We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We prove a large deviation principle for the slow-fast rough differential equations (RDEs) under the controlled rough path (RP) framework. The driver RPs are lifted from the mixed fractional Brownian motion (FBM) with Hurst parameter $H\in (1/3,1/2)$. Our approach is based on the continuity of the solution mapping and the variational framework for mixed FBM. By utilizing the variational representation, our problem is transformed into a qualitative property of the controlled system. In particular, the fast RDE coincides with Itô stochastic differential equation (SDE) almost surely, which possesses a unique invariant probability measure with frozen slow component. We then demonstrate the weak convergence of the controlled slow component by averaging with respect to the invariant measure of the fast equation and exploiting the continuity of the solution mapping.
Currently, there is an increasing demand for parallel mechanisms with fewer inputs and more outputs in aerospace, antennas, and recreational facilities. Therefore, this paper proposes a new parallel mechanism (PM) with a separation of constraints and drives, facilitating centralized drive management. Based on screw theory, the type synthesis of new parallel mechanisms with 3T (T representing translation), 3R (R representing revolute), 2T1R, and 2R1T is proposed. Three-degree-of-freedom (3-DOF) parallel mechanisms with fewer inputs and multiple outputs are proposed. Taking the 3RPS-PPPS parallel mechanism as an example, the closed-loop vector method is employed to solve for the lengths of actuated branches. A complete Jacobi matrix is constructed. The motion/force transmission performance of the 3RRS/PPPS parallel mechanism is better than the 3RRS parallel mechanism. Centralized management of drive branches greatly reduces the number of drives, making maintenance and repair easier. It has many application scenarios in antennas, recreational facilities, and other occasions.
The incidence of depression among college students is increasing year by year, which has a serious impact on social development. As a non-drug intervention, music therapy can affect individual psychological state through emotional catharsis, emotion regulation and other ways, which has attracted more and more attention in recent years, and is expected to provide an effective auxiliary means for the management of depression in college students.
Subjects and Methods
A total of 200 college students were randomly divided into the control group and the experimental group. The students in the control group maintained their usual learning lifestyle. The experimental group received 30 minutes of music therapy four times a week for a total of 8 weeks. Beck Depression Checklist was used to evaluate the degree of depression symptoms, and SPSS statistical software was used to analyze the data.
Results
The results showed that the mean score of depressive symptoms in the experimental group decreased from 28.4±5.2 before the intervention to 15.2±3.8 after the intervention, while the score of the control group decreased by less than 1 (P< 0.001). The BDI score of the music therapy group was significantly lower than that of the control group (P< 0.05), and the difference was statistically significant.
Conclusions
The results show that music therapy has a significant therapeutic effect on depression intervention of college students, which can effectively reduce the symptoms of depression and improve the emotional state of college students.
The incidence of adolescent depressive disorder is globally skyrocketing in recent decades, albeit the causes and the decision deficits depression incurs has yet to be well-examined. With an instrumental learning task, the aim of the current study is to investigate the extent to which learning behavior deviates from that observed in healthy adolescent controls and track the underlying mechanistic channel for such a deviation.
Methods
We recruited a group of adolescents with major depression and age-matched healthy control subjects to carry out the learning task with either gain or loss outcome and applied a reinforcement learning model that dissociates valence (positive v. negative) of reward prediction error and selection (chosen v. unchosen).
Results
The results demonstrated that adolescent depressive patients performed significantly less well than the control group. Learning rates suggested that the optimistic bias that overall characterizes healthy adolescent subjects was absent for the depressive adolescent patients. Moreover, depressed adolescents exhibited an increased pessimistic bias for the counterfactual outcome. Lastly, individual difference analysis suggested that these observed biases, which significantly deviated from that observed in normal controls, were linked with the severity of depressive symoptoms as measured by HAMD scores.
Conclusions
By leveraging an incentivized instrumental learning task with computational modeling within a reinforcement learning framework, the current study reveals a mechanistic decision-making deficit in adolescent depressive disorder. These findings, which have implications for the identification of behavioral markers in depression, could support the clinical evaluation, including both diagnosis and prognosis of this disorder.
