To apply hydrotalcites more effectively to the problem of dye wastewater, the effects of divalent metal ions on the structure and stability of hydrotalcites, especially on their photocatalytic activity, were compared. In the present study, M/Cr hydrotalcites (M3Cr-CO3-LDHs) (in which M = Mg, Co, Ni, Cu, Zn), where the M/Cr molar ratio was 3, were prepared by the co-precipitation method. The structures and properties were characterized using powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric-differential thermal analysis (TG-DTA), and UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that five kinds of M3Cr-CO3-LDHs were synthesized successfully, and the layered structure of the samples obtained was regular and the crystal phase was single. When methylene blue (MB) solution was exposed to ZnCr-CO3-LDHs, H2O2, and visible light irradiation, more than 90.67% of the methylene blue (MB) was removed after 140 min. The photocatalytic activity of the samples was in the order: Co3Cr-CO3-LDHs > Mg3Cr-CO3-LDHs > Cu3Cr-CO3-LDHs > Zn3Cr-CO3-LDHs > Ni3Cr-CO3-LDHs. The results of a catalytic mechanism study showed that photocatalytic degradation of MB involved a demethylation reaction, with the reactive species containing •O2-, •OH, and h+.

Currently, most wheel-legged robots need to complete the switching of the wheel-and-leg modal in a stationary state, and the existing algorithms of statically switching the wheel-leg modal cannot meet the control requirements of multimodal switching dynamically for robots. In this paper, to achieve efficient switching of the wheel-and-leg modal for a quadruped robot, the novel transformable mechanism is designed. Then, a multimodal coordination operation control framework based on multiple algorithms is presented, incorporating the minimum foot force distribution method (algorithm No.1), the minimum joint torque distribution method (algorithm No.2), and the method of combining the single rigid body dynamic model with quadratic programming (algorithm No.3). In the process of switching wheel-leg modal dynamically, the existing algorithm No.3 is prone to produce the wrong optimal force due to the change of the whole-body rotational inertia. Therefore, an improved algorithm No.1 and algorithm No.2 are proposed, which do not consider the change in the body’s inertia. The control effects of the three algorithms are compared and analyzed by simulation. The results show that algorithm No.3 can maintain a small error in attitude angle and speed tracking regardless of whether the robot is under multilegged support or omnidirectional walking compared to the other two algorithms. However, proposed algorithms No.1 and No.2 can more accurately track the target speed when the robot is walking with wheels raising and falling. Finally, a multi-algorithm combination control scheme formulated based on the above control effects has been demonstrated to be effective for the dynamic switching of the wheel-and-leg modal.

Human gait trajectory prediction is a long-standing research topic in human–machine interaction. However, there are two shortcomings in the current gait trajectory prediction technology. The first shortcoming is that the neural network model of gait prediction only predicts dozens of future time frames of gait trajectory. The second shortcoming is that the gait prediction neural network model is uninterpretable. We propose the Interpretable-Concatenation former (IC-former) model, which can predict long-term gait trajectories and explain the prediction results by quantifying the importance of data at different positions in the input sequence. Experiments prove that the IC-former model we proposed not only makes a breakthrough in prediction accuracy but also successfully explains the data basis of the prediction.

We aimed to describe associations between diet quality in adolescence and adulthood and knee symptoms in adulthood. Two hundred seventy-five participants had adolescent diet measurements, 399 had adult diet measurements and 240 had diet measurements in both time points. Diet quality was assessed by Dietary Guidelines Index (DGI), reflecting adherence to Australian Dietary Guidelines. Knee symptoms were collected using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Data were analysed using zero-inflated negative binomial regressions. The overall adolescent DGI was not associated with adult knee symptoms, although lower intake of discretionary foods (e.g. cream, alcohol, bacon and cake) in adolescence was associated with lower pain (mean ratio (MR) 0·96) and dysfunction (MR 0·94). The overall adult DGI was not associated with knee symptoms; however, limiting saturated fat was associated with lower WOMAC (Pain: MR 0·93; stiffness: MR 0·93; dysfunction: MR 0·91), drinking water was associated with lower stiffness (MR 0·90) and fruit intake was associated with lower dysfunction (MR 0·90). Higher DGI for dairy products in adulthood was associated with higher WOMAC (Pain: MR 1·07; stiffness: MR 1·13; dysfunction: MR 1·11). Additionally, the score increases from adolescence to adulthood were not associated with adult knee symptoms, except for associations between score increase in limiting saturated fat and lower stiffness (MR 0·89) and between score increase in fruit intake and lower dysfunction (MR 0·92). In conclusion, the overall diet quality in adolescence and adulthood was not associated with knee symptoms in adulthood. However, some diet components may affect later knee symptoms.

