Microstructural Study of High Temperature Creep in Q460E Steel Based on the Solidification Method

A tensile creep test has been carried out to study the high temperature creep mechanism of Q460E steel and thus develop a better understanding about how the creep phenomenon affects the performance of a cast slab. Because the heating process in the solidification method is more similar to the actual solidification process of casting a slab, the high temperature tensile creep test was conducted by using the solidification method. Further observation of the microstructure was carried out after the tensile creep test has been carried out. The microstructure of the Q460E steel after the high temperature tensile creep test and water quenching observed with a metallographic microscope revealed mainly martensite and retained austenite. From the observation with a transmission electron microscope (TEM) it could be found that dislocation and its substructure were the root cause which triggered high temperature creep deformation of the Q460E steel. In addition, the formation of a subboundary also provided the impetus to creep deformation

Observation of acoustic spin

Unlike optical waves, acoustic waves in fluids are described by scalar pressure fields, and therefore are considered spinless. Here, we demonstrate experimentally the existence of spin in acoustics. In the interference of two acoustic waves propagating perpendicularly to each other, we observed the spin angular momentum in free space as a result of the rotation of local particle velocity. We successfully measured the acoustic spin, and spin induced torque acting on a lossy acoustic meta-atom that results from absorption of the spin angular momentum. The acoustic spin is also observed in the evanescent field of a guided mode traveling along a metamaterial waveguide. We found spin-momentum locking in acoustic waves whose propagation direction is determined by the sign of spin. The observed acoustic spin could open a new door in acoustics and their applications for the control of wave propagation and particle rotation.Comment: 17 pages, 3 Figure

Multicentre, prospective, randomised controlled trial to evaluate hexaminolevulinate photodynamic therapy (Cevira) as a novel treatment in patients with high-grade squamous intraepithelial lesion: APRICITY phase 3 study protocol

INTRODUCTION: High-risk human papilloma virus (HPV)-associated cervical cancer is the fourth most common cancer in women worldwide. Current treatments of high-grade squamous intraepithelial lesion (HSIL) of the cervix are based on invasive surgical interventions, compromising cervical competence and functionality. APRICITY is a multicentre, prospective, double-blind, randomised controlled phase 3 study further evaluating the efficacy and safety of Cevira, an integrated drug-delivery and light-delivery device for hexaminolevulinate photodynamic therapy, which shows promise as a novel, non-invasive outpatient therapy for women with HSIL. METHODS AND ANALYSIS: Patients with biopsy-confirmed HSIL histology are invited to participate in the study planned to be conducted at 47 sites in China and 25 sites in Ukraine, Russia and the European Union. The aim is to include at least 384 patients, which will be randomised to either Cevira or placebo group (2:1). All patients will be assessed 3 months after first treatment and a second treatment will be administered in patients who are HPV positive or have at least low-grade squamous intraepithelial lesion. Primary endpoint is the proportion of the responders 6 months after first treatment. Secondary efficacy and safety endpoints will be assessed at 6 months, and data for secondary performance endpoints of the Cevira device will be collected at 3 months and 6 months, in case second treatment was administered. All patients in the Cevira group will be enrolled in an open, long-term extension study for 6 months to collect additional efficacy and safety data (study extension endpoints). ETHICS AND DISSEMINATION: The study was approved by the ethics committee of the Peking Union Medical College Hospital and Hannover Medical University, Germany. Findings will be disseminated through peer review publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT04484415; clinicaltrials.gov

Value of loop electrosurgical excision procedure conization and imaging for the diagnosis of papillary squamous cell carcinoma of the cervix

BackgroundLoop electrosurgical excision procedure (LEEP) conization and hysterectomy are performed for some patients with papillary squamous cell carcinoma (PSCC), whereas only hysterectomy is performed for others. We aimed to determine the optimal management for PSCC.MethodsPatients diagnosed with PSCC by colposcopy-directed biopsy between June 2008 and January 2020 who underwent LEEP conization and hysterectomy or only hysterectomy at our hospital were enrolled. Results of cervical cytology, high-risk human papillomavirus testing, transvaginal sonography, pelvic magnetic resonance imaging, LEEP, hysterectomy, and pathology testing of colposcopy-directed biopsy samples were analyzed.ResultsA total of 379 women were diagnosed with PSCC by colposcopy-directed biopsy; 174 underwent LEEP before hysterectomy and 205 underwent only hysterectomy. Patients underwent and did not undergo LEEP were aged 47 ± 11 years and 52 ± 11 years, respectively. Among women who underwent LEEP, the agreement between LEEP and hysterectomy pathology was 85.1%. For women who underwent only hysterectomy, the agreement between preoperative clinical staging and pathological staging after hysterectomy was 82.4%. For patients with preoperative imaging indicative of malignancy, the accuracy of LEEP for diagnosing and staging PSCC was 88.5%, whereas for the hysterectomy-only group, it was 86.2%. For patients without malignancy detected with imaging, the accuracy of LEEP for diagnosing and staging PSCC was 81.6%; however, for those who did not undergo LEEP, it was 70.0%.ConclusionFor women diagnosed with PSCC by colposcopy-directed biopsy, LEEP conization is necessary for an accurate diagnosis when imaging does not indicate cancer; however, LEEP is not necessary when imaging indicates cancer