Sepsis is a clinical syndrome characterised by a severe disorder of pathophysiology caused by infection of pathogenic micro-organisms. The addition of antioxidant micronutrient therapies such as thiamine to sepsis treatment remains controversial. This study explored the effect of thiamine on the prognosis of patients with sepsis. This study was a retrospective study involving patients with sepsis from the Medical Information Mart for Intensive Care IV. Patients were divided into two groups, the thiamine received group (TR) and the thiamine unreceived group (TUR), according to whether they were supplemented with thiamin via intravenous while in the intensive care unit (ICU). The primary outcome was ICU mortality. The association between thiamine and outcome was analysed using the Cox proportional hazards regression model, propensity score matching (PSM), generalised boosted model-based inverse probability of treatment weighting (IPTW) and doubly robust estimation. A total of 11 553 sepsis patients were enrolled in this study. After controlling for potential confounders using Cox regression models, the TR group had a statistically significantly lower ICU mortality risk than the TUR group. The hazard ratio of ICU mortality for the TR group was 0·80 (95 % CI 0·70, 0·93). We obtained the same results after using PSM, IPTW and doubly robust estimation. Supplementation with thiamine has a beneficial effect on the prognosis of patients with sepsis. More randomised controlled trials are needed to confirm the effectiveness of thiamine supplementation in the treatment of sepsis.
Numerous technologies have contributed to the recent development of agriculture, especially the advancement in hyperspectral remote sensing (HRS) constituted a revolution in crop monitoring. The widespread use of HRS to obtain crop parameters suggests the need for a review of research advances in this area. HRS offers new theories and methods for studying crop parameters, but much work needs to be done both experimentally and theoretically before we can truly understand the physical and chemical processes that predict these crop parameters. The study focuses on the following elements: 1) The article provides a relatively comprehensive introduction to HRS and how it can be applied to crop monitoring; 2) Current state-of-the-art techniques are summarized and analyzed to inform further advances in crop monitoring; 3) Opportunities and challenges for crop monitoring applications using HRS are discussed, and future research is summarized. Finally, through a comprehensive discussion and analysis, the article proposes new directions for using HRS to study crop characteristics, such as new data mining techniques including deep learning provide opportunities for efficient processing of large amounts of HRS data; combining the temporal and dynamic characteristics of crop parameters and vegetation growth processes will greatly improve the accuracy of crop parameter detection and monitoring; multidata fusion and multiscale data assimilation will become HRS monitoring. Multidata fusion and multiscale data assimilation will become another research hotspot for HRS monitoring of crop parameters.
Anaemia is a global public health problem affecting women worldwide, and reproductive-age women are at increased risk. We conducted a population-based cross-sectional study analysing the prevalence of overall anaemia and anaemia according to severity in Chinese pre-pregnant women to update current knowledge on anaemia epidemiology. Based on the National Free Preconception Check-up Projects supported by the Chinese government, 5 679 782 women participating in this project in 2017 were included in the present study. The cyanmethemoglobin method was applied to assess Hb concentrations. Univariate and multivariate logistic regressions were applied for associated factors. The prevalence of anaemia among Chinese pre-pregnant women was 21·64 % (mild: 14·10 %, moderate: 7·17 % and severe : 0·37 %). The prevalence of overall and severe anaemia was the highest in Tibet and the lowest in Beijing among thirty-one provinces. Women’s age, region, ethnic origin, educational level, occupation and pregnancy history were all correlated with anaemia. Women with B blood type (adjusted OR (aOR) = 0·89), higher BMI (overweight: aOR = 0·84; obesity: aOR = 0·70) and alcohol consumption (aOR = 0·69) were less likely to have anaemia, while those with rhesus negative blood type (aOR = 1·10), history of anaemia (aOR = 2·60), older age at menarche (aOR = 1·19), heavy menstrual blood loss (aOR = 1·39), longer menstrual period (aOR = 1·09) and shorter menstrual cycle (aOR = 1·08) were more likely to suffer from anaemia. Meat or egg eaters were not significantly associated with severe anaemia. Anaemia is of moderate public health significance among Chinese pre-pregnant women. Interventions should be considered to prevent anaemia to the greatest extent possible to avoid potential harm in this population.
The molten-salt method was used to synthesize CaBi2Ta2O9 (CBTa) powder, and the influence of temperature on the structure and micromorphology of products was investigated using X-ray diffraction and the scanning and transmission electron microscope. The results showed that highly crystalline CBTa nanoplates exhibit single orthorhombic symmetry and could be obtained in the temperature range of 850–900 °C. Among which, the nanoplates prepared at 900 °C have optimal properties (average grain size of 1.7 μm and uniform size distribution). Above 900 °C, various CaO–Ta2O5 binary compounds, Bi2O3, and BiTaO4 formed due to the decomposition of CBTa and subsequent reactions of decomposition products, transforming plate-like grains to cuboid nano-particles with a small amount of prismatic grains. Possible reaction mechanisms at different synthesizing temperature were proposed. This work provides a method for the preparation of template grains to synthesize textured CaBi2Ta2O9 high-temperature piezoelectric ceramics by the template grain growth method.
