期刊文献+
共找到19篇文章
< 1 >
每页显示 20 50 100
Temperature Sensitivity of Nitrogen Dynamics of Agricultural Soils of the United States 被引量:1
1
作者 amitava chatterjee Alexsandro Felipe de Jesus +6 位作者 Diksha Goyal Sailesh Sigdel Larry J. Cihacek Bhupinder S. Farmaha Sindhu Jagadamma Lakesh Sharma Daniel S. Long 《Open Journal of Soil Science》 2020年第7期298-305,共8页
Soil temperature controls gaseous nitrogen losses through nitrous oxide (N<sub>2</sub>O) and ammonia (NH<sub>3</sub>) fluxes. Eight surface soils from agricultural fields across the United Stat... Soil temperature controls gaseous nitrogen losses through nitrous oxide (N<sub>2</sub>O) and ammonia (NH<sub>3</sub>) fluxes. Eight surface soils from agricultural fields across the United States were incubated at 10<span style="white-space:nowrap;">°</span>C, 20<span style="white-space:nowrap;">°</span>C, and 30<span style="white-space:nowrap;">°</span>C, and N<sub>2</sub>O and NH<sub>3</sub> flux were measured twice a week for 91 and 47 d, respectively. Changes in cumulative N<sub>2</sub>O and NH<sub>3</sub> flux and net N mineralization at three temperatures were fitted to calculate Q<sub>10</sub> using the Arrhenius equation. For the majority of soils, Q<sub>10</sub> values for the N<sub>2</sub>O loss ranged between 0.23 and 2.14, except for Blackville, North Carolina (11.4) and Jackson, Tennessee (10.1). For NH<sub>3</sub> flux, Q<sub>10</sub> values ranged from 0.63 (Frenchville, Maine) to 1.24 (North Bend, Nebraska). Net soil N mineralization-Q<sub>10</sub> ranged from 0.96 to 1.00. Distribution of soil organic carbon and total soil N can explain the variability of Q<sub>10</sub> for N<sub>2</sub>O loss. Understanding the Q<sub>10</sub> variability of soil N dynamics will help us to predict the N loss. 展开更多
关键词 Arrhenius Equation Soil Organic Carbon Inorganic Nitrogen Gaseous Losses of Nitrogen
下载PDF
Fragipan Horizon Changes Using Annual Ryegrass and Other Admendments
2
作者 Lloyd Murdock Anastasios Karathanasis +2 位作者 Dottie Call Dana L. Dinnes amitava chatterjee 《Open Journal of Soil Science》 2024年第6期388-397,共10页
A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received se... A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received several treatments with various amendments for different periods ranging from 9 to 17 months. The amendments included annual ryegrass or Festulolium residues, powder limestone and various humate compounds alone or in combination with the grass residues. The results suggested a significant effect of ryegrass and Festulolium in reducing penetration resistance into the top 10 cm of the fragipan within 9 - 17 months, particularly when used in combination with certain humate materials such as Leonardite. Apparently, this is the result of the release of certain soluble organic compounds from the plant residues or the humate amendments that increase the solubility of Si and Al associated with the fragipan brittleness, thus decreasing the density of the compacted fragipan material. 展开更多
关键词 Fragipan Fragipan Horizon Fragipan Soils Changing the Fragipan Annual Ryegrass Changes Fragipan Festulolium Changes Fragipan Amendments That Change the Fragipan
下载PDF
Soil carbon pools of six ecological regions of the United States 被引量:3
3
作者 amitava chatterjee 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第5期1933-1938,共6页
