Investigation on Combination of Airflow Disturbance and Sprinkler Irrigation for Horticultural Crop Frost Protection

Frost tends to be detrimental to the growth and development of horticultural crops, leading to yield or quality reduction with sizable economic losses. Therefore, it is very important to develop frost protection technology for horticultural crops. In this study, the development of frost protection technology is reviewed, and the research of mechanized frost protection technology in recent years is analyzed. In view of the poor frost protection effect of some single mechanized frost protection technology, the combination frost protection technology is put forward. The combination frost protection technology with airflow disturbance and sprinkler irrigation is discussed and analyzed

Some issues in studies on the atmospheric instability of convective storms

Atmospheric instability is one of the necessary conditions for the occurrence of severe convective weather, which is characterized by its intricacies. This paper first briefly reviews the air parcel theory and points out its limitations in application, for example, changes in pressure and vorticity of the environmental atmosphere inevitably caused by the strong upward motion of parcels in convective storms. Then, the concepts of static instability, symmetric instability, and other types of instability are reviewed. A special focus is given to summarizing the conditions for conditional instability, moist absolute instability, and conditional symmetric instability, as well as their relationship with the occurrence and development of convective storms, with some misunderstandings being clarified. The most effective method for determining conditional instability is to make a finite virtual displacement of the parcel and then use convective available potential energy (CAPE) for identification. However, the calculation of CAPE and convective inhibition is sensitive to the temperature and moisture of the parcel, and they should be computed and corrected using virtual temperature. The optimal CAPE value has better representativeness than that of the surface-based CAPE. In strong vertical wind shear and low CAPE environments, the acceleration effect of dynamic disturbance pressure gradient caused by rotation is crucial for the development of severe convective storms. Convective instability does not necessarily correspond to conditional instability. A straightforward method for distinguishing conditional symmetric instability is to use saturated equivalent geostrophic potential vorticity. We further summarize the mesoscale rainband characteristics caused by this type of instability

Modification of TiO_2 Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti^(3+) Complex

As one of the most promising semiconductor oxide materials, titanium dioxide (TiO_2) absorbs ultraviolet (UV) light but not visible light. To address this limitation, the introduction of Ti^(3+) defects represents a common strategy to render TiO_2 visible-light-responsive. Unfortunately, current hurdles in Ti^(3+) generation technologies impeded the widespread application of Ti^(3+) modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti^(3+) sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO_2 nanoparticles, spontaneous electron injection from the dibron-bound O^(2-) site to adjacent Ti^(4+) site leads to an extremely stable blue surface Ti^(3+)‒O^(-•) complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO_2, Nb_2O_5 and In_2O_3. Furthermore, the as-prepared photoelectronic device using this strategy affords 10^3 fold higher visible light response, and the fabricated perovskite solar cell shows an enhanced performance

Modification of TiO_2 Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti^(3+) Complex

As one of the most promising semiconductor oxide materials, titanium dioxide (TiO_2) absorbs ultraviolet (UV) light but not visible light. To address this limitation, the introduction of Ti^(3+) defects represents a common strategy to render TiO_2 visible-light-responsive. Unfortunately, current hurdles in Ti^(3+) generation technologies impeded the widespread application of Ti^(3+) modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti^(3+) sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO_2 nanoparticles, spontaneous electron injection from the dibron-bound O^(2-) site to adjacent Ti^(4+) site leads to an extremely stable blue surface Ti^(3+)‒O^(-•) complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO_2, Nb_2O_5 and In_2O_3. Furthermore, the as-prepared photoelectronic device using this strategy affords 10^3 fold higher visible light response, and the fabricated perovskite solar cell shows an enhanced performance

EBV-Encoded LMP1 Upregulates Igκ 3′Enhancer Activity and Igκ Expression in Nasopharyngeal Cancer Cells by Activating the Ets-1 through ERKs Signaling

