检索结果-南通市图书馆

Effect of Long-Term Fertilization on Soil Enzyme Activities Under Different Hydrothermal Conditions in Northeast China

引用

Agricultural Sciences in China 2011年第3期10卷 412-422页

作者： jiao xiao-guang GAO Chong-sheng LU Guo-hong SUI Yu-yu iang University Harbin 150080 P.R. China Northeast Institute of Geography and Agri-Ecology Chinese Academy of Sciences Harbin 150040 P.R.China Shenyang Institute of Atmospheric Environment Chinese Meteorological Administration Shenyang 110016 P.R.China Shenyang Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 P.R.China

Human activities have altered weather patterns by causing an increase in greenhouse gas. The effects of climate change have been studied, including effects on some ecosystems throughout the world. There are many studies on changes in the soil due to climate change, but much of them did not extend their research to soil enzyme that integrates information on soil microbial status and soil physical-chemical conditions. Meanwhile, there are lots of experimental fields established to study effects of long-term fertilization on soil enzyme activities, but many did not compare the difference of soil enzyme activities and did not analyze the effect of climatic factors on soil enzyme activities with long-term fertilization under different hydrothermal conditions. In this study, we compared soil enzyme activities of three long-fertilization stations which had different hydrothermal conditions in Northeast China, and analyzed the relationship of hydrothermal condition, soil chemical properties with soil enzyme activities. Hydrothermal conditions （annual temperature and total rainfall） decreased in order of Gongzhuling （Jilin Province, China ） Harbin （Heilongjiang Province, China） Heihe （Heilongjiang Province, China） over the course of the long-term fertilization experiment. Sunshine hours showed the longest in Gongzhuling, the second in Heihe, and the last in Harbin. However, the order of soil enzymes was not in agreement with hydrothermal conditions. Overall, the order of soil enzymes for the same treatment among three stations was consistent in 2008 with in 2009. Correlation analysis demonstrated that different soil enzymes achieved the different affected levels by climatic factors under different fertilization treatments. Urease activity showed a significant relationship with sunshine hours in no fertilizer （CK） treatment （R=-0.91, P0.01） and relative humidity in mineral fertilizers plus manure （MNPK） treatment （R=0.82, P0.05）. Phosphatase activity exhibited a negative corr

关键词： soil enzyme long-term fertilization hydrothermal conditions soil chemical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

减水减氮对黑土设施茄子产量与土壤剖面氮素盈余的影响

引用

中国土壤与肥料 2024年第6期 110-119页

作者：李仕勇朱帅许思思吕雪梅王耀陈一民隋跃宇周萌焦晓光黑龙江大学现代农业与生态环境学院黑龙江哈尔滨150080 中国科学院东北地理与农业生态研究所黑土区农业生态重点实验室黑龙江哈尔滨150081

黑土设施蔬菜生产中普遍存在施肥过量和灌水频繁的问题,通过研究减水减氮对黑土设施大棚蔬菜产量、土壤剖面硝态氮累积以及土壤-蔬菜系统氮素盈余的影响,可以为优化黑土设施蔬菜生产中的氮素养分管理技术、减少氮素损失、减轻环境污染... 详细信息

黑土设施蔬菜生产中普遍存在施肥过量和灌水频繁的问题,通过研究减水减氮对黑土设施大棚蔬菜产量、土壤剖面硝态氮累积以及土壤-蔬菜系统氮素盈余的影响,可以为优化黑土设施蔬菜生产中的氮素养分管理技术、减少氮素损失、减轻环境污染提供科学依据。以典型黑土菜地为研究对象,设不施氮肥处理(CK)、常规水肥处理(WF)、80%常规水处理(80%WF)、80%常规肥处理(W80%F)4个处理,研究减水减氮对设施茄子产量、氮素利用效率、土壤剖面硝态氮累积和土壤-蔬菜系统的氮盈余状况的影响。与CK处理相比,WF、80%WF、W80%F处理产量均显著提高。与WF处理相比,W80%F处理茄子产量无显著变化,但80%WF处理茄子产量显著降低6.44%~8.40%;减水减氮处理的果实吸氮量较WF处理无显著变化;与WF处理相比,80%WF处理的氮肥利用率、氮肥农学效率、氮肥偏生产力显著降低11.00%、56.66%、6.21%,W80%F处理的氮肥农学效率、氮肥偏生产力显著提高11.22%、24.69%;同时,与WF处理相比,80%WF处理的0~100 cm土层的硝态氮累积量显著提高3.90%~7.73%,W80%F处理显著降低3.60%~6.07%,各处理土壤氮素盈余量维持在195.24~234.69kg/hm^(2)。此外,土壤氮素盈余与灌溉量、施氮量和硝态氮累积量显著相关。减水减氮处理可以显著增加0~60 cm土壤中的氮素盈余并将硝态氮有效保存在100 cm内的土层中,减少淋失风险,达到高效生产和减少环境污染的双重目的。