Mineralisable soil organic carbon(SOC)pools vary with ecosystem type in response to changes in climate,vegetation and soil properties.Understanding the effect of climate and soil factors on SOC pools is critical for p... Mineralisable soil organic carbon(SOC)pools vary with ecosystem type in response to changes in climate,vegetation and soil properties.Understanding the effect of climate and soil factors on SOC pools is critical for predicting change over time.Surface soil samples from six ecoregions of the United States were analyzed for permanganate oxidizable C(KMnO4-C)and mineralizable C pools.Variations of SOC ranged from 7.9 mg g^-1(Florida site)to 325 mg g^-1(Hawaii site).Mineralisable C pools and KMnO4-C were highest in soils from the Hawaii site.Mean annual precipitation explains SOC and resistant C pool variations.Clay content was related to mineralisable active C pools and bacterial abundance.Mean annual precipitation and clay content are potential variables for predicting changes in SOC pools at large spatial scales. 展开更多
关键词 Permanganate oxidizable carbon(KMnO4-C) Resistant carbon pool Mean residence time Soil carbon pools United States
下载PDF
Uncertainty Theory Based Novel Multi-Objective Optimization Technique Using Embedding Theorem with Application to R &D Project Portfolio Selection 被引量:2
4
作者 Rupak Bhattacharyya amitava chatterjee Samarjit Kar 《Applied Mathematics》 2010年第3期189-199,共11页
This paper introduces a novice solution methodology for multi-objective optimization problems having the coefficients in the form of uncertain variables. The embedding theorem, which establishes that the set of uncert... This paper introduces a novice solution methodology for multi-objective optimization problems having the coefficients in the form of uncertain variables. The embedding theorem, which establishes that the set of uncertain variables can be embedded into the Banach space C[0, 1] × C[0, 1] isometrically and isomorphically, is developed. Based on this embedding theorem, each objective with uncertain coefficients can be transformed into two objectives with crisp coefficients. The solution of the original m-objectives optimization problem with uncertain coefficients will be obtained by solving the corresponding 2 m-objectives crisp optimization problem. The R & D project portfolio decision deals with future events and opportunities, much of the information required to make portfolio decisions is uncertain. Here parameters like outcome, risk, and cost are considered as uncertain variables and an uncertain bi-objective optimization problem with some useful constraints is developed. The corresponding crisp tetra-objective optimization model is then developed by embedding theorem. The feasibility and effectiveness of the proposed method is verified by a real case study with the consideration that the uncertain variables are triangular in nature. 展开更多
关键词 Uncertainty Theory UNCERTAIN Variable EMBEDDING THEOREM α-Optimistic and α-Pessimistic Value R & D Project PORTFOLIO Selection
下载PDF
Tile Drainage and Nitrogen Fertilizer Management Influences on Nitrogen Availability, Losses, and Crop Yields 被引量:1
5
作者 Rakesh Awale amitava chatterjee +1 位作者 Hans Kandel Joel K. Ransom 《Open Journal of Soil Science》 2015年第10期211-226,共16页
Installing tile drainage facilitates early planting and field operations, and tiling has tremendously increased in the Red River Valley (RRV) due to recent wet cycles. This experiment studied tile drainage and N-ferti... Installing tile drainage facilitates early planting and field operations, and tiling has tremendously increased in the Red River Valley (RRV) due to recent wet cycles. This experiment studied tile drainage and N-fertilizer management effects on N availability, N losses, and yields of corn (Zea mays L.) and sugarbeet (Beta vulgaris L.) in a naturally poorly-drained Fargo soil during the 2012-2013 growing seasons. Regardless of drainage, applying 146 kg N ha-1 with nitrapyrin resulted similar soil N availability to 180 kg N ha-1 without nitrapyrin in sugarbeet in both years. In corn, application of nitrapyrin resulted either higher or similar soil N levels to