新媒体时代大学生人际关系疏离矫正的路径选择——基于马克思交往理论的思考

新媒体时代的来临,打破了人们交往的常规模式。大学生在进入高校后,面对复杂的人际关系,难免出现人际交往方面的困惑。能够高效处理复杂人际交往关系,是大学生自身价值得到实现、个人得到全面发展的重要标志。本研究以新媒体时代大学生人际交往为切入点,分析当前大学生人际交往的现状,探寻导致其人际交往疏离的原因,结合马克思交往理论,提出矫正大学生人际交往疏离倾向的对策,以期帮助大学生在现实社会环境中更好地展开人际交往,助力他们健康成长。

Effect of friction heat on tribological behavior of M2 steel against GCr15 steel in dry sliding systems

The tribological behavior depends significantly on friction heat under high sliding velocity. Many factors influence the conduction rate of friction heat, such as thermophysical properties of the pairs, the formation components of interface-film, environment mediums, etc. Through theoretical and experimental studies on surface temperature, the heat partition approaches have been applied to the pairs of M2 steel against GCr 15 steel to compare and discuss their tribological behavior in dry sliding contact. The results indicate that the values of the contact pressure have little effect on the heat partition at a high sliding velocity of 40 m/s. Furthermore, the degree of correlation between the dynamic temperature and friction coefficient is obvious, and the correlation degree of parameters increases as the pressure grows. A close correlation exists among the temperatures measured from different points of the pin specimen. At last, X-ray diffraction analysis denotes that the carbides of secondary M6C are separated out during the process of friction.

Exploration of risk factors for hemoglobinuria and acute kidney injury following iliofemoral venous mechanical thrombectomy

Objective: To evaluate the risk factors for hemoglobinuria and acute kidney injury(AKI) after percutaneous mechanical thrombectomy(MT) with or without catheter-directed thrombolysis(CDT) for iliofemoral deep vein thrombosis(IFDVT).Methods: Patients with IFDVT who had MT with the Angio Jet catheter(group A), MT plus CDT(group B), or CDT alone(group C) from January 2016 to March 2020 were retrospectively evaluated. Hemoglobinuria was monitored throughout the treatment course, and postoperative AKI was assessed by comparing the preoperative(baseline) and postoperative serum creatinine(sCr) levels from the electronic medical records of all patients. AKI was defined as an elevation in the sCr level exceeding 26.5 μmol/L within 72 h after the operation according to the Kidney Disease Improving Global Outcomes criteria.Results: A total of 493 consecutive patients with IFDVT were reviewed, of which 382(mean age, 56 ± 11 years;41% of them were females;97 in group A, 128 in group B, and 157 in group C) were finally analyzed. Macroscopic hemoglobinuria was evident in 44.89% of the patients of the MT groups(101/225, 39 in group A, and 62 in group B), with no significant difference between the groups(P = 0.219), but not in the patients in group C. None of the patients developed AKI(mean sCr difference-2.76 ± 13.80 μmol/L, range =-80.20 to 20.60 μmol/L) within 72h after surgery.Conclusions: Rheolytic MT is an independent risk factor for hemoglobinuria. A proper aspiration strategy, hydration, and alkalization following thrombectomy are particularly favorable for preventing AKI.

Triboelectric behaviors of materials under high speeds and large currents

Using special testers,the triboelectric behaviors of several materials were investigated in this paper under the conditions of high speeds and large currents.The obtained results revealed that the tribological behaviors and current-conducting characteristics have complicated interrelationships.Worsening in the servicing conditions can obviously deteriorate the tribological as well as electrical behaviors;high sliding speeds and large electrical currents can worsen the tribological and electrical conductivity properties,while an appropriate contact pressure can benefit the electrical contact properties.Further analyses reveal that the worsening effects of the above factors,such as frictional heat,arc discharge,arc heat,and surface morphology,result in poor triboelectric contact performance.Among these,the electric arc is one of the most serious factors,because the occurrence of an electric arc may cause severe oxidation,melting,and roughening of the contact surface,thereby causing deterioration in the current-conducting quality as well as material loss.

