摘要：时代幽人缥缈孤鸿——简论蔡琰周昌梅⒇在建安文坛上，蔡琰以才华著称，是我国文学史上第一位博学出众的女诗人。她的作品根据《隋书·经籍志》著录有一卷，但保存下来的只有三首诗，即五言《悲愤诗》、骚体《悲愤诗》以及《胡笳十八拍》。由于史籍记载的粗略和抵牾，后人...

摘要：拉赫玛尼诺夫的钢琴作品是俄罗斯乃至世界钢琴艺术中不可多得的宝贵财富,是浪漫主义时期最后一位优秀的作曲家,同时也是当时世界上屈指可数的杰出钢琴家。他除有众多钢琴作品之外还有交响乐、歌剧以及艺术歌曲等。他的《24首钢琴前奏曲》无论在创作手法还是在演奏特点上都极具个性。通过分析《g小调前奏曲》的演奏来进一步掌握拉赫玛尼诺夫钢琴作品的演奏特点。

摘要：The low cycle fatigue behavior of zirconium−titanium−steel composite plate under symmetrical and asymmetric stress control was *** effects of mean stress and stress amplitude on cyclic deformation,ratcheting effect and damage mechanism were discussed in *** results show that under symmetric stress control,the forward ratcheting deformation is *** asymmetric stress control,the ratcheting strain increases rapidly with mean stress and stress amplitude *** high stress amplitude,the influence of mean stress is more *** addition,by studying the variation of strain energy density,it is found that the stress amplitude mainly promotes the fatigue damage,while the mean stress leads to the ratcheting *** addition,fractographic observation shows that the crack initiates in the brittle metal compound at the interface,and the steel has higher resistance to crack ***,the accuracy of life prediction model considering ratcheting effect is discussed in detail,and a high-precision life prediction model directly based on mean stress and stress amplitude is proposed.

摘要：保健食品包装色彩应鲜明、纯度较高 ,色调洁净而沉稳 ,注重商品的形象色 ;才能使求购者产生可以入口的感觉 ,令人对其保健作用有信服感。

摘要：本文将生活模块模拟为一个空间框架——虚杆桁架体系,论述了这个体系在在位、运输、起吊、上驳等各种荷载条件下的设计准则和结构分析方法,讨论了模块结构的特点和结构布置的合理性。本文涉及的内容也可适用于其他海上模块。

摘要：提出了高温构件寿命预测的三级工程评定方法 ,对不同使用阶段的高温构件进行不同层次的寿命预测 ,达到有效、经济、实用的目标。

摘要：设计并实验了一种新的数字闭环光纤陀螺调制方式,比较了目前常用的调制方式同实验中调制方式的差异。实验结果表明,采用新调制方式的光纤陀螺能很好地实现闭环工作方式,实测到陀螺的各项性能同原调制方式相仿。但对新调制方式中更好的死区抑制效果预期,在实验中并未明显观测到。

摘要：基于委托代理、公共资源、动机激励和卡尔多-希克斯效率等理性思维,分析了学位点评估与调整工作的系统特征,总结了实践经验,建立了指导思想、基本原则、评价维度和参考程序等学位点评估与调整的逻辑框架,指出了设计评价指标时应注意的问题和风险管控措施。

摘要：以锆酸丁酯为源,通过溶胶凝胶法制备了一种光敏ZrO2溶胶,在熔石英表面通过提拉法镀制具有负性光刻胶性质的光敏凝胶薄膜。在此基础上,设计色分离光栅(CSG)的结构,通过二次曝光、显影过程,制备了具有三台阶结构的CSG。对光栅形貌进行表征,周期为210μm,单台阶高度约为500nm,光栅面积为30mm×30mm。采用Nd:YAG激光器对衍射效率进行了测量,测得CSG对355nm激光衍射效率达到约88.4%,1064nm及532nm激光的衍射效率分别为5.7%和4.2%。

摘要：In order to simultaneously measure the initiation toughness of pure mode Ⅰ and mode Ⅱ cracks in one specimen,a large-size double-cracked concave-convex plate(DCCP)specimen configuration was *** tests were implemented in the drop plate impact *** gauges were employed to measure impact loads and crack initiation *** corresponding numerical model was established by using the dynamic finite difference program AUTODYN,and the experimental-numerical method and ABAQUS code were utilized to obtain the initial fracture toughness of the *** experiments and numerical research,we concluded that the DCCP specimen is suitable for measuring the initial fracture toughness of pure mode Ⅰ and mode Ⅱ cracks at the same time;the dynamic initiation toughness increases with the increase of loading rate and the crack initiation time decreases with increasing loading rate;the initiation toughness of mode Ⅱ crack is 0.5 times that of mode Ⅰ crack when subjected to the same loading *** the pre-crack in the vicinity of the bottom of a sample,when its length increases from 20 to 100 mm,the dynamic initiation toughness of the pure mode Ⅰ crack gradually decreases,and the longer the lower crack length is,the easier the crack would initiate,but the dynamic initiation toughness of pure mode Ⅱ crack varies little.