Knowledge management and firm innovative performance with the moderating role of transformational leadership

Purpose – This study aims to examine the effect of knowledge management on firm innovative performance and the moderating effect of ransformational leadership in the relationship between knowledge management and firm innovative performance. Design/methodology/approach – In total, 200 managers of participating Malaysian public listed service companies responded to a self-report set of the survey questionnaire. Partial least quaresstructural equation modelling technique is used to estimate the main effects of knowledge management, particularly its infrastructures and processes, on firm innovative performance and the moderating effects of transformational leadership on the relationship. Findings – Knowledge management infrastructures and knowledge management processes both have statistically significant and positive effects on firm innovative performance. In addition, transformational leadership significantly and negatively moderates the relationships. Practical implications – The findings of this study can be a reference for the Malaysian public listed service companies to understand how and why managing well knowledge management infrastructures and processes can improve firm innovative performance. Moreover, this study highlights the role of transformational leaders in the context of knowledge management. Originality/value – This study brings about managerial viewpoints of the relationship between knowledge management and firm innovative performance, with the moderating role of transformational leadership

Hyperbranched Poly(ester-enamine) from Spontaneous Amino-yne Click Reaction for Stabilization of Gold Nanoparticle Catalysts

Hyperbranched polymers have garnered much attention due to attractive properties and wide applications, such as drug‐controlled release, stimuli‐responsive nano‐objects, photosensitive materials and catalysts. Herein, two types of novel hyperbranched poly(ester‐enamine) (hb‐PEEa) were designed and synthesized via the spontaneous amino‐yne click reaction of A2 monomer (1, 3‐bis(4‐piperidyl)‐propane (A2a) or piperazine (A2b)) and B3 monomer (trimethylolpropanetripropiolate). According to Flory's hypothesis, gelation is an intrinsic problem in an ideal A2+B3 polymerization system. By controlling the polymerization conditions, such as monomer concentration, molar ratio and rate of addition, a non‐ideal A2+B3 polymerization system can be established to avoid gelation and to synthesize soluble hb‐PEEa. Due to abundant unreacted alkynyl groups in periphery, the hb‐PEEa can be further functionalized by different amino compounds or their derivates. The as‐prepared amphiphilic PEG‐hb‐PEEa copolymer can readily self‐assemble into micelles in water, which can be used as surfactant to stabilize Au nanoparticles (AuNPs) during reduction of NaBH4 in aqueous solution. As a demonstration, the as‐prepared PEG‐hb‐PEEa‐supported AuNPs demonstrate good dispersion in water, solvent stability and remarkable catalytic activity for reduction of nitrobenzene compounds

A Binary-Medium Constitutive Model for Artificially Structured Soils Based on the Disturbed State Concept and Homogenization Theory

Triaxial compression tests were carried out on artificially structured soil samples at confining pressures of 25, 37.5, 50, 100, 200, and 400 kPa. A binary-medium constitutive model for artificially structured soils is proposed based on the experimental results, the disturbed state concept (DSC), and homogenization theory. A new constitutive model for artificially structured soils was formulated by regarding the structured soils as a binary medium consisting of bonded blocks and weakened bands. The bonded blocks are idealized as bonded elements whose deformation properties are described by elastic materials, and the weakened bands are idealized as frictional elements whose deformation properties are described by the Lade-Duncan model. By introducing the structural parameters of breakage ratio and local strain coefficient, the nonuniform distribution of stress and strain within a representative volume element can be given based on the homogenization theory of heterogeneous materials. The methods for determination of the model parameters are given on the basis of experimental results. Comparisons of predictions with experimental data demonstrate that the new model provides satisfactory qualitative and quantitative modeling of many important features of artificially structured soils