Iridium (Ir) has an extremely high melting point (2443 °C), high chemical stability and is one of the most promising high-temperature materials. However, Ir is more difficult to process compared with other face-centered cubic metals, such as Ni and Al, which limits its applications. To solve this problem, we study the effect of 32 alloying elements (X) on stacking fault energy of dilute Ir-based alloys generated by shear deformation using the first-principles calculations. The investigation reveals that there are many alloying elements studied herein decrease the stacking fault energy of face-centered cubic (fcc) Ir, and the most effective element in reducing stacking fault energy of fcc Ir is Zn. The microscopic mechanism is caused by electron redistribution in the local stacking fault area. These results are expected to provide valuable guidance for the further design and application of Ir-based alloys.
Clay often has severe detrimental impacts on cement-based materials. Therefore, it is necessary to investigate the mechanism causing the deterioration to improve the service life of cement-based materials. Based on accurate dimensional analysis, a mechanism that influences clay is proposed: the intercalation of the side chains of superplasticizer molecules in the interlayer space of the clay. To lessen this harmful effect, a new clay-resistant admixture (CRA) possessing cationic groups of small molecular size was synthesized through a novel dimensional design. The length and width of the side chains of this superplasticizer molecule were 9.50–17.50 and 0.25–0.40 nm, respectively, with a radius of ~3.74 nm in solvent, which is larger than the interlayer spacing of montmorillonite (i.e. 1.09–2.14 nm). The longitudinal and latitudinal lengths of the CRA molecule were 0.468 and 9.456 nm, respectively, ensuring intercalation in the interlayer of montmorillonite. The increase in interlayer spacing of the clay was 0.364 nm following addition of polycarboxylate superplasticizer (PCE) plus CRA and 0.632 nm following addition of PCE, which suggests that the CRA plays the role of a ‘sacrificial agent’ that is preferentially intercalated into the interlayer space of clay to further prevent the side chains of the superplasticizer molecules from entering the interlayer. The aim of this study was to propose a suitable means of synthesizing a new CRA to address the impact of clay through dimensional design and mechanism analysis, which contributes to the theoretical study and technological improvement of cement-based materials.
Biological hydrogel is important in drug delivery system and tissue engineering. In this paper, we prepared a series of biological hydrogels with N,O-carboxymethyl chitosan (CS) and oxidized safflower and ligusticum wallichii polysaccharide-II (oxidized SLWP-II). Morphological analysis indicated the N,O-carboxymethyl CS/oxidized SLWP-II hydrogels (CSLHs) had porous interior structures, pore diameter ranged from tens to hundreds of micrometers. In vitro release test showed, with proportion of N,O-carboxymethyl CS to oxidized SLWP increasing from 1:1 to 1:3, cumulative release of bovine serum albumin decreased from 99 to 82%. In vitro cytotoxicity study showed that the developed hydrogels were not cytotoxic during one week of culturing with WI-38 cells, and they have a role in promoting cell proliferation. So the N,O-carboxymethyl CS/oxidized safflower and ligusticum wallichii polysaccharide-II hydrogels might have potential application in the drug delivery system and tissue engineering.
Both diabetes and depression have become serious public health problems and are major contributors to the global burden of disease. People with diabetes have been shown to have higher risk of depression. The purpose of this study was to observe the differences in depression between older Chinese adults with known or unknown diabetes.
Methods:
Data came from the national baseline survey of China Health and Retirement Longitudinal Study (CHARLS). The Center for Epidemiologic Studies Depression Scale was used to assess depression. Participants with a history of diabetes diagnosis were considered to have known diabetes, and those with newly-diagnosed diabetes were considered to have unknown diabetes. Multiple logistic regression analysis was applied to estimate odds ratio (OR) for depression in predictor variables.
Results:
Overall, 39.1% of the 2,399 participants with diabetes suffered from depression. The prevalence of depression was significantly higher (p < 0.001) in people with known diabetes (43.5%) than those with unknown diabetes (35.1%). The biggest differences between the two groups were found in the middle aged, in women, in the less educated and in married people. In known diabetes, people treated with traditional Chinese medicine (TCM) coupled with oral western medicine (WM) and/or insulin had two-fold odds of depression compared to those without treatment.
