Search

In view of the problem of strong fluctuation of control signal in the existing active disturbance rejection control algorithm for air speed regulation of mine local ventilator, which causes shock and vibration of frequency converter and motor, an improved active disturbance rejection control algorithm was proposed. The algorithm uses an improved method combining the arctangent function and the power function, the arctangent function enhances the linearity of control algorithm, ensures better smoothness at the origin of the function, and the power function guarantees the tracking speed of the control algorithm, and speed up the convergence of the control algorithm. The improved active disturbance rejection control algorithm is applied to the air speed regulation of mine local ventilator. The voltage signal processed by the control algorithm is used as the input signal of inverter of the local ventilator, and output frequency signal changes the speed of the asynchronous motor, so as to realize the dynamic adjustment of air speed of the local ventilator.The simulation results show that the improved active disturbance rejection control algorithm has obvious improvement in control speed and anti-interference ability compared with the existing PID control algorithm and active disturbance rejection control algorithm, which can adjust the air speed of local ventilator rapidly and stably.

Background and ObjectiveInterstitial lung disease with lung cancer (ILD-LC) is rare and its management has not been fully described. This study aimed to investigate the management and prognosis of ILD-LC patients in China.MethodsThe present analysis is a retrospective real-world cohort study. Clinical data of ILD-LC patients were obtained from 3 hospitals in China. The overall survival (OS) of patients was analyzed. Univariate and multivariate regression analyses were performed.ResultsOne hundred eighty-four ILD-LC patients included were biased toward male (85.3%), smokers (75.5%), idiopathic pulmonary fibrosis (IPF) (58.2%) patients with comorbidities (67.9%) and ECOG-PS score of 1 (65.2%). Most patients were advanced peripheral non-small cell lung cancer. The initial anti-cancer regimen for ILD-LC is mainly chemotherapy, and patients with early-stage LC prefer surgery. In the anti-cancer cohort, the number of ILD-LC patients who underwent the 2nd and 3rd or more anti-cancer regimens were 78 (55.7%) and 32 (22.8%), respectively. In the non-anticancer cohort, the median OS was 3.5 months. In the early-stage cohort, the median OS was 14.2 months in the systematic therapy group; however, the median OS was not reached in the surgery group. In the advanced-stage cohort with systematic therapy, the median OS was 7.2 months. Interstitial pneumonia (IIP) and anti-angiogenesis were associated with OS in the univariate analysis, whereas anti-angiogenesis was an independent protective factor for advanced LC with ILD.ConclusionPatients with ILD-LC have very poor prognosis. Appropriate anti-tumor treatment can prolong the survival time of patients who can tolerate it. Targeted therapy and immunotherapy are alternative treatments for LC patients with mild ILD. For ILD patients with advanced LC, antiangiogenic regimens significantly improve the prognosis of the disease.

Abstract Background: Benign and malignant brain tumors have different histopathological characteristics, including different degrees of tissue infiltration and inflammatory response. The aim of this retrospective study was to compare the incidence of postoperative nausea between the two categories of brain tumors in patients undergoing awake craniotomy. Methods: After IRB approval, we retrospectively extracted data from perioperative records between January 2005 and December 2010. Patients were divided based on the postoperative histopathological diagnosis into two groups, benign and malignant. The incidence of nausea, rescue anti-emetics, pain scores and postoperative analgesic requirements were compared between the two groups up to 12 hours postoperatively. Intraoperative anti-emetic, anesthetic, and analgesic regimens were also assessed. Limitations of this study include the retrospective design, the arbitrary dichotomization of tumors as benign or malignant, and the inability to gather accurate data regarding vomiting from the medical record. Results: Data from 415 patients were available for analysis, with 115 patients in the benign group and 300 patients in the malignant tumor group. A higher postoperative mean pain score was found in the benign brain tumor group compared to the malignant brain tumor group (P < 0.05). However, there was no difference in the incidence of nausea between the two groups. Conclusion: The different histopathological characteristics of brain tumors have no association with postoperative nausea in patients undergoing awake craniotomy. Patients with benign brain tumors experience more pain than patients with malignant brain tumors. This difference in postoperative pain may be due to the younger age of the patients in the benign group. [ABSTRACT FROM AUTHOR]

Background: The presence of midline shift on neuroradiologic studies in brain tumor patients represents mass effect from the tumor and surrounding edema. We hypothesized that baseline cerebral edema as measured by midline shift would increase postoperative nausea (PON). We studied the incidence of PON in brain tumor patients, with and without midline shift on preoperative magnetic resonance (MRI) or computed tomographic (CT) imaging, undergoing awake craniotomy. Methods: After IRB approval, we retrospectively extracted data from perioperative records between January 2005 and December 2010. Post-craniotomy nausea and pain scores were collected. Intraoperative anti-emetic, anesthetic, and analgesic regimens were assessed. Both the rescue anti-emetic and cumulative postoperative analgesic requirements were collected up to 12 hours postoperatively. The amount of midline shift on preoperative neuroimaging was gathered from radiology reports. Univariate comparisons between groups (no midline shift vs. midline shift) were made with t-tests for continuous variables, and chi-square tests for categorical variables. A multivariable analysis was performed to identify predictors of postoperative nausea. Limitations of this study include the retrospective design and the inability to gather accurate data regarding vomiting from the medical record. Results: Data from 386 patients were available for analysis. Patients were divided into two groups: no midline shift (n = 283) and midline shift (n = 103). The mean midline shift distance was 5.96 mm (95% CI [5.32, 6.59]). There was no difference in the incidence of nausea or pain scores between the two groups. More malignant brain tumor patients were in the midline shift group, as determined by the postoperative histopathological diagnosis (P < 0.05). Patients in the midline shift group also had longer anesthesia and surgical times (P < 0.05). Conclusion: In patients undergoing a standardized anesthetic for awake craniotomy for tumor resection, the presence of preoperative midline shift did not correlate with postoperative nausea. [ABSTRACT FROM AUTHOR]

