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The excitation technology for high-g-level shock environment experiments is currently a topic of interest, for which velocity amplification by collisions of vertically stacked bodies has been used to develop high-g shock tests with great success. This study investigated the superelastic collision effects generated during high-velocity one-dimensional three-body impacts. Theoretical formulae were derived in brief for an analytical investigation of the collisions. Four experiments were performed with different initial velocities obtained from free-falls from different heights. Velocity gains larger than 5 were obtained for the three-body collisions, and coefficients of restitution larger than 2.5 were observed for the second impact. The experimental results well verified the existence of superelastic collision effects in the one-dimensional three-body impacts.

The shock tester based on a three-body, single-level velocity amplifier is especially suitable for high-g shock tests of lightweight and compact pieces. This study focuses on disclosing some key technologies that affect whether the velocity amplifier could achieve a high-g level shock experimental environment. Equations describing the first collision are deduced and some key design criteria are proposed. The key conditions for formation of the opposite collision are proposed for the second collision, which is the most important point, to obtain a high-g shock environment. A test platform was constructed, and experiments were conducted with different shock rods, pulse shapers, and initial velocities. The test results fully demonstrated the powerful ability of the single-level velocity amplifier for high-g shock experiments and tell us that a duralumin alloy or carbon fiber is suitable to design shock rods.

InN/InGaN quantum dots (QDs) are found to establish a nonlinear constant phase element (CPE) response over a wide frequency range, measured by electrochemical impedance spectroscopy (EIS). The intrinsic surface donors together with the near-surface electron accumulation layer form the fractional capacitor. The magnitude of the impedance and the phase angle depend on the QD structural parameters and contact area. Importantly, they consistently change with applied voltage, constituting the nonlinear CPE response. A noise-filtering DC voltmeter with the phase angle as readout is proposed.

Background: Family doctor contract service is an important instrument to carry out the hierarchical medical system in China. As the capital of China, Beijing's family doctor contract services are leading the country. This study aims to research the status of family doctor contract services in the suburbs of Beijing, the contract awareness, the degree of trust and the emerging ethical problems between doctors and patients, so as to evaluate the influences of the contract awareness and trust degree of the contract parties on the subjects’ renewal intention. We expect to explore the feasible ways to solve the obstacle to building doctor-patient mutual trust in family doctor contract services in the suburbs of Beijing. Methods: First, the members of the research team analyzed the statistical data on the services contracted by family doctors. Then, we applied the multi-stage stratified random sampling method to chose a sample of 202 medical staff in the family doctor teams and 197 residents from 4 suburb areas in Beijing. A semi-structured individual in-depth interview method was used to conduct face-to-face interview with 36 medical staff in the family doctor teams. Results: The number of teams and personnel contracted by family doctors has increased year by year, and the resident contracting rate has slowly increased since then a decline in 2015. In 2018, the contracting rate of residents dropped. In that year, the average contracting rate for family doctor services in Beijing was 33.86%. The self-evaluation of the contracted residents on the family-doctor signing service system shows that only 68 (34.5%) contracted residents know a lot about it, while 11 (5.6%) signed residents said they did not understand the system at all. Thirty-two percent of the medical staff surveryed by the questionnaire said the attributes of the relationships between the two parties was a trust relationship, but 50.5% of the medical staff and 68.0% of the contacted residents still said that the nature of both parties just was a relationship of diagnosis and treatment. In addition, only 16.3% of the contracted residents are active in performing the contract, and 2% of the signed are very active. From the perspective of medical staff in family doctor teams, the contracting residents' trust in family doctors’ contracting services and medical staff is underestimated. Moreover, for maintaining a long-term and stable contracting service relationship, the willingness of the residents is significantly higher than that of family doctors in providing such services. Conclusions: This study evaluates the status of contract awareness, the mutual trust between doctors and patients, and the willingness to renew the contracts. It also points out that the family doctor contracting service system hinders the construction of doctor-patient mutual trust. The governments and relevant medical institutions should respect the choices of the residents to enter such contracts at their proper times and places. Meanwhile, they should reasonably define and standardize the content of family doctor contracting service programs to improve the sense of gain of both parties. Futhermore, relevant organizations should take practicable measures to address the lack of staff in the family doctor teams, reduce the nonmedical workload of medical staff, and ensure the implementation of the services contracted family doctors, and draft effective incentives to improve the initiatives of both parties.

n-InGaN/p-Cu2O core-shell nanowire (NW) p–n junctions enable efficient self-powered photoelectrochemical photodetectors (PEC PDs) in the visible. The photocurrent density under one-sun illumination is enhanced by 8 times compared to that of bare InGaN NW PEC PDs due to maximized photocarrier separation in the built-in electric field of the p–n junction. The responsivity reaches 173 μA/W under one-sun illumination. The response times of 30–40 ms are among the shortest achieved for PEC PDs. Together with the long-time stability and reusability, a robust, easy to fabricate, and easy to operate self-powered PEC PD is introduced.

