Monitoring of soil moisture and irrigation forecast under the condition of drip irrigation in greenhouse

The accurate prediction of the soil moisture in greenhouse can improve the accuracy of irrigation forecast, thus saving water and increasing production. In this paper, the monitoring data were obtained from the greenhouse in Agricultural Demonstration Park of Northland Spring, Wuqing District, Tianjin. The soil moisture was predicted based on the GM (1,1) model, and the effect of water-saving and increased production was tested with the results of the economic irrigation research in the same area. The results show that the GM (1,1) model has a higher accuracy of soil moisture prediction. The correlation coefficient (R2) of the predicted value and the measured value is higher than 0.9; the small error probability P is 1; the mean relative prediction errors are all less than 0.1. Therefore, the GM (1,1) model can be used to predict soil moisture content

Research on Economic Irrigation Scheduling of Crops for Drip Irrigation in Greenhouse

Aiming at the problem of water waste in the traditional greenhouse vegetable irrigation, economic irrigation schedule of three kinds of vegetables (tomato, cucumber and eggplant) were studied. The experiment was carried out in the North Country Spring Agricultural Demonstration Park in Wuqing District, Tianjin, from April 2018 to December 2018. Three vegetables were tested in 100% (no drought) and 50% (drought) irrigation. The water balance method was used to simulate the change of soil moisture content under greenhouse drip irrigation. The crop coefficient parameters, the temperature stress index, water stress index and dry matter conversion factor were determined using the measured data. The results show that the parameters have good applicability and can be used to describe the effects of water and temperature stress on crop growth and yield. Based on the objective of maximum economic benefit per unit area, the economic irrigation schedule of crops was determined. The analysis showed that the use of the economic irrigation schedule can save the irrigation water and increase production

Adolescent Mouse Takes on An Active Transcriptomic Expression During Postnatal Cerebral Development

Postnatal cerebral development is a complicated biological process precisely controlled by multiple genes. To understand the molecular mechanism of cerebral development, we compared dynamics of mouse cerebrum transcriptome through three developmental stages using high-throughput RNA-seq technique. Three libraries were generated from the mouse cerebrum at infancy, adolescence and adulthood, respectively. Consequently, 44,557,729 (infancy), 59,257,530 (adolescence) and 72,729,636 (adulthood) reads were produced, which were assembled into 15,344, 16,048 and 15,775 genes, respectively. We found that the overall gene expression level increased from infancy to adolescence and decreased later on upon reaching adulthood. The adolescence cerebrum has the most active gene expression, with expression of a large number of regulatory genes up-regulated and some crucial pathways activated. Transcription factor (TF) analysis suggested the similar dynamics as expression profiling, especially those TFs functioning in neurogenesis differentiation, oligodendrocyte lineage determination and circadian rhythm regulation. Moreover, our data revealed a drastic increase in myelin basic protein (MBP)-coding gene expression in adolescence and adulthood, suggesting that the brain myelin may be generated since mouse adolescence. In addition, differential gene expression analysis indicated the activation of rhythmic pathway, suggesting the function of rhythmic movement since adolescence; Furthermore, during infancy and adolescence periods, gene expression related to axon repulsion and attraction showed the opposite trends, indicating that axon repulsion was activated after birth, while axon attraction might be activated at the embryonic stage and declined during the postnatal development. Our results from the present study may shed light on the molecular mechanism underlying the postnatal development of the mammalian cerebrum

Solar overall water-splitting by a spin-hybrid all-organic semiconductor

Abstract Direct solar-to-hydrogen conversion from pure water using all-organic heterogeneous catalysts remains elusive. The challenges are twofold: (i) full-band low-frequent photons in the solar spectrum cannot be harnessed into a unified S 1 excited state for water-splitting based on the common Kasha-allowed S 0  → S 1 excitation; (ii) the H+ → H2 evolution suffers the high overpotential on pristine organic surfaces. Here, we report an organic molecular crystal nanobelt through the self-assembly of spin-one open-shell perylene diimide diradical anions (:PDI2-) and their tautomeric spin-zero closed-shell quinoid isomers (PDI2-). The self-assembled :PDI2-/PDI2- crystal nanobelt alters the spin-dependent excitation evolution, leading to spin-allowed S 0 S 1  → 1 (TT) → T 1  + T 1 singlet fission under visible-light (420 nm~700 nm) and a spin-forbidden S 0  → T 1 transition under near-infrared (700 nm~1100 nm) within spin-hybrid chromophores. With a triplet-triplet annihilation upconversion, a newly formed S 1 excited state on the diradical-quinoid hybrid induces the H+ reduction through a favorable hydrophilic diradical-mediated electron transfer, which enables simultaneous H2 and O2 production from pure water with an average apparent quantum yield over 1.5% under the visible to near-infrared solar spectrum