检索结果-南通市图书馆

Microstructure evolution and mechanical properties of PESR 55Cr17Mo1VN plastic die steel during quenching and tempering treatment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2021年第12期28卷 1625-1633页

作者： Cong-peng Kang Fu-bin Liu huai-bei Zheng hua-bing Li Zhou-hua Jiang Kui Chen Hao-yang Suo Xin-hao Yu School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan114002LiaoningChina

55Cr17Mo1VN high nitrogen martensitic stainless steel is usually applied to the high-quality mold,which is largely produced by the pressurized electro slag remelting *** microstructure evolution of quenching and tempering heat treatment were investigated and an optimal heat treatment process to achieve excellent mechanical properties was found *** main precipitates in the steel included carbon-rich type M_(23)C_(6) and nitrogen-rich type M_(2)*** increasing austenitizing temperature,the equivalent diameter of the precipitates got fined,and retained austenite content increased significantly when the austenitizing temperature exceeded 1020℃.The fracture mode gradually changed from brittle fracture to ductile fracture with increasing tempering temperature from 200 to 550℃.The experimental steel tempered at 350℃ achieved a good combination of hardness(60.6 HRC)and strength(2299.2 MPa)to meet service *** M_(23)C_(6) precipitated along martensite lath boundaries and the secondary hardening phenomenon occurred when the tempering temperature was 450℃.Due to the high nitrogen content,M_(2)N precipitated from the inside of laths and matrix when tempered at 550℃.

关键词： Microstructure Mechanical property Plastic die steel Quenching Tempering Precipitate

玉米大豆间作对喀斯特区土壤理化性质及微生物碳代谢特征的影响

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

作物学报 2025年第1期51卷 273-284页

作者：钱玉平宿兵兵高吉星阮粉花李亚伟茅林春滇西应用技术大学普洱茶学院云南普洱665000 兰州交通大学环境与市政工程学院甘肃兰州730070 甘肃省农业科学院作物研究所甘肃兰州730070 浙江大学生物系统工程与食品科学学院浙江杭州310000

为探明喀斯特区玉米大豆带状复合种植对土壤理化性质及微生物群落结构多样性的影响,本研究设置玉米大豆间作(MSI)、玉米单作(MM)和大豆单作(SM) 3种模式,采用Biolog-ECO微孔培养法,旨在揭示玉米大豆种植模式对土壤微生物碳源代谢活性、... 详细信息

为探明喀斯特区玉米大豆带状复合种植对土壤理化性质及微生物群落结构多样性的影响,本研究设置玉米大豆间作(MSI)、玉米单作(MM)和大豆单作(SM) 3种模式,采用Biolog-ECO微孔培养法,旨在揭示玉米大豆种植模式对土壤微生物碳源代谢活性、多样性以及土壤性质的影响及其机制。结果表明,与MM及SM相比, MSI土壤微生物群落丰富度指数(McIntoshindex)分别显著提高了11.90%和58.40%,平均颜色变化率(averagewellcolordevelopment, AWCD)分别显著增加了24.50%和80.10%,羧酸类、氨基酸类和酚酸类碳源的平均相对吸光度分别显著提高了34.50%、63.70%和61.80%;碳源代谢指纹图谱表明,MSI模式中土壤微生物通过提高衣康酸的代谢活性进而增加了对羧酸类碳源的利用,通过提高L-苯丙氨酸、L-苏氨酸和甘氨酰-L-谷氨酸的代谢活性从而增加了氨基酸类碳源利用,通过提高吐温40、吐温80和肝糖的代谢活性从而增加了对多聚类碳源的利用;同时, MSI处理土壤SOC分别较MM和SM显著提高8.50%和72.84%, NH_4~+-N和TN含量分别较SM处理显著增加46.70%和33.30%;主成分分析表明,提取的2个主成分解释了碳源利用总变异的79.69%,种植模式对碳源代谢的综合利用能力表现为MSI>MM>SM,其中MSI土壤微生物群落对羧酸类、氨基酸类和多聚类代谢利用能力最强;冗余分析则表明,显著影响碳源代谢利用的2个环境因子分别是TN (53.50%)和SOC (30.90%),其中TN促进了羧酸类和氨基酸类碳源的代谢利用, SOC加强了胺类和酚酸类碳源的利用。综上可见,玉米大豆间作模式土壤微生物碳代谢的偏好性主要由微生物群落结构多样性引起,同时又受土壤全氮和有机质含量的调控,表明微生物群落结构与土壤理化因子间的互作可能是大豆玉米复合种植增产增效的一个关键因素。