split-N application. In 2013, application of urea alone increased soil N availability during the early corn growing season under the undrained condition, whereas nitrapyrin delayed N release in the tile-drained soils. Corn and sugarbeet yields averaged 7.4 and 47.0 Mg·ha-1 in 2012, and averaged 8.3 and 38.3 Mg·ha-1 in 2013, respectively, with no significant differences among N-sources. However, corn yield increased on an average by 27.6% with N-fertilizer application over unfertilized control in 2013. In 2012, sugarbeet root impurity (% sucrose loss to molasses) increased by 13.8% and 17.2% with 146 kg N ha-1 plus nitrapyrin and 180 kg N ha-1 treatments, respectively, compared to unfertilized control. Besides, higher N rates were usually associated with greater daily soil N2O emissions, with the maximum flux of 105 g N2O-N ha-1·d-1 recorded under corn. Addition of fertilizer-N increased NH3 volatilization losses up to 1.9% and 0.5% of the applied-N in corn and sugarbeet, respectively. Tile drainage influenced soil N availability more than crop yield during two years of study. Nitrogen management can have pronounced effects on N availability and losses. A long-term study is needed to investigate the fertilizer-N use efficiency of crops under tile drainage condition. 展开更多
关键词 SUBSURFACE Drainage Nitrogen Nitrous Oxide Ammonia VOLATILIZATION NITRATE LEACHING
下载PDF
Evaluation of Soil Potassium Test to Improve Fertilizer Recommendations for Corn 被引量:1
6
作者 Manbir K. Rakkar David W. Franzen amitava chatterjee 《Open Journal of Soil Science》 2015年第5期110-122,共13页
The soil potassium (K) test methodology is under increased evaluation due to the soil sample drying effect, temporal variations of test results and inconsistent crop response to applied K fertilizers. Ten on-farm tria... The soil potassium (K) test methodology is under increased evaluation due to the soil sample drying effect, temporal variations of test results and inconsistent crop response to applied K fertilizers. Ten on-farm trials were conducted in 2014 in eastern North Dakota to determine the corn response to different K-fertilizer rates and to assess the variation of soil K test levels between air-dried (KDry) and field moist (KMoist) soil samples during the corn growing season. Significant differences were observed between KDry and KMoist soil K test results. The ratio of KDry/KMoist showed high correlation with cation exchange capacity (r = 0.63, p < 0.10), Organic matter (r = 0.61, p < 0.10) and (Ca + Mg)/K ratio (r = 0.64, p < 0.10) from the 1 M ammonium acetate extractant, while pH, electrical conductivity, clay (%), and soil moisture showed non-significant correlation. On average, KDry resulted in higher soil K test levels than KMoist and pattern of deviation was different for surface and sub-surface soil samples. Soil K analysis of samples collected during the fall and spring showed large enough variations to affect the soil test interpretation category which was used to make fertilizer recommendations. Corn yield increased significantly with applied K fertilizer at only three out of 8 sites with beginning K levels below the current critical level of 150 ppm, and one response was at a site with K level above the critical level. Therefore, use of either the KDry or KMoist method alone may not be adequate to predict K response in some North Dakota soils. 展开更多
关键词 POTASSIUM Soil TEST Methodology FERTILIZER RECOMMENDATIONS GRAIN Yield
下载PDF
MMP-2 Inhibitory Activity of PBS Extract of Guava Leaves 被引量:1
7
作者 Atanu Mondal Ramanuj Mukherjee +1 位作者 Subhajit Mondal amitava chatterjee 《American Journal of Plant Sciences》 2021年第12期1761-1767,共7页
