To send 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 sending content to .
To send content items to your Kindle, first ensure email@example.com
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 sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent 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.
A series of double-perovskite LaAMnNiO6 (A = La, Pr, Sm) catalysts with mesoporous morphology was prepared by a sol–gel method and further applied into photothermal synergistic degradation of gaseous toluene. Transmission electron microscopy and Brunauer–Emmett–Teller characterizations confirmed that double-perovskite LaAMnNiO6 (A = La, Pr, Sm) had obvious mesoporous structure, which can provide a larger specific surface area and further enhancing the reactivity of catalyst. UV-vis and X-ray photoelectron spectroscopy characterization illustrated that LaSmMnNiO6 possessed higher adsorption oxygen content and light absorption capacity, which contribute to the occurrence of catalytic oxidation in the Mars–van Krevelen redox cycle mechanism. A group of active tests showed that the double-perovskite LaSmMnNiO6 catalyst had a lower reaction initiation temperature (starting reaction at 75 °C) and a lower activity temperature of optimal reaction (more than 90% at 255 °C). Moreover, the research on reaction kinetics of the catalyst demonstrated that LaAMnNiO6 (A = La, Pr, Sm) had lower activation energy and thus exhibited better catalytic activity. The results of the study indicate that the double-perovskite LaAMnNiO6 (A = La, Pr, Sm) has broad application prospects in the field of volatile organic pollutant degradation.
Suicide attempt is an important indicator of suicide and potential future mortality. However, the prevalence of suicide attempts has been inconsistent across studies. This meta-analysis aimed to examine the prevalence of suicide attempts in individuals with schizophrenia and associated correlates.
Relevant publications in Embase, PsycINFO, PubMed, Web of science and Cochrane were systematically searched. Data on the prevalence of suicide attempts in individuals with schizophrenia were pooled using a random-effects model.
Thirty-five studies with 16 747 individuals with schizophrenia were included. The pooled lifetime prevalence of suicide attempts was 26.8% (95% CI 22.1–31.9%; I2 = 97.0%), while the 1-year prevalence, 1-month prevalence and the prevalence of suicide attempts from illness onset were 3.0% (95% CI 2.3–3.7%; I2 = 95.6%), 2.7% (95% CI 2.1–3.4%; I2 = 78.5%) and 45.9% (95% CI 42.1–49.9%; I2 = 0), respectively. Earlier age of onset (Q = 4.38, p = 0.04), high-income countries (Q = 53.29, p < 0.001), North America and Europe and Central Asia (Q = 32.83, p < 0.001) were significantly associated with a higher prevalence of suicide attempts.
Suicide attempts are common in individuals with schizophrenia, especially those with an early age of onset and living in high-income countries and regions. Regular screening and effective preventive measures should be implemented as part of the clinical care.
In this study, a thermal–elastic–plastic finite element model is proposed to investigate the effect of volume energy density on the temperature field, molten pool size, and residual stress distribution in the selective laser melting (SLM) process of Inconel 718 alloy. A temperature-dependent thermal–mechanical property of materials is considered, as well as the properties conversion between powder layer and solidified alloy. Within the scope of the study parameters, the simulated molten pool size increases with increasing volume energy density and exhibits linear growth relationship, which are validated by the experimental results and show a good agreement. In addition, five scanning strategies are adopted to study the effect of these scanning strategies on the residual stress distribution in this research. The results show that the residual stress distribution of SLM Inconel 718 specimen largely depends on the scanning strategy. Finally, to reveal the mechanism of residual stress formation, the restraint bar model is used to further analyze the formation mechanism of residual stress during the SLM process.
For a multiplier Hopf algebra pairing 〈A,B〉, we construct a class of group-cograded multiplier Hopf algebras D(A,B), generalizing the classical construction of finite dimensional Hopf algebras introduced by Panaite and Staic Mihai [Isr. J. Math. 158 (2007), 349–365]. Furthermore, if the multiplier Hopf algebra pairing admits a canonical multiplier in M(B⊗A) we show the existence of quasitriangular structure on D(A,B). As an application, some special cases and examples are provided.
To assess the effect of famine exposure during early life on dietary patterns, chronic diseases, and the interaction effect between famine exposure and dietary patterns on chronic diseases in adulthood.
