长输管道焊接修复结构的全尺寸实验

完成了一组"扣帽子"和"补板"两种形式的管道焊接修复结构的全尺寸爆破试验,测量了修复结构中的爆破压力和应变分布,并分析了应力集中、屈服极限载荷等。结果表明,修复结构的屈服极限和完好管道相比有所降低,最低为完好管道屈服极限的85%,而各种修复结构的爆破压力基本相同,约为完好管道爆破压力的96%,爆破是由于最大剪应力的韧性过载引起的韧性破坏;单孔管道的破裂位置均远离焊接结构处,多孔管道的爆破发生在两管帽之间,说明多管帽修复结构不利于管道承压;修复结构存在一定程度的应力集中,疲劳试验的结果还表明,修复结构有较好的抗疲劳破坏能力。通过试验,验证了管道焊接修复结构的承压能力。     

But,Words Can Never Hurt Me If … : Cultural Relativity in Evaluating Appraisals,Attributions, and Consequences of Hurtful Messages

The study explored the influence of self-construals, a well-investigated and important dimension of culture, on the process of feeling and responding to hurt. Participants responded to a survey measuring self-construals, overall hurt feelings, mood, attributions, and relational consequences. The findings revealed that interdependence was positively associated with hurt feelings, but found no support for the relationship between independence and hurt. Independence was associated with positive moods subsequent to receipt of a hurtful message, whereas greater negative moods were related to higher degrees of interdependence. Independence was related to greater potential for using assertive responses. Finally, higher degrees of interdependence were related to the perception of greater strain on the relationship. The results, taken as a whole, demonstrate that the way in which people experience hurtful messages is influenced, in part, by specific cultural values. As such, the way self is construed in relation to the environment must be taken into consideration in future theorizing on hurt in interpersonal relationships.     

Evolution laws of strength parameters of soft rock at the post-peak considering stiffness degradation

To evaluate the strength attenuation law of soft rock in the western mining area of China, we established an evolution model for the strength parameters of soft mudstone at the post-peak stage by employing a tri-linear strain softening model. In the model, a stiffness degradation coefficient co and a softening modulus coefficient a were introduced to take into account the stiff- ness degradation, and the subsequent yield surfaces at post-peak stage were all assumed to meet the Molar-Coulomb yield criterion. Furthermore, attenuation laws of stiffness and strength parameters of soft mudstone were analyzed according to an engineering case. Finally, the model＇s accuracy was verified by comparison of results from numerical calculation and tri-axial compression tests. Results showed that the attenuation of the friction angle was dominated mainly by the instantaneous stress states and damage features, while the attenuation law of cohesion was also related to the plastic behavior. The degradation rates of strength param- eters decreased with increasing confining pressure and the friction angle tended towards its initial value. Residual strengths were also enhanced with increasing confming pressure. The results indicate that the evolution model can accurately describe the strain softening behavior of soft rock.     

Ti60合金镦锻过程的有限元模拟

采用刚塑性有限元法,对Ti60合金锭坯镦粗过程进行了有限元模拟,重点分析了锭坯各部分应力、应变的分布变化规律.结果表明:锻锤对锭坯端面的温降有较大的影响,应尽量避免长时间接触,以免端表面塑性严重下降,产生裂纹,间断镦锻有利于改善镦粗效果;端面、表面是高应力区,是加工缺陷的多发区,尤其是端面与表面交界处同时又是高应变区,极易出现缺陷,倒角处理有缓解作用;端面附近存在较大的变形死区,需要在后续工艺改善该区变形量,换向镦拔可以提高锭坯整体的变形均匀度,有利于成品的综合性能.本文模拟结果可以为钛合金镦粗工艺设计提供参考.     

Associations between sexual abuse and family conflict/violence, self-injurious behavior, and substance use: the mediating role of depressed mood and anger

Objective

To examine whether depressed mood and anger mediate the effects of sexual abuse and family conflict/violence on self-injurious behavior and substance use.

Methods

A cross-sectional national survey was conducted including 9,085 16-19 year old students attending all high schools in Iceland in 2004. Participants reported frequency of sexual abuse, family conflict/violence, self-injurious behavior, substance use, depressed mood, and anger.