Conclusion:
The knowledge of having diabetes, treatments and suffering from other chronic diseases were associated with the higher prevalence of depression in people with known diabetes compared to those with unknown diabetes. Prevention of depression in diabetics should receive more attention in the middle aged, women and the less education.
To evaluate dietary intake based on the Chinese Food Pagoda (CFP) and to determine what factors may be associated with adherence to CFP guidelines for older Chinese.
Design
This cross-sectional population-based study used 24 h recall over three consecutive days to assess dietary intake and adherence to CFP among older Chinese participating in the China Health and Nutrition Survey 2009.
Setting
Nine provinces across four diverse regions (Northeast, East Coast, Central and West).
Subjects
A total of 2745 older Chinese, aged 60–69 years (n 1563) and ≥70 years (n 1182), with dietary data.
Results
None of the participants reached all ten food group recommendations. More than half of the participants exceeded the recommended amount for grains (63 %), oil (62·8 %) and salt (55·7 %). Ten per cent of the participants consumed dairy, while merely 0·5 % met the recommended amount. Average Chinese Food Pagoda Score (CFPS) was 3·3 in men and 3·5 in women, far below the maximum possible score of 10. Women had 0·26 higher CFPS than men (P<0·001; 95 % CI 0·16, 0·36). People living in medium and high urbanicity areas had significantly higher scores than those living in low urbanicity areas (P<0·001). Also, there were significant differences in CFPS according to gender, BMI, work status, education level and region.
Conclusions
Few older Chinese are meeting the intake of the various food groups based on the recommendations in the CFP guidelines, thus increasing the risk of malnutrition and non-communicable diseases. Action is needed to increase dissemination and uptake of nutrition education, with interventions targeted at socio-economic regions. Moreover, specific dietary guidelines for older Chinese people should be developed.
Graphene oxide (GO) is one of the most attractive inorganic nanofillers in proton exchange membranes (PEMs) for its large specific surface area and high proton conductivity. The proton conductivity of GO nanosheet is known to be orders of magnitude greater than the bulk GO, thus it is essential to improve the dispersion of GO nanosheets in the PEM matrix to achieve higher conductivity. In this study, we report a facile and effective method to fabricate a GO/sulfonated poly ether ether ketone (SPEEK) composite membrane with well-dispersed GO nanosheets in SPEEK matrix by using electrospinning technique for direct methanol fuel cell application. The composite membrane exhibits improved proton conductivity, dimensional stability and methanol barrier property due to the presence of well-dispersed GOs. It is believed that the GO nanosheets can not only induce continuous channels for proton-conducting via Grotthuss mechanism, but also act as methanol barriers to hinder the methanol molecules from passing through the membrane.
Little is known about the macronutrient intake status of older Chinese people. The present study evaluated the macronutrient intake status of older Chinese people (aged ≥ 60 years), investigated whether they had intake levels that met the Dietary Reference Intakes (DRI), and explored the associations between macronutrient intakes and age groups, sex, education levels, work status, BMI groups, urbanicity levels and four socio-economic regions of China (Northeast, East Coast, Central and Western). Dietary intake data of 2746 older Chinese with complete dietary intake data in the Longitudinal China Health and Nutrition Survey (2009 wave) carried out across four diverse regions were analysed. Dietary intake data were obtained by interviews using 24 h recalls over three consecutive days. The MUFA:SFA ratios were calculated based on the Chinese Food Composition Table. Less than one-third of the older Chinese people included in the present study had intake levels meeting the adequate intake for carbohydrate-energy and fat-energy; less than one-fifth had intake levels meeting the recommended nutrient intake for protein-energy; and more than half of the older people had fat-energy intakes higher than the DRI. There were strong associations between the proportions of energy from the three macronutrients and education levels, urbanicity levels and the four socio-economic regions of China, with older people living in the East Coast region having different patterns of macronutrient-energy intakes when compared with those living in the other three regions. Macronutrient intakes across different urbanicity levels in the four regions revealed considerable geographical variations in dietary patterns, which will affect the risk factors for non-communicable diseases. Clinical interventions and public health policies should recognise these regional differences in dietary patterns.