关键词：减水减氮设施茄子土壤剖面硝态氮累积量氮素盈余

来源：

维普期刊数据库

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

Inner-shell ionization cross sections of atoms by positron impact

引用

Communications in Theoretical Physics 2024年第6期76卷 142-147页

作者： Yuan-Cheng Wang Jia Ma Li-guang jiao Stephan Fritzsche College of Physical Science and Technology Shenyang Normal UniversityShenyang 110034China Helmholtz-Institut Jena D-07743 JenaGermany GSI Helmholtzzentrum für Schwerionenforschung GmbH D-64291 DarmstadtGermany College of Science Shenyang Aerospace UniversityShenyang 110136China College of Physics Jilin UniversityChangchun 130012China Theoretisch-Physikalisches Institut Friedrich-Schiller-Universität Jena07743 JenaGermany

The relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obtain the inner-shell ionization cross sections of multi-electron atoms(Ni,Cu,Y,Ag,Au,Yb,Ta,and Pb)for positron impact energies from the thresholds up to 105ke *** is good agreement between the present calculations and the experimental *** constant in the acceleration term derived from the Wannier law is determined to be 0.2 and 0.5 for the K-and L-shells,respectively.

关键词： positron scattering ionization cross section binary-encounter-Bethe model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly Thermoconductive,Strong Graphene‑Based Composite Films by Eliminating Nanosheets Wrinkles

引用

Nano-Micro Letters 2024年第1期16卷 328-340页

作者： guang xiao Hao Li Zhizhou Yu Haoting Niu Yagang Yao College of Engineering and Applied Sciences Jiangsu Key Laboratory of Artificial Functional Materialsand Collaborative Innovation Center of Advanced MicrostructuresNational Laboratory of Solid State MicrostructuresNanjing UniversityNanjing 210093People’s Republic of China Institute of Laser Manufacturing Henan Academy of SciencesZhengzhou 450052People’s Republic of China Center for Quantum Transport and Thermal Energy Science School of Physics and TechnologyNanjing Normal UniversityNanjing 210023People’s Republic of China

Graphene-based thermally conductive composites have been proposed as effective thermal management materials for cooling high-power electronic ***,when flexible graphene nanosheets are assembled into macroscopic thermally conductive composites,capillary forces induce shrinkage of graphene nanosheets to form wrinkles during solution-based spontaneous drying,which greatly reduces the thermal conductivity of the ***,graphene nanosheets/aramid nanofiber(GNS/ANF)composite films with high thermal conductivity were prepared by in-plane stretching of GNS/ANF composite hydrogel networks with hydrogen bonds andπ-π*** in-plane mechanical stretching eliminates graphene nanosheets wrinkles by suppressing inward shrinkage due to capillary forces during drying and achieves a high in-plane orientation of graphene nanosheets,thereby creating a fast in-plane heat transfer *** composite films(GNS/ANF-60 wt%)with eliminated graphene nanosheets wrinkles showed a significant increase in thermal conductivity(146 W m^(−1)K^(−1))and tensile strength(207 MPa).The combination of these excellent properties enables the GNS/ANF composite films to be effectively used for cooling flexible LED chips and smartphones,showing promising applications in the thermal management of high-power electronic devices.

关键词： Graphene Aramid nanofiber Wrinkles elimination In-plane stretching Thermal conductivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact wear properties of dissimilar joints between bainitic frogs and pearlite rails

引用

Journal of Iron and Steel Research International 2024年第1期31卷 275-287页

作者： Pin-yong Zeng Chun-guang Zuo xiao-yu Zhang Wei Li Tribology Research Institute Southwest Jiaotong UniversityChengdu610031SichuanChina

The impact wear behavior and damage mechanism of dissimilar welded joints between U26Mn frog and U75 V rail before and after normalizing treatment were studied by cyclic impact *** experiment indicated that the impact wear volume of the joints increased with the increasing number of impact *** main wear mechanisms include pitting wear,mild fatigue wear,delamination wear,and fatigue wear,and plastic deformation was the primary impact wear *** them,fatigue wear had the greatest influence on wear volume,while other wear mechanisms had limited *** impact wear resistance of the base material was better than that of the heat-affected *** treatment was beneficial to improving the impact wear resistance of welded joints owing to its effect to promote pearlite recovery,grain refinement,and uniform distribution of *** martensite generated in the rail welded joints aggravated the impact wear damage to the materials,which should be avoided.

