BACKGROUND: The role of the left midfusiform gyrus as a target for visual word processing has been a topic of discussion. Numerous studies have utilized alphabetic writing for subject matter. However, few have addres...BACKGROUND: The role of the left midfusiform gyrus as a target for visual word processing has been a topic of discussion. Numerous studies have utilized alphabetic writing for subject matter. However, few have addressed visual processing of Chinese characters in the left midfusiform gyrus. OBJECTIVE: To verify visual processing of Chinese characters and images in the left midfusiform gyrus using functional magnetic resonance imaging. DESIGN, TIME AND SETTING: A blocked design paradigm study. Experiments were performed at the Room of Magnetic Resonance, Guangdong Provincial Second People's Hospital, China from May to June 2009. PARTICIPANTS: A total of eight undergraduate students were recruited from Guangzhou University of China, comprising two females and six males, aged 20-23 years. The subjects were right-handed which was determined by a Chinese standard questionnaire. None of the subjects had a history of psychoneurosis, familial disease, color blindness, or color weakness. METHODS: A total of eight undergraduates were enrolled as subjects. Picture-naming and verb generation tasks were employed through the use of functional magnetic resonance imaging. Analysis of Functional Neurolmages software was used to process the data. MAIN OUTCOME MEASURES: Visual processing of Chinese characters and images in the left midfusiform gyrus was measured. RESULTS: Picture-naming and verb generation tasks were shown to significantly activate the bilateral midfusiform gyrus. Activation occurred in the visual word form area of the left midfusiform gyrus. CONCLUSION: The left midfusiform gyrus plays a general role in visual processing of Chinese characters and images.展开更多
Distribution of different forms of sulphur(S)and carbon-nitrogen-sulphur relationships were studied in surface and subsurface soils of some tea growing areas of Northeastern India.The soils were strongly acidic in rea...Distribution of different forms of sulphur(S)and carbon-nitrogen-sulphur relationships were studied in surface and subsurface soils of some tea growing areas of Northeastern India.The soils were strongly acidic in reaction(pH-4.0 to 5.5),low to very high in organic carbon(4 to 54 g kg^-1),with cation exchange capacity(8.8 to 19.2 cmol(p+)kg^-1)and base saturation(50 to 77%).Organic S mostly contributed to the total-sulphur(62 to 77%)followed by Non sulphate S(28.8 to 37.2%)and sulphate S(0.7 to 1.4%).Except sulphate S,other forms of sulphur showed significant positive correlation among themselves as well as with organic carbon and total nitrogen.The C:N,C:S,N:S and C:N:S ratio varied from 8.2 to 10.0,6.18 to 71.57,0.62 to 7.26 and 100:10.1:1.4 to 100:12.2:16.2 respectively.Wider C:N:S ratios in all the surface and sub-surface soils indicated that the major portion of nitrogen and sulphur in tea growing soils of Northeastern India is locked up in organic combination which might pose as a potential threat towards tea plantation if application of sulphur is continuously ignored.展开更多
Three-word Primer is one of Chinese classics of enlightenment. It has the distinctive senses of beauty in form, meaning and rhymes. This paper focuses on the Relevance Theory which plays an important role in guiding t...Three-word Primer is one of Chinese classics of enlightenment. It has the distinctive senses of beauty in form, meaning and rhymes. This paper focuses on the Relevance Theory which plays an important role in guiding to translate Three-word Primer. After analyzing some examples from two translated versions, it's then suggested that it be necessary and important to translate poems in one language into poems in another language.展开更多
This paper,after introducing the definition and forms of cultural image,focuses on the detailed comparison and analysis of cultural image of animal words both in English and in Chinese from four aspects,that is,same a...This paper,after introducing the definition and forms of cultural image,focuses on the detailed comparison and analysis of cultural image of animal words both in English and in Chinese from four aspects,that is,same animal word,same cultural image;same animal word,different cultural images;different animal words,same cultural image;different animal words,different cultural images.展开更多
