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The influence of inter-band rock on rib spalling in longwall panel with large mining height

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International Journal of Mining Science and Technology 2024年第4期34卷 427-442页

作者： Jiachen wang Meng Li zhaohui wang Zheng Li Han Zhang Shixiong Song School of Energy and Mining Engineering China University of Mining and Technology-BeijingBeijing 100083China Coal Industry Engineering Research Center of Top-coal Caving Mining Beijing 100083China Faculty of Engineering Hokkaido UniversitySapporo 060-8628Japan

In order to improve rib stability,failure criteria and instability mode of a thick coal seam with inter-band rock layer are analysed in this study.A three-dimensional mechanical model is established for the rib by considering the rock layer.A safety factor is defined foy the rib,and it is observed that the safety factor exhibits a positive correlation with the thickness and strength of the inter-band rock.A calculation method for determining critical parameters of the rock layer is presented to ensure the rib stability.It is revealed that incomplete propagation of the fracture at the hard rock constitutes a fundamental prerequisite for ensuring the rib stability.The influence of the position of the inter-band rock in the coal seam on failure mechanism of the rib was thoroughly investigated by developing a series of physical models for the rib at the face area.The best position for the inter-band rock in the coal seam is at a height of 1.5 m away from the roof line,which tends to provide a good stability state for the rib.For different inter-band rock positions,two ways of controlling rib by increasing supports stiffness and flexible grouting reinforcement are proposed.

关键词： Rib spalling Inter-band rock Large mining height Limit analysis Physical model experiment Numerical simulation

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

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Journal of Integrative Agriculture 2024年第3期23卷 836-848页

作者： Yingxia Dou Hubing Zhao Huimin Yang Tao wang Guanfei Liu zhaohui wang Sukhdev Malhi Coliege of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China Ministry of Agriculture and Rural AffairsYangling 712100China Department of Renewable Resources University of AlbertaEdmonton T6G 2H1Canada

Water is the key factor limiting dryland wheat grain yield.Mulching affects crop yield and yield components by affecting soil moisture.Further research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance analysis.The results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,respectively.The average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) treatment.There were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically signifiant.Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,respectively.The relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in CK.In terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three treatments.Based on the three analysis methods,we found that spike number and ET were positively correlated with grain yield.However,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in CK.Suifcient SWSSF could indirectly increase spike number and ET in the three treatments.Based on these results,mulch can improve yield an

关键词： dryland winter wheat plastic mulch spike number straw mulch

Implications of agricultural success in the Yellow River Basin and its strategy for green development

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Frontiers of Agricultural Science and Engineering 2024年第1期11卷 122-133页

作者： Gang HE zhaohui wang Qichao ZHU Jianbo SHEN Fusuo ZHANG College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Key Laboratory of Low-carbon Green Agriculture in Northwestern China Ministry of Agriculture and Rural AffairsBeijing 100125China College of Resources and Environmental Sciences National Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China

The Yellow River Basin is an important food production area and an ecological challenge for China, where environmental protection and water scarcity are the major constraints. For the upper reaches of the Yellow River Basin,optimizing the adoption of chemicals in agricultural production and integrating crops with livestock are the key strategies for protecting the eco-environment.For dryland agriculture in the middle and upper reaches, this study summarizes four aspects of efficient precipitation techniques in terms of collection,storage, conservation, and use, which have greatly improved crop yields and supported dryland crop production. Irrigated agriculture in the middle and lower reaches is the core area of China's grain production, where the area under water-saving irrigation reached 13.0 Mha in 2018, greatly improving water use. Compared with 1998, cereal production in 2018 increased by 62.2 Mt under similar total water withdrawals(49.7 billion to 51.6 billion m~3),and the annual soil erosion at the Tongguan Hydrological Observatory reduced by 584 million m~3 in 2018, achieving great success in environmental protection and efficient water use. The Chinese government has set a goal for the Yellow River Basin to become the national leader in environmental protection and efficient water use by 2035. Such a high demand requires the combined efforts of the whole community, as well as the adoption of new technologies,coordinated basin-wide development, and adequate policy support.