Cross-sectional study. Dietary patterns were derived by factor analysis. Multivariate quantile regression and log-binomial regression were used to evaluate the impact of famine exposure on dietary patterns, chronic diseases and the interaction effect between famine exposure and dietary patterns on chronic diseases, respectively.
Adults aged 45–60 years (n 939).
‘Healthy’, ‘high-fat and high-salt’, ‘Western’ and ‘traditional Chinese’ dietary patterns were identified. Early-childhood and mid-childhood famine exposure were remarkably correlated with high intake of the traditional Chinese dietary pattern. Compared with the non-exposed group (prevalence ratio (PR); 95 % CI), early-childhood (3·13; 1·43, 6·84) and mid-childhood (2·37; 1·05, 5·36) exposed groups showed an increased PR for diabetes, and the early-childhood (2·07; 1·01, 4·25) exposed group showed an increased PR for hypercholesterolaemia. Additionally, relative to the combination of non-exposed group and low-dichotomous high-fat and high-salt dietary pattern, the combination of famine exposure in early life and high-dichotomous high-fat and high-salt dietary pattern in adulthood had higher PR for diabetes (4·95; 1·66, 9·05) and hypercholesterolaemia (3·71; 1·73, 7·60), and significant additive interactions were observed.
Having suffered the Chinese famine in childhood might affect an individual’s dietary habits and health status, and the joint effect between famine and harmful dietary pattern could have serious consequences on later-life health outcomes.
In this paper, we review the status of the multifunctional experimental platform at the National Laboratory of High Power Laser and Physics (NLHPLP). The platform, including the SG-II laser facility, SG-II 9th beam, SG-II upgrade (SG-II UP) facility, and SG-II 5 PW facility, is operational and available for interested scientists studying inertial confinement fusion (ICF) and a broad range of high-energy-density physics. These facilities can provide important experimental capabilities by combining different pulse widths of nanosecond, picosecond, and femtosecond scales. In addition, the SG-II UP facility, consisting of a single petawatt system and an eight-beam nanosecond system, is introduced including several laser technologies that have been developed to ensure the performance of the facility. Recent developments of the SG-II 5 PW facility are also presented.
This study was designed to explore the association between undernutrition in the growth period and cardiovascular risk factors in a middle-aged Chinese population. A total of 1756 subjects, aged 45–60 years, were invited to participate in the Hefei Nutrition and Health Study and divided into three groups according to their self-reported animal food intake in the growth period. Group 1, Group 2 and Group 3 were defined as undernutrition, nutritional improvement and the good nutrition group, respectively. In the three groups, the subjects in Groups 1 and 2 had more oil and salt intake (P<0.001), and less eggs and milk intake (P<0.001), when compared with the subjects in Group 3. After adjusting for age, education, smoking status and other confounding factors, it was found that male participants who experienced nutritional improvement before age 18 had higher risk of hypertension [odds ratio (OR)=1.68; 95% confidence intervals (CI): 1.05, 2.69] than those with good nutrition, and female participants with undernutrition (OR=1.52; 95% CI: 1.01, 2.29) and nutritional improvement (OR=1.68; 95% CI: 1.04, 2.69) before age 18 had a higher risk of hypertension than those with good nutrition. For diabetes, obesity, hypercholesterolemia and hypertriglyceridemia, our results did not found difference among the three groups both in male and female. Our findings indicated that nutritional deficiency in childhood was associated with bad dietary behaviors and a significantly increased risk of hypertension in middle age. Therefore, early adequate nutrition is very important for the prevention of non-communicable diseases later.
The icing wind tunnel can simulate the air flow at a high altitude; such an air flow contains supercooled droplets moving at certain velocities. An integrated experiment method was proposed, and it included the icing test and shear stress measurements in the simulated environment of the icing wind tunnel. The error caused by the change in experimental environments was completely eliminated with this novel method. Thus, there was no discrepancy between the real-time and experimental values of shear stress between the ice and substrate. The experiments of icing and shear stress measurements are carried out by varying the following parameters: icing temperature, mean volume diameter (MVD) of droplets, and surface roughness of the substrate. The results indicate that the shear stress between the ice and the substrate increases with the decrease in temperature provided the temperature is relatively high. When the MVD value is 22 μm, the liquid water content is about 1 g/m3 and surface roughness is 2 μm. Under these conditions, the shear stress reaches its maximum value at a temperature of –15°C. The shear stress is also affected by the MVD values of droplets, and the surface roughness of substrate.
