50 resultados para Direct effect
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
The electronic structure, electron g factor, and Stark effect of InAs1-xNx quantum dots are studied by using the ten-band k center dot p model. It is found that the g factor can be tuned to be zero by the shape and size of quantum dots, nitrogen (N) doping, and the electric field. The N doping has two effects on the g factor: the direct effect increases the g factor and the indirect effect decreases it. The Stark effect in quantum ellipsoids is high asymmetrical and the asymmetry factor may be 319. (c) 2007 American Institute of Physics.
Resumo:
Pool boiling of degassed FC-72 on a plane plate heater has been studied experimentally in microgravity. A quasi-steady heating method is adopted, in which the heating voltage is controlled to increase exponentially with time. Compared with terrestrial experiments, bubble behaviors are very different, and have direct effect on heat transfer. Small, primary bubbles attached on the surface seem to be able to suppress the activation of the cavities in the neighborhoods, resulting in a slow increase of the wall temperature with the heat flux. For the high subcooling, the coalesced bubble has a smooth surface and a small size. It is difficult to cover the whole heater surface, resulting in a special region of gradual transitional boiling in which nucleate boiling and local dry area can co-exist. No turning point corresponding to the transition from nucleate boiling to film boiling can be observed. On the contrary, the surface oscillation of the coalesced bubble at low subcooling may cause more activated nucleate sites, and then the surface temperature may keep constant or even fall down with the increasing heat flux. Furthermore, an abrupt transition to film boiling can also be observed. It is shown that heat transfer coefficient and CHF increase with the subcooling or pressure in microgravity, as observed in normal gravity.
Resumo:
小麦(Triticum aestivum L.)是世界上种植面积最大,总产量最高,食物加工种类最丰富的粮食作物,占世界人口35 %-40 %的人们以此为主要食物。因此小麦产量的高低和品质的优劣直接影响人们对食物需求的安全和满意程度,也影响着人类的营养平衡以及面粉和食品加工业的发展。随着生活水平的提高,人们对于小麦的品质越来越重视。培育优质专用小麦新品种,制定优质专用小麦品种品质生态区划,从而在不同程度上实现小麦的区域化种植和产业化经营具有重要的意义。 影响小麦品质的因素主要是遗传因素和环境因素,其中环境因素又包括各种自然生态因素和人为因素。研究表明,小麦品质的环境间的差异大于品种间的差异,气候条件是影响小麦品质的最重要的因子,小麦品质的地域间的差异反映出了小麦的品质区域分布规律。为了满足市场对不同品质小麦的需求,对小麦进行区域化研究具有重要的理论和现实意义。本研究结合四川的地理、气候特点,研究不同品质类型与生态环境的关系,为在复杂的生态环境内进行品质区划提供依据。 本研究首先根据四川省小麦种植区域的生态特点,在四川省多个典型生态区:川南丘陵的荣县、川西南高原的西昌、川西平原的双流布点种植,采用的小麦试验材料为不同品质类型:中筋小麦川育12、川育14、川育16由本所提供;弱筋小麦川麦32和强筋小麦川麦36由四川省农科院作物所提供。通过研究品质性状与品种及各个生态因子包括地点、土壤土质差异等的关系,明确不同生态环境中适宜种植的小麦品种类型,强筋小麦、中筋小麦更适合于在荣县、双流地区种植,弱筋小麦更适合于在西昌地区种植,为品种品质区划奠定基础。 其次,选择了本课题组育成的稳定中间品系,对其品质性状SDS沉降值进行了多年测定。分析了品质性状SDS沉降值与多种气候因子的相关性,结果表明SDS沉降值与日均温、日照时数成正相关,与降水量成负相关,为品质育种提供了理论依据。 此外,以中筋小麦新品种小麦川育14为材料,应用三元二次正交旋转回归模型设计试验,研究主要栽培因子播期、密度和施肥量对产量的影响,并建立函数模型。经计算机模拟寻优,筛选出了高产高效栽培组合措施,并确定了置信域。结合四川省不同的地理情况,在平原和丘陵地区分别进行实验,并各自建立了高产高效栽培组合措施,为川育14品种的推广提供了理论指导。 Wheat is one of the most important crops in the world. About 35%-40% people all over the world, take the wheat as their most important food. So the quality, as well as the quantity of the wheat makes a direct effect on people’s demands of food and their satisfaction. It also effects on human’s healthy, and the development of the Food processing industry. With the development of the living standard, people pay more attention to the quality of wheat. So, we set a special ecology zoning for wheat. It is significant to carry out planting the wheat in special zoning in varying degrees. The main factors affecting wheat quality are heredity and environment including many ecological factors and the factors in cultivation. As to the quality,the difference between ecology and cultivation is more important than the difference between special wheat. In so many factors, climate is the most important one. From the difference in quality between different zones,we can conclude the rule of distribution abort quality of wheat. Finding out the intersection of numerous wheat not only can meet the demand of food production,but also has important signification in theory and realism。