关键词：玉米大豆土壤微生物碳源代谢活性土壤理化性质 Biolog-ECO

Yield potential and nitrogen use efficiency of China's super rice

同方期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2017年第5期16卷 1000-1008页

作者： WANG Fei peng Shao-bing National Key Laboratory of Crop Improvement Huazhong Agricultural UniversityWuhan 430070P.R.China Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River Ministry of Agriculture/College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan 430070P.R.China

In 1996, a mega project that aimed to develop rice varieties with super-high yield potential （super rice） was launched by the Ministry of Agriculture （MOA） in China using a combination of the ideotype approach and intersubspecific heterosis. Significant progress has been made in the last two decades, with a large number of super rice varieties being approved by the MOA and the national average grain yield being increased from 6.21 t ha^-1 in 1996 to 6.89 t ha^-1 in 2015. The increase in yield potential of super rice was mainly due to the larger sink size which resulted from larger panicles. Moreover, higher photosynthetic capacity and improved root physiological traits before heading contributed to the increase in sink size. However, the poor grain filling of the later-flowering inferior spikelets and the quickly decreased root activity of super rice during grain filling period restrict the achievement of high yield potential of super rice. Furthermore, it is widely accepted that the high yield potential of super rice requires a large amount of N fertilizer input, which has resulted in an increase in N consumption and a decrease in nitrogen use efficiency （NUE）, although it remains unclear whether super rice per se is responsible for the latter. In the present paper, we review the history and success of China＇s Super Rice Breeding Pro- gram, summarize the advances in agronomic and physiological mechanisms underlying the high yield potential of super rice, and examine NUE differences between super rice and ordinary rice varieties. We also provide a brief introduction to the Green Super Rice Project, which aims to diversify breeding targets beyond yield improvement alone to address global concerns around resource use and environmental change. It is hoped that this review will facilitate further improvement of rice production into the future.

关键词： super rice yield potential nitrogen use efficiency Green Super Rice

Invariant Sets and Exact Solutions to Nonlinear Diffusion Equations with x-Dependent Convection and Absorption

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第10期50卷 821-826页

作者： JIA hua-bing XU Wei Department of Applied Mathematics Northwestern Polytechnical University Xi＇an 710072 China Department of Matheinatics Baoji University of Arts and Sciences Baoji 721013 China

In this paper, we introduce a new invariant set Eo={u：ux=f＇（x）F（u）＋ε[g＇（x）-f＇（x）g（x）]F（u）×exp（-∫^u1/F（z）dz）}where f and g are some smooth functions of x, ε is a constant, and F is a smooth function to be determined. The invariant sets and exact sohltions to nonlinear diffusion equation ut = （ D（u）ux）x ＋ Q（x, u）ux ＋ P（x, u）, are discussed. It is shown that there exist several classes of solutions to the equation that belong to the invariant set Eo.

关键词： invariant set exact solution nonlinear diffusion equations rotation group scaling group

Emergency laparoscopic partial splenectomy for ruptured spleen:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第46期20卷 17670-17673页

作者： Yun-Qiang Cai Chun-Lin Li hua Zhang Xin Wang bing peng Department of Hepatopancreatobiliary Surgery West China HospitalSichuan University

Splenic rupture is a common consequence of blunt abdominal trauma. Emergency splenectomy is indicated when conservative management is not effective. With better understanding of the immunologic function of the spleen, surgeons have begun to perform the splenic-preserving surgery. However, it is technical challenge to perform emergency laparoscopic partial splenectomy for patient with spleen rupture. A 15-year-old male patient suffered from grade. spleen injury basing on the American association for the surgery of trauma splenic injury scale. Conservative treatment failed to success basing on the dramatically decreased hemoglobin level. During the laparoscopic exploration, we found that two individual ruptures were associated with the upper pole of spleen. An emergency laparoscopic partial splenectomy was successfully carried out. The operative time was approximate 150 min and the estimated blood loss was 200 mL. The post-operative course was uneventful and the patient was discharged on the 7th post-operative day. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