Terminus fluctuation and area change in mountain glaciers in the middle Chinese Tien Shan over the past four decades are examined, based on Landsat multispectral scanner (MSS), Enhanced Thematic Mapper Plus (ETM+), Système Probatoire pour l’Observation de la Terre (SPOT) highresolution visible (HRV) imagery, topographical maps and China Glacier Inventory data using Geographical Information System (GIS) and remote-sensing techniques. This study shows that the glaciers in the study area have undergone continuous recession between 1963 and 2000. Over the past 37 years the total glacier area decreased from 55 × 106 m2 to 48 × 106 m2 (a 13% decrease). The glaciers at low elevations decreased more rapidly than those at high elevations. Seven of the ten large valley glaciers in the study area retreated by at least 150 ± 49 m during this period. The average rate of recession for these glaciers was 4–8 m a−1. The recession rate between 1986 and 2000 was larger than between 1963 and 1986. The glacier changes in the study area were similar to those in the Ürümqi river basin in the northern Chinese Tien Shan. It is apparent that temperature rise over the past four decades has had a profound impact on these glaciers.
Restudy of the limestone slab containing the type suite of Arthricocephalus chauveaui Bergeron, 1899 (Trilobita), the type species of Arthricocephalus Bergeron, 1899, shows that specimens of three species, each representing a separate genus, are present on the slab and were likely included in the original concept of the species. Besides A. chauveaui, the slab contains specimens of Oryctocarella duyunensis (Qian, 1961) and Duyunaspis duyunensis Zhang and Qian in Zhou et al., 1977. Bergeron (1899) illustrated one exoskeleton from the type suite of A. chauveaui only and apparently based much of his written description on that specimen. This specimen was clearly intended to be the type specimen of A. chauveaui. Subsequently, Lane et al. (1988) designated another specimen, which was not originally illustrated, as the lectotype, and this specimen is referable to Oryctocarella duyunensis. As revised here, Bergeron’s illustrated specimen should be regarded as the lectotype of A. chauveaui. Such designation stabilizes the concepts of both Arthricocephalus and A. chauveaui. Arthricocephalites Qian in Lu et al., 1974 and Haliplanktos Blaker and Peel, 1997 are regarded as junior synonyms of Arthricocephalus. Oryctocarella Tomashpolskaya and Karpinski, 1961, which was previously regarded as a junior synonym of Arthricocephalus, is revived as a valid genus. Oryctocarella includes a number of species previously assigned to Arthricocephalus. The type species of both Arthricocephalus and Oryctocarella, together with related species, are described on the basis of new material.
The surfacing welding has been widely utilized in the industrial equipment manufacturing and repairs. The wear properties of surfacing alloys have an important effect on the whole performance of repaired components. The solution treatment (T4) and solution treatment followed by aging (T6) effects on the dry sliding wear behavior of surfacing AZ91 magnesium alloys with tungsten inert gas welding were investigated in this work. The results demonstrated that the surfacing alloy without treatment exhibited poor wear resistance, due to the massive intermetallic β-phases (Mg17Al12). These phases were believed to produce stress concentrations in the particle-to-matrix interface and tended to generate cracks during friction. The T4 alloy had more improved wear resistance than the as-received alloy. The T6 treatment improved the wear resistance further, resulting from the high density dispersed fine β-phase precipitation in the α-Mg matrix, which enhanced the alloy strength and hardness and decreased the subsurface metal deformation degree caused by friction.
Change mode and effects analysis (CMEA) is a powerful technique for measuring product flexibility toward future changes and diminishing the cost of redesign as well as shortening time to market. As a systematic methodology, it provides an in-depth view for the investigation of potential changes, causes, and effects in designs, products, and processes. Traditional CMEA determines the risk priorities of change modes by using change potential number, which requires the risk factors of design flexibility, occurrence, and readiness to be precisely evaluated. However, this is not always possible in real applications due to the uncertainty and subjectivity involved in the early design stages. It has been criticized much for its deficiencies in criteria weighting of the risk factors, change potential number calculation, and risk priorities determination of the change modes. This paper presents a systematic evaluation approach for determining a more rational rank of change modes by combining with the entropy weight method, rough number, and grey relational analysis. In this study, the entropy weight method is adopted to calculate the relative importance of risk factors. Rough number is presented to aggregate individual weights and preferences, and to manipulate the vagueness in the evaluation process. Then a rough number enhanced grey relational analysis is proposed to evaluate the risk ranking of change modes. Finally, a practical example is put forward to validate the performance of the proposed method. The result shows that the proposed change mode evaluation method can effectively overcome the shortcomings of traditional CMEA and strengthen the objectivity of product flexibility measurement.