Objective: To evaluate the degree to which electronic medical records (EMRs) were used in primary care and the value of EMRs as perceived by primary care workers in China. Methods: A cross-sectional survey was conducted on 2719 physicians (n = 2213) and nurses (n = 506) selected from 462 community health centres across all regions of mainland China except for Tibet. Regional differences in the responses regarding the functionality of existing EMR systems and the perceived value of EMRs were examined using Chi-square tests and ordinal regression analyses. Results: Less than 59% of the community health centres had adopted EMRs. More than 89% of the respondents believed that it was necessary to adopt EMRs in primary care. Of the existing EMR systems, 50% had access to telehealth support for laboratory, imaging or patient consultation services. Only 38.4% captured data that met all task needs and 35.4% supported referral arrangements. &ldquo, Management of chronic conditions&rdquo, was voted (66%) as the top preferred feature of EMRs. Higher levels of recognition of the value of EMRs were found in the relatively more developed eastern region compared with their counterparts in other regions. Conclusions: Rapid EMR adoption in primary care is evident in mainland China. The low level of functionality in data acquisition and referral arrangements runs counter to the requirements for &ldquo, management of chronic conditions&rdquo, the most preferred feature of EMRs in primary care. Regional disparities in the realised value of EMRs in primary care deserve policy attention.

Our previous report based on a 10 g (gravity) silicon-based inertial micro-switch showed that the contact effect between the two electrodes can be improved by squeeze-film damping. As an extended study toward its potential applications, the switch with a large proof mass suspended by four flexible serpentine springs was redesigned to achieve 5 g threshold value and enhanced threshold accuracy. The impact of the squeeze-film damping on the threshold value was theoretically studied. The theoretical results show that the threshold variation from the designed value due to fabrication errors can be reduced by optimizing the device thickness (the thickness of the proof mass and springs) and then establishing a tradeoff between the damping and elastic forces, thus improving the threshold accuracy. The design strategy was verified by FEM (finite-element-method) simulation and an experimental test. The simulation results show that the maximum threshold deviation was only 0.15 g, when the device thickness variation range was 16&ndash, 24 &mu, m, which is an adequately wide latitude for the current bulk silicon micromachining technology. The measured threshold values were 4.9&ndash, 5.8 g and the device thicknesses were 18.2&ndash, 22.5 &mu, m, agreeing well with the simulation results. The measured contact time was 50 &mu, s which is also in good agreement with our previous work.

Contact time is one of the most important properties for inertial micro-switches. However, it is usually less than 20 μs for the switch with rigid electrode, which is difficult for the external circuit to recognize. This issue is traditionally addressed by designing the switch with a keep-close function or flexible electrode. However, the switch with keep-close function requires an additional operation to re-open itself, causing inconvenience for some applications wherein repeated monitoring is needed. The switch with a flexible electrode is usually fabricated by electroplating technology, and it is difficult to realize low-g switches (

Inertial micro-switches have great potential in the applications of acceleration sensing, due to the integrated advantages of a small size, high integration level, and low or even no power consumption. This paper presents an overview of the recent advancements made in research on the sensitive direction, threshold acceleration, contact effect, and threshold accuracy of inertial micro-switches. The reviewed switches were categorized according to the performance parameters, including multi-directional switches, multi-threshold switches, persistent closed switches, flexible-electrode switches, and low-g high-threshold-accuracy switches. The current challenges and prospects are also discussed.

Aiming to implement a low-cost single-photodetector-based NIR micro-spectrometer, we present a novel flame retardant 4 (FR4)-driven micro-grating for spectral dispersion and spatial scanning. It consists of a silicon blazed grating directly bonded onto the FR4 actuator platform and an integrated differential electromagnetic angle sensor. Owing to the better shock and vibration reliability, larger aperture, shorter fabrication cycle, and much lower cost, it may be a potential alternative to conventional silicon microelectromechanical systems scanning micro-gratings. The micro-spectrometer prototype based on this device shows a spectral range of 800-1800 nm, a spectral accuracy of ±1.3 nm, and a 10 nm spectral resolution.