Experiments were carried out on a vegetable field with Peking cabbage(Brassica pekinensis (Lour.) Rupr.), cabbage (Brassica, chinensis var. oleifcra Makino and nemoto),green cabbage (Brassica chinensis L.), spinach (S...Experiments were carried out on a vegetable field with Peking cabbage(Brassica pekinensis (Lour.) Rupr.), cabbage (Brassica, chinensis var. oleifcra Makino and nemoto),green cabbage (Brassica chinensis L.), spinach (Spinacia oleracea L.) and rape(Brassica campestrisL.) to study the effects of N forms and N rates on their growth and nitrate accumulation. Theresults indicated that application of ammonium chloride, ammonium nitrate, sodium nitrate and ureasignificantly increased the yields and nitrate concentrations of Peking cabbage and spinach.Although no significant difference was found in the yields after application of the 4 N forms,nitrate N increased nitrate accumulation in vegetables much more than ammonium N. The vegetableyields were not increased continuously with N rate increase, and oversupply of N reduced the plantgrowth, leading to a yield decline. This trend was also true for nitrate concentrations in somevegetables and at some sampling times. However, as a whole, the nitrate concentrations in vegetableswere positively correlated with N rates. Thus, addition of N fertilizer to soil was the major causefor increases in nitrate concentrations in vegetables. Nitrate concentrations were much higher inroots, stems and petioles than in blades at any N rate.展开更多
Effects of different levels of compost application on the amounts and percentage distribution of organic N forms in whole soils and particle size fractions were investigated. Soil samples were collected from three plo...Effects of different levels of compost application on the amounts and percentage distribution of organic N forms in whole soils and particle size fractions were investigated. Soil samples were collected from three plots: (a) F, only chemical fertilizers;(b) F+LC, chemical fertilizers plus low level of compost;(c) F+HC, chemical fertilizers plus high level of compost. Each soil sample was divided into five fractions: coarse sand-sized aggregate (CSA), medium sand-sized aggregate (MSA), fine sand-sized aggregate (FSA), silt-sized aggregate (SIA) and clay-sized aggregate (CLA) fractions. The sand fractions were subdivided into decayed plants (DP) and mineral particles (MP). The amounts of total N and different organic N forms in the whole soils as well as size fractions generally increased with increasing the amount of compost. In the whole soils, percentage distribution of non-hydrolysable-N and amino sugar-N increased by compost application while the distribution values of the hydrolysable ammonium- N and unidentified-N decreased. The application did not affect the distribution degree of amino acid-N. In the size fractions, the distribution values of most organic N forms increased in the CSA-DP, MSA-DP and FSA-DP fractions by compost application. In the CLA fractions, the amounts and percentage distribution of organic N forms were the highest, although the application caused decreases in their distribution values. These findings indicate that the CLA fraction merit close attention as an important reservoir of various organic N.展开更多
Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-pola...Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy. Of the detectable 15N-signal intensity in the spectra of soil humic substances 71%-79% may be attributed to amide groups, 10%-18% to aromatic/aliphatic amines and 6%~11% to indole- and pyrrole-like N. Whereas in the spectrum of the fulvic acid from weathered coal 46%, at least, of the total 15N-signal intensity might be assigned to pyrrole-like N, 14% to aromatic/aliphatic ammes, and the remaining intensities could not be assigned with certainty. Data on nonhydrolyzable residue of protein-sugar mixture and a 15N-labelled soil fulvic acid confirm the formation of nonhydrolyzable heterocyclic N during acid hydrolysis. Project (No. 39790100) supported by the National Natural Science Foundation of China.展开更多
The growth, chlorophyll composition, photosynthesis, respiration, K uptake and root K+ secretion offlue-cured tobacco as thected by different concentrations of N supplied as urea, NaNO3 and NH4NO3 werestudied under th...The growth, chlorophyll composition, photosynthesis, respiration, K uptake and root K+ secretion offlue-cured tobacco as thected by different concentrations of N supplied as urea, NaNO3 and NH4NO3 werestudied under the experimental condition of sand culture. The results showed that the content of K in thefiue-cured tobacco was not merely related with root vitality and uptake but also closely related with root cellmembrane structure and K+ secretion.展开更多