The use of a corn–earthworm coculture (CE) system is an eco-agricultural technology that has been gradually extended due to its high economic output and diverse ecological benefits for urban agriculture in China. However, the effect of CE on weed occurrence has received little attention. A 5-yr successive experiment (2015 to 2019) was conducted to compare weed occurrence in CE and a corn (Zea mays L.) monoculture (CM). The results show that CE significantly decreased weed diversity, the dominance index, total weed density, and biomass, but increased the weed evenness index. The 5-yr mean number of weed species per plot was 8.4 in CE and 10.7 in CM. Compared with those in CM, the 5-yr mean density and biomass of total weeds in CE decreased by 59.2% and 66.6%, respectively. The effect of CE on weed occurrence was species specific. The mean density of large crabgrass [Digitaria sanguinalis (L.) Scop.], green foxtail [Setaria viridis (L.) P. Beauv.], goosegrass [Eleusine indica (L.) Gaertn.], and common purslane (Portulaca oleracea L.) in CE decreased by 94.5%, 78.1%, 75.0%, and 45.8%, whereas the mean biomass decreased by 96.2%, 80.8%, 76.9%, and 41.4%, respectively. Our study suggests that the use of CE could suppress weed occurrence and reduce herbicide inputs in agriculture.

The ablation and acceleration of diamond-like high-density carbon foils irradiated by thermal X-ray radiations are investigated with radiation hydrodynamics simulations. The time-dependent front of the ablation wave is given numerically for radiation temperatures in the range of 100–300 eV. The mass ablation rates and ablation pressures can be derived or implied from the coordinates of ablation fronts, which agree well with reported experiment results of high-density carbon with radiation temperatures Trad in the range of 160–260 eV. It is also found that the $T_{{\rm rad}}^3$ scaling law for ablation rates does not apply to Trad above 260 eV. The trajectories of targets and hydrodynamic efficiencies for different target thicknesses can be derived from the coordinates of ablation fronts using a rocket model and the results agree well with simulations. The peak hydrodynamic efficiencies of the acceleration process are investigated for different foil thicknesses and radiation temperatures. Higher radiation temperatures and target thicknesses result in higher hydrodynamic efficiencies. The simulation results are useful for the design of fusion capsules.

The soil weed seedbank is the source of future weed infestations. Seed predation can result in a large number of seed losses, thus contributing to weed biocontrol. Earthworms are important predators of seeds and seedlings and affect seeds and seedling survival after gut passage. A study was conducted to assess the ability of Pheretima guillelmi (Kinberg) to ingest and digest the seeds and seedlings of 15 main farmland weed species. Pheretima guillelmi ingested the seeds and seedlings of each weed species tested. The percentages of seeds and seedlings ingested were 96.7% to 100% and 21.7% to 94.2%, respectively. Pheretima guillelmi showed greater ingestion of seeds than seedlings for each species and digested the seeds and seedlings of each weed species tested to varying extents. The percentages of seeds and seedlings digested were less than 15% irrespective of the weed species. Passage through the gut of P. guillelmi affected the survival of seeds and seedlings. The germination of large crabgrass [Digitaria sanguinalis (L.) Scop.], green foxtail [Setaria viridis (L.) P. Beauv.], goosegrass [Eleusine indica (L.) Gaertn.], Chinese sprangletop [Leptochloa chinensis (L.) Nees], Malabar sprangletop [Leptochloa fusca (L.) Kunth], redroot pigweed (Amaranthus retroflexus L.), common purslane (Portulaca oleracea L.), barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.], and ricefield flatsedge (Cyperus iria L.) seeds egested by P. guillelmi decreased by 46%, 49%, 47%, 25%, 38%, 26%, 32%, 13%, and 15%, respectively, compared with their respective controls. In contrast to seed ingestion, ingestion of seedlings by P. guillelmi was fatal to individuals of all weed species; no seedlings survived passage through the gut. Our results indicate that predation of weed seeds and seedlings by P. guillelmi probably depletes the soil weed seedbank and that the introduction of P. guillelmi into fields is a potential strategy for weed biocontrol in farmland.

