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Abstract To delve into the adaptability of the full section SBM boring process during its inaugural application, this paper innovatively put forward an adaptability evaluation model for the SBM shaft boring within composite deep strata. This model is with the degree of adaptability T as the quantitative criterion. Initially, the evaluation index system of SBM boring adaptability is established. The determination of the adaptive standard for evaluation indexes and the calculation parameters of the model is based on a comprehensive approach that encompasses rock abrasion testing and extensive field investigations. Furthermore, based on the principle of AHP, the weight total ranking of SBM boring adaptability evaluation indexes is given under this method. Ultimately, fuzzy mathematics theory is introduced, and the fuzzy comprehensive evaluation and its verification is conducted. The results show that: the five factors that have the greatest influence on the adaptability of SBM boring in composite deep strata are, in order: I 3 > I 5 > I 4 > I 6 > I 11. Based on the adaptability evaluation model of SBM boring and by the principle of weighted average, the adaptability of the SBM boring process response is “strong adaptability”. Through the engineering case, the scientific rationality of the SBM adaptability evaluation method in the composite deep strata has been verified.

Abstract The mechanical behavior and fracture mechanisms of deep fractured rocks under explosive dynamic loads are critical for understanding rock instability in engineering applications such as blasting operations. This study aims to investigate how the presence of pre-existing cracks and different stress states affect the mechanical properties and fracture patterns of rock-like specimens under dynamic loading conditions. We utilized a Split Hopkinson Pressure Bar (SHPB) with an active confining pressure loading device to conduct impact compression tests on rock-like specimens containing pre-existing cracks. These tests were performed under uniaxial and triaxial stress states to simulate various in-situ stress conditions. The study revealed three key findings: (1)The dynamic compressive strength of specimens with pre-existing cracks exhibited a non-monotonic relationship with crack inclination angle under uniaxial stress, contrasting with an increasing trend under confining pressure, highlighting the significant effects of confining pressure and strain rate. (2)Confining pressure significantly altered the failure modes, with specimens failing predominantly in axial tension at 0° and 90° crack inclinations, and a mix of axial tension and shear at 30° and 60°, indicating complex failure mechanisms. (3)The pre-existing crack angle under confining pressure influenced the propagation path and fractal dimension of the specimen, with an increasing angle correlating to higher fractal dimensions and a positive impact on compression peak stress. The research provides valuable insights into the complex fracture behavior of fractured rocks under dynamic loads, which can inform the design of blasting parameters in deep engineering. It also offers critical knowledge for preventing rock instability-related disasters, thus holding significant theoretical and practical importance in the field of rock mechanics and engineering.

High performance concrete (HPC) has the characteristics of high strength, high brittleness and low toughness, so it can not be widely used in engineering field. The rubber particles themselves have good elasticity and excellent wear resistance. To this end, rubber particles were used to prepare high performance rubber concrete (HPRC) instead of fine aggregate, and compressive strength and splitting tensile strength tests were carried out according to standard test methods. These data were evaluated, and it was found that adding different mesh number (10 mesh, 20 mesh, 30 mesh) and different content (10%, 20%, 30%) of rubber particles reduced the compressive and tensile properties of high-performance rubber concrete to different degrees. The rubber particles with l size of 30 mesh and content of 10% have the least influence on the mechanical properties of high-performance rubber concrete, and the compressive strength and tensile strength of HPC 28 days only decrease by 18.19% and 5.56%, respectively. From the damage form, the addition of rubber particles makes the high performance concrete change from brittle to ductile. The research shows that recycling rubber from waste tires into concrete manufacturing is an environmentally friendly and feasible waste management strategy. These results have the potential to replace concrete in construction and promote sustainable growth.