PBS (Phosphate Buffed Saline), pH 7.4 extract of Guava leaves (<i>Psidium</i> <i>guajava</i> L.) inhibits the active MMP-2 like molecule both of plant origin as well as active MMP-2 of human (b... PBS (Phosphate Buffed Saline), pH 7.4 extract of Guava leaves (<i>Psidium</i> <i>guajava</i> L.) inhibits the active MMP-2 like molecule both of plant origin as well as active MMP-2 of human (breast cancer patients’ saliva) origin. The zymogram and ELISA were developed of different samples following standard methods. The isolation and identification of the new MMP-2 inhibitor(s) for its molecular characterization is under investigation. 展开更多
关键词 MMP-2 INHIBITOR Guava Leaves Cancer
下载PDF
Effect of Black Tea Polyphenol on Cell-ECM Interaction and MMP
8
作者 Nabanita Bhattacharyya Subhajit Mondal +6 位作者 Shuvojit Moulik Sathi Paul Shreoshi Bhattacharrya Alok Kumar Hazra Md. Nasim Ali Anjan Adhikari amitava chatterjee 《American Journal of Plant Sciences》 2017年第4期856-866,共11页
Tea is one of the most widely consumed beverages in the world. Black tea, obtained from the leaves of Camellia sinensis is the preferred beverage in India and in most western countries. Epidemiological studies on blac... Tea is one of the most widely consumed beverages in the world. Black tea, obtained from the leaves of Camellia sinensis is the preferred beverage in India and in most western countries. Epidemiological studies on black tea and cancer are limited. However, preliminary studies indicate a positive correlation between black tea consumption and a lower incidence of breast and ovarian cancer. In the present communication, we wanted to see the effect of black tea extract and the polyphenol theaflavin on cell-ECM interaction, MMP activity etc. to strengthen the anti-cancer effect of black tea. 展开更多
关键词 BLACK TEA POLYPHENOL MMP ECM CANCER
下载PDF
Relationship among Different Soil Biochemical Methods to Determine Soil Health
9
作者 amitava chatterjee Umesh Acharya 《Open Journal of Soil Science》 2018年第11期303-313,共11页
Numerous soil biochemical methods are used to determine the soil health status, but the relationships among these methods are not well understood. Relationships among soil biochemical tests, 1) chloroform fumigated mi... Numerous soil biochemical methods are used to determine the soil health status, but the relationships among these methods are not well understood. Relationships among soil biochemical tests, 1) chloroform fumigated microbial biomass C (CFMBC), 2) permanganate oxidizable C (POXC), 3) Solvita CO2-burst (Solvita), 4) Solvita labile amino nitrogen (SLAN), and short-term soil CO2 efflux during laboratory incubation using (v) Alkali-base trap (Alkali) and (vi) infrared gas analyzer (IRGA), were evaluated for nine agricultural soils collected across the Red River Valley of North Dakota and Minnesota, USA. Not a single test is comprehensive to relate with all soil biochemical tests. Coefficient of variation percentage for particular method varied with soil type. Among six tests, CFMBC is significantly (p < 0.05) related with Alkali (r = 0.37), Solvita (r = 0.57), SLAN (r = 0.52), and POXC (r = 0.68). Soil CFMBC correlates with most of soil biochemical tests and can be potential to determine soil biochemical condition. 展开更多
关键词 CHLOROFORM Fumigated Microbial Biomass CARBON Solvita CO2-Burst SOIL Labile AMINO Nitrogen (SLAN) PERMANGANATE Oxidizable CARBON Infrared Gas ANALYZER SOIL Organic CARBON
下载PDF
Integrin Alpha-V Beta-3-Matrix Metalloproteinase-2 (MMP-2), Cross-Talk
10
作者 Hrishikesh Sil amitava chatterjee 《Journal of Cancer Therapy》 2015年第9期793-802,共10页
