况,并探讨相关危险因素,为改善患者预后及术后生活质量提供参考。方法:采用前瞻性队列研究,收集2015年2月至2017年12月期间在成都市第五人民医院和四川大学华西医院神经外科择期行经鼻蝶垂体瘤手术患者360例,计算术后6h、6~12h、12~24h PONV发生率,按照是否发生PONV分为病例组和对照组,采用多因素Logistic回归模型分析垂体瘤经鼻蝶手术后发生PONV的相关危险因素。结果:经鼻蝶垂体瘤术后PONV总体发生率为26.27%(96/360),其中PONV症状为中、重度者占79.17%;有42例(43.75%)发生在术后6h内。与无功能型垂体瘤相比,泌乳素瘤(PRL)术后PONV发生率的发生率更高,差异有统计学意义(40.00%vs.25.33;χ~2=6.638,P=0.010)。单因素分析显示:性别、垂体瘤大小、手术时间、有无脂肪填塞、术后疼痛、晕动病史是经鼻蝶垂体瘤术后发生PONV的危险因素(P<0.05)。多因素Logistic回归分析显示:女性、手术时间长、术后中重度疼痛、有晕动病史是经鼻蝶垂体瘤术后发生PONV的独立危险因素(P<0.05)。结论:女性、手术时间长、术后中重度疼痛、有晕动病史是其独立危险因素。应针对危险因素,采用综合措施减少PONV的发生。
Study of Air Quality Objectives(AQOs)and long-term changes of air pollution plays a decisive role in formulating and refining pollution control *** this study,10-year variations of six major air pollutants were analyz...
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Study of Air Quality Objectives(AQOs)and long-term changes of air pollution plays a decisive role in formulating and refining pollution control *** this study,10-year variations of six major air pollutants were analyzed at seven monitoring sites in Hong Kong *** continuous decrease of annual averaged concentrations of NO_(2),SO_(2),CO,PM_(2.5)and PM_(10)and numbers of days with severe pollution conditions validated the efficiency of the series of air pollution control schemes implemented by the Hong Kong region ***,there is still a big gap to meet the ultimate targets described by the World Health ***,the concentration of O_(3)at roadside and urban stations increased by 135%±25%and 37%±18%from 2011 to 2020,respectively,meanwhile the highest 8 hr averaged O_(3)concentration was observed as 294μg/m^(3)at background station in 2020,which pointed out the increasing ozone pollution in Hong Kong *** was a great decrease in the annual times of air quality health index(AQHI)laying in“high”,“very high”and“serious”categories from 2011 to 2020 with the decrease rate of 89.70%,91.30%and 89.74%at roadside stations,and 79.03%,95.98%and 72.73%at urban stations,***,the number of days categorized as“high”or above at roadside station was twice more than that in the urban station during the past ten ***,more policies and attentions should be given to the roadside air quality and its adverse health effect to pedestrians on street.
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