The mechanical behavior of splitting tensile damage and the law of stress wave propagation of rock-like materials (RLM) are of great significance to further reveal the dynamic disaster mechanism of the deep rock mass. The meso-damage mechanical behavior and stress wave propagation characteristics of RLM disks under impact splitting were studied by using a large diameter split Hopkinson pressure bar (SHPB). In terms of dynamic damage, the splitting tensile stress-compression strain curves of RLM disks obviously showed three stages of mechanical behavior evolution: initial elastic-plastic deformation, pre-peak plastic damage, and post-peak brittle fracture failure. The macro-damage of RLM disks increased with the increase of strain rate. The meso-tensile fracture was the result of both the initial meso-damage and the impact splitting meso-damage. The dynamic splitting damage variable defined based on the damage fracture energy can accurately describe the damage evolution characteristics of impact splitting on RLM disks. In the aspect of stress wave propagation, the peak value of transmission stress showed an advanced effect with the increase of incident stress wave. In the early stage (0–50 μs), the transmission stress wave ratio (σT/σI) increased with the increase of strain rate, while in the later stage (82–200 μs), the transmission stress wave ratio (σT/σI) decreased with the increase of strain rate. The stress wave propagation law in the process of impact splitting on RLM disks was clearly revealed based on the stress wave propagation model established by the one-dimensional elastic stress wave theory. Finally, the dynamic mechanical mechanism of splitting damage and fracture of RLM disks under different strain rates was discussed deeply.

Abstract Background The prevalence of abnormal weight is on the rise, presenting serious health risks and socioeconomic problems. Nonetheless, there is a lack of studies on the medical cost savings that can be attained through the mitigation of abnormal weight. The aim of this study was to estimate the impact of abnormal weight on healthcare costs in China. Methods The study employed a 4-wave panel data from China Family Panel Studies (CFPS) between 2012 and 2018 (11,209 participants in each wave). Inpatient, non-inpatient and total healthcare costs were outcome variables. Abnormal weight is categorized based on body mass index (BMI). Initially, the two-part model was employed to investigate the impact of overweight/obesity and underweight on healthcare utilisation and costs, respectively. Subsequently, the estimated results were utilised to calculate the overweight/obesity attributable fraction (OAF) and the underweight attributable fraction (UAF). Results In 2018, healthcare costs per person for overweight and obese population were estimated to be $607.51 and $639.28, respectively, and the underweight population was $755.55. In comparison to people of normal weight, individuals who were overweight/obese (OR = 1.067, p

Community nurses play a key role in providing continuous home care for patients with chronic diseases. However, a perfect system of responsibilities and requirements has not yet been formed, and nurses cannot provide high-quality nursing services for home-based patients. We attempted to construct an index of the scope of practice for community nurses providing home-based transitional care for patients with chronic diseases and to guide nurses in playing an active role in transitional care work. From March to May 2023, 14 representative community nurses from the Shanghai Community Health Service Center were selected for group interviews and 2 rounds of Delphi consultation. A total of 14 valid questionnaires were collected. The authority coefficients were 0.94 and 0.93, and the Kendall coefficients were 0.56 and 0.59 for the 2 rounds of expert consultation ( P

In this study, through a series of static mechanical tests and split Hopkinson pressure bar (SHPB) dynamic impact tests, the static and dynamic mechanical parameters of yellow sandstone are determined, and the Holmquist–Johnson–Cook model parameters of the rock are determined by the test data and theoretical calculation. The feasibility of a numerical model is verified, based on which the SHPB impact process under different axial pressure is subjected to numerical analysis. The results show that with increasing impact load, the degree of rock breakage increases, and the dynamic compressive strength and dynamic elastic modulus increase continuously. With the application and increase of axial pressure, the dynamic compressive strength and dynamic elastic modulus of the rock decrease gradually under the same impact load, and the maximum cumulative strain keeps increasing, indicating that under the influence of axial pressure, micro-cracks in the rock have initially developed and expanded. With increasing axial pressure, the rock is more vulnerable to breakage, and its weakening degree keeps increasing. The energy utilization rate of one-dimensional dynamic and static combined loading is affected by the axial compression ratio and impact load. At low axial compression ratio, the rock has high impact resistance but high energy utilization rate; at high axial compression ratio, the rock has low impact resistance but low energy utilization rate. Therefore, the combination of axial compression ratio and impact velocity can improve the crushing effect and energy utilization rate on the premise of clear crushing form requirements.

To clarify the functional orientation of community health nurses in the continuous care of patients with chronic diseases and to encourage community nurses to play their expected roles in extended nursing work. In this study, conducted from May to July 2020, the staff of Shanghai Community Health Service Center were sampled, and representative medical staff were selected for in-depth interviews and focus group discussions. Eighteen community medical staff members participated. The functions of community nurses in the continuous care of patients with chronic diseases are mainly as follows: ① undertaking individualized projects for patients’ continuous treatment, nursing and rehabilitation; ② creating “peer education” conditions for patients; ③ providing supportive care to family caregivers; and ④ participating in the whole process of family doctor team health management. The results provide a reminder for nurse managers that under the new mission, community nurses need “one specialty and multiple abilities,” appropriate nursing technology and good health management skills. The training of community nurses should better meet the practical needs of patients with chronic diseases.

