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Antibiotic contaminants such as tetracycline (TC) from agricultural production have become widely distributed and persistently accumulated in aquatic environments (rivers, lakes, and oceans), posing severe threats to ecological security and human health. This study developed a modified rice-straw-derived biochar through NaOH activation and ball-milling-assisted Fe3O4 loading, which simultaneously enhanced TC adsorption capacity and enabled magnetic recovery. The Box–Behnken design (BBD) response surface methodology was employed to optimize three key preparation parameters: ball-milling time (A, 39.95 min), frequency (B, 57.23 Hz), and Fe3O4/biochar mass ratio (C, 2.85:1), with TC adsorption capacity as the response value. The modified biochar was systematically characterized using SEM, BET, FTIR, XRD, and XPS, while adsorption mechanisms were elucidated through kinetic studies, isotherm analyses, and pH-dependent experiments. The results demonstrate that modification via ball-milling with Fe3O4 loading significantly enhanced the biochar’s tetracycline adsorption capacity. The maximum adsorption capacity of the modified biochar reached 102.875 mg/g, representing a 114.85% increase from the initial value of 47.882 mg/g observed for the pristine biochar. Furthermore, the modified biochar exhibited excellent stability, maintaining robust adsorption performance across a wide pH range. The primary adsorption mechanisms involved metal coordination complexation, supplemented by hydrogen bonding, π-π interactions, and pore filling.

Based on carrier rate equation, a new model is proposed to explain the non-exponential nature of time-resolved photoluminescence (TRPL) decay curves in the polar InGaN/GaN multi-quantum-well structures. From the study of TRPL curves at different temperatures, it is found that both radiative and non-radiative recombination coefficients vary from low temperature to room temperature. The variation of the coefficients is compatible with the carrier density of states distribution as well as the carrier localization process. These results suggest that there is a novel method to calculate the internal quantum efficiency, which is a complement to the traditional one based on temperature dependent photoluminescence measurement.

Many multi-story residential buildings have been built in villages to improve the living quality of rural residents in China. Therefore, village morphology has dramatically changed compared to the past. Since northern China continues to suffer from environmental problems, improving village ventilation by optimizing village morphology is essential for creating a good rural environment. In this study, 17 morphology models were categorized based on 383 actual villages in Tianjin. In addition, the ventilation capacity of courtyards and streets and residents’ health risks of different morphology cases were analyzed. For the northwest wind direction, the ventilation capacity of the courtyards in the northern part of the village can be improved when there are multi-story residences in the north or west of the village. Accordingly, in the southeast wind direction, multi-story buildings in the south or east of the village can improve the courtyard ventilation in the southern part of the village. In addition, multi-story buildings in the west or east of the village can form ventilation corridors in the northwest or southeast wind direction. The morphologies without multi-story buildings in the west or east of the village were recommended to be applied in the village planning in Tianjin due to good ventilation capacity and low exposure risks.

The spin and optical polarization based on a coupled InGaN/GaN quantum well (QW) and quantum dots (QDs) structure is investigated. In this structure, spin-electrons can be temporarily stored in QW, and spin injection from the QW into QDs via spin-conserved tunneling is enabled. Spin relaxation can be suppressed owing to the small energy difference between the initial state in the QW and the final states in the QDs. Photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements are carried out on optical spin-injection and -detection. Owing to the coupled structure, spin-conserved tunneling mechanism plays a significant role in preventing spin relaxation process. As a result, a higher circular polarization degree (CPD) (~49.1%) is achieved compared with conventional single layer of QDs structure. Moreover, spin relaxation time is also extended to about 2.43 ns due to the weaker state-filling effect. This coupled structure is believed an appropriate candidate for realization of spin-polarized light source.

Computational fluid dynamics (CFD) was adopted to investigate the influence of the three-section opening strategy in the Z type centripetal radial flow reactor on the uniformity of the gas flow, which aimed to optimize the opening rate of the reactor. The simulation results showed that as the pore-opening ratio of are 10%, 16% and 29% for three sections from top to bottom of the central channel, the opening rate of the circular channel perforated plate is 10–12%, 21–25% and 30–40% from top to bottom, respectively; the uniformity of the reactor was then achieved. Through the simulation results, it was also found that the change in the opening rate at the center pipe perforated plate had a greater contribution to the gas flow mal-distribution inside the reactor. The contribution of the change in the opening rate of the annular channel perforated plate to the uniformity of the gas flow inside the reactor was smaller than that of the center pipe. Annular channel width should not be smaller, such that gas flow malfunction inside the reactor could be avoided, although high-speed velocity cases were encountered.

Proton-exchange-membrane fuel cells (PEMFCs) have the characteristics of zero emissions, a low operating temperature and high power density, and have great potential in improving energy-utilization efficiency. However, fuel cells are still quite expensive as a result of the cost of key components, including the membranes, catalysts and bipolar plates of PEMFCs. As a result of the cost and importance of these items, most researchers have focused on improving the lifetime and performance of fuel-cell stacks in recent years. In contrast, seals, sealants and adhesives play a more mundane role in the overall performance of a fuel cell, but failure of these materials can lead to reduced system efficiency, system failure and even safety issues. Little attention has been paid to the performance and durability of these products but as other fuel-cell components improve, these seals are becoming an even more critical link in the long-term performance of fuel cells. This article highlights the importance and background of fuel-cell seals. The latest research progress on the mechanical properties and structural optimization of different sealing materials is reviewed.

