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The reaction mechanism of palladium(0)-catalyzed reaction of aryl iodides, norbornene, and di-tert-butyldiaziridinone has been studied theoretically. Two reaction mechanisms were calculated. The reaction mechanism involving Cs2CO3combination first followed by alkene insertion is calculated to be preferred to the one in which alkene insertion occurs first followed by Cs2CO3combination. The calculations suggest that the reaction proceeds via C–I bond oxidative addition, CsI·CsCO3cluster anion formation, alkene insertion, C–H bond activation, N–N bond oxidative addition, and two successive C(sp2)–N bond-forming, and C(sp3)–N bond-forming reductive elimination steps. The N–N bond oxidative addition involves the rate-determining transition state with a free energy barrier of 29.4 kcal/mol. The role of base Cs2CO3played during CsI·CsCO3cluster anion formation and N–N bond oxidative addition process has been discussed according to the formation of relatively strong Pd–O bond. The role of base K2CO3has been calculated and compared with Cs2CO3.

This paper analyzes and studies the definition of the voltage transformer secondary load, examines the practical purposes of the measured values of the voltage transformer secondary load, and presents a variety of testing methods to analyze and compare the differences. This paper gives the test methods of the voltage transformer secondary load when the connection of the voltage transformer is the Y / Y in a three-phase three-wire power supply system, filling the blank of this type of test method in the industry. When other units within the industry carry out such work, the conclusions of this paper are available for reference, and the conclusions of this paper can be referred when drafting relevant regulations in the future.

Reported here is the Rh and Zn cocatalyzed [4 + 2] cycloaddition of newly designed yne-vinylcyclobutanones, which can generate 5/6 or 6/6 bicyclic products with an all-carbon quaternary bridgehead center. The reaction has a broad scope and can realize chirality transfer from enantioenriched substrates to the cycloadducts. The key to the success of this [4 + 2] reaction is the introduction of a vinyl group to cyclobutanones, which helps the C–C cleavage of vinylcyclobutanones via oxidative addition. This C–C cleavage step is synergistically aided by Zn coordination to the carbonyl group of vinylcyclobutanones. Of the same importance, visual kinetic analysis and computational studies have been carried out to support the dual activation in the rate-determining C–C cleavage, to derive the rate law of the [4 + 2] reaction, to understand another role of Zn in helping the in situ generation of the cationic Rh catalyst and preventing catalyst deactivation, and to analyze the key transition states and intermediates involved.

In order to clarify the influence of saline water irrigation to plant growth and distribution ofsoil water-salt, and providing theoretical basis for sustainable water supply of ecological constructionin desert area, the data of soil water-salt and plant growth was observed at Tarim Desert HighwayShelter-forest Ecological Project No. 17 well. The law of soil water and salt spatial distribution wasanalyzed, and the responses of plant growth to 4 different irrigation amounts were studied by singleelement variance analysis. The results were as follows: the soil water content reaches or is close tosaturation in layer of 100~120cm under the 420mm irrigation water condition; The soil water contentreaches or is close to saturation in layer of 160~180cm under the 233.1mm irrigation water condition;The soil water content reaches or is close to saturation in layer of 180~200cm under the 285.6mm irrigation water condition; The soil water content reaches or is close to saturation in layer of160~180cm under the 201.6mm irrigation water condition. The vertical distribution law of soilssalinity is that the soil salt can enter groundwater after 3 days of irrigation, and be gathered in 0~30cmsoil layer. There were no significant differences except the Tamarix plant height in plant growthindexes among 4 different irrigation quantities treatments.

Based on Life Cycle Cost Analysis for Endless Rope Winch, this paper introduces the new design concept-Design For Green Cost (DFGC), and describes the specific design and methods of Endless Rope Winch in saving energy, reducing cost and other aspects, so as to improve efficiency and the green degree of winches by the greatest extent

The aim of the system is to standardize coal miners’ safety behavior and reduce the occurrence of the accident. The paper introduces the overall design of the system and detailed analysis of the structure. All the models are built in 3D software for virtools4.0. The combination of the modules in virtools4.0 and scripts realize the function of each component. The control box based on PLC is developed on our own. The system provides the training miners with a realistic virtual environment through the virtual operating platform and hardware equipments. Compared to the traditional training methods, this system has great significance for improving the quality of training.