The present study aimed to detect comparative expression of integrin αVβ3 and its involvement in expression and activation of matrix metalloproteinase-2 (MMP-2) in 25 malignant human breast tumor and adjacent normal... The present study aimed to detect comparative expression of integrin αVβ3 and its involvement in expression and activation of matrix metalloproteinase-2 (MMP-2) in 25 malignant human breast tumor and adjacent normal breast tissues from different clinical TNM stages (DCIS to T4) of the disease and possible involvement of known regulating parameters of MMP-2 like TIMP-2, MT1-MMP and EMPRIN. Integrin αVβ3 was highly expressed in tumors than adjacent normal breast tissues. Pro-MMP-2(72-KD) was mainly expressed in adjacent normal tissues compared to tumors. The mature forms of MMP-2 (68 KD and 64 KD) were found only in tumors. Appreciable expression of TIMP-2 and induction of MT1-MMP and EMPRIN in T2-T4 stages suggested their possible role in MMP-2 activation. Over expression Integrin αVβ3 in tumors than adjacent normal breast tissues was an indication of cancer progression with involvement of integrin signaling. We conclude that, the co-precipitation of MMP-2 with αvβ3 by anti-αv antibody is a strong indication that integrin αvβ3 is a surface receptor for MMP-2 and αvβ3-MMP-2 complex on the surface of tumor cells may play a very important role in determining the invasive property and malignant behavior of tumor tissues. The positive expression of endogenous inhibitor of MMP-2, TIMP-2 may have an appreciable role in activation of this protease and risk of malignancy in advanced stage of the disease. The enhanced expression of MT1-MMP and EMPRIN suggested a role for these factors in gelatinase regulation. However the exact mechanism(s) remains to be investigated. Finally, evaluation of integrin αVβ3 associated MMP-2 expression and activity may add valuable information and can possibly be therapeutic target. The clinical exploitation of integrins will provide oncologists with novel therapeutic strategies for the treatment of malignancy in breast cancer. 展开更多
关键词 Breast Cancer MMP-2 Alpha V BETA3 MT1-MMP TIMP-2 EMPRIN VEGF
下载PDF
Studies on Focal Adhesion Kinase in human breast cancer cell MDA-MB-231
11
作者 Kirat Kumar Ganguly Triparna Sen +2 位作者 Sekhar Pal Jaydip Biswas amitava chatterjee 《Advances in Biological Chemistry》 2012年第1期29-42,共14页
AIM: 1) To study the participation of Focal Adhesion Kinase (FAK) in regulation of Breast Cancer cell migration in relation with MMP-9 and other signaling proteins. 2) To study the effect of some natural products on F... AIM: 1) To study the participation of Focal Adhesion Kinase (FAK) in regulation of Breast Cancer cell migration in relation with MMP-9 and other signaling proteins. 2) To study the effect of some natural products on FAK. METHODS: Cell culture, Western Blot, Immunoprecipitation, Immunocytochemistry, Zymography, SiRNA transfection, RT-PCR, Real-Time PCR. RESULTS: For our study on FAK, we selected invasive Breast Cancer cell line MDA-MB-231 and treated the cells with Fibronectin (FN). Treatment of FN was found to increase FAK expression, phosphorylation (Tyr 397). FAK was found to be involved in re- gulation of breast cancer cell migration and MMP-9 expression, activity. Fi-bronectin increases association of FAK with integrin α5β1, Paxillin, Actin, ERK, PI3K and localization at Focal Adhesion sites. FAK was found to be involved in modulation of ERK and PI3K phosphorylation. Moreover, FAK signal was found to be transduced through ERK and PI3K, which modulate MMP-9 and thereby cell migration. CONCLUSION: FAK expression, phosphorylation and processing are induced in response to Cell-ECM interactions. Integrin α5β1 is involved in FN induced FAK phosphorylation. FAK is a potent regulator of MMP-9 expression and activity. FAK is involved in regulation of ERK and PI3K phosphorylation. ERK and PI3K are involved in FAK regulated MMP-9 expression & activity. FAK regulates MMP-9 expression and activity and thereby migration of human breast cancer cell. By the regulation of FAK, cell attachment and migration may be regulated by Curcumin, ATRA or EGCG treatment. It may be concluded that invasive potential of breast cancer cells may be modulated by regulation of FAK. 展开更多