Resilience is essential for frontline health workers to cope with the unfavorable situations, especially under public health emergencies. Emergency room (ER) nurses are a special cohort of health professionals that may present moderate level of resilience. This study aimed to identify factors that are correlated with resilience in this special cohort to provide directions for intervention and management. ER nurses that have encountered a public health emergency within 3 months were recruited using purposive sampling and snowball technique for the study. Questionnaires, including Connor-Davidson Resilience Scale (CD-RISC), Zung Self-Rating Depression Scale (SDS), and Maslach Burnout Inventory-Human Services Survey (MBI-HSS) were established, followed by an in-depth interview to identify different clusters of themes. Thirteen ER nurses were recruited, and the average CD-RISC score was 66 ± 21. Resilience was negatively correlated with SDS index, and positively correlated with personal accomplishment. Five clusters of themes were identified from in-depth interviews, including physical tolerability, psychological tolerability, tenacity of internal drive, institutional implementation, and external adjustment. This study identified factors associated with resilience in ER nurses under public health emergencies, providing useful information for future directions for intervention.

An undesirable psychological state may deteriorate individual's weight management-related behaviors. This study aims to see if ineffective weight control measures were linked to depressive symptoms during pregnancy. We conducted a cross-sectional questionnaire survey of 784 pregnant women and collected information on sociodemographic factors, maternal characteristics, depression, and weight management activities throughout pregnancy (exercise management, dietary management, self-monitoring regulation, and management objectives). About 17.5% of pregnant women exhibited depressive symptoms. The mean score on dietary management was upper-middle, exercise management and self-monitoring regulation were medium, and management objectives were lower-middle. Multivariable linear regression analysis revealed that pregnant women with depressive symptoms had lower levels of exercise management (β = −1.585, p = 0.005), dietary management (adjusted β = −0.984, p = 0.002), and management objectives (adjusted β = −0.726, p = 0.009). However, there was no significant relationship between depressive symptoms and pregnant women's self-monitoring regulating behavior (p > 0.05). The findings indicated the inverse association between depressive symptoms and gestational weight management behaviors. These results offer important indications for pregnancy weight management professionals by highlighting the need for mental health interventions for pregnant women experiencing depressive symptoms.

The recycling of waste tire rubber resources and its application in the field of civil engineering materials have the importance of the economy, environmental protection, and promoting the development of civil engineering materials. In this work, rubber cement mortar short-column was used as the research object, and the cyclic loading-unloading tests with finite cycles were carried out under three different loading modes (I, II, and III). A series of basic characteristics of rubber cement mortar under three different cyclic loading-unloading modes were further discussed and analysed, such as energy, deformation, damping ratio, failure mode mechanism, and crack development mechanism. The results showed that when the rubber content was 30%, the energy damage was reduced by 13.7 ~ 45.7%, and the cumulative damping ratio was increased by 57.0%. The evolution characteristics of the hysteresis loops in the loading-unloading curves in the form of ''non-closed crescent'' were explained. The development mechanism of cracks based on the principle of minimum energy was revealed, and the evolution characteristics of cracks were confirmed. The crack resistance effect of rubber cement mortar was explained by the property of damping energy dissipation of rubber particles. The purpose is to better apply rubber-cement composites to seismic structures, underground structures, and road engineering.

Inappropriate gestational weight gain has become a public health concern that threatens maternal and child health. Pregnant women's ability to manage their weight during pregnancy directly impacts their weight gain. In this study, we integrated the protection motivation theory and the information-motivation-behavioral skills model to develop an integrative theoretical model suitable for pregnancy weight management and reveal significant explainable factors of weight management behaviors during pregnancy. Based on a cross-sectional survey of 550 pregnant women from Jiangsu province, we came up with our findings. The results showed that several factors influenced pregnancy weight management behavior. According to the research, information, self-efficacy, response costs, and behavioral skills were significantly associated with weight management behaviors during pregnancy, while behavioral skills were also significant mediators of information, self-efficacy, and behavior. Furthermore, the information related to pregnancy weight management had the biggest impact on weight management behavior during pregnancy. The results of the model fit were acceptable and the integrative model could explain 30.6% of the variance of weight management behavior during pregnancy, which implies that the integrative theoretical model can effectively explain and predict weight management behaviors during pregnancy. Our study provides practical implications for the integrative model in improving pregnancy weight management behavior and offers a theoretical base for the weight management of pregnant women.