Mn18Cr18N, the high-nitrogen steel, is the 2nd generation material for manufacturing the retaining ring of firepower generators. In this paper, the hot deformation behavior of the material was investigated by thermo-m...Mn18Cr18N, the high-nitrogen steel, is the 2nd generation material for manufacturing the retaining ring of firepower generators. In this paper, the hot deformation behavior of the material was investigated by thermo-mechanical modeling tests. And the flow stress curves of the steel were obtained for various combinations of the temperature and strain rate. Based on the results of the tests, the complex forming process of a retaining ring including punching, expanding and extrusion with an enclosure was put forward and simulated by means of numerical simulation method. The results indicate that the process is a novel and force-saved practical technology for manufacturing heavy retaining rings.展开更多
Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and...Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and phosphorus(P)in forest plant-soil-microbe systems remains unclear.Methods:We conducted a meta-analysis based on 751 pairs of observations to evaluate the responses of plant,soil and microbial biomass C,N and P nutrients and stoichiometry to N addition in different N intensity(050,50–100,>100 kg·ha^(-1)·year^(-1)of N),duration(0–5,>5 year),method(understory,canopy),and matter(ammonium N,nitrate N,organic N,mixed N).Results:N addition significantly increased plant N:P(leaf:14.98%,root:13.29%),plant C:P(leaf:6.8%,root:25.44%),soil N:P(13.94%),soil C:P(10.86%),microbial biomass N:P(23.58%),microbial biomass C:P(12.62%),but reduced plant C:N(leaf:6.49%,root:9.02%).Furthermore,plant C:N:P stoichiometry changed significantly under short-term N inputs,while soil and microorganisms changed drastically under high N addition.Canopy N addition primarily affected plant C:N:P stoichiometry through altering plant N content,while understory N inputs altered more by influencing soil C and P content.Organic N significantly influenced plant and soil C:N and C:P,while ammonia N changed plant N:P.Plant C:P and soil C:N were strongly correlated with mean annual precipitation(MAT),and the C:N:P stoichiometric flexibility in soil and plant under N addition connected with soil depth.Besides,N addition decoupled the correlations between soil microorganisms and the plant.Conclusions:N addition significantly increased the C:P and N:P in soil,plant,and microbial biomass,reducing plant C:N,and aggravated forest P limitations.Significantly,these impacts were contingent on climate types,soil layers,and N input forms.The findings enhance our comprehension of the plant-soil system nutrient cycling mechanisms in forest ecosystems and plant strategy responses to N deposition.展开更多
The syntheses of 5 new 17-membered macrocycles containing naphthalene ring are reported. The macrocycle ring in each of these new ligands contains an O2N3-donor set. Structures of these new compounds were characterize...The syntheses of 5 new 17-membered macrocycles containing naphthalene ring are reported. The macrocycle ring in each of these new ligands contains an O2N3-donor set. Structures of these new compounds were characterized by IR,1H NMR, MS and elemental analysis.展开更多
We use a lot of devices in our daily life to communicate with others. In this modern world, people use email, Facebook, Twitter, and many other social network sites for exchanging information. People lose their valuab...We use a lot of devices in our daily life to communicate with others. In this modern world, people use email, Facebook, Twitter, and many other social network sites for exchanging information. People lose their valuable time misspelling and retyping, and some people are not happy to type large sentences because they face unnecessary words or grammatical issues. So, for this reason, word predictive systems help to exchange textual information more quickly, easier, and comfortably for all people. These systems predict the next most probable words and give users to choose of the needed word from these suggested words. Word prediction can help the writer by predicting the next word and helping complete the sentence correctly. This research aims to forecast the most suitable next word to complete a sentence for any given context. In this research, we have worked on the Bangla language. We have presented a process that can expect the next maximum probable and proper words and suggest a complete sentence using predicted words. In this research, GRU-based RNN has been used on the N-gram dataset to develop the proposed model. We collected a large dataset using multiple sources in the Bangla language and also compared it to the other approaches that have been used such as LSTM, and Naive Bayes. But this suggested approach provides excellent exactness than others. Here, the Unigram model provides 88.22%, Bi-gram model is 99.24%, Tri-gram model is 97.69%, and 4-gram and 5-gram models provide 99.43% and 99.78% on average accurateness. We think that our proposed method profound impression on Bangla search engines.展开更多