关键词： Dissimilar welded joint Impact wear Bainitic steel Damage mechanism Wear rate

来源：

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

p-wave resonances in the exponential cosine screened Coulomb potential

引用

Communications in Theoretical Physics 2024年第7期76卷 105-113页

作者： Yuan-Cheng Wang Li guang jiao Aihua Liu Yew Kam Ho Stephan Fritzsche College of Physical Science and Technology Shenyang Normal UniversityShenyang 110034China College of Physics Jilin UniversityChangchun 130012China Helmholtz-Institut Jena D-07743 JenaGermany GSI Helmholtzzentrum fur Schwerionenforschung GmbH D-64291 DarmstadtGermany Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China Institute of Atomic and Molecular Sciences Academia SinicaTaipei 10617TaiwanChina

We perform benchmark calculations of the p-wave resonances in the exponentially cosine screened Coulomb potential using the uniform complex-scaling generalized pseudo-spectral *** present results show significant improvement in calculation accuracy compared to previous predictions and correct the misidentification of resonance electron configuration in previous *** is found that the resonance states approximately follow an n^(2)-scaling law which is similar to the bound *** birth of a new resonance would distort the trajectory of an adjacent higher-lying resonance.

关键词： complex-scaling method shape resonance generalized pseudospectral method exponential cosine screened Coulomb potential

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Regulated reaction pathway of CO_(2)photoreduction into CH_(4)by metal atom pair sites

引用

Rare Metals 2024年第9期43卷 4620-4627页

作者： Dong-Po He guang-Bing Huang Jun Hu Yang Wu xiao-Dong Li Qing-Xia Chen Shan Zhu Wen-Sheng Yan Jun-Fa Zhu Yang Pan Xing-Chen jiao Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Hefei National Research Center for Physical Sciences at Microscale National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China Max Planck Institute of Microstructure Physics Weinberg 206120 HalleGermany State Grid Anhui Electric Power Research Institute Hefei 230601China

The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often *** achieve the desired product,it is crucial to manipulate the reaction ***,we build the metal atom pair sites for selective CO_(2)photoreduction into *** a prototype,Ni atom pair sites loaded on the Mo S_(2)nanosheets were synthesized and verified by highresolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS)and X-rayabsorption near edge structure spectra(XANES).In-situ Fourier transform infrared spectroscopy(FTIR)monitors the*CHO group,a crucial intermediate in CH_(4)production,during CO_(2)photoreduction on the Ni-Mo S_(2)nanosheets,whereas this monitoring is not observed for the Mo S_(2)***,theoretical calculations disclose that over the Ni-Mo S_(2)nanosheet slab,the formation energy of*CHO intermediates is determined to be lower(0.585 e V)than the desorption energy of*CO intermediates for CO production(0.64 e V),implying the higher selectivity of CH_(4)production.

关键词： steps dioxide desired

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Waterproof Perovskite Quantum Dots for In-vivo Photoluminescence Bioimaging

引用

Chemical Research in Chinese Universities 2024年第5期40卷 901-906页

作者： jiao Ziyue WANG Xinli GAO Jie HUANG xiao WANG Yi Key Laboratory of Advanced Light Conversion Materials and Biophotonics School of Chemistry and Life ResourcesRenmin University of ChinaBeijing100872P.R.China

Perovskite quantum dots(PQDs)have demonstrated great promise in bioimaging applications owing to their outstanding photophysical ***,their practicality is seriously limited by the instability of PQDs against *** we develop a post-synthetic ligand exchange strategy to construct silica-coated PQD(PQD@SiO_(2))nanocrystals,which results in the simultaneous improvement of photoluminescence efficiency and moisture *** importantly,compared to the classical in-situ ligand exchange method of fabricating PQD@SiO_(2),the issues of chemical etching and resultant photoluminescence degradation are judiciously *** the proposed PQD@SiO_(2),we showcase their robust usefulness in labeling chlorella,paving the way for PQD-based in-vivo photoluminescence bioimaging methodology.