Results

Sexual abuse and family conflict/violence had direct effects on self-injurious behavior and substance use among both genders, when controlling for age, family structure, parental education, anger, and depressed mood. More importantly, the indirect effects of sexual abuse and family conflict/violence on self-injurious behavior among both males and females were twice as strong through depressed mood as through anger, while the indirect effects of sexual abuse and family conflict/violence on substance use were only significant through anger.

Conclusions

These results indicate that in cases of sexual abuse and family conflict/violence, substance use is similar to externalizing behavior, where anger seems to be a key mediating variable, opposed to internalizing behavior such as self-injurious behavior, where depressed mood is a more critical mediator.

Practice implications

Practical implications highlight the importance of focusing on a range of emotions, including depressed mood and anger, when working with stressed adolescents in prevention and treatment programs for self-injurious behavior and substance use.     

Improved production of spiramycin by mutant Streptomyces ambofaciens

INTRODUCTION which the hydroxyl group is acetylated, and spi- ramycin III in which the same position is propio- Spiramycin belongs to the macrolide antibi- nylated (Omura et al., 1979). The addition of short-otics group. The molecular structure of spiramycin chain fatty acids stimulates the production of spi-consists of a 16-membered branched lactonic ring …     

Understanding when parental aspirations negatively affect student outcomes: The case of aspiration-expectation inconsistency

Psychological and sociological studies have often shown how parental aspirations positively influence children’s academic outcomes. However, less is known about how outcomes are affected when parents have aspirations that are higher than the child’s expectations for himself or herself. In this study, aspiration refers to the level of schooling parents ambition for their child while expectation refers to the level the child believes he or she will attain. Using US longitudinal data from a sample of tenth grade students (n = 7,635), I show two circumstances when parental aspirations negatively affect academic outcomes. Confirming previous research on status attainment and blocked opportunities, parents and children who expect less than college have, on average, worse academic outcomes. However, challenging the expectancy-value theory, students whose parents have inconsistently higher aspirations for them also experience worse outcomes. The findings suggest that unnecessarily high and unrealistic parental aspirations can disadvantage students’ performance.     

Rate-dependent constitutive model of poly（ethylene terephthalate） for dynamic analysis

Uniaxial tensile testing at strain rates ranging from 10-3 to 10-1 s-1 was carried out to study the rate-dependent me-chanical behavior for poly（ethylene terephthalate） （PET） used in the packaging industry. The experimental results show that a rate-dependent plastic behavior exists for PET material. The value of the yield strength was found to increase with the increasing strain rate. A new constitutive model based on the improved Cowper-Symonds rate-dependent constitutive model is proposed to describe the mechanical behavior of PET material in the strain rate ranging from 10-3 to 10-1 s-1, providing more accurate material data for the subsequent simulation analysis of drop test and dynamic buckling. The predictions obtained using the proposed model are compared with experimental results of the improved Cowper-Symonds model. The simulating results of the proposed model agree well with the experimental data. For a low strain rate, the predictions of this model are more precise than those obtained using the improved Cowper-Symonds model. This confirms that the new constitutive model is suitable for describing the me-chanical behavior of PET material at a low strain rate and modeling impact problem.     

虚拟仪器技术在实验教学中的应用

将虚拟仪器技术应用于教学实验是解决实验室仪器设备缺乏和陈旧老化等问题的有效途径。本文利用我院现有的美国NI公司虚拟仪器硬件和LabVIEW软件开发包,通过＂基于虚拟仪器技术的纯弯曲梁正应力分布实验＂项目的开发,在虚拟仪器技术应用于实验教学方面进行了尝试,取得了一定的成果。     

当代大学生道德与传统文化教育的角色紧张

传统文化教育是高校道德教育重要组成部分,接受传统文化的教育与熏陶是贯穿当代大学生人文修养塑造的始终。中国传统文化内容博大精深,中国传统文化的教育与示范作用在潜移默化中影响着当代人的心智。是中华民族在生息繁衍中形成的理论化和非理论化的精神成果的浓缩,是进行道德教育的良好媒介,对于建构当代大学生思想政治教育体系具有重要的指向价值。文章诠释了传统文化教育的涵义及精髓,剖析了当代大学生传统文化教育与大学生道德的角色紧张,通过传统文化教育在大学生道德教育中的价值实现探讨有效的大学生道德教育方法。