Results of a 10-year decomposition experiment indicated that the annual mineralization rate of organic N in newly-formed humus varied with the type of original plant materials and the water regimes for decomposition, ...Results of a 10-year decomposition experiment indicated that the annual mineralization rate of organic N in newly-formed humus varied with the type of original plant materials and the water regimes for decomposition, ranging from 0.028 to 0.074. The mineralization rate under waterlogged conditions was higher than that under upland conditions. The proportion of α-amino acid N in humus newly-formed under waterlogged conditions was slightly higher than that under upland conditions. It decreased gradually with time, while the proportion of nonhydrolyzable N showed no consistent trend, irrespective of the water regimes for decomposition. The distribution of amino acids in humus newly- formed from different plant materials under various water regimes was quite similar with that in original plant materials, and only minor differences could be found among them. For example, in comparison to original plant materials, the newly-formed humus contained higher proportions of isoleucine, cystine, γ-amino-butync acid and ornithine, and lower proportions of phenylalanine and proline. Moreover the proportion of phenylalanine was higher in the humus newly-formed under waterlogged conditions than that under upland conditions.展开更多
In the hot forming of Mn18Cr18N steel, such problems as easy cracking, difficult controlling of forming paramenters often occur. In this paper,the variation rule of the plasticity of the steel, the starting mechanis...In the hot forming of Mn18Cr18N steel, such problems as easy cracking, difficult controlling of forming paramenters often occur. In this paper,the variation rule of the plasticity of the steel, the starting mechanism of micro-crack and its generating characteristics were studied with the combination of thermodynamic simulation test, micro-simulation and FEM, the related data of microstructure change and hot forming parameters were produced. The hot forming process of 600MW generator retaining ring was analyzed as an example.展开更多
The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-d...The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-de Vriesmodified Korteweg-de Vries equation for the atmosphere,oceanic fluids and plasmas.With symbolic computation,beginning with a presumption,we work out certain scaling transformations,bilinear forms through the binary Bell polynomials and our scaling transformations,N solitons(with N being a positive integer)via the aforementioned bilinear forms and bilinear auto-Bäcklund transformations through the Hirota method with some solitons.In addition,Painlevé-type auto-Bäcklund transformations with some solitons are symbolically computed out.Respective dependences and constraints on the variable/constant coefficients are discussed,while those coefficients correspond to the quadratic-nonlinear,cubic-nonlinear,dispersive,dissipative and line-damping effects in the atmosphere,oceanic fluids and plasmas.展开更多
English words in pairs are a special form of English idioms, which have different kinds and are used widely. For English learners, words in pairs are one of the difficult points. This paper discusses their form patter...English words in pairs are a special form of English idioms, which have different kinds and are used widely. For English learners, words in pairs are one of the difficult points. This paper discusses their form patterns, semantic relations, grammatical functions, rhetoric features and their application in translation. Its purpose is to help learners understand and use them accurately and correctly so as to improve language expressing ability.展开更多
Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days a...Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days and partitioned into acid-insoluble (MHA) and acid-soluble (MFA) fractions. The nitrogen forms in these polymers were studied by using the 15N cross polarization-magic angle spinning nuclear magnetic resonance (CPMAS NMR) technique in combination with chemical methods. The 15N nuclear magnetic resonance (NMR) data showed that while the yield, especially the MHA/MFA ratio, varied considerably with the concentrations of the reactants, the nitrogen distribution patterns of these polymers were quite similar.From 65% to 70% of nitrogen in them was in the secondary amide and/or indole form with 24%~25% present as aliphatic and/or aromatic ammes and 5% to 11% as pyrrole and/or pyrrole-like nitrogen. More than half (50%~77%) of the N in these polymers were nