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

Study on the breakdown characteristics of multiple-reignition secondary arcs on EHV/UHV transmission lines

A long-gap AC arc with a length of more than ten meters (secondary arc) are normally generated at the short-circuit arc channel after a single-phase-to-ground fault. In previous studies, arc breakdowns of secondary arcs have mainly been considered as electrical breakdowns, ignoring the role of heat in the arc channel. Besides, the extinction-reignition theory of secondary arc, i.e., dielectric strength recovery theory, still lack the support of experimental data. In this study, based on the equivalent experiments performed in the laboratory, the influences of compensation degree of transmission lines, initial recovery voltage gradient of air gap, test current, wind speed, and wind direction on the breakdown characteristics of secondary arcs are studied and statistically analyzed. The laws of the transient recovery voltage (TRV) and of the rate of rise of recovery voltage (RRRV) also studied by considering the influencing factors mentioned above. The results of this study will provide a more complete experimental basis for the theory of extinction–reignition of secondary arcs and a deeper understanding of the transient characteristics of arc breakdow

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Servo constraint control for mechanical systems: friction force depending on control design

In this paper, the problem of motion of controlled mechanical systems under a servo constraint is considered. The servo constraint which is prescribed by the designer is supposed to be non-ideal, that is, it does work in a virtual displacement. The second order form constraint is introduced to obtain a closed-form (i.e., analytical form) control input. The final servo control contains two parts: the first one generates the constraint force so that the constraint is exactly followed, while the second one can be designed by the designer for the facility, such as to compensate the effects of the friction force. After geometrical analysis applied to the Coulomb friction forces, we found that they actually depend on the control forces (i.e., the two are coupled). Application to a 3-DOF robot manipulator is made

Composition of plagioclases in volcanic rocks of King George Island, Antarctica with reference to the petrogenetic significance

Plagioclases occur mainly as phenocrysts in volcanic rocks of King George Island, South Shetland Islands, West Antarctica. In basaltic andesites and andesites of Keller Peninsula and Ullman Spur (Admiralty Bay), they are high structure state labradorite-andesines; and in high-Al basalts and basaltic andesites of Barton and Weaver peninsulas (Maxwell Bay), they are high structure state bytownite-anorthites. ΣREE, La/Yb ratios and δEu values of plagioclases from Admiralty Bay are higher than those from Maxwell Bay. All plagioclases have rather identical chondrite-normalized transitional element distribution patterns, probably reflecting that crystal structure rather than composition of plagioclase controls their diversity. Compositions of plagioclases depend chiefly on those of their host rocks, compositional differences of plagioclases reveal that basaltic magmas in the Admiralty Bay are are more evolved than in Maxwell Bay area

A New Approach to the Robust Control Design of Fuzzy Automated Highway Systems

In this paper, a new approach to the decentralized control design for vehicle platooning for uncertain automated highway systems is proposed. The uncertainty in the system, which is nonlinear and (possibly) fast time-varying, is bounded. The bound is assumed to be within a prescribed fuzzy set. A creative transformation is made to the system, which converts a local problem to a global problem. Based on the fuzzy description of the uncertainty bound and the transformation, a class of decentralized control is proposed in which each vehicle only needs the knowledge of its preceding vehicle in the platoon. No acceleration feedback or the information of the leading vehicle is required. Both the vehicle platooning system and the control are deterministic, hence not if-then fuzzy rule-based. The performance of the resulting controlled system is twofold. First, the collision avoidance performance is guaranteed under any safe initial conditions regardless of the value of the uncertainty. Second, the minimization of a fuzzy-based performance index is guaranteed based on an optimal choice of a control design parameter. Numerical simulations are conducted to validate the efficiency of the proposed algorithm

Purity and Authenticity Identification of 'Yuexiu No.3' Cucumber Hybrid Seeds Based on SSR Molecular Markers

