基于CIMISS的土壤水分质控应用研究

气象资料业务系统MDOS(meteorological data operation system)的质控方法使用通用阈值去质控土壤水分数据,会漏检和误检出部分疑误数据,且疑误结果多以“未通过降水关系检查”为主,降低值班人员的数据审核效率。为了提高土壤水分质控效率,结合本地土壤特性,分析海南土壤水分历史数据,总结适合本地的阈值范围参数,提出基于CIMISS(China integrated meteorological information service system)的MQCSM(multiple quality control method of soil moisture)算法。该算法引入时变检查、持续性检查等检查方法,多重质控原始土壤水分数据,能快速、准确地质控出疑误数据,并分类展示疑误结果于web监控页面工值班人员筛查。业务试用结果表明,对比现有质控方法,该算法能准确、有效地筛查出疑误土壤水分疑误数据,且质控监视平台实时展示疑误结果,提高了值班人员对疑误数据的审核效率。     

On splitting-based numerical methods for nonlinear models of European options

We present a large class of nonlinear models of European options as parabolic equations with quasi-linear diffusion and fully nonlinear hyperbolic part. The main idea of the operator splitting method (OSM) is to couple known difference schemes for nonlinear hyperbolic equations with other ones for quasi-linear parabolic equations. We use flux limiter techniques, explicit–implicit difference schemes, Richardson extrapolation, etc. Theoretical analysis for illiquid market model is given. The numerical experiments show second-order accuracy for the numerical solution (the price) and Greeks Delta and Gamma, positivity and monotonicity preserving properties of the approximations.     

Finite-time stability and stabilisation of singular discrete-time linear positive systems with time-varying delay

ABSTRACT

In this paper, the problem of finite-time stability and stabilisation for positive singular discrete-time linear systems with time-varying delay is investigated. We first present novel delay-dependent sufficient conditions for positivity and finite-time stability of the unforced systems. We then apply the obtained results to solve finite-time stabilisation problem of the considered systems. The sufficient conditions for the positivity and finite-time stabilisable of such systems are formulated in terms of a standard linear programming (LP) problem. Numerical examples are provided to illustrate the effectiveness and advantages of our results.     

Divergent trajectories in the aging mind: Changes in working memory for affective versus visual information with age.

Working memory mediates the short-term maintenance of information. Virtually all empirical research on working memory involves investigations of working memory for verbal and visual information. Whereas aging is typically associated with a deficit in working memory for these types of information, recent findings suggestive of relatively well-preserved long-term memory for emotional information in older adults raise questions about working memory for emotional material. This study examined age differences in working memory for emotional versus visual information. Findings demonstrate that, despite an age-related deficit for the latter, working memory for emotion was unimpaired. Further, older adults exhibited superior performance on positive relative to negative emotion trials, whereas their younger counterparts exhibited the opposite pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

《化工原理》教学中学生学习积极性的培养

化工原理是化学化工类专业的一门技术基础课,文章从结合学生所学专业与课本理论知识、加强学生参与意识、灵活运用教学法等方面着手,就如何激发学生学习积极性,提高教学效果作了一些有益的探讨。     

疑似危险物的鉴定与评估

为配合公安机关对疑似危险物进行鉴定和评估,由国家颁布的国家标准《化学品物理危险性测试导则》和《GB/T 13226-1991工业雷管铅板试验方法》,被系统地应用于危险物的爆炸性试验鉴定与评估标准。其中,联合国隔板试验1(a)、克南试验1(b)和时间/压力试验1(c)用于鉴别危险物是否具有爆炸性;雷管敏感度试验5(a)用于确定危险物对强烈机械刺激的敏感度;铅板试验用于鉴定各种火雷管、电雷管和导爆管雷管是否具有爆炸性。利用上述试验方法,对硝酸铵(AN)和高氯酸铵(AP)样品,以及某公安机关缴获的疑似黑火药和导火索、疑似硝铵炸药、疑似电雷管和火雷管等危险物,进行了燃烧性或爆炸性的鉴定和评估。结果表明,AN不能用工业雷管起爆,AP以及与AN的混合物均具有爆炸性,能用工业雷管起爆,验证了该爆炸性试验鉴定与评估标准的有效性。疑似硝铵炸药可用联合国隔板试验1(a)鉴别出是否具有爆炸性,疑似黑火药和疑似导火索可用燃烧试验定性鉴别出是否具有燃烧性,疑似电雷管和疑似火雷管可用铅板试验鉴别出是否具有爆炸性。     

Are the memories of older adults positively biased?

There is disagreement in the literature about whether a "positivity effect" in memory performance exists in older adults. To assess the generalizability of the effect, the authors examined memory for autobiographical, picture, and word information in a group of younger (17-29 years old) and older (60-84 years old) adults. For the autobiographical memory task, the authors asked participants to produce 4 positive, 4 negative, and 4 neutral recent autobiographical memories and to recall these a week later. For the picture and word tasks, participants studied photos or words of different valences (positive, negative, neutral) and later remembered them on a free-recall test. The authors found significant correlations in memory performance, across task material, for recall of both positive and neutral valence autobiographical events, pictures, and words. When the authors examined accurate memories, they failed to find consistent evidence, across the different types of material, of a positivity effect in either age group. However, the false memory findings offer more consistent support for a positivity effect in older adults. During recall of all 3 types of material, older participants recalled more false positive than false negative memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related positivity enhancement is not universal: Older Chinese look away from positive stimuli.

Socioemotional selectivity theory postulates that with age, people are motivated to derive emotional meaning from life, leading them to pay more attention to positive relative to negative/neutral stimuli. The authors argue that cultures that differ in what they consider to be emotionally meaningful may show this preference to different extents. Using eye-tracking techniques, the authors compared visual attention toward emotional (happy, fearful, sad, and angry) and neutral facial expressions among 46 younger and 57 older Hong Kong Chinese. In contrast to prior Western findings, older but not younger Chinese looked away from happy facial expressions, suggesting that they do not show attentional preferences toward positive stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

You never lose the ages you’ve been: Affective perspective taking in older adults.

Aging appears to be associated with a growing preference for positive over negative information (Carstensen, Mikels, & Mather, 2006). In this study, we investigated potential awareness of the phenomenon by asking older people to recollect material from the perspective of a young person. Young and older participants listened to stories about 25- and 75-year-old main characters and then were asked to retell the stories from the perspective of the main characters. Older adults used relatively more positive than negative words when retelling from the perspective of a 75- versus 25-year-old. Young adults, however, used comparable numbers of positive and negative words regardless of perspective. These findings contribute to a growing literature that points to developmental gains in the emotion domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related affective modulation of the startle eyeblink response: Older adults startle most when viewing positive pictures.

Previous studies reveal age by valence interactions in attention and memory, such that older adults focus relatively more on positive and relatively less on negative stimuli than younger adults. In the current study, eyeblink startle response was used to measure differences in emotional reactivity to images that were equally arousing to both age groups. Viewing positive and negative pictures from the International Affective Picture System had opposite effects on startle modulation for older and younger adults. Younger adults showed the typical startle blink pattern, with potentiated startle when viewing negative pictures compared to positive pictures. Older adults, on the other hand, showed the opposite pattern, with potentiated startle when viewing positive pictures compared to viewing negative and neutral pictures. Potential underlying mechanisms for this interaction are evaluated. This pattern suggests that, compared with younger adults, older adults are more likely to spontaneously suppress responses to negative stimuli and process positive stimuli more deeply. (PsycINFO Database Record (c) 2011 APA, all rights reserved)