In our research, according to the complex geography in Sichuan province, we study the relationship between numerous kinds of quality characters in wheat and the ecology. So, we can set a foundation for more research. In this research, firstly, we plant wheat in some typical ecological regions of SICHUAN province: RONGXIAN(south of SC)、XICHANG(south of SC), SHUANGLIU(west of SC). The materials of the experiments: ChuanYu12, ChuanYu14, ChuanYu16(from our institute), Chuanmai32, Chuanmai36 (from the Chinese academy of agriculture sciences of Sichuan. Through the research on the relationship between the quality of wheat and those ecology factors, we can make a definition that which area is perfect matched with which kind of wheat. And it can satisfy the demand of people. Secondly, select many sorts of wheat from our research group. All of them are selected and bred more than 3 years(2003-2005). And we make every-year determination as well. We’ve gotten SDS value from those 9, and various data on factors of climate. We also got to know the relation ship between those numbers. Thirdly, use Chuanyu14 as material, the mathematical model of the relation between the production of wheat and main agricultural measures such as date, density and fertilizer. The model was established by association of three elements two return, rotate and regression. We set a suitable model and get a suitable method which can make high harvest. Based on various kinds of geographical regions in Sichuan province, we set different models which can be used in plain and hill. So, we can plant Chuan Yu 14 in Sichuan province under the result in research.
Resumo:
结构光视觉传感器是视觉焊缝跟踪系统获得焊缝信息的重要组成部分,其测量误差与性能对焊缝跟踪系统的总体测量精度及可靠性有着直接影响。本文对应用于焊缝跟踪的结构光视觉传感器进行误差分析,包括传感器硬件系统结构误差、激光散斑噪声误差及镜头畸变误差等,并对不同结构方式下的视觉传感器建立了数学模型,具体分析了结构参数对其误差的影响,提出结构光视觉焊缝跟踪传感器优化设计方法,并依据仿真结果给出结构优化设计参数,最后通过实验验证了该优化设计方法的正确性。
Resumo:
Firstly, established sequence stratigraphy of Sinian System-Middle Triassic Series framework in Sichuan basin,be divided into 21 second-level sequence stratigraphy and 105 third-level sequence stratigraphy.From many aspects,discussed sequence stratigraphy characteristic. On the foundation of structure unconformity and fission track analysis, on the ground of An county-Shuinin county regional seismic section, using the positive evolution equilibrium principle technology, comprehensivly be mapped structure evolution of Sichuan basin. It can be divided into seven stages, that is :Pre-Sinian basement stage, cratonic depression basin(Z1-S)stage, cratonic rifted basin(D-T2)stage, passive continental margin(T3x1-3)stage, foreland basin(T3x4-6)stage, depression basin (Jurassic Period-Miocene Epoch) stage, formed basin (Holocene Epoch) stage. Analysis on structure evolution history,burial history,source rocks thermal evolution history, Maoba changxing formation gas pool forming process can be classified into four stages: ancient lithological oil pool stages in Indosinian-early Yanshanian period(T-J1-2), ancient structure- lithological gas pool stages in middle Yanshanian period(J3-K1), structure- lithological gas pool setting stages in last Yanshanian period(K2), structure- lithological gas pool adjusting and transformation stages in Himalayan period(R-Q). Maoba feixianguan formation gas pool forming process can be classified into two stages: second structure gas pool stages in last Yanshanian period(K2),second structure gas pool physical adjusting and transformation stages in Himalayan period(R-Q),and summarize reservoir formation model. On the base of newest exploration achievement and petroleum geologic comprehensive research , demonstrate how structure controls hydrocarbon accumulation. Structure controlling source rocks behaves structure controlling main source rocks’sedimentary facies, medium-large pools mainly located at center or margin of hydrocarbon generation. Structure controlling palaeo-karst reservoirs ,reef and beach facies reservoirs, fault and fracture reservoirs. Structure controlling palaeo-uplift, and palaeo-uplift controlling hydrocarbon migration, active reservoirs’forming, palaeo-structure traps forming. Structure controls distribution of mudstone and gypsolith, controls preservation. Structure controls hydrocarbon conducting, structure traps forming and hydrocarbon accumulation. Whether or no, Structure controls total process of basin forming-source rocks’generation- hydrocarbon accumulation. It is direct effect results of structure movements that large traps’ conditions, conducting migration conditions, high quality preservation. source rocks’condition and reservoirs’ condition are the indirect effect results. In the last analysis, “source rock controlling theory”, “high quality reservoir mainly controlling theory”, “palaeo-uplift controlling theory” and “current structure deciding theory” are structure controlling hydrocarbon accumulation. There are high variability and complex mechanisms in Sichuan basin , but the regional hydrocarbon accumulation conditions are very well, such as abundant source rocks, matching process of hydrocarbon accumulation and many exploration areas. By means of integrated analysis, put forward hydrocarbon exploration direction and large-middle targets of China Petroleum and Chemical Corporation .Thus, more and more hydrocarbon proved reserve and output in Sichuan basin will be contributed to China energy industry in a long future time.