关键词： Ecological agriculture drylands agriculture irrigation water-saving technology policy support

Enhancing the deep-red/near-infrared fluorescence of higher rylene diimides via the chalcogen-annulation strategy

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Science China Chemistry 2024年第4期67卷 1324-1333页

作者： Kai Chen Xiao Chen Ke Hu Yilun Zhao Yujian Liu Guogang Liu Jinquan Chen Wei Jiang Zhigang Shuai Da-Hui Qu zhaohui wang Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Organic Optoelectronics and Molecular Engineering Department of ChemistryTsinghua UniversityBeijing 100084China State Key Laboratory of Precision Spectroscopy East China Normal University500 Dongchuan RoadShanghai 200241China

Deep-red/near-infrared fluorescence is highly suitable for bioimaging owing to its ability to deeply penetrate tissues,organs,and live animals.However,developing organic fluorophores with high deep-red/near-infrared fluorescence quantum yield(Φ_(FL))and fluorescent brightness remain a significant challenge owing to the energy gap law.Herein,we developed a straightforward and effective chalcogen-annulation strategy by introducing O,S and Se into the bay region of TDI and QDI fluorophores,realizing the increase ofΦFLand fluorescent brightness up to 10 times.To our best knowledge,this study potentially stands as the pioneering instance showcasing the anti-heavy-atom effect of chalcogens,and the absoluteΦFL(93%)and fluorescent brightness(128,200 cm^(-1)mol^(-1)L)of Se-TDI is among top deep-red/near-infrared organic fluorophores currently available.The femtosecond transient absorption(fs-TA)measurements show the absence of obvious changes of the excited state lifetime after the introduction of chalcogens in TDI and QDI fluorophores,indicating that intersystem crossing(ISC)can be neglected in TDI and QDI fluorophores.Theoretical calculations further reveal the chalcogen-annulation strategy increase the radiative rates and reduce the reorganization energy of several accepting modes at the ground state in TDI fluorophores,leading to the suppression of internal conversion(IC)processes.Our chalcogen-annulation strategy,which effectively increases the Φ_(FL)and restricts the IC processes,while remaining unaffected by the heavy-atom effect,offers novel insights and theoretical support for the design and synthesis of deep-red/near-infrared organic fluorophores with high Φ_(FL)and fluorescent brightness.

关键词： π-extended rylene diimides chalcogen-annulation strategy deep-red/near-infrared fluorescence

Synthesis,Structures,and Chiroptical Properties of NBN-Doped Helicenes with Boron Atoms in the Inner Rims

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Precision Chemistry

Precision Chemistry 2024年第1期2卷 28-39页

作者： Weiwen Zhuang Yujian Liu Ziqi Deng Yu Guo Philip C.Y.Chow David Lee Phillips Wei Jiang zhaohui wang Junzhi Liu State Key Laboratory of Synthetic Chemistry HKU-CAS Joint Laboratory on New Materials and Department of ChemistryThe University of Hong KongPokfulamHong KongChina Key Laboratory of Organic Optoelectronics and Molecular Engineering Department of ChemistryTsinghua UniversityBeijing 100084China Department of Mechanical Engineering The University of Hong KongPokfulamHong KongChina

The precise synthesis of helicenes with topologically defined length and specific heteroatomic perturbation in the screw-like conjugated skeletons plays an emerging role in the manipulation of chiral materials.Facile,selective,and programmable routes to helicenes or heterohelicenes are highly desirable yet challenging for structure-chiroptical property relationship studies.Herein,we report the synthesis and characterization of NBN-doped helicenes with boron atoms in the inner rims,enabled by the highly regioselective one-pot borylation of rationally designed precursors with,namely,fold-in or pan-out manner.The incorporation of nonbonded boron and nitrogen atoms resulted in narrow-band emission and improved optical properties for the single-stranded carbon helix.In addition,numbers and arrangement modes of fused six-membered rings have distinct effects on configurational stability and chiroptical properties,revealing that BN-[6]H with strong circular dichroism is a promising candidate for chiral sensors.The combination of experimental and theoretical studies on these helical structures might provide insights into the design of helically chiral small-molecule-based sensors or emitters.

