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Polyimide (PI) faces new challenges in meeting the requirements of low coefficient of thermal expansion (CTE), low dielectric content/loss, and high thermal stability to be utilized effectively as a substrate for flexible electronic materials. At present research, the CTE of PI films can be reduced to around 5 ppm/K, with Tg > 420 °C. However, it is difficult to balance low CTE and high Tg at the same time, and reducing dielectric performance is even more difficult. This study focused on synthesizing four types of PI films (using BPDA as the dianhydride) by employing biphenyl structure diamines (PDA, BZD, DPT, DMP) with an increasing number of benzene rings. The improvement in CTE, dielectric properties, and thermal stability was observed with an increase in the number of benzene rings and a decrease in the number of imine rings in the PI horizontal structure. The Tetraphenylene PI-DMP exhibited values of ε and tanθ as 3.31 and 4.73 ‰ respectively under 10 GHz. Additionally, the biphenyl PI films demonstrated commendable thermal stability (Tg = 442°C), outstanding mechanical properties (elastic modulus > 10 GPa), and a low CTE (2 ppm/K within the temperature range of 50–300 °C, and close to the 3.6 ppm/K CTE of monocrystalline silicon). The low CTE, high thermal stability, and low dielectric properties that 5G flexible substrate materials need to be qualified are simultaneously reflected in this study. MS theoretical calculations were used to analyze the results. The excellent consistency with experimental results can promote the feasibility of MS theory in PI dielectric properties at high-frequency (10 Ghz). This innovative approach is anticipated to provide foldable chip fields with intrinsic biphenyl PI materials possessing low dielectric, low CTE, and high thermal stability.

Nonlinear boolean equation systems play an important role in a wide range of applications. Grover's algorithm is one of the best-known quantum search algorithms in solving the nonlinear boolean equation system on quantum computers. In this paper, we propose three novel techniques to improve the efficiency under Grover's algorithm framework. A W-cycle circuit construction introduces a recursive idea to increase the solvable number of boolean equations given a fixed number of qubits. Then, a greedy compression technique is proposed to reduce the oracle circuit depth. Finally, a randomized Grover's algorithm randomly chooses a subset of equations to form a random oracle every iteration, which further reduces the circuit depth and the number of ancilla qubits. Numerical results on boolean quadratic equations demonstrate the efficiency of the proposed techniques.

Aiming at the problem that the geometric accuracy design index of machine tools is difficult to be determined reasonably in the geometric precision design process of CNC machine tools, this paper presents a mapping model between geometric tolerance of the workpiece and end pose error (positional and orientational error of the tool relative to the workpiece) of the machine tool considering structure distortion of cutting process system. Only considering the factors of the machine tool geometric errors, this paper first establishes the relationship between the geometric tolerance requirements of the workpiece and relative pose error at the end of machine tools, and completes the estimation of the machine tools end pose error. Then this paper analyzes the elastic deformations of the cutting process system caused by the cutting force. These elastic deformations produce machining errors. Based on the above analysis, the estimated variation range of the end pose error can be adjusted by the emulation of the geometric tolerance of the workpiece and used as the geometric accuracy design index of machine tools. This paper takes the international standard small size contour processing test piece as an example to explain the application process of the proposed model.

The rotational performance of the spindle-bearing system has critical influence upon the geometric shape and surface roughness of the machined parts. The effects of preload and preload method on the rotational performance of the spindle-bearing system is explored experimentally to reveal the role of preload and preload method in spindle rotational performances under different speeds. A test rig on which both the rigid preload and elastic preload can be realized, equipped with variable preload spindle-bearing system, is developed. Based on the mechanical model, the relationship of the axial preload and negative axial clearance of the spindle-bearing system is provided. Rotating sensitive radial error motion tests are conducted for evaluating synchronous and asynchronous radial errors of the variable preload spindle-bearing system under different rotating speeds and preload methods. The change regularity of synchronous and asynchronous radial errors with preloads under different rotating speeds are given. The results show that the preload plays an important role on the rotational performance of spindle-bearing system. The rigid preload is more efficient in achieving better rotational performance than elastic preload under the same rotating speed. Furthermore, this article significantly guides the preload designing and assembling of the new spindle-bearing system.