Accurate torque control is a critical issue in the compliant human–robot interaction scenario, which is, however, challenging due to the ever-changing human intentions, input delay, and various disturbances. Even worse, the performances of existing control strategies are limited on account of the compromise between precision and stability. To this end, this paper presents a novel high-performance torque control scheme without compromise. In this scheme, a new nonlinear disturbance observer incorporated with equivalent control concept is proposed, where the faster convergence and stronger anti-noise capability can be obtained simultaneously. Meanwhile, a continuous fractional power control law is designed with an iteration method to address the matched/unmatched disturbance rejection and global finite-time convergence. Moreover, the finite-time stability proof and prescribed control performance are guaranteed using constructed Lyapunov function with adding power integrator technique. Both the simulation and experiments demonstrate enhanced control accuracy, faster convergence rate, perfect disturbance rejection capability, and stronger robustness of the proposed control scheme. Furthermore, the evaluated assistance effects present improved gait patterns and reduced muscle efforts during walking and upstair activity.

Previous studies have shown conflicting findings regarding the relationship between maternal vitamin D deficiency (VDD) and fetal growth restriction (FGR). We hypothesised that parathyroid hormone (PTH) may be an underlying factor relevant to this potential association. In a prospective birth cohort study, descriptive statistics were evaluated for the demographic characteristics of 3407 pregnancies in the second trimester from three antenatal clinics in Hefei, China. The association of the combined status of vitamin D and PTH with birth weight and the risk of small for gestational age (SGA) was assessed by a multivariate linear and binary logistic regression. We found that declined status of 25-hydroxyvitamin D is associated with lower birth weight (for moderate VDD: adjusted β = −49·4 g, 95 % CI −91·1, −7·8, P < 0·05; for severe VDD: adjusted β = −79·8 g, 95 % CI −127·2, −32·5, P < 0·01), as well as ascended levels of PTH (for elevated PTH: adjusted β = −44·5 g, 95 % CI −82·6, −6·4, P < 0·05). Compared with the non-VDD group with non-elevated PTH, pregnancies with severe VDD and elevated PTH had the lowest neonatal birth weight (adjusted β = −124·7 g, 95 % CI −194·6, −54·8, P < 0·001) and the highest risk of SGA (adjusted risk ratio (RR) = 3·36, 95 % CI 1·41, 8·03, P < 0·01). Notably, the highest risk of less Ca supplementation was founded in severe VDD group with elevated PTH (adjusted RR = 4·67, 95 % CI 2·78, 7·85, P < 0·001). In conclusion, elevated PTH induced by less Ca supplementation would further aggravate the risk of FGR in pregnancies with severe VDD through impaired maternal Ca metabolism homoeostasis.

The Chinese National Twin Registry (CNTR), initiated in 2001, has now become the largest twin registry in Asia. From 2015 to 2018, the CNTR continued to receive Chinese government funding and had recruited 61,566 twin-pairs by 2019 to study twins discordant for specific exposures such as environmental factors, and twins discordant for disease outcomes or measures of morbidity. Omic data, including genetics, genomics, metabolomics, and proteomics, and gut microbiome will be tested. The integration of omics and digital technologies in public health will advance our understanding of precision public health. This review introduces the updates of the CNTR, including study design, sample size, biobank, zygosity assessment, advances in research and future systems epidemiologic research.