中国人群伤残权重测量:聚焦癌症,量化评估伤残权重对癌症疾病负担估计的影响

伤残权重对于量化评估非死亡相关健康损失至关重要.全球范围看,目前仅有少数国家或地区对伤残权重进行了评估,且极少有肿瘤特异性的伤残权重结果报道.本研究基于大样本人群估计中国人群肿瘤特异性伤残权重,并比较不同伤残权重对量化评估肿瘤疾病负担的影响.基于开放式网络调查,采用配对比较的方法进行伤残权重的测量.伤残寿命损失年(YLDs)估计为不同瘤种各时期肿瘤的患病人数与其对应时期的伤残权重乘积之和.研究共收集到44,069份有效调查问卷,估计了包含18类恶性肿瘤在内的254个健康状态的残疾权重.其中,诊断和初始治疗阶段的肿瘤特异性伤残权差异较大,脑瘤的伤残权重最高为0.619(95%不确定性区间(UI):0.606~0.632),口咽癌伤残权重最低,为0.167(95%UI:0.158~0.176).不同肿瘤伤残权重对YLDs估计影响较大,所有肿瘤合计的YLDs差异超过30%.本研究提供的肿瘤特异性伤残权重可以为精确估计肿瘤疾病负担提供重要的数据支持.

Research on cutting characteristics of fiber bundle with high-speed photography

Cutting is an essential and complicated process in many fields.Efficient and low-consumption cutting operations are of great significance for environmental protection and energy conservation.The development of high performance cutting parts relies on a deep understanding of the cutting process and cutting mechanism.In this research,a new type of cutting test bench with high-speed photography was developed,and the cutting tests were conducted on the jute fiber bundle from quasi-static cutting at 10 mm/s to dynamic cutting in the speed range of 0.6-2.4 m/s.The cutting process was captured by a high-speed camera.Analysis shows that compression exists before quasi-static cutting,and the compression force curve with respect to the compression ratio follows an exponential function.The cutting speed has a significant effect on cutting energy.The cutting energy consumption is not a monotonous function of cutting speed owing to the combined effect of elastic deformation and friction of fibers.The cutting energy increases with increasing cutting speed in the range of 0.6-1.2 m/s due to the increase of the friction within fibers and the friction between the blade and fibers.The cutting energy decreases with increasing cutting speed in the range of 1.2-1.8 m/s,and tends to be a fixed value when the cutting speed exceeds 1.8 m/s due to the stabilized elastic deformation and friction coefficient.From the perspective of energy saving,it is meaningless to increase the blade speed excessively when cutting fiber bundles.

Effect of plantar pressure on stepping friction under cross-slope condition

There are various walking pavements in daily life.Slip accidents will happen if required friction for safe walking is greater than available friction between the foot and ground surface.Existing researches mostly focus on horizontal or slope pavements,whereas the cross-slope walkways are less.A self-developed gait friction test platform was used to test friction,distribution of plantar pressure and spatiotemporal parameters of human walking under cross-slope condition.With the increase of cross-slope angles,the mediolateral friction increases(R^(2)=0.972,P<0.001),the anterior-posterior friction shows no sig-nificant change(R^(2)=0.758,P=0.017),the normal pressure decreases(R^(2)=0.915,P=0.007),and the high foot is more prone to slip and fall than low foot.Therefore,plantar pressure distribution of both feet was shifted to left.The gait cycle was prolonged(P<0.001),swing period of both feet decreased(P=0.029)and support period increased(P=0.015)with the increase of cross-slope angle.

Research progress on the characteristics of current-carrying tribology in electrical transmission

The electrical transmission between moving parts requires contact pairs such as rolling rings,sliding rings,connectors,etc.These functional contact pairs can be defined as current-carrying frictional pairs because they need to bear the transmission of current while enduring friction and wear.The rough current-carrying frictional pairs are typical contact surface withstands the load of force,heat,and electricity,resulting in the unique contact characteristics of the current-carrying pair.The research progress of current-carrying tribology has been reviewed in this paper.The correlation mechanism between tribological performance and current-carrying performance has been summarized.The composite and competitive relationship between mechanical damage and electrical damage has been discussed.Methods for evaluating the dynamic performance of current-carrying tribology has been proposed.The spatiotemporal non-uniformity of current-carrying frictional damage has been revealed.Future research trends are expected at the end.