Background: This study investigated the effectiveness and safety of switching from Basalin® to Lantus® in Chinese patients with diabetes mellitus (DM). Methods: A retrospective chart review conducted using the electronic medical records of patients hospitalized at the Qingdao Endocrine and Diabetes Hospital from 2005 to 2016. All patients were diagnosed with DM and underwent switching of insulin from Basalin to Lantus during hospitalization. Data collected included fasting (FBG), pre- and post-prandial whole blood glucose, insulin dose, reasons for insulin switching and hypoglycemia. Four study time points were defined as: hospital admission, Basalin initiation, insulin switching (date of final dose of Basalin), and hospital discharge. Blood glucose measurements were imputed as the values recorded closest to the dates of these four time points for each patient. Results: Data from 73 patients (70 patients with type 2 diabetes, 2 with type 1, and 1 undisclosed) were analyzed. At admission, mean glycated hemoglobin (HbA1c) and FBG were 8.9% (SD=1.75) and 9.98 (3.22) mmol/L, respectively. Between Basalin initiation and insulin switch, mean FBG decreased from 9.68 mmol/L to 8.03 mmol/L (p

The spindle rotational accuracy is an important indicator to evaluate the characteristic of a machine tool. In this article, an easy-to-use measuring module is proposed based on virtual instrument platform. A new method for measuring rotational speed and angular orientation using an adaptive filtering method to processing the target installation eccentricity is proposed, instead of using the encoder. This method can reduce the measuring cost and make the measurement more convenient, without affecting the measuring accuracy. Meanwhile, the selective principle of target installation eccentricity for rotating sensitive direction is investigated by theoretical analysis and numerical simulation. Based on the proposed method, measuring module is developed. National Instruments data acquisition card and capacitive sensors are used to acquire the displacement signals of the spindle rotational error motion. Contrast experiments with the commercial measuring software are performed to validate the feasibility and repeatability of the proposed measuring module. The experimental results demonstrate that the developed measuring module can reach the same precision using less test parameters.

Dynamic stiffness and damping of the headstock, which is a critical component of precision horizontal machining center, are two main factors that influence machining accuracy and surface finish quality. Constrained Layer Damping (CLD) structure is proved to be effective in raising damping capacity for the thin plate and shell structures. In this paper, one kind of high damping material is utilized on the headstock to improve damping capacity. The dynamic characteristic of the hybrid headstock is investigated analytically and experimentally. The results demonstrate that the resonant response amplitudes of the headstock with damping material can decrease significantly compared to original cast structure. To obtain the optimal configuration of damping material, a topology optimization method based on the Evolutionary Structural Optimization (ESO) is implemented. Modal Strain Energy (MSE) method is employed to analyze the damping and to derive the sensitivity of the modal loss factor. The optimization results indicate that the added weight of damping material decreases by 50%; meanwhile the first two orders of modal loss factor decrease by less than 23.5% compared to the original structure.

The milling stability is one of the important evaluation criterions of dynamic characteristics of machine tools, and it is of great importance for machine tools’ design and manufacturing. The milling stability of machine tools generally varies with the position combinations of moving parts. The traditional milling stability analysis of machine tools is based on some specific positions in the whole workspace of machine tools, and the results are not comprehensive. Furthermore, it is very time-consuming for operation and calculation to complete analysis of multiple positions. A new method to rapidly evaluate the stability of machine tools with position dependence is developed in this article. In this method, the key position combinations of moving parts are set as the samples of calculation to calculate the dynamic characteristics of machine tools with SAMCEF finite element simulation analysis software. Then the minimum critical axial cutting depth of each sample is obtained. The relationship between the position and the value of minimum critical axial cutting depth at any position in the whole workspace can be obtained through established response surface model. The precision of the response surface model is evaluated and the model could be used to rapidly evaluate the milling stability of machine tools with position dependence. With a precision horizontal machining center with box-in-box structure as an example, the value of minimum critical axial cutting depth at any position is shown. This method of rapid evaluation of machine tools with position-dependent stability avoids complicated theoretical calculation, so it can be easily adopted by engineers and technicians in the phase of design process of machine tools.