关键词： Nitrogen-boron Helicenes Borylation Chiroptical properties Narrow-band emission

Optimized NPK fertilizer recommendations based on topsoil available nutrient criteria for wheat in drylands of China

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Journal of Integrative Agriculture 2024年第7期23卷 2421-2433页

作者： enjie Yang Jie Yu Yanhang Li Bingli Jia Longgang Jiang Aijing Yuan Yue Ma Ming Huang Hanbing Cao Jinshan Liu Weihong Qiu zhaohui wang Key Laboratory of Plant Nutrition and Agri-environment in Northwest China Ministry of Agriculture and Rural Affairs/College of Natural Resources and EnvironmentNorthwest A&F UniversityYangling 712100China

The optimized management of crop fertilization is very important for improving crop yield and reducing the consumption of chemical fertilizers.Critical nutrient values can be used for evaluating the nutritional status of a crop,and they reflect the nutrient concentrations above which the plant is sufficiently supplied for achieving the maximum potential yield.Based on on-farm surveys of 504 farmers and 60 field experimental sites in the drylands of China,we proposed a recommended fertilization method to determine nitrogen(N),phosphorus(P),and potassium(K)fertilizer input rates for wheat production,and then validated the method by a field experiment at 66 different sites in northern China.The results showed that wheat grain yield varied from 1.1 to 9.2 t ha^(-1),averaging 4.6 t ha^(-1),and it had a quadratic relationship with the topsoil(0-20 cm)nitrate N and soil available P contents at harvest.However,yield was not correlated with the inputs of N,P,and K fertilizers.Based on the relationship(exponential decay model)between 95–105%of the relative yield and topsoil nitrate N,available P,and available K contents at wheat harvest from 60 field experiments,the topsoil critical nutrient values were determined as 34.6,15.6,and 150 mg kg^(-1)for soil nitrate N,available P,and available K,respectively.Then,based on five groups of relative yield(>125%,115–125%,105–115%,95–105%,and<95%)and the model,the five groups of topsoil critical nutrient levels and fertilization coefficients(Fc)were determined.Finally,we proposed a new method for calculating the recommended fertilizer input rate as:Fr=Gy×Nr×Fc,where Fr is the recommended fertilizer(N/P/K)input rate;Gy is the potential grain yield;Nr is the N(N_(rN)),P(N_(rP)),and K(N_(rK))nutrient requirements for wheat to produce 1,000 kg of grain;and Fc is a coefficient for N(N_c)/P(P_c)/K(K_c)fertilizer.A 2-year validated experiment confirmed that the new method reduced N fertilizer input by 17.5%(38.5 kg N ha^(-1))and P fertilizer input by 43.5%(57.5 kg P_2O_5 ha^(-1))in northern

关键词： fertilization method dryland wheat soil nutrient critical value soil nitrogen topsoil nutrients

Introducing urea into tirapazamine derivatives to enhance anticancer therapy

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National Science Review 2024年第4期11卷 245-253页

作者： Yajun Xu Jianlin Lv Chaoying Kong Ya Liu Kun wang zhaohui Tang Xuesi Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China