关键词 FAK FIBRONECTIN MMP-9 Cell MIGRATION BREAST Cancer
下载PDF
Tumor Cell-Extracellular Matrix Interaction Modulates MMP-1 in Breast Cancer
12
作者 Sekhar Pal Kirat Kumar Ganguly +2 位作者 Shyamsundar Mandal Jaydip Biswas amitava chatterjee 《Journal of Cancer Therapy》 2015年第4期375-382,共8页
Increased MMP-1 expression in various tumor cells is significantly correlated with cancer progression. Enhanced secreted and intracellular level of MMP-1 is found in breast cancer cell line MDA-MB-231 in presence of E... Increased MMP-1 expression in various tumor cells is significantly correlated with cancer progression. Enhanced secreted and intracellular level of MMP-1 is found in breast cancer cell line MDA-MB-231 in presence of ECM glycoprotein fibronectin. To extrapolate this study into in vivo system, we observed the expression of MMP-1, fibronectin and α5β1 integrin, which is the receptor for fibronectin, in breast cancer tissue samples. Expression of active form of MMP-1 was increased in tumor samples compared with the non-tumor counterpart. In some samples pro-MMP-1 was decreased but active form was increased in tumor part. The difference was more prominent in advanced stage tumor. ELISA showed appreciable increase in expression of α5 and β1integrins in tumor tissue in comparison to the non tumor counterpart in case of advanced stage tumor. Though there is no appreciable difference in fibronectin concentration, enhanced α5, β1 integrin expression may mediate enhanced cell-ECM interaction to upregulate MMP-1 in tumor samples compared with the matched control. 展开更多
关键词 α5β1 INTEGRIN Signaling ECM FIBRONECTIN MMP-1
下载PDF
Salivary Active MMP-2 of Breast Cancer Patients Is Inhibited by Guava Leaves PBS Extract
13
作者 Ramanuj Mukherjee Syandan Sinha Ray +1 位作者 Subhajit Mondal amitava chatterjee 《American Journal of Plant Sciences》 2022年第5期650-658,共9页
Matrixmetalloproteinase-2 (MMP-2), also called gelatinase-A, is a 72 Kd protein present in chromosome 16 in human. It is a zinc binding protein, responsible for the degradation of Extra Cellular Matrix (ECM) in normal... Matrixmetalloproteinase-2 (MMP-2), also called gelatinase-A, is a 72 Kd protein present in chromosome 16 in human. It is a zinc binding protein, responsible for the degradation of Extra Cellular Matrix (ECM) in normal physiological as well as disease processes like arthritis and cancer. It has a specific role in the cancer development and angiogenesis. MMP-2 contributes to cell migration. MMPs are the key to normal development as well as in the pathology of cancer and other inflammatory diseases. The inhibitors of MMP-2 activity are very important in maintaining the normal activity of MMP-2 and have an important role in the management of cancer. Regulation of MMP-2 activity is done by inhibitors like, TIMPs. In this report, we are discussing about a possible inhibitor(s) present in the PBS extract of guava leaves, inhibiting the active MMP-2 present in the saliva of breast cancer patients. 展开更多
关键词 MMP-2 Inhibitor SALIVA Breast Cancer
下载PDF
Studies on Focal Adhesion Kinase in Human Breast Cancer Tissue
14
作者 Kirat Kumar Ganguly Triparna Sen +2 位作者 Syamsundar Mandal Jaydip Biswas amitava chatterjee 《Journal of Cancer Therapy》 2012年第1期7-19,共13页
