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A permanent magnet synchronous motor (PMSM) is widely used in different scenarios such as electric vehicles, rail transit systems and so forth, due to its distinct advantages including high power density, high efficiency and high reliability, especially its wide speed range. However, as its rotational speed increases until it reaches the base speed, it will be constrained by the increasing back electromotive force (EMF) and the inverter’s voltage limit. To address this bottleneck, the flux-weakening control (FWC, i.e. weak magnetic control) technology is developed to weaken the air-gap magnetic field by regulation of the d-axis current. This article provides a systematic review of FWC issues, including the main challenges faced by FWC, the basic principle of FWC, the classic FWC strategies and the innovative FWC strategies. Finally, this article summarizes and compares characteristics and the applications of different FWC strategies mentioned in the references, in order to provide the reference for the further research and the development of FWC technology.

Extensive magmatism and Large Igneous Provinces (LIPs) may form at continental margins during continental breakup. While high mantle temperatures and geochemical fertility (such as plume activity) are typically considered the causes of magmatic generation, the role of lithospheric strength remains underexplored. Here, we employ two-dimensional thermomechanical models to reveal that rifting within strong cratonic lithosphere can trigger a pronounced syn-breakup magmatic surge, which may be responsible for the formation of volcanic margins and even LIPs characterized by syn-breakup magmatism. This surge results from enhanced asthenospheric upwelling driven by the collapse of elevated rift flanks, a process that occurs only when lithospheric strength is sufficiently high. Multidisciplinary evidence from the Labrador Sea-Baffin Bay rift system supports this mechanism, linking its excessive magmatism to high lithospheric strength. This framework demonstrates that such excessive magmatism does not require an anomalously hot mantle or special mantle fertility, offering a new perspective on the genesis of volcanism and LIPs along continental margins.

This study randomly selected 550 undergraduate students from Heze University for a questionnaire survey, aiming to examine whether their perception of educational equity has an impact on their academic performance. The results of this survey indicate that more than half of the students reported having experienced educational inequality in their academic careers, and the overall sense of equity among the tested students was relatively high (average score of 4.055, total score of 5). The results of this study indicate that the three dimensions of the survey questionnaire, namely the sense of educational opportunity equity, the sense of equity in the educational process, and the sense of equity in educational outcomes, were subjected to descriptive statistical analysis and regression analysis on the average scores of 19 questions and the academic performance of students. The results were all at the 0.01 level (two tailed), indicating a significant correlation. This indicates that the sense of educational equity among college students will have a certain impact on their academic performance. Similarly, compared to similar studies on junior high school students in the past, the same results have been obtained, indicating that a sense of educational equity will have a certain degree of impact on students' academic performance.

Plate tectonics distinguishes Earth from the other terrestrial planets but its initiation mechanism and onset time are debated. We propose plate tectonics was initiated by the deposition of magnetite‐rich banded iron formations (BIFs) through biogeochemical iron cycling in Neoarchean oceans. In the photic zone of proto‐continental margins, photoferrotrophic bacteria efficiently oxidized the dissolved Fe(II) and induced massive precipitation of ferric oxyhydroxide, which would rapidly react with Fe(II)‐rich hydrothermal fluids from coeval vigorous volcanism in Neoarchean oceans to produce magnetite‐rich BIFs. Mechanical models demonstrate that the localization of high‐density BIF deposition near proto‐continents induces collapse of the lithosphere and can initiate the earliest subduction. The peak deposition of BIFs in 2.75–2.40 Ga provides a time constraint on the inception of plate tectonics. Plain Language Summary Plate tectonics provides a basic framework for understanding geological processes on Earth. Although the subduction of cold and heavy oceanic lithosphere can maintain the operation of plate tectonics, its initiation mechanism remains unclear. To reveal the origin mystery of plate tectonics, it is necessary to clarify how and when the first subduction on Earth began. In this study, we propose a hypothetical model that links Earth's biological processes with the origin of plate tectonics. In the photic zone of the Neoarchean continental margins, the anaerobic metabolism of photoferrotrophic bacteria greatly promoted the massive deposition of magnetite‐rich banded iron formations (BIFs). Our mechanical calculations show that within an acceptable sedimentary thickness, these heavy BIF deposits can provide enough downward force to rupture the Neoarchean continental margins and initiate the earliest subduction. The peak deposition of BIFs in 2.75–2.4 Ga further implies the onset time of global plate tectonics. Key Points The biologically induced deposition of magnetite‐rich banded iron formations (BIFs) at proto‐continental margins can initiate plate tectonics The peak deposition of BIFs in 2.75–2.4 Ga indicates the onset time of plate tectonics Biological activities have an important influence on the tectonic behavior of Earth

The Continent-Ocean Transition (COT) in the young Tyrrhenian basin documents mantle exhumation punctuated with multiple episodes of discrete oceanic crust formation. This observation challenges prevailing models of magma-poor COTs, which typically describe mantle exhumation preceding the emplacement of oceanic crust. Notably, this COT developed without the conventional conditions associated with magma-poor rifted margins, such as slow rifting velocities and chemically depleted mantle sources. A key observation is the low shear-wave velocity observed in the uppermost mantle of the Tyrrhenian basin and its adjacent onshore regions, which correlates with subduction-related volcanism, suggesting the presence of a hydrated mantle wedge with low rheological strength. Here, we show that, based on 3D magmatic-thermomechanical numerical modeling, the episodic formation of oceanic crust within the Tyrrhenian basin’s COT results from the mechanical weakness of the mantle. The lithospheric mantle is exhumed to the surface through exhumation channels initiated within the weak mantle zone. The subsequent flow of partially molten mantle toward these channels leads to the development of multiple short-lived spreading centers. Our findings shed light on characteristics and mechanisms shaping the COT of marginal basins, where their opening is influenced by subduction processes. This study shows that the mechanical weakness of the mantle in the Tyrrhenian Basin leads to its exhumation at the continent-ocean transition, which is simultaneously punctuated with discrete oceanic crust.

