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【Objective】 In view of the lack of integrated facilities for measuring and controlling flow of Doudou (agricultural) channel in irrigation area, an integrated quantity control building-Measurement and Control Integrated Water Distribution Farm Gate was designed to explore its performance on trapezoidal channel. 【Method】 Using the combination of agricultural gate control disc valve and circular pipe to form an integrated water distribution gate (hereinafter referred to as the water distribution gate), the hydraulic characteristics and flow formulas of the water distribution gate under different flow rates and different opening of the agricultural gate control disc valve are studied by model test. 【Result】 ①The flow formula of Water Distribution Farm Gate was fitted and designed. The average error of the flow calculated by the formula was 4.34% compared with the measured flow, and the measurement error of flow was less than ±5%, which met the water accuracy requirements of irrigation area. ②The “optimal water head” of Water Distribution Farm Gate is between 0.475 and 0.575 L in the overall length of the pipeline.③The water distribution gate mainly produces local head loss and head loss along the distance when the water flow passes through the disc valve, and the range of head loss is 29.54% to 38.89%. 【Conclusion】 When the flow rate is in the range of 30 - 65 m3/h, under different flow conditions and disc valve opening degree, the water metering can be carried out in the final channel of the irrigation area. Therefore, Water Distribution Farm Gate has a high prospect of popularization and practical application value in the future.

[Purpose/Significance] This article uses some projects'peer review results as an example to explore the effectiveness of peer review based on expert knowledge. [Method/Process] It uses data envelopment analysis to measure the R&D efficiency of the projects. The evaluation model is a CCR model modified by super-efficiency, and the efficiency index is used as a verification standard for the effectiveness of peer review results. The data source is 126 "948 projects" implemented by the State Forestry Administration, covering 13 input and output evaluation indicators. [Results/Conclusions] The experiment found that there was a moderate positive correlation between the project peer review results and the actual R&D efficiency (DEA super efficiency), and the Spearman correlation coefficient ρ=0.250 (Sig.

In this work, layer-by-layer organic photovoltaics (LbL OPVs) were prepared by sequentially spin-coating PM1 and L8-BO solutions. The solvent additive 1,8-diiodooctane (DIO), which has a high boiling point, and solid additive l,3,5-trichlorobenzene (TCB), which has a high volatile, were deliberately selected to incorporate with the L8-BO solutions. The power conversion efficiency (PCE) of LbL OPVs was considerably enhanced from 17.43% to 18.50% by employing TCB as the additive, profiting by the concurrently increased short-circuit current density (JSC) of 26.74 mA cm−2 and a fill factor (FF) of 76.88%. The increased JSCs of LbL OPVs with TCB as additive were ascribed to the tilted-up absorption edge in the long wavelength range and the external quantum-efficiency spectral difference between LbL OPVs with and without TCB as an additive. The molecular arrangement of L8-BO and the PM1 domain was enhanced with TCB as an additive, which was most likely responsible for the increased charge mobilities in the layered films processed with additives. It was indicated that the dynamic film-forming process of the acceptor layers plays a vital role in achieving efficient LbL OPVs by employing additive strategy. Over 6% PCE improvement of the LbL OPVs with PM1/L8-BO as the active layers can be achieved by employing TCB as additive. [ABSTRACT FROM AUTHOR]

In this work, pseudo-bilayer planar heterojunction (PPHJ) all-polymer solar cells (APSCs) were constructed on the basis of the commonly used PY-IT and PM6 as the acceptor and donor, respectively. A nonfullerene small molecular acceptor (NF-SMA) BTP-eC9 was incorporated into the PY-IT layer as the solid additive in consideration of its similar building block to PY-IT. BTP-eC9 can serve as a photon capture reinforcer and morphology-regulating agent to realize more adequate photon capture, as well as a more orderly molecular arrangement for effective carrier transport. By incorporating 2 wt% BTP-eC9, the efficiency of PM6/PY-IT-based PPHJ-APSCs was boosted from 15.11% to 16.47%, accompanied by a synergistically enhanced short circuit current density (JSC, 23.36 vs. 24.08 mA cm−2) and fill factor (FF, 68.83% vs. 72.76%). In another all-polymer system, based on PBQx-TCl/PY-DT as the active layers, the efficiency could be boosted from 17.51% to 18.07%, enabled by the addition of 2 wt% L8-BO, which further verified the effectiveness of using an NF-SMA as a solid additive. This work demonstrates that incorporating an NF-SMA as a solid additive holds great potential for driving the development of PPHJ-APSCs. [ABSTRACT FROM AUTHOR]

As construction continues, a large number of concrete engineering facilities will be put into use in permafrost areas, which poses a challenge to the long-term service of concrete materials. To investigate the evolution of strength and pore structure of concrete under the cold permafrost environment, concrete compressive strength tests and mercury intrusion tests were performed at four molding temperatures (5°C, 10°C, 15°C, and 20°C) under continuous −5°C curing and standard curing conditions. Under negative-temperature curing, the strength of concrete at an early age reached about 80% that of standard curing; however, its strength at a later age was comparable to that at 28 days under standard curing. Under negative-temperature curing, the most probable pore size and porosity at 28 days of age were larger than those under standard curing. Increasing the molding temperature was beneficial for the promotion of the internal hydration reaction of concrete, refining its microscopic pore structure, and promoting its strength development. The strength of concrete with different porosities and average pore diameters could be predicted better using the Atzeni model or the bivariate Hasselmann model. Based on maturity theory, an equivalent age model of concrete under a permafrost temperature environment was established. The prediction deviation of the model was controlled within ±5% , so the model can be used to predict the time-dependent strength of concrete in permafrost zones. [ABSTRACT FROM AUTHOR]