Lateral flow assay (LFA) has played pivotal roles in many emergency public safety incidents, such as coronavirus disease diagnostics; however, the present double-line (test and control line) design strategy for LFA strips greatly restricts their applications in high-throughput quantitative analysis because the limited sample diffusion distance on the strips constrains the number of test/control lines. Herein, a novel single-line-based LFA (sLFA) strip, which combines test and control line, is developed by exploiting an orthogonal emissive upconversion nanoparticle (UCNP) as a signal reporter on the test line, where one emission can be used as a reporting signal and the other as a calibrating signal. This UCNP-based test line with an interior reference also can play a validating role as a control line, and hence capturing antibodies are not needed for control lines, greatly saving fabrication costs. As a proof-of-concept, this novel sLFA strip is successfully explored to accurately and rapidly detect aflatoxin B1. Moreover, due to the removal of control lines, such a novel strategy greatly reduces the strip size, facilitating the design of a testing array for multiple detections of different samples. The test line herein is designed in a ring shape, and several test rings are assembled to be a chip for the testing of multiple samples. To our knowledge, this is the first demonstration of single-line-based LFA strips, which will significantly improve the detection capacities and accuracies and reduce the testing costs of LFA strips in real sample applications ranging from food analysis to in vitro diagnostics.

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Stable operation is a challenge for hydropower stations with multi-turbine hydraulic coupled division systems with a common penstock. In this paper, the serious power fluctuations in a power station with such a division system are analyzed. The fluctuations occur in many conditions without any movement of the regulating system. The mathematical analysis illustrates that pressure fluctuation is responsible for power fluctuations. The computational fluid dynamics (CFD) method provided by ANSYS is used to study the flow pattern in penstocks. The vortex caused by the irrational structure of trifurcation is the reason for pressure fluctuations. Several methods are proposed to optimize the flow stability and three cases are simulated based on these measures. The calculation results of three cases prove the effectiveness of these measures. The measure of setting the new guide plate is finally conducted, and the output power fluctuations vanish. The flow calculation plays a role in the analysis and optimization of the hydraulic system of the hydropower unit. Some rules are summarized from the cases and are helpful in the design of trifurcation in a division system with a common penstock.

In recent years, biochar has been widely used for soil remediation because of its good soil amendment efficacy, but the effect of biochar addition on mineralization of soil organic matter (SOM) is still controversial. Earthworms, as common soil macrofauna, may change the effect of biochar on soil carbon stabilization. Therefore, 0.5% (w/w) corn biochar was added to top and deep soils respectively in the presence or absence of earthworms for 43 days of incubation experiment. The CO2 release rates were monitored on the 2nd, 8th, 15th, 22th, 29th, 36th, and 43th days, differences in soil respiration rates and cumulative emissions were compared between biochar, earthworm and mixed culture groups, and changes in SOM composition were measured by DOC and 3D fluorescence before and after the culture groups. The results showed that the addition of biochar reduced the SOM mineralization, and the presence of earthworms significantly increase the soil respiration rate and soil carbon emission. Compared to deep soil, earthworms had a stronger respiration effect on top soil. In the short term, the addition of biochar stimulated the mineralization, especially in the topsoil, from earthworms. However, in the long time, the addition of biochar was beneficial to the reduction of the mineralization of SOM.