Conventional fuel consumption prediction (FCP) models using neural networks usually adopt driving parameters, such as speed and acceleration, as the training input, leading to a low prediction accuracy and a poor correlation between fuel consumption and driving behavior. To address this issue, the present study introduced jerk (an acceleration derivative) as an important variable in the training input of four selected neural networks: long short-term memory (LSTM), recurrent neural network (RNN), nonlinear auto-regressive model with exogenous inputs (NARX), and generalized regression neural network (GRNN). Furthermore, the root-mean-square error (RMSE), relative error (RE), and coefficient of determination (R2) were used to evaluate the prediction performance of each model. The results from the comparison experiment show that the LSTM model outperforms the other three models. Specifically, the four selected neural network models exhibited an improved accuracy in fuel consumption prediction after the jerk was added as a new variable to the training input. LSTM exhibited the greatest improvement under the high-speed expressway scenario, in which the RMSE decreased by 14.3%, the RE decreased by 28.3%, and the R2 increased by 9.7%.

Antibiotic contaminants such as tetracycline (TC) from agricultural production have become widely distributed and persistently accumulated in aquatic environments (rivers, lakes, and oceans), posing severe threats to ecological security and human health. This study developed a modified rice-straw-derived biochar through NaOH activation and ball-milling-assisted Fe[sub.3]O[sub.4] loading, which simultaneously enhanced TC adsorption capacity and enabled magnetic recovery. The Box–Behnken design (BBD) response surface methodology was employed to optimize three key preparation parameters: ball-milling time (A, 39.95 min), frequency (B, 57.23 Hz), and Fe[sub.3]O[sub.4]/biochar mass ratio (C, 2.85:1), with TC adsorption capacity as the response value. The modified biochar was systematically characterized using SEM, BET, FTIR, XRD, and XPS, while adsorption mechanisms were elucidated through kinetic studies, isotherm analyses, and pH-dependent experiments. The results demonstrate that modification via ball-milling with Fe[sub.3]O[sub.4] loading significantly enhanced the biochar’s tetracycline adsorption capacity. The maximum adsorption capacity of the modified biochar reached 102.875 mg/g, representing a 114.85% increase from the initial value of 47.882 mg/g observed for the pristine biochar. Furthermore, the modified biochar exhibited excellent stability, maintaining robust adsorption performance across a wide pH range. The primary adsorption mechanisms involved metal coordination complexation, supplemented by hydrogen bonding, π-π interactions, and pore filling.

We revisit the mass-size relation of molecular cloud structures based on the column density map of the Cygnus-X molecular cloud complex. We extract 135 column density peaks in Cygnus-X and analyze the column density distributions around these peaks. The averaged column density profiles, \\(N(R)\\), around all the peaks can be well fitted with broken power-laws, which are described by an inner power-law index \\(n\\), outer power-law index \\(m\\), and the radius \\(R_{\\rm TP}\\) and column density \\(N_{\\rm TP}\\) at the transition point. We then explore the \\(M-R\\) relation with different samples of cloud structures by varying the \\(N(R)\\) parameters and the column density threshold, \\(N_0\\), which determines the boundary of a cloud structure. We find that only when \\(N_0\\) has a wide range of values, the \\(M - R\\) relation may largely probe the density distribution, and the fitted power-law index of the \\(M-R\\) relation is related to the power-law index of \\(N(R)\\). On the contrary, with a constant \\(N_0\\), the \\(M - R\\) relation has no direct connection with the density distribution; in this case, the fitted power-law index of the \\(M - R\\) relation is equal to 2 (when \\(N_0\\ge N_{\\rm TP}\\) and \\(n\\) has a narrow range of values), larger than 2 (when \\(N_0\\ge N_{\\rm TP}\\) and \\(n\\) has a wide range of values), or slightly less than 2 (when \\(N_0< N_{\\rm TP}\\)).

The conventional strategy for cancer gene therapy offers limited control of specificity and efficacy. A possible way to overcome these limitations is to construct logic circuits. Here we present modular AND gate circuits based on CRISPR-Cas9 system. The circuits integrate cellular information from two promoters as inputs and activate the output gene only when both inputs are active in the tested cell lines. Using the luciferase reporter as the output gene, we show that the circuit specifically detects bladder cancer cells and significantly enhances luciferase expression in comparison to the human telomerase reverse transcriptase-renilla luciferase construct. We also test the modularity of the design by replacing the output with other cellular functional genes including hBAX , p21 and E-cadherin . The circuits effectively inhibit bladder cancer cell growth, induce apoptosis and decrease cell motility by regulating the corresponding gene. This approach provides a synthetic biology platform for targeting and controlling bladder cancer cells in vitro . Tools derived from synthetic biology offer powerful means to refine drug delivery and disease detection. Liu et al . engineer a logical AND gate using CRISPR-Cas9 to drive gene expression only cells in which two promoters are active, and use it to selectively inhibit the growth of bladder cancer cells in vitro .