PurposeThe purpose of this paper is to explore concrete design methodology which can improve production technology.Design/methodology/approachAn application of advanced process control (APC) on distributed control systems (DCS) was designed by defining the project target, scope, and control strategy. Calculation is based on heat and mass conservation, such as RPID=FC 203×900×(DC 241 PV‐400)×1.06/500 DC 241 PV; CATRATE=LEVELRATE×0.22×3.14/4. The quality controller writes the control target on the density controller, which writes the initial value or output value onto the DCS.FindingsThe technique has dramatically increased the control quality of the DCS system: production capacity of the equipment has been improved and the aim of fecundity with little input is realized. The transit time of the product name is shortened and the excess stock is reduced.Originality/valueThe paper is aimed at operational researches and engineers.

C60-incorporated TiO2 nanorods were prepared in a hydrothermal process. Rhodamine B (RhB) as a model pollutant was used to probe the photocatalytic activity of products. The results showed that the...

With the rapid development of the information age, information technology has been widely applied to various industries and fields, educators have begun to explore the use and practice in the field of education. Given the traditional college English writing teaching efficiency is not high, and the bad effect caused by the heavy student curriculum teaching of English writing class scarcity issues. Use Microsoft Office Word assisted English writing technologies to replace the original form of writing paper and ink intersect, advocating students to use the Internet technology to support writing in English, using the E -mail technically good online English writing teaching follow-up courses, the technical advantages for PowerPoint English writing, English writing only changed the means of teaching and training, the environment and the teaching process, teachers and students to deepen the relative relationship between teaching and learning, and can effectively improve the level of students' interest in writing and English writing.

Squeeze-film damping and acceleration load are two major issues in the design of inertial micro-switches. In order to deeply and systematically study these two issues, this paper proposes a typical vertically-driven inertial micro-switch, wherein the air and electrode gaps were chosen to design the required damping ratio and threshold value, respectively. The switch was modeled by ANSYS Workbench, and the simulation program was optimized for computational accuracy and speed. Transient analysis was employed to investigate the relationship between the damping ratio, acceleration load, and the natural frequency, and the dynamic properties (including contact bounce, contact time, response time, and threshold acceleration) of the switch. The results can be used as a guide in the design of inertial micro-switches to meet various application requirements. For example, increasing the damping ratio can prolong the contact time of the switch activated by short acceleration duration or reduce the contact bounce of the switch activated by long acceleration duration; the threshold value is immune to variations in the damping effect and acceleration duration when the switch is quasi-statically operated; the anti-jamming capability of the switch can be improved by designing the sensing frequency of the switch to be higher than the acceleration duration but much lower than the other order frequencies of the switch.

Background Migrant workers are a unique phenomenon in the process of China's economic transformation. The household registration system classifies them as temporary residents in cities, putting them in a vulnerable state with an unfair share of urban infrastructure and social public welfare. The amount of pressure inflicted by migrant workers in Beijing, as one of the major migration destinations, is currently at a threshold. This study was designed to assess the factors associated with health-seeking behavior and to explore feasible solutions to the obstacles migrant workers in China faced with when accessing health-care. Methods A sample of 2,478 migrant workers in Beijing was chosen by the multi-stage stratified cluster sampling method. A structured questionnaire survey was conducted via face-to-face interviews between investigators and subjects. The multilevel methodology (MLM) was used to demonstrate the independent effects of the explanatory variables on health seeking behavior in migrant workers. Results The medical visitation rate of migrant workers within the past two weeks was 4.8%, which only accounted for 36.4% of those who were ill. Nearly one-third of the migrant workers chose self-medication (33.3%) or no measures (30.3%) while ill within the past two weeks. 19.7% of the sick migrants who should have been hospitalized failed to receive medical treatment within the past year. According to self-reported reasons, the high cost of health service was a significant obstacle to health-care access for 40.5% of the migrant workers who became sick. However, 94.0% of the migrant workers didn't have any insurance coverage in Beijing. The multilevel model analysis indicates that health-seeking behavior among migrants is significantly associated with their insurance coverage. Meanwhile, such factors as household monthly income per capita and working hours per day also affect the medical visitation rate of the migrant workers in Beijing. Conclusion This study assesses the influence of socio-demographic characteristics on the migrant workers' decision to seek health care services when they fall ill, and it also indicates that the current health service system discourages migrant workers from seeking appropriate care of good quality. Relevant policies of public medical insurance and assistance program should be vigorously implemented for providing affordable health care services to the migrants. Feasible measures need to be taken to reduce the health risks associated with current hygiene practices and equity should be assured in access to health care services among migrant workers.