Objective To investigate the determinants of willingness and practice of physicians’ online medical services (OMS) uptake based on social ecosystem theory, so as to formulate OMS development strategies.Design Cross-sectional survey.Setting Research was conducted in two comprehensive hospitals and two community hospitals in Jiangsu, China, and the data were gathered from 1 June to 31 June 2020.Participants With multistage sampling, 707 physicians were enrolled in this study.Outcome measure Descriptive statistics were reported for the basic characteristics. χ2 test, Mann-Whitney U test and Spearman’s correlation analysis were used to perform univariate analysis. Linear regression and logistic regression were employed to examine the determinants of physicians’ OMS uptake willingness and actual uptake, respectively.Results The mean score of the physicians’ OMS uptake willingness was 17.33 (range 5–25), with an SD of 4.39, and 53.3% of them reported having conducted OMS. In the micro system, factors positively associated with willingness included holding administrative positions (b=1.03, p

In order to obtain the relationship between fractal dimension and energy dissipation of rock-like materials under initial stress state, a variable cross-section split Hopkinson pressure bar (SHPB) test system with active confining pressure loading device was used to carry out impact compression and splitting tests on cemented sand specimens. The impact test results show that (1) the prediction value on the fragmentation degree of cemented sand specimens by using the fractal model is basically consistent with the screening results of actual test, which verifies the applicability of the fractal calculation model given in this study; (2) the more the fracture energy dissipated in the crushing process of cemented sand specimens, the more serious the fragmentation degree is, and accordingly the larger the fractal dimension is, that is, the fracture energy is positively correlated with the fractal dimension; (3) there is an exponential relationship between the fractal dimension and energy dissipation of cemented sand specimens under initial stress, which is so different from that under no initial stress. The experimental results in this study can be used to modify the fractal damage model for rock blasting considering the initial stress.

At present, a similar material most commonly used in the similarity model experiment of rock blasting is cement mortar. However, it is not transparent, which leads to the problem that the cracks in the model made of cement mortar after the test cannot be observed directly. Therefore, a kind of transparent hard rock-like material that can replace the existing model material to solve the above problem was developed in this study. This transparent hard rock-like material is made of a mixture of rosin saturated solution (RSS), epoxy resin (ER), and curing agent (CA), and its physical and mechanical properties are similar to those of hard rock through relevant tests. In addition, it is found through the blasting model test that the model specimen made of transparent hard rock-like materials has the characteristic of “direct observation” after blasting test, which conforms to the rock blasting fracture mechanism. Hence, it can replace the existing nontransparent model materials to be applied in rock blasting similar model experiment. The results from this study are helpful to the further experimental study of blasting crack propagation in deep rock mass.

In order to study the fragmentation energy dissipation characteristics of cemented sand specimens under confining pressure and impact loads, the energy consumption of cemented sand specimens was analyzed through an impact compression and split test performed at different loading rates with different impact pressures by using a variable cross section SHPB (split Hopkinson pressure bar) with an active confining pressure loading apparatus. The results show that (1) the absorbed energy and incident energy were in a linear relationship and the proportion between them was relatively constant under confining pressure, and the absorbed energy had a quadratic relationship with the incident energy under zero confining pressure. (2) The fracture energy ratio increased with the increase in incident energy, the damage energy ratio decreased with the increase in incident energy, and the damage energy ratio were always higher than the fracture energy ratio under confining pressure. (3) The energy absorbed by the cemented sand specimens decreased sharply with the increase of confining pressure under the same incident wave energy conditions, and the reflected wave energy and transmitted wave energy increased. (4) When the incident wave energy was constant, the ratio of the energy causing surface fractures to the energy absorbed by the cemented sand specimens decreased sharply with the increase of confining pressure, while the energy causing crack growth and damage increased sharply. These conclusions may guide similar models of blasting tests in the future.