Intraplate volcanism in the Changbaishan region of northeast China is underlain by a deep subduction-related earthquake cluster in the mantle transition zone, but the underlying physical connections between them remain elusive. Here we use teleseismic double-difference tomography to obtain high-resolution images of the subducting Pacific slab to provide better constraints on slab morphology and potential relationships with volcanism and deep-focus seismicity. Our results reveal a narrow slab tongue penetrating the lower mantle, flanked to the north and south by slab stagnating in the mantle transition zone. This geometry creates a gap for sub-slab hot materials to ascend, providing a deep mantle source for Changbaishan volcanism. Additionally, the slab tongue is warped, which spatially coincides with a cluster of deep earthquakes, implying that an active deformation zone causes the clustered deep earthquakes. Our findings demonstrate that Changbaishan volcanism and deep-focus earthquakes are fundamentally controlled by the subducting slab’s dynamic morphology beneath northeast China. Changbaishan volcanism and clustered deep-focus earthquakes in northeast China are driven by the dynamic morphology of the subducted Pacific slab, which is induced by its local penetration into the lower mantle, according to teleseismic tomography.

Many epidemiological studies have found a positive association of periodontal disease (PD) with risk of head and neck cancer (HNC), but the findings are varied or even contradictory. In this work, we performed a meta-analysis to ascertain the relationship between PD and HNC risk. We searched the PubMed, Embase, and Cochrane Library databases for relevant observational studies on the association between PD and HNC risk published up to March 23, 2013. Data from the included studies were extracted and analyzed independently by two authors. Meta-analysis was performed using RevMan 5.2 software. We obtained seven observational studies involving two cohort and six case-control studies. Random-effects meta-analysis indicated a significant association between PD and HNC risk (odds ratio = 2.63, 95% confidence interval = 1.1.68 - 4.14; p < 0.001), with sensitivity analysis showing that the result was robust. Subgroup analyses based on adjustment for covariates, study design, PD assessment, tumor site, and ethnicity also revealed a significant association. Based on currently evidence, PD is probably a significant and independent risk factor of HNC.

[corrected] Epidemiological studies have shown that tooth loss is associated with risk of head and neck cancer (HNC); however, the results were inconsistent. Therefore, we conducted a meta-analysis to ascertain the relationship between tooth loss and HNC. We searched for relevant observational studies that tested the association between tooth loss and risk of HNC from PubMed and were conducted up to January 30, 2013. Data from the eligible studies were independently extracted by two authors. The meta-analysis was performed using the Comprehensive Meta-Analysis 2.2 software. Sensitivity and subgroup analyses were conducted to evaluate the influence of various inclusions. Publication bias was also detected. Ten articles involving one cohort and ten case-control studies were yielded. Based on random-effects meta-analysis, an association between tooth loss and HNC risk was identified [increased risk of 29% for 1 to 6 teeth loss (OR = 1.29, 95% CI = 0.52-3.20, p = 0.59), 58% for 6 to 15 teeth loss (OR = 1.58, 95% CI = 1.08-2.32, p = 0.02), 63% for 11+ teeth loss (OR = 1.63, 95% CI = 1.23-2.14, p<0.001), 72% for 15+ teeth loss (OR = 1.72, 95% CI = 1.26-2.36, p<0.001), and 89% for 20+ teeth loss (OR = 1.89, 95% CI = 1.27-2.80, p<0.001)]. The sensitivity analysis shows that the result was robust, and publication bias was not detected. Based on the current evidence, tooth loss is probably a significant and dependent risk factor of HNC, which may have a dose-response effect. People who lost six or more teeth should pay attention to symptoms of HNC, and losing 11 teeth or 15 teeth may be the threshold.

Introduction Patients with BRAF V600E-mutated/microsatellite stable (MSS) metastatic colorectal cancer (mCRC) are associated with a poor prognosis. Backline treatment has minimal efficacy. Multi-target inhibitors of the RAS-RAF-MEK signaling pathway combined with PD-1 monoclonal antibody may be a promising strategy for BRAF V600E-mutated mCRC. Methods This prospective phase I trial enrolled patients to explore tolerability and safety of the VCC regimen in previously treated patients with BRAF V600E-mutated/MSS mCRC. Enrolled patients treated with VCC therapy every 2 weeks (cetuximab 500mg/m 2 ; camrelizumab 200 mg; vemurafenib 960 mg orally once daily). Adverse events and efficacy were monitored and recorded throughout the administration and follow-up period. Results This trial enrolled 12 eligible patients. Total 2 patients had DLT: one had grade 3 thrombocytopenia and immune myocarditis, another had grade 3 vaginal bleeding. Adverse events (AEs) of grade 3 or higher occurred in 50% of patients. Grade 3 AEs were mainly drug-related fever (25.0%), drug-related rash (16.7%). Median overall survival (OS) and PFS were 7.19 months and 3.47 months, respectively. The ORR and DCR were 33.3% and 66.7%. One patient achieved CR. three patients achieved PR. An abnormal CD4/CD8 ratio was associated with a higher risk of progression. Different efficacy of VCC regimen may be attributed to the difference in tumor immune environment. Conclusions A combination of vemurafenib, cetuximab combined with camrelizumab exhibited manageable adverse reactions and efficacy in BRAF V600E-mutated/MSS patients with metastatic colorectal cancer who progressed after standard treatment. This is a pilot study and a larger phase II trials is planned to validate the findings. (ClinicalTrials.gov ID: NCT05019534).