【Objective】'Yuexiu No.3' cucumber is a variety that is widely promoted in the South China region due to its strong growth, high yield, disease resistance, and stress tolerance. This study aims to establishing a rapid, accurate and effective method for seed purity identification.【Method】200 pairs of primers were used to select SSR markers with specificity based on the principle of complementary band pattern between the parents and 'Yuexiu No.3'. The seed purity identification results obtained using these primers were compared with the field biological identification results to verify their accuracy. The seeds of five cucumber varieties 'Zhongnong 108', 'Yuanfeng No.6', 'Jinlv No.5', 'Zhongnong No.8' and 'Jinyan No.4' and other 49 cucumber germplasm materials were selected and detected simultaneously with ' Yuexiu 3 ' cucumber varieties to identify the specificity of the selected SSR primers.【Result】Two pairs of SSR primers (3B-10 and 2B-41) were screened out from 200 pairs of primers that met the requirement of forming complementary bands between parental bands, PCR amplification using the 3B-10 primer produced a 160 bp maternal-specific band (P1-A) and a 190 bp paternal-specific band (P2-B). By comparing the sequencing results of the specific bands (P1-A, P2-B), it was found that the P2-B had an additional 6-base simple repeat sequence compared to the P1-A at positions 49-79 bp. PCR amplification using the 2B-41 primer produced a 218 bp maternal-specific band (P1-C) and a 206 bp paternal-specific band (P2-D). By comparing the sequencing results of the specific bands(P1-C, P2-D), it was found that the P1-C had a deletion of 12 bases compared to the P2-D at positions 120-131 bp. The results showed that these two pairs of SSR primers were able to effectively distinguish 'Yuexiu No.3' hybrid seeds from their parents and accurately identify the seed purity of 'Yuexiu No.3' cucumbers. In addition, the seed purity identification results of the two pairs of SSR primers were consistent with the field biological identification results. Both pairs of primers were capable of effectively distinguishing the 'Yuexiu No.3' cucumber seeds from the seeds of five other cucumber varieties, namely 'Zhongnong 108', 'Yuanfeng No.6', 'Jinlv No.5', 'Zhongnong No.8'and 'Jinyan No.4', as well as 49 other germplasm resources. However, among these 49 germplasm resources, 3B-10 displayed a higher level of polymorphism. Therefore, SSR marker 2B-41 was more suitable for confirming the authenticity of the 'Yuexiu No.3' cucumber variety.【Conclusion】The 3B-10 and 2B-41 pairs of SSR primers can rapidly, accurately and efficiently identify the purity of 'Yuexiu No.3' hybrid cucumber seeds. The identification is simple and low cost, which can replace the traditional method of hybrid seed purity identification, and has high commercial application value

Volcanic geology of Admiralty Bay, King George Island, Antarctica

At Admiralty Bay of central King George Island, Keller Peninsula, Ullman Spur and Point Hennequin are main Tertiary volcanic terranes. Field investigation and isotopic datings indicate that, there occurred three periods of eruptions (three volcanic cycles) and accompanying N-toward migration of the volcanic center on Keller Peninsula. After the second period of eruptions, the crater collapsed and a caldera was formed, then later eruptions were limited at the northern end of the peninsula and finally migrated to Ullman Spur. Thus Keller Peninsula is a revived caldera, and its volcanism migrated toward E with time. Point Hennequin volcanism happened more or less simultaneously with the above two areas, but has no clear relation in chemical evolution with them, frequently it belongs to another independent volcanic center

Downregulation of CRABP2 Inhibit the Tumorigenesis of Hepatocellular Carcinoma In Vivo and In Vitro

Cellular retinoic acid-binding protein 2 (CRABP2) binds retinoic acid (RA) in the cytoplasm and transports it into the nucleus, allowing for the regulation of specific downstream signal pathway. Abnormal expression of CRABP2 has been detected in the development of several tumors. However, the role of CRABP2 in hepatocellular carcinoma (HCC) has never been revealed. The current study aimed to investigate the role of CRABP2 in HCC and illuminate the potential molecular mechanisms. The expression of CRABP2 in HCC tissues and cell lines was detected by western blotting and immunohistochemistry assays. Our results demonstrated that the expression levels of CRABP2 in HCC tissues were elevated with the tumor stage development, and it was also elevated in HCC cell lines. To evaluate the function of CRABP2, shRNA-knockdown strategy was used in HCC cells. Cell proliferation, metastasis, and apoptosis were analyzed by CCK-8, EdU staining, transwell, and flow cytometry assays, respectively. Based on our results, knockdown of CRABP2 by shRNA resulted in the inhibition of tumor proliferation, migration, and invasion in vitro, followed by increased tumor apoptosis-related protein expression and decreased ERK/VEGF pathway-related proteins expression. CRABP2 silencing in HCC cells also resulted in the failure to develop tumors in vivo. These results provide important insights into the role of CRABP2 in the development and development of HCC. Based on our findings, CRABP2 may be used as a novel diagnostic biomarker, and regulation of CRABP2 in HCC may provide a potential molecular target for the therapy of HCC