The length of record (LOR) method is an evaluation method that provides quantitative advice for the amount of computational data required for use of the indicators of hydrological alteration (IHA). The use of multi-index hydrological indicators to reflect river hydrological-ecological characteristics is the essence of the IHA method, while the LOR evaluation result using a single index does not have practical application value in the absence of IHA data volume. In this paper, we expand the LOR method from single index version into multi-index version, apply it to comprehensively analyze the credibility of hydrological alteration (HA) multi-indicators under different data volumes, and explore the relationship between multi-index LOR results and data requirements. Combined with the hydrological-ecological relationship, the practical application criteria of LOR dimension reduction under the condition of multiple HA indicators is given. The results show that the LOR results corresponding to each group of indicators in IHA have different data requirements, so an in-depth understanding of the hydrological-ecological relationship is the key to LOR's application of IHA data dimension reduction. In addition, we discuss the limitations of the LOR method of multi-index dimension reduction and its application value in IHA calculations. [ABSTRACT FROM AUTHOR]

Involvement in extracurricular activities provides youth with opportunities to develop important personal skills, abilities, and preferences, and to build meaningful social support networks. Historically, students who are deaf or hard of hearing (SDHH) have had limited access to opportunities for both academic and occupational development, including extracurricular participation, although legal changes such as the Americans with Disabilities Act (1990) and the Individuals with Disabilities Education Improvement Act (2004) have shifted this landscape. Drawing from data available in the National Longitudinal Transition Survey 2 (NLTS2) and controlling for demographic covariates, we examine the predictive role overall extracurricular involvement and the breadth of that involvement play in postsecondary outcomes, including education, employment, independent living, and self-beliefs, for approximately 1,000 SDHH ages 14 to 18. We also describe the extracurricular activities in which SDHH are most often involved. Our findings suggest that overall involvement in extracurricular activities significantly predicted independent living, and that involvement in more than one activity significantly predicted postsecondary enrollment. We also discuss the limitations of the study design and implications for future research. It is clear that participation in extracurricular activities in high school benefits SDHH later in life. [ABSTRACT FROM AUTHOR]

A compact multiband bow-tie dipole slot antenna fed by coplanar waveguide (CPW) is proposed in this paper. Multiple resonant mode technique and notch-band technique have been combined in this design to form triple-band operation just by adding single elements. Based on this, a pair of hairpin-shaped branches is implemented on each arm of the bow-tie slot antenna. A notch-band property is achieved compared with the original wideband bow-tie antenna (without branches). Meanwhile, a new lower resonant frequency is obtained by using this kind of structure, which means that the size is compact in nature, and the triple-band operation is achieved. The notch-band and lower resonant frequency can be tuned by changing the length of the branch. The parameters of the antenna, including reflection coefficients, current distributions, radiation patterns and gain, are achieved by numerical simulations and measurements. The results indicate that the slot size of the proposed antenna is 52 4mm x 22 3mm, and the proposed antenna can offer triple-band operation at 2.39-2.50 GHz (4.5%), 3.38-3.79 GHz (11.4%) and 4.87-6.23 GHz (24.5%), which is suitable for WLAN in the 2.4/5.2/5.8-GHz band and WiMAX in the 3.5/5.5-GHz bands. [ABSTRACT FROM AUTHOR]

Through a series of static mechanical tests and (SHPB) dynamic impact tests, the static and dynamic mechanical parameters of rock as represented by yellow sandstone are determined, and the Holmquist-Johnson-Cook model parameters of the rock are calibrated using the test data and theoretical calculations. The feasibility of a numerical model is verified, and numerical analysis of the SHPB impact process under different radial pressure pre-loading is carried out on the basis of good verification. The results show that with increasing impact load, the degree of rock breakage increases, as does the dynamic tensile strength. With the application of increasing pre-static pressure, the dynamic tensile strength of the rock decreases gradually, and the maximum radial cumulative strain increases continuously under a given impact pressure, indicating that micro-cracks in the rock develop initially and then expand under the influence of pre-static pressure; the rock is more easily broken, and its weakening degree increases. Under coupled dynamic and static loading, the energy utilization rate of rock in the Brazilian splitting process is jointly affected by axial compression ratio and impact load. Too large a pressure ratio will reduce the strain-rate sensitivity of rock, resulting in low energy utilization rate, while too low an axial compression ratio will make the dynamic tensile strength of rock relatively high, which is not conducive to tensile failure. Therefore, on the premise of clear fracture form requirements, a suitable combination of axial compression ratio and impact velocity can improve the rock crushing effect and energy utilization rate. [ABSTRACT FROM AUTHOR]