Resumo:
Job Burnout has been a focus of the Occupational Stress Research. As a typical,helping occupation, teacher has attracted widely attention and researches in the areas of pedagogy and psychology. The special subgroup of teacher, headmasters who are the elites of the Basic Education, is ignored. The research about principals’ Job Burnout is nearly blank after analyzing related documents and information. With the development of the society, people pay more and more attention to the education and put more demands on the headmasters, especially middle-school principals. They are required not only to be good educators, who are equipped with all the inner qualities as a teacher, but also good managers. So the main purpose of this research was to compare the principal group with ordinary teacher group, and reveal underling factors, such as background variables and psychological protection variables. A representative sample of Wenzhou middle school principals sized 192 and a sample of middle school teacher sized 302 were sampled from various schools. The educational version of burnout inventory, self consistency scale, and interpersonal trust scale were administrated to the two samples, together with some demographic variables of interest. The applicability and equivalence of the three instruments used in this study were checked. Based on well-established reliability and cross-sample congruence of measures, the difference between principals and teachers was test. Then the contributing factors were analysis gradually. The five background variables were examined one by one in the two samples separately. A multiple covariance analysis was conducted to test whether there remained any difference between these two samples on the variables of interest. Regression analysis was used to further control the effect of self harmony and interpersonal trust to test the difference between two samples. Mediating analysis was conducted to build the relationship among the three constructs. The main results of the research were stated as following: 1. The internal consistency coefficients of all the scales were good, and no difference exited between the two groups. The measurement equivalence of three instruments was established well. The measures could be applied to and comparing the two samples. 2. The self-harmony, and interpersonal trust of principals were better than the ordinary middle-school teachers. Job Burnout of principals was significant lower than teachers. 3. Demographic variables like the gender, age groups, income levels, disricts, and the type of school, were important influencing factors. The difference patterns of the variables on these five variables in two samples had similarity and distinction. 4. After controlling the background variables, there remained significant difference between principals and teachers on the variables of interest. 5. Job Burnout negatively correlated with self-harmony and interpersonal trust. That is to say,the lower the degree of self-harmony and interpersonal are, the serious of the Job Burnout is, The correlation between the self-harmony and the interpersonal trust was positive. 6. After statistically controlling the background variables and psychological variables, there still exited significant difference between two groups of this study. Also, self harmony and interpersonal trust were significant protection predictors to different aspect of job burnout. 7. Mediating analysis was conducted to the residual score of the three constructs after controlling the five variables and group membership. Self harmony partially mediated the relationship between interpersonal trust and job burnout. That is, interpersonal trust had indirect effect to burnout mediated by self harmony, also had direct effect to burnout.