The milling stability of thin-walled component is an important problem in the aviation manufacturing industry. The milling stability is influenced by both deflection characteristic and dynamic characteristic of workpiece. Moreover, in the material removal, the deflection and dynamic characteristics of workpiece are time-variant on the change of machining positions. Thus, the milling stability is also time-variant. In order to investigate the time variation of deflection and dynamic characteristics of workpiece, a new computational model was established in this paper. Based on the influences of the deflection and the dynamic characteristics of workpiece, a new stability lobes diagram which can show different stability domains and chatter domains in different process positions was obtained. Experimental testing has been conducted to validate the established new model.

Complicated skin and soft tissue infections (cSSTI) are some of the most commonly treated infections in hospitals, and place heavy economic burdens on patients and society. Here we report the findings from an analysis of cSSTI based on a retrospective study which was conducted within the Chinese inpatient population. We focused our research on the analysis of the patient population, antibiotic treatment, clinical outcome and economic burden. The study population comprised 527 selected patients hospitalized between 2008 and 2013. Among the hospitalizations with microbiological diagnoses, 61.41% (n = 113) were diagnosed as infected with Gram-positive bacteria, while 46.20% (n = 85) were infected with Gram-negative bacteria. The most commonly found Gram-positive bacteria was Staphylococcus aureus (40.76%, n = 75), and the most common Gram-negative bacteria was Escherichia coli (14.13%, n = 26). About 20% of the Staphylococcus aureus were methicillin-resistant. The resistance rate of isolated Staphylococcus aureus or Escherichia coli to penicillin was around 90%; in contrast, the resistance rate to vancomycin, linezolid or imipenem was low (

This study aims to propose a data-driven framework that takes unstructured free text narratives in Chinese Electronic Medical Records (EMRs) as input and converts them into structured time-event-description triples, where the description is either an elaboration or an outcome of the medical event.Our framework uses a hybrid approach. It consists of constructing cross-domain core medical lexica, an unsupervised, iterative algorithm to accrue more accurate terms into the lexica, rules to address Chinese writing conventions and temporal descriptors, and a Support Vector Machine (SVM) algorithm that innovatively utilizes Normalized Google Distance (NGD) to estimate the correlation between medical events and their descriptions.The effectiveness of the framework was demonstrated with a dataset of 24,817 de-identified Chinese EMRs. The cross-domain medical lexica were capable of recognizing terms with an F1-score of 0.896. 98.5% of recorded medical events were linked to temporal descriptors. The NGD SVM description-event matching achieved an F1-score of 0.874. The end-to-end time-event-description extraction of our framework achieved an F1-score of 0.846.In terms of named entity recognition, the proposed framework outperforms state-of-the-art supervised learning algorithms (F1-score: 0.896 vs. 0.886). In event-description association, the NGD SVM is superior to SVM using only local context and semantic features (F1-score: 0.874 vs. 0.838).The framework is data-driven, weakly supervised, and robust against the variations and noises that tend to occur in a large corpus. It addresses Chinese medical writing conventions and variations in writing styles through patterns used for discovering new terms and rules for updating the lexica.

The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•-, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil.

One laboratory-based and two non-laboratory-based models with and without blood pressure measures are developed based on data of 14815 men and 16617 women aged 25–64 years. During the followup 1134 men and 566 women developed coronary heart disease (CHD). The area under the receiver operating characteristic curve (95% CI) for prediction of CHD incidence was 0.823 (0.807–0.839) for the laboratory-based model, 0.808 (0.791–0.824) and 0.803 (0.787–0.820) for the non-laboratory-based models with and without systolic blood pressure in men (P0.10). Compared with the model without blood pressure, the non-laboratory-based model with blood pressure tended to reclassify individuals into the higher risk categories for both event and nonevent groups in both genders. The study concludes the predictive property of the non-laboratory-based models are good.