This study addresses the Chinese Second World War victims' reparations movement (CWRM) against Japan as a case of contemporary Chinese memory politics. While many studies indicate the Chinese government's use of the war memories for political purposes, ours focuses on how official discourses are translated into citizens' political participation and how the state–society interactions lead to variation in the development of the movement sectors within the case of CWRM. Drawing on textual and ethnographic data and a theoretical “dynamic statism,” we argue that the central government's ambivalent attitude towards this ideologically useful yet institutionally troublesome movement created room for local governments and the movement to pursue their own causes. Yet the local and central governments' strong interventions, either facilitation or repression, discouraged civil society's participation and led to the underdevelopment of some movement sectors. In the sectors where the local governments held an attitude of absenteeism or co-operation, the movement was able to mobilize resources from civil society and state institutions and finally developed well.
The effect of a Cu layer on the electronic structure and magnetic properties of Ni3Fe was studied by employing the discrete-variational method in the framework of density-functional theory. Three models were established for Ni3Fe(6), Ni3Fe(3)/Cu(3)/Ni3Fe(3), and Ni3Fe(3)/Cu(3). The charge transfer, magnetic moment, and spin exchange split at the Fermi level were obtained for Fe and Ni atoms in a Ni3Fe layer. The related characterizations of Ni3Fe were estimated from those of Fe and Ni atoms. It was discovered that the magnetic properties of the Ni3Fe layer improved when adjacent to Cu layer due to the improvement of the corresponding properties of the Fe atoms in the Ni3Fe. However, the magnetic moment and the spin exchange split of the Ni atoms in the Ni3Fe decreased when the Ni3Fe was adjacent to a Cu layer.
Comprehensive results are presented on the influence of interfaces on electronic structure and giant magnetoresistance (GMR). Two structures were calculated for Co5/Cu3/Co5 and Co3/Cu/Co/Cu3/Co/Cu/Co3, where numbers stand for monolayer numbers of atoms, by employing the discrete variational method in the framework of the local spin density approximation. It has been found that the electron spin-dependent scattering is very strong at the interfaces compared to the interiors of the ferromagnetic layers, independent of the moment alignment configuration. The calculation results of total energy for various magnetization configuration revealed that antiferromagnetic exchange coupling was present between any of the ferromagnetic layers separated by Cu layers at zero field in the Co3/Cu/Co/Cu3/Co/Cu/Co3. The evaluated GMR ratio for the Co3/Cu/Co/Cu3/Co/Cu/Co3 (about 35.1%) was much larger than that of the Co5/Cu3/Co5 (about 21.0%), indicating large GMR effect could be expected with more interfaces when the thicknesses were the same. The result also indicated that the negative polarization of 4s electrons could reduce the GMR effect.
The effect of A-site vacancy order-disorder states on diffuse phase transition (DPT) of tungsten bronze Pb1−xBaxNb2O6 (PBN) ferroelectrics has been investigated. The A-site vacancy disordered PBN ceramics exhibit notable variations of the Curie temperatures (i.e., the temperatures at the dielectric maximum permittivities) up to 12 °C in response to frequency changed from 0.1 KHz to 100 KHz. The largest frequency dispersion occurred at the morphotropic phase boundary of 1 − X = 0.63, along with the lowest Curie point. In contrast, the A-site vacancy ordered PBN ceramics present little frequency dispersion in the range of 2 °C from 0.1 KHz to 100 KHz. Dielectric constants of the disordered PBN ceramics were generally higher than those of the ordered ones. In comparison with the ordered PBN ceramics, the Curie points of the disordered ceramics were shifted from lower to higher temperature as the Pb2+ cation percentage was decreased; i.e., the Curie temperatures of the disordered PBN ceramics were lower than those of the ordered ones when 1 − X ≥ 0.70, but higher when 1 − X ≤ 0.65. These differences are suggested to inherently result from the A-site vacancy order-disorder states. The relationship between the A-site vacancy order-disorder states and the dielectric properties has also been confirmed with studies of thermal hysteresis.
The order-disorder states of the A-site vacancy of PBN solid solution affected by different thermal treatments were studied with the aid of High Resolution Electron Microscopy (HREM). PBN ceramics around the morphotropic phase boundary were prepared through two routes to control ordering degree of the A-site vacancy: (1) samples through quenching processes resulted in chaotic states of the A-site vacancies and misfit anti-phase boundary; (2) samples through slow cooling led to an ordered structure of the vacancies in the A1-site. The ordered A1-site vacancies were modulated by interchanges of the sublattices of the ordered vacancies and the Pb2+ cations in the A1-sites along both and orientations, forming a narrow discommensurate wall between two anti-phase domains. The anti-phase domains were observed as a regular belt structure with dimensions of about 45 nm × (≥120) nm. The belt nano-domain structures were a result of quasi-equilibrium thermodynamic processes.