Tirapazamine（TPZ） has been approved for multiple clinical trials relying on its excellent anticancer potential.However,as a typical hypoxia-activated prodrug（HAP）,TPZ did not exhibit survival advantages in Phase Ⅲ clinical trials when used in combination therapy due to the insufficient hypoxia levels in patients' tumors.In this study,to improve the therapeutic effects of TPZ,we first introduced urea to synthesize a series of urea-containing derivatives of TPZ.All urea-containing TPZ derivatives showed increased hypoxic cytotoxicity（9.51-30.85-fold） compared with TPZ,while maintaining hypoxic selectivity.TPZP,one of these derivatives,showed 20-fold higher cytotoxicity than TPZ while maintaining a similar hypoxic cytotoxicity ratio.To highly efficiently deliver TPZP to the tumors and reduce its side effects on healthy tissues,we further prepared TPZP into a nanodrug with fibrin-targeting ability:FT11-TPZP-NPs.CA4-NPs,a vascular disrupting agent,was used to increase the fibrin level within tumors and exacerbate tumor hypoxia.By being combined with CA4-NPs,FT11-TPZP-NPs can accumulate in the hypoxia-aggravated tumors and activate sufficiently to kill tumor cells.After a single-dose treatment,FT11-TPZP-NPs+CA4-NPs showed a high inhibition rate of 98.1% against CT26 tumor models with an initial volume of ～480 mm3and four out of six tumors were completely eliminated;it thereby exerted a significant antitumor effect.This study provides a new strategy for improving the therapeutic effect of TPZ and other HAPs in anticancer therapy.

关键词： tirapazamine vascular disrupting agent hypoxia-activated prodrug combretastatin A4 urea

A Novel Sensing Imaging Equipment Under Extremely Dim Light for Blast Furnace Burden Surface:Starlight High-Temperature Industrial Endoscope

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 893-906页

作者： Zhipeng Chen Xinyi wang Weihua Gui Jilin Zhu Chunhua Yang zhaohui Jiang The authors are with the School of Automation Central South UniversityChangsha 410083China

Blast furnace(BF)burden surface contains the most abundant,intuitive and credible smelting information and acquiring high-definition and high-brightness optical images of which is essential to realize precise material charging control,optimize gas flow distribution and improve ironmaking efficiency.It has been challengeable to obtain high-quality optical burden surface images under high-temperature,high-dust,and extremelydim(less than 0.001 Lux)environment.Based on a novel endoscopic sensing detection idea,a reverse telephoto structure starlight imaging system with large field of view and large aperture is designed.Combined with a water-air dual cooling intelligent self-maintenance protection device and the imaging system,a starlight high-temperature industrial endoscope is developed to obtain clear optical burden surface images stably under the harsh environment.Based on an endoscope imaging area model,a material flow trajectory model and a gas-dust coupling distribution model,an optimal installation position and posture configuration method for the endoscope is proposed,which maximizes the effective imaging area and ensures large-area,safe and stable imaging of the device in a confined space.Industrial experiments and applications indicate that the proposed method obtains clear and reliable large-area optical burden surface images and reveals new BF conditions,providing key data support for green iron smelting.

关键词： Blast furnace(BF) burden surface extremely dim light industrial endoscope sensing imaging starlight

Revolutionary entrapment model of uniformly distributed swarm robots in morphogenetic formation

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Defence Technology（防务技术） 2024年第1期31卷 496-509页

作者： Chen wang zhaohui Shi Minqiang Gu Weicheng Luo Xiaomin Zhu Zhun Fan Shantou University ShantouGuangdongChina National University of Defense Technology ChangshaChina Key Lab of Digital Signal and Image Processing of Guangdong Province China

This study proposes a method for uniformly revolving swarm robots to entrap multiple targets,which is based on a gene regulatory network,an adaptive decision mechanism,and an improved Vicsek-model.Using the gene regulatory network method,the robots can generate entrapping patterns according to the environmental input,including the positions of the targets and obstacles.Next,an adaptive decision mechanism is proposed,allowing each robot to choose the most well-adapted capture point on the pattern,based on its environment.The robots employ an improved Vicsek-model to maneuver to the planned capture point smoothly,without colliding with other robots or obstacles.The proposed decision mechanism,combined with the improved Vicsek-model,can form a uniform entrapment shape and create a revolving effect around targets while entrapping them.This study also enables swarm robots,with an adaptive pattern formation,to entrap multiple targets in complex environments.Swarm robots can be deployed in the military field of unmanned aerial vehicles’(UAVs)entrapping multiple targets.Simulation experiments demonstrate the feasibility and superiority of the proposed gene regulatory network method.

关键词： Swarm intelligence Revolutionary entrapment Flocking Robots Gene regulatory network Vicsek-model Entrapping multiple targets