Accumulating evidence indicates that epithelial cancer cells, including nasopharyngeal carcinoma (NPC) cells, express immunoglobulins (Igs). We previously found that the expression of the kappa light chain protein in NPC cells can be upregulated by the EBV-encoded latent membrane protein 1 (LMP1). In the present study, we used NPC cell lines as models and found that LMP1-augmented kappa production corresponds with elevations in ERKs phosphorylation. PD98059 attenuates LMP1-induced ERKs phosphorylation resulting in decreased expression of the kappa light chain. ERK-specific small interfering RNA blunts LMP1-induced kappa light chain gene expression. Luciferase reporter assays demonstrate that immunoglobulin κ 3′ enhancer (3′Eκ) is active in Igκ-expressing NPC cells and LMP1 upregulates the activity of 3′Eκ in NPC cells. Moreover, mutation analysis of the PU binding site in 3′Eκ and inhibition of the MEK/ERKs pathway by PD98059 indicate that the PU site is functional and LMP1-enhanced 3′Eκ activity is partly regulated by this site. PD98059 treatment also leads to a concentration-dependent inhibition of LMP1-induced Ets-1 expression and phosphorylation, which corresponds with a dose-dependent attenuation of LMP1-induced ERK phosphorylation and kappa light chain expression. Suppression of endogenous Ets-1 by small interfering RNA is accompanied by a decrease of Ig kappa light chain expression. Gel shift assays using nuclear extracts of NPC cells indicate that the transcription factor Ets-1 is recruited by LMP1 to the PU motif within 3′Eκ in vitro. ChIP assays further demonstrate Ets-1 binding to the PU motif of 3′Eκ in cells. These results suggest that LMP1 upregulates 3′Eκ activity and kappa gene expression by activating the Ets-1 transcription factor through the ERKs signaling pathway. Our studies provide evidence for a novel regulatory mechanism of kappa expression, by which virus-encoded proteins activate the kappa 3′ enhancer through activating transcription factors in non-B epithelial cancer cells

Electrical Characteristics of 3D Trench Electrode Germanium Detector with Nested Complementary Cathodes

High-purity germanium detectors, widely employed in fields such as aerospace applications based on radiation detection principles, have garnered attention due to their broad detection range and fast response time. However, these detectors often require larger sensitive area volumes to achieve larger signals and higher detection efficiency. Additionally, the large distance between the electrodes contributes to an issue of incomplete charge collection, which significantly restricts their application in space applications. To enhance the electrical performance of high-purity germanium detectors, this study introduces a strategy: designing the detector’s cathode electrode into a 3D trench shape with nested complementary cathodes. This design greatly reduces the electrode spacing, endowing the detector with superior electrical characteristics, such as a smaller dead zone and improved charge collection efficiency. Performance simulations of the novel detector structure were conducted using the semiconductor device simulation software Sentaurus TCAD (2019.03). The simulation results confirmed that the nested complementary 3D trench electrode high-purity germanium detector exhibits excellent electrical features, including a larger sensitive area volume, rapid charge collection, and good cell isolations. This approach has the potential to effectively expand the application scenarios of high-purity germanium detectors. Depending on different operational environments and requirements, nested complementary 3D trench electrode high-purity germanium detectors of appropriate structural dimensions can be chosen. The experimental findings of this study hold a significant reference value for enhancing the overall structure of high purity germanium detectors and facilitating their practical application in the future

Back-contact configuration energizes perovskite photovoltaic modules

In this viewpoint, recent hot topics in the photovoltaic community, interdigitated back contact (IBC) cells, are systematically reviewed from the view of device configuration. Two categories of IBC designs on the most popular perovskite solar cells (PSCs) were discussed, and a planar back-contact perovskite module was first proposed. The device configuration, fabrication methods, working mechanism, optimization strategies, and future development directions of this novel PSC module were put forward to show its superiorities in the module performance, processing difficulty, and extensible functionality among present perovskite modules, presenting promising potential to improve the competitiveness of perovskite technology in the photovoltaic market