This study attempted to investigate and validate whether epididymis cold storage could be a suitable alternative for short-term preservation of spermatozoa. Mouse cauda epididymides and spermatozoa were preserved at 4–8°C from 1 day to 6 weeks. From days 1 to 10, motility and fertility were daily examined when motility loss occurred. From week 1, spermatozoa were used for intracytoplasmic sperm injection (ICSI) at weekly intervals to test their fertility, and spermatozoa DNA integrity was determined by comet assay. We found that motility and progressive motility scores gradually decreased with storage time. In nearly all spermatozoa, DNA integrity was maintained from days 1 to 10, but the percentage of spermatozoa with damaged DNA significantly increased from week 2 to week 6. Spermatozoa retained fertility until day 6, although fertility gradually decreased after day 3. From week 1 to week 5, fertilization rates by ICSI were more than 82.69% but decreased gradually after week 3. We found that spermatozoa preserved in the epididymis at 4–8°C had progressively lower motility, fertility and proportion of undamaged DNA, but could still fertilize oocytes. However, all the parameters of cold-preserved spermatozoa were completely inferior to that from cold-preserved cauda epididymides. The results imply that cold storage of cauda epididymides could be conducive to short-term preservation of spermatozoa, and the cold-stored spermatozoa can resist DNA denaturation, which is necessary for maintaining reproductive ability.
The purpose of the present study was to examine the influence of maternal pre-pregnancy BMI and gestational weight gain (GWG) on initiation and duration of infant breast-feeding in a prospective birth cohort study.
Breast-feeding information was collected at 1, 3, 6 and 12 months postpartum. The association of pre-pregnancy BMI and GWG with delayed lactogenesis II and termination of exclusive breast-feeding was assessed with logistic regression analysis. The risk of early termination of any breast-feeding during the first year postpartum was assessed with Cox proportional hazards models.
Urban city in China.
Women with infants from the Ma’anshan Birth Cohort Study (n 3196).
The median duration of any breast-feeding in this cohort was 7·0 months. Pre-pregnancy obese women had higher risks of delayed lactogenesis II (risk ratio=1·89; 95 % CI 1·04, 3·43) and early termination of any breast-feeding (hazard ratio=1·38; 95 % CI 1·09, 1·75) adjusted for potential maternal and infant confounders, when compared with normal-weight women. No differences in breast-feeding initiation or duration of exclusive breast-feeding according to pre-pregnancy BMI were found. Moreover, GWG was not associated with any poor breast-feeding outcomes.
The present study indicated that pre-pregnancy obesity increases the risks of delayed lactogenesis II and early termination of any breast-feeding in Chinese women.
A mathematical multi-zone ice accretion model used in the numerical simulation of icing on airfoil surface based on three water states, namely, continuous film, rivulets and beads is studied in this paper. An improved multi-zone roughness model is proposed. According to the flow state of liquid water and film flow, rivulets flow governing equations are established to calculate film mass distribution, film velocity, rivulet wetness factor and rivulet mass distribution. Force equilibrium equations of droplet are used to establish the critical conditions of water film broken into rivulets and rivulets broken into beads. The temperature conduction inside the water layer and ice layer is considered. Using the proposed model ice accretion on a NACA0012 airfoil profile with a 4° angle of attack under different icing conditions is simulated. Different ice shapes like glaze ice, mixed ice and rime ice are obtained, and the results agree well with icing wind tunnel experiment data. It can be seen that, water films are formed on the surface, and heights of the films vary with icing time and locations. This results in spatially-temporally varying surface roughness and heat transfer process, ultimately affects the ice prediction. Model simulations indicate that the process of water film formation and evolution cannot be ignored, especially under glaze ice condition.