Resumo:
Previous researches about family caregiving revealed that caregiving has both negative and positive effects on caregivers’ well-being. Based on Lawton’s two-factor model, this study aims at examining how caring for old parents would affect adult daughters’ psychological well-being. According to Lawton, objective stressors as caregiving would arouse two different kinds of caregivers’ subjective appraisal, i.e., negative appraisal and positive appraisal, which in turn correlate with the negative and positive dimensions of caregivers’ psychological well-being, respectively. There were two main purposes of this study: a) to verify both the negative and positive paths in the two-factor model and their relatively independence; and b) to examine the effects of relationship quality between caregiver and care-recipient on those paths. The results are as follows: 1) Caregiving stressors have significant positive predictive effect on caregivers’ negative appraisal, but have no direct effect on caregivers’ positive appraisal. 2) Caregivers’ negative appraisal has significant positive predictive effect on their negative emotional experience, while caregivers’ positive appraisal has significant positive predictive effect on their positive emotional experience. 3) Certain dimensions of relationship quality, including the Appreciation and General Appraisal, have significant negative predictive effect on caregivers’ negative appraisal, and have significant positive predictive effect on caregivers’ positive appraisal. 4) The Appreciation dimension of relationship quality moderates the path from caregiving demands to caregivers’ burden; and the General Appraisal of relationship quality moderates the path from caregivers’ positive appraisal to life satisfaction. Based on the above results, the researcher concluded that a) both the negative path and positive path exist in caregiving process, and they are relatively independent from each other; and b) relationship quality does moderate certain paths in the model. Meanwhile, the main effect of relationship quality on caregivers’ experience is also significant and more remarkable. This study attempts to explain these results in terms of coping resources. Both relationship quality and many other factors might be explained as resources that caregivers utilize to cope with stress of caregiving. With more resources, caregivers tend to appraise more positively, and less negatively, and vice versa. However, the resources which might affect caregivers’ positive appraisal, as well as the ways they work, may be different from that affect caregivers’ negative appraisal.
Resumo:
Organizations are increasingly turning to team-based structures to contend with the pressure of the increasing global competition, consolidation, innovation and need for diverse skills, expertise, and experiences. This ongoing transformation in the basic organization of work has captured the attention of researcher. And group and team research has become increasingly centered in the fields of organizational psychology and organizational behavior since the 1990s. A great deal empirical studies were conducted; a number of variables contributing to team effectiveness and several IPO models were summarized. But teamwork behaviors, the dynamic and adaptive interactions among team members during the task completion, were still very vague. So were the team task characteristics, an important input variable of the IPO models. The effects of team task characteristics and teamwork behaviors on team effectiveness were explored according to IPO model on the basis of the reviews on previous studies, the Hierarchical Conceptual Structure of Teamwork Behaviors (Rousseau et al.,2006), and the task characteristic theory(Hackman & Oldman, 1975). The questionnaire data from 479 team members and 110 team managers of 22 organizations were analyzed. The results indicate: A. Teamwork behaviors consist of 13 behavioral dimensions: team mission analysis, goal specification, planning, coordination, cooperation, information exchange, performance monitoring, backing-up behaviors, intra-team coaching, collaborative problem solving, team practice innovation, psychological support and integrative conflict management. The hierarchical conceptual structure was partly supported with five variable identified, i.e., preparation of work accomplishment, task-related collaborative behaviors, work assessment behaviors, team adjustment behaviors and the management of team maintenance. The formal four variables are in a sequential way. B. The task characteristic theory at individual level is applicable to the team level. This means that the team task characteristics consist of task variety, identity, significance, feedback, autonomy, interdependence. C. The correlations among task characteristics, teamwork behaviors and outcomes support the IPO model. The regulation of team performance mediated the effects of task meaningfulness and interdependence on team outcomes, with the direct effects of task meaningfulness on the preparation behaviors and the direct effects of interdependence on the task-related collaborative behaviors. The management of team maintenance mediated the effects of autonomy on team cohesion and satisfaction. The regulation of team performance has a direct effect on the team performance and the management of team maintenance. And the management of team maintenance has a direct effect on the team attitude and the regulation of team performance.