Poly(4,4',4''-tris[4-(2-bithienyl)pheny]amine) (PTBTPA) was electrochemically synthesized on a ZnO-coated ITO electrode to form a PTBTPA/ZnO nanocomposite electrode. The composite film exhibited a noticeable electrochromism, with reversible color changes from orange in the reduced state (0 V), olive green in the middle state (0.9 V) to dark gray in the oxidized state (1.2 V). Furthermore, the composite film showed a fast switching time of 0.92 s and a high optical contrast of 65% at 1100 nm, and retained 97% of its original electroactivity after 500 cycles, while PTBTPA film had switching time of 1.63 s and an optical contrast of 52% at 1100 nm, and retained 75% of its original electroactivity. The results demonstrated that the electrochromic performances were significantly enhanced through incorporating PTBTPA with ZnO nanorods. ZnO nanorods were introduced to modify the structure of the electrode: on one hand, to offer a directional attraction for the counterions, and on the other hand, to enhance the adhesion between the polymer and the ITO electrode. Accordingly, a conducting polymer/inorganic nanocomposite system could improve the polymer's electrochromic performance, especially in terms of the switching speed and long-term stability of the electrochromic materials. [ABSTRACT FROM AUTHOR]

Abstract: The TbFe6 −x Ga6+ x compounds (x=0, 0.5, 1.0 and 1.45) have been prepared and studied by X-ray powder diffraction and magnetization measurements. The structure of the compound TbFe6 −x Ga6+ x transfers from the orthorhombic ScFe6Ga6-type structure (space group Immm) (x=0 and 0.5) to the tetragonal ThMn12-type structure (space group I4/mmm) (x=1.0 and 1.5) and the volume of the unit cell increases as Ga content increases. The lattice parameters are a=0.85551, b=0.8626 and c=0.50717nm for TbFe6Ga6, and a=0.86938 and c=0.50918nm for TbFe4.55Ga7.45. The magnetization measurements indicate all the TbFe6 −x Ga6+ x compounds have magnetic ordering. The Curie temperatures decrease from 492K for TbFe6Ga6 to 327K for TbFe4.55Ga7.45. The magnetization of the TbFe 6−x Ga6+ x decreases with temperature decreases below its magnetic ordering temperature due to the increasing Tb-sublattice magnetization which is antiparallel to the Fe-sublattice magnetization. [Copyright &y& Elsevier]

Four new water-soluble constituents, oblongaroside A (1), oblongar ester A (2), oblongaroside B (3), and oblongaroside C (4), were isolated along with four known compounds: 4-O-β-d-glucopyranosyl-3-hydroxybenzalcohol (5), 7-methoxyl-4-O-β-d-glucopyranosyl-3-hydroxybenzalcohol (6), 4-O-β-d-glucopyranosyl-3-hydroxybenzoic acid (7), and 3,4-dihydroxybenzoic acid (8) from the leaves of Ilex oblonga. Identification of their structures was achieved by 1D and 2D NMR experiments, including 1H-1H COSY, NOESY, HMQC, and HMBC methods and FAB mass spectral data. [ABSTRACT FROM AUTHOR]

Well-aligned and randomly grown multiwall nanotubes (MWNTs) fabricated by the radio-field-induced self-bias hot-filament chemical vapour deposition method demonstrate that the growth mechanisms are either ‘tip growth’ or ‘base growth’ depending on the size of the catalyst metal particles involved. The carbon nanotubes (CNTs) can also be successfully grown on iron-like bulk alloys when preceded by hydrogen plasma etching. The high yield of CNT fabricated on oxidized metal alloys is attributed to the high active surface area that ensues from etching. The change in field emission currents of MWNTs with temperature is not sensitive but is detectable within the range 300–20 K. This is interpreted to be due to the high aspect ratio of CNTs. [ABSTRACT FROM AUTHOR]

Introduction to Engineering Management is recognized as the first enlightening course for freshmen majoring in engineering management. Its teaching effect significantly impacts the cultivation of engineering management professionals. The engineering management professional certification management information platform refers to EPMI. By complying with the EPMI, this study investigates the teaching system of the ideological and political education of the course, teaching mode and teaching feedback mechanism. Compared with existing conventional teaching scheme, the novel teaching scheme enriches the content and form of the course, promotes the curriculum teaching system more systematic and scientific, helps students further clarify the focus of professional learning, which enables them to achieve the curriculum teaching goals more effectively.

In recent years, engineering education professional certification is an important direction for the development of engineering education in our country. Colleges and universities across the country have established various professional student training systems in accordance with the requirements of engineering certification. This article gives a brief introduction to the design and development process of civil engineering certification management information system according to the training standards of engineering certification. The aim of this study is to solve the problem of low efficiency of civil engineering professional engineering certification.

Concrete plays an important role in modern engineering construction. Concrete quality relates directly to the quality of the project life cycle and the safety of people's lives and property. Based on the theories and methods of IOT technology, this article applies IOT technology to concrete mixing plant equipment, creatively proposes an integrated system of concrete mixing plants, to control the whole process and the whole cycle of concrete production, and improve the quality of concrete. The practical application of the system has greatly improved concrete production efficiency and production quality.