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21.
When the police have no suspect, they may ask an eyewitness to construct a facial composite of that suspect from memory. Faces are primarily processed holistically, and recently developed computerized holistic facial composite systems (e.g., EFIT-V) have been designed to match these processes. The reported research compared children aged 6–11 years with adults on their ability to construct a recognizable EFIT-V composite. Adult constructor's EFIT-Vs received significantly higher composite-suspect likeness ratings from assessors than children's, although there were some notable exceptions. In comparison to adults, the child constructors also overestimated the composite-suspect likeness of their own EFIT-Vs. In a second phase, there were no differences between adult controls and constructors in correct identification rates from video lineups. However, correct suspect identification rates by child constructors were lower than those of child controls, suggesting that a child's memory for the suspect can be adversely influenced by composite construction. Nevertheless, all child constructors coped with the demands of the EFIT-V system, and the implications for research, theory, and the criminal justice system practice are discussed.  相似文献   
22.
The particle-size distribution in silica powder prepared by the sol–gel method has been determined by dynamic light scattering analysis. The average diameter of the particles was found to be 250?nm. Using a low-temperature nitrogen adsorption–desorption technique, it was found that the synthesised powder may be referred to as mesoporous materials. Polystyrene/silica composite films were fabricated by casting from o-xylene solutions. It was found, using thermogravimetry, that incorporation of silica leads to an increase in both the onset temperature of polymer degradation and in the temperature at which the maximum rate of weight loss occurs. Using differential scanning calorimetry, the phase transitions from the glassy state to the elastic one were studied for the polymeric materials. New data relating to the effect of silica on the glass-transition temperature, Tg, of composites with a low weight fraction of SiO2 were found. Specifically, we found a non-monotonic concentration dependence of the value of Tg. The present results advocate for employing silica as an effective filler for producing polymer composites with enhanced thermal properties.  相似文献   
23.
We report an abnormally high residual dislocation density in aluminium in an Al/Ti/Al laminate annealed at 873 K for seven days. The residual dislocation density reaches 7.5 × 1014 m?2, higher than that in aluminum after severe plastic deformation processes such as accumulative roll bonding and high-pressure torsion. It is proposed that the high residual dislocation density may result from obstruction of the movement of TiAl3 nanoparticles by the grain boundary and Ti atoms conglomerating at vacancies distributed in the aluminium matrix at a high temperature for a sufficient time to allow a relatively stable crystal.  相似文献   
24.

The first stages of thermal relaxation towards equilibrium in a Zr 57 Ti 5 Cu 20 Al 10 Ni 8 bulk metallic glass have been studied by differential scanning calorimetry, X-ray diffraction, transmission electron microscopy and high-resolution electron microscopy. These coupled experiments rule out for this glass the existence of a phase separation on the nanometric scale preceding the onset of crystallization. The first step of crystallization is of the primary type, that is it consists of the nucleation of nanocrystallites in the amorphous matrix with which they coexist in metastable equilibrium. The very high nucleation rate leads to a nanometric composite structure with a number density of about 7 2 10 24 m -3 of 3-4nm crystallites, occupying a volume fraction of about 15%. These features, as well as the crystallization kinetics observed during isochronal or isothermal heating, are discussed.  相似文献   
25.
26.
Transplantation continues to push the frontiers of medicine into domains that summon forth troublesome ethical questions. Looming on the frontier today is human facial transplantation. We develop criteria that, we maintain, must be satisfied in order to ethically undertake this as-yet-untried transplant procedure. We draw on the criteria advanced by Dr. Francis Moore in the late 1980s for introducing innovative procedures in transplant surgery. In addition to these we also insist that human face transplantation must meet all the ethical requirements usually applied to health care research. We summarize the achievements of transplant surgery to date, focusing in particular on the safety and efficacy of immunosuppressive medications. We also emphasize the importance of risk/benefit assessments that take into account the physical, aesthetic, psychological, and social dimensions of facial disfiguration, reconstruction, and transplantation. Finally, we maintain that the time has come to move facial transplantation research into the clinical phase.  相似文献   
27.
现实中的环境决策,往往要在多个由"金钱-环境"复合而成的结果间做选择。人们如何对异质复合结果进行评估与选择,是决策研究面临的新课题。本研究着重考察个体金钱取向和环境取向的相对强度对复合收益风险决策的影响。结果表明,无论是采用自陈量表(实验1)或内隐联想测验(实验2)来测量价值取向,还是采用混词造句任务(实验3)来启动价值取向,均发现价值取向相对强度对复合风险决策有显著影响。(1)相比于金钱取向占优的个体,环境取向占优的个体在进行复合风险决策时更偏好环境风险较小的复合选项;(2)在复合选项等价匹配任务中,环境取向占优的个体会赋予复合选项中的环境收益以更高权重,倾向于用更多的金钱收益来弥补环境收益的风险折扣;(3)在复合收益风险概率匹配任务中,环境取向占优的个体更倾向于为获取倍增的环境收益而承担更大的复合收益风险。作为对复合结果风险决策的首次探索,本研究初步回答了不同价值取向的个体在金钱-环境复合风险决策中更倾向于规避什么风险、拿什么冒险以及为什么冒险等问题,为今后进一步开展复合决策研究打下了理论和方法基础。  相似文献   
28.
A method is presented for investigating two aspects of the sensitivity of a linear composite to the values of its weights.  相似文献   
29.
Research suggests component skill performance has a strong positive relationship with composite skill performance. This study examined the association between accuracy and fluency for the component-composite relationship within multiplication. One hundred and fifty-seven fifth-graders did one-minute assessments for single-digit, and multi-digit multiplication problems. The results demonstrated the students achieved high levels of accuracy but low levels of fluency. Strong correlations between the component-composite skill fluency suggest that fluent component skills may have a significant role in composite skill performance. Moderate/low correlations between component and composite skill accuracy indicate that more than one skill component may contribute to composite skill acquisition.  相似文献   
30.
Methods for the treatment of item non-response in attitudinal scales and in large-scale assessments under the pairwise likelihood (PL) estimation framework and under a missing at random (MAR) mechanism are proposed. Under a full information likelihood estimation framework and MAR, ignorability of the missing data mechanism does not lead to biased estimates. However, this is not the case for pseudo-likelihood approaches such as the PL. We develop and study the performance of three strategies for incorporating missing values into confirmatory factor analysis under the PL framework, the complete-pairs (CP), the available-cases (AC) and the doubly robust (DR) approaches. The CP and AC require only a model for the observed data and standard errors are easy to compute. Doubly-robust versions of the PL estimation require a predictive model for the missing responses given the observed ones and are computationally more demanding than the AC and CP. A simulation study is used to compare the proposed methods. The proposed methods are employed to analyze the UK data on numeracy and literacy collected as part of the OECD Survey of Adult Skills.  相似文献   
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