Resumo:
Emotional support, as an important form of social supports, has great impact on the life of both caregivers and receivers. Many studies on adult children and old parents indicate that emotional support is closely related to parents’ well-being, and the relation quality between old parents and adult children is one of the factors influencing adult children’s support offering. However, the study on adolescents’ emotional support to their parents is quite rare. What’s more, it has been found that emotional support skills children have learnt at home have life-time influence on children’s response to other’s emotional needs. It is assumed that to some extent the emotional support styles between parents and adolescents are relatively stable, and they are related to the care children give to their parents after they advance to old age. Hence, it is necessary to study the emotional support of adolescent in order to at last improve the well-being of old parents. Totally speaking, the aim of this study is to explore the relation between parenting styles and adolescents’ emotional support offering, as well as the effects of mother-child relationships. In addition, culture is a factor having impact on parenting styles, parent-child relationships and emotional support. So we have designed this cross-cultural study to explore cultural differences. The results are as follows: (1) As to Chinese and Indonesian mothers, their Acceptance of adolescents’ behaviors has significant positive predictive effect on children’s emotional support. Besides, the Intimacy and Approval dimensions of mother-child relationships partially mediate the path from parenting styles to emotional support offering, and those effects have no significant difference in China and Indonesia. (2) Chinese and Indonesian mother’s Rejection to adolescents has significant positive predictive effect on Conflict between mothers and adolescents, but has no direct effect on adolescents’ emotional support offering. (3) Adolescents’ support offering has no significant predictive effect on their willingness to help their parents. (4) Adolescents’ support offering has significant predictive effect on their motivation to provide emotional support to their parents. However, the relation between adolescents’ support offering and the willingness to help their parents is not clear. (5) Adolescents have scored high in Acceptance parenting style dimension and relatively low in Rejection dimension, which indicate that mothers in China and Indonesia adopt positive parenting styles. Both Chinese and Indonesian mother-child relationships are good. However, Indonesian adolescents have perceived more Intimacy and Approval from mothers, and there is no significant difference between Chinese and Indonesian adolescents and mothers in the dimension of Conflict.
Resumo:
The PtRu/C electrocatalyst with high loading (PtRu of 60 wt%) was prepared by synergetic effect of ultrasonic radiation and mechanical stirring. Physicochemical characterizations show that the size of PtRu particles of as-prepared PtRu/C catalyst is only several nanometers (2-4 nm), and the PtRu nanoparticles were homogeneously dispersed on carbon surface. Electrochemistry and single passive direct methanol fuel cell (DMFC) tests indicate that the as-prepared PtRu/C electrocatalyst possessed larger electrochemical active surface (EAS) area and enhanced electrocatalytic activity for methanol oxidation reaction (MOR). The enhancement could be attributed to the synergetic effect of ultrasound radiation and mechanical stirring, which can avoid excess concentration of partial solution and provide a uniform environment for the nucleation and growth of metal particles simultaneously hindering the agglomeration of PtRu particles on carbon surface.
Resumo:
The electrochemistry of cytochrome c was studied at the PVP-modified gold electrode. It was found that the promoter effect is related to the amount of PVP at the gold electrode. From our results, it can be seen that the nitrogen element in the polymer is important for accelerating the electron transfer of cytochrome c.
Resumo:
The promoter effect of halogen anions for heterogeneous electron transfer between cytochrome c and a gold electrode was studied. It was found that the order of the promoter ability of halogen anions is I- > Br- > Cl- > F-. In addition, factors which can affect the promoter effect were discussed.