Aim: To study Expression and Phosphorylation status of Focal Adhesion Kinase (FAK) in Human Breast Cancer tissue. To study the relation of FAK with standard clinicopathological parameters of Human Breast Cancer. Metho... Aim: To study Expression and Phosphorylation status of Focal Adhesion Kinase (FAK) in Human Breast Cancer tissue. To study the relation of FAK with standard clinicopathological parameters of Human Breast Cancer. Methods: Tissue collection, Protein extraction, RNA isolation, Western Blot, Immunohistochemistry, RT-PCR, ELISA, Statistical analysis. Results: All the four techniques showed upregulated expression, phosphorylation (Tyr-397) and processing of FAK in human breast cancer tissue compared to the adjacent non-tumor tissue of the same patient. Upregulation of FAK was found to be increased parallely with the advancement of cancer. Localisation of FAK was found to be membrano-cytoplasmic. FAK is upregulated both in protein and mRNA level. Expression and phosphorylation of FAK is increased specifically in the tumor regions compared to the surrounding non-tumor region. Upregulation of FAK was frequently found in ER-positive and PR-positive but Her2/neunegative breast cancer cases. Conclusion: FAK has crucial role in development and progression of human breast cancer. FAK may be considered as an indicator of human breast cancer progression. FAK processing may be considered as an indicator of invasive potential of breast cancer. FAK may be considered as a clinical indicator of human breast cancer development and progression. 展开更多
关键词 FAK HUMAN BREAST CANCER
下载PDF
Variation in soil organic matter accumulation and metabolic activity along an elevation gradient in the Santa Rosa Mountains of Southern California, USA
15
作者 amitava chatterjee George D JENERETTE 《Journal of Arid Land》 SCIE CSCD 2015年第6期814-819,共6页
Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic ... Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic matter and metabolic rates along an elevation gradient(289–2,489 m) in the Santa Rosa Mountains, California, USA from subalpine and montane pine forests through chaparral to desert. From base(289 m) to summit(2,489 m), 24 sites were established for collecting soil samples under canopies and inter-canopy spaces, at 0–5 and 5–15 cm soil depths increments. Soil organic matter(SOM) content was determined using weight loss on ignition at 550°C and soil CO2 efflux(R) was measured at day 5(R5) and day 20(R20) of incubation. Changes in SOM content along the elevation gradient showed a significant relationship(P〈0.05) but R5 and R20 were not related to either elevation or SOM content. However, the ratio of R and SOM(R5/SOM) showed a strong relationship across the mountains at both soil depths. R5/SOM, as an indicator of carbon use efficiency, may be applicable to other semi-arid transects at larger scale modeling of soil metabolic processes. 展开更多
关键词 elevation gradient soil organic matter CO2 efflux metabolic activity
下载PDF
Saline-Sodic Soils:Potential Sources of Nitrous Oxide and Carbon Dioxide Emissions? 被引量:8
16
作者 Upasana GHOSH Resham THAPA +2 位作者 Thomas DESUTTER HE Yangbo amitava chatterjee 《Pedosphere》 SCIE CAS CSCD 2017年第1期65-75,共11页
Increasing salt-affected agricultural land due to low precipitation, high surface evaporation, irrigation with saline water, and poor cultural practices has triggered the interest to understand the influence of salt o... Increasing salt-affected agricultural land due to low precipitation, high surface evaporation, irrigation with saline water, and poor cultural practices has triggered the interest to understand the influence of salt on nitrous oxide (N20) and carbon dioxide (CO2) emissions from soil. Three soils with varying electrical conductivity of saturated paste extract (ECe) (0.44-7.20 dS m-1) and sodium adsorption ratio of saturated paste extract (SARe) (1.1-27.7), two saline-sodic soils (S2 and S3) and a non-saline, non-sodic soil (S1), were incubated at moisture