关键词： Laparoscopy Minimal invasive Partial splenectomy Splenic rupture Splenic trauma

Fractional derivative statistical damage model of unsaturated expansive soil based on unified hydraulic effect

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第9期20卷 2769-2782页

作者： ZHANG hua WANG peng School of Architecture and Civil Engineering Chengdu UniversityChengdu 610106China Sichuan Provincial Engineering Research Center of City Solid Waste Energy and Building Materials Conversion and Utilization Technology Chengdu UniversityChengdu 610106China Geotechnical Engineering Institute Sichuan Institute of Building ResearchChengdu 610081China Sichuan Engineering Research Center for Mechanical Properties and Engineering Technology of Unsaturated Soils Chengdu UniversityChengdu 610106China

Unsaturated expansive soil is widely distributed in China and has complex engineering *** paper proposes the unified hydraulic effect shear strength theory of unsaturated expansive soil based on the effective stress principle,swelling force principle,and soil–water *** the viscoelasticity and structural damage of unsaturated expansive soil during loading,a fractional hardening–damage model of unsaturated expansive soil was *** model parameters were established on the basis of the proposed calculation method of shear strength and the triaxial shear experiment on unsaturated expansive *** proposed model was verified by the experimental data and a traditional damage *** proposed model can satisfactorily describe the entire process of the strain-hardening law of unsaturated expansive ***,by investigating the damage variables of the proposed model,it was found that:(a)when the values of confining pressure and matric suction are close,the coupling of confining pressure and matric suction contributes more to the shear strength;(b)there is a damage threshold for unsaturated expansive soil,and is mainly reflected by strength criterion of infinitesimal body;(c)the strain hardening law of unsaturated expansive soil is mainly reflected by fractional derivative operator.

关键词： Unsaturated expansive soil Unified hydraulic effect Shear strength theory Hardening-damage model Fractional derivative

Microglial Calcium:An Exquisite Sensor for Neuronal Activity

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2021年第4期37卷 582-584页

作者： Jiyun peng bing-Xing Pan Institute of Life Science Nanchang UniversityNanchang330031China

With the development of in vivo imaging techniques,it was discovered early in this century that microglia are highly dynamic even in the resting state[1].However,for over a decade,little has been learned about how the... 详细信息

关键词： dynamic vivo resting

Lower Bounds for Moments of Quadratic Twisted Self-dual GL(3)Central L-values

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2023年第11期39卷 2139-2148页

作者： Sheng Hao hua bing Rong huaNG Data Science Institute and School of Mathematics Shandong UniversityJi’nan 250100P.R.China

In this paper,we prove the conjectured order lower bound for the k-th moment of central values of quadratic twisted self-dual GL(3)L-functions for all k≥1,based on our recent work on the twisted first moment of centr... 详细信息

关键词： GL(3)cusp form lower bound quadratic twist central value L-function

Connection Between Continuous Optimization and Turán Densities of Non-uniform Hypergraphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2021年第4期37卷 858-866页

作者： Xiao-bing GUO Yue-jian peng School of Mathematics Hunan UniversityChangsha410082China

A classical result of Motzkin and Straus established the connection between the Lagrangian of a graph and its maximum *** it,they gave a new proof of Turán’s *** aroused the interests in studying the connection between continuous optimization and extremal problems in *** 2009,*** Bulòand *** extended the result of Motzkin-Straus to r-uniform ***,Johnston and Lu initiated the study of the Turán density of a non-uniform *** optimization problems related to several types of non-uniform hypergraphs and its applications on Turán densities have also been *** this paper,we obtain a Motzkin-Straus type of results for all non-uniform *** it,we give an upper bound of the Turán density of a complete non-uniform hypergraph.

关键词： hypergrapli maximum clique polynomial optimization