关键词： Perovskite Quantum dot Photoluminescence Stability Bioimaging

来源：

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

Buckling Properties of Water-Drop-Shaped Pressure Hulls with Various Shape Indices Under Hydrostatic External Pressure

引用

China Ocean Engineering 2024年第1期38卷 1-17页

作者： DING xiao-de ZHANG Jian WANG Fang jiao Hui-feng WANG Ming-lu School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Shanghai Engineering Research Center of Marine Renewable Energy College of Engineering Science and Technol-ogyShanghai Ocean UniversityShanghai 201306China China Ship Scientific Research Center Wuxi 214082China

The water-drop-shaped pressure hull has a good streamline,which has good application prospect in the underwater ***,this study conducted analytical,experimental and numerical investigation of the buckling properties of water-drop-shaped pressure hulls under hydrostatic pressure.A water-drop experiment was conducted to design water-drop-shaped pressure hulls with various shape *** critical loads for the water-drop-shaped pressure hulls were resolved by using Mushtari’s *** numerical simulations including linear buckling analysis and nonlinear buckling analysis including eigenmode imperfections were *** results indicated that the critical loads resolved by Mushtari's formula were in good agreement with the linear buckling loads from the numerical *** formula can be extended to estimate the buckling capacity of water-drop-shaped pressure *** addition,three groups of pressure hulls were fabricated by using stereolithography,a rapid prototyping ***,three groups of the pressure hulls were subjected to ultrasonic measurements,optical scanning,hydrostatic testing and numerical *** experimental results were consistent with the numerical *** results indicate that the sharp end of the water-drop-shaped pressure hulls exhibited instability compared with the blunt *** paper provides a new solution to the limitations of experimental studies on the water-drop-shaped pressure hulls as well as a new configuration and evaluation method for underwater observatories.

关键词： buckling pressure hull water drop underwater observatory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Lipid-lowering effects of gefarnate in statin-treated patients with residual hypertriglyceridemia:a randomized controlled study

引用

Journal of Geriatric Cardiology 2024年第8期21卷 791-798页

作者： Jing SHI Ming-Lu XU Mei-jiao HE Wan-Lan BO Hai-Yu ZHANG Dang-Hui SUN Ding-Yu WANG xiao-Yu WANG Qun SHAO Yu-jiao PAN Yu ZHANG Chen-guang DAI Jing-Ying WANG Lin-Wei ZHANG guang-Zhong LIU Yue LI for the GPROT Study Group Department of Cardiology the First Affiliated HospitalHarbin Medical UniversityHarbinChina Department of Gastroenterology the Fourth Affiliated HospitalHarbin Medical UniversityHarbinChina Department of Cardiology Harbin Medical University Cancer HospitalHarbinChina Department of Cardiology Shenzhen People’s HospitalShenzhenChina National Key Laboratory of Frigid Zone Cardiovascular Diseases Harbin Medical UniversityHarbinChina NHC Key Laboratory of Cell Transplantation Key Laboratory of Cardiovascular Disease Acousto-Optic Electromagnetic Diagnosis and Treatment in Heilongjiang ProvinceHeilongjiang Province Clinical Medical Research Center for Hypertensionthe First Affiliated HospitalHarbin Medical UniversityHarbinChina Institute of Metabolic Disease Heilongjiang Academy of Medical ScienceHarbinChina 不详

BACKGROUND The prevention of coronary artery disease(CAD)faces dual challenges:the aspirin-induced gastrointestinal injury,and the residual cardiovascular risk after statin *** acetate(Gefarnate)is an anti-ulcer *** was reported that geraniol might participate in lipid metabolism through a variety of *** aim of this study was to assess the lipid-lowering effects of gefarnate in statin-treated CAD patients with residual *** In this prospective,open-label,randomized,controlled trial,69 statin-treated CAD patients with residual hypertriglyceridemia were randomly assigned to gefarnate group and control group,received gefarnate(100 mg/3 times a day)combined with statin and statin alone,*** baseline and after one-month treatment,the levels of plasma triglyceride,high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C)and total cholesterol were *** After one-month gefarnate treatment,triglyceride level was significantly lowered from 2.64 mmol/L to 2.12 mmol/L(P=0.0018),LDL-C level lowered from 2.7 mmol/L to 2.37 mmol/L(P=0.0004),HDL-C level increased from 0.97 mmol/L to 1.17mmol/L(P=0.0228).Based on statin therapy,gefarnate could significantly reduce the plasma triglyceride level(P=0.0148)and increase the plasma HDL-C level(P=0.0307).Although the LDL-C and total cholesterol levels tended to decrease,there was no statistically significant *** The addition of gefarnate to statin reduced triglyceride level and increased HDL-C level to a significant extent compared to statin alone in CAD patients with residual *** suggested that gefarnate might provide the dual benefits of preventing gastrointestinal injury and lipid lowering in CAD patients.

关键词： nat alone Lipid

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：