levels of 40%, 60%, and 80% water-filled pore space (WFPS) for 30 d, with or without nitrogen (N) fertilizer addition (urea at 525μg g-1 soil). Evolving CO2 and N20 were estimated by analyzing the collected gas samples during the incubation period. Across all moisture and N levels, the cumulative N20 emissions increased significantly by 39.8% and 42.4% in S2 and S3, respectively, compared to S1. The cumulative CO2 emission from the three soils did not differ significantly as a result of the complex interactions of salinity and sodicity. Moisture had no significant effect oi1 N20 emissions, but cumulative CO2 emissions increased significantly with an increase in moisture. Addition of N significantly increased cumulative N20 and CO2 emissions. These showed that saline-sodic soils can be a significant contributor of N20 to the environment compared to non-saline, non-sodic soils. The application of N fertilizer, irrigation, and precipitation may potentially increase greenhouse gas (N20 and CO2) releases from saline-sodic soils. 展开更多
关键词 CO2 electrical conductivity greenhouse gas emission MOISTURE N fertilizer application N20 SALINITY SODICITY sodiumadsorption ratio
原文传递
Carbon Dioxide and Nitrous Oxide Emissions from Naturally Occurring Sulfate-Based Saline Soils at Different Moisture Contents 被引量:6
17
作者 Resham THAPA amitava chatterjee +1 位作者 Abbey WICK Kirsten BUTCHER 《Pedosphere》 SCIE CAS CSCD 2017年第5期868-876,共9页
Soil salinization may negatively affect microbial processes related to carbon dioxide (CO2) and nitrous oxide (N20) emissions. A short-term laboratory incubation experiment was conducted to investigate the effects... Soil salinization may negatively affect microbial processes related to carbon dioxide (CO2) and nitrous oxide (N20) emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity (EC) and moisture content on CO2 and N20 emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0-15 and 15-30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space (WFPS) at 25 ~C. The measured depth-weighted EC of the saturated paste extract (ECe) across the sampling positions ranged from 0.43 to 4.65 dS m-1. Potential nitrogen (N) mineralization rate and CO2 emissions decreased with increasing soil ECe, but the relative decline in soil CO2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N20 emissions decreased from 133 g N20-N kg-1 soil at ECe ( 0.50 dS m-1 to 72 μg N20-N kg-1 soil at ECe = 4.65 dS m-1. In contrast, at 90% WFPS, soil N20 emissions increased from 262 g N20-N kg-1 soil at ECe : 0.81 dS m-1 to 849 g N20-N kg-1 soil at ECe : 4.65 dS m-1, suggesting that N20 emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil ECe and pattern of rainfall over the season need to be considered when up-scaling N20 and CO2 emissions from field to landscape scales. 展开更多
关键词 electric conductivity C and N mineralization SALINITY sulfate salts soil salinization soil water-filled pore space
原文传递
启发式信号处理及其应用进展
18
作者 amitava chatterjee 张进兴 《国外科技新书评介》 2014年第6期17-18,共2页
复杂的、顶尖的信号处理算法的研究和应用在过去的40多年中一直保持活跃,特别是通信、控制理论、评估、模式识别、电器电子系统、机械系统设计等领域。一维信号处理与多维信号处理,即图像和视频处理,近年来受到了惊人的关注,研究的... 复杂的、顶尖的信号处理算法的研究和应用在过去的40多年中一直保持活跃,特别是通信、控制理论、评估、模式识别、电器电子系统、机械系统设计等领域。一维信号处理与多维信号处理,即图像和视频处理,近年来受到了惊人的关注,研究的焦点从最初发展的传统算法,逐渐演变成采用基于启发式的方法解决信号处理问题。 展开更多
关键词 信号处理算法 启发式 应用 机械系统设计 多维信号处理 控制理论 模式识别 电子系统
原文传递
图像处理中的计算智能
19
作者 amitava chatterjee 张进兴 《国外科技新书评介》 2014年第3期24-24,共1页
基于计算智能的技术作为可行的、数学工具已经有超过十年的时间,它们广泛地应用于许多系统和领域,诸如:信号处理、自动化控制、机器人学、电力系统等。图像处理也吸引了众多对基于计算智能的技术应用感兴趣的研究者,是一个很受关注... 基于计算智能的技术作为可行的、数学工具已经有超过十年的时间,它们广泛地应用于许多系统和领域,诸如:信号处理、自动化控制、机器人学、电力系统等。图像处理也吸引了众多对基于计算智能的技术应用感兴趣的研究者,是一个很受关注的研究问题及现实问题。最初,大部分的研究工作,主要集中在发展常规模糊系统、 展开更多
关键词 计算智能 图像处理 电力系统 自动化控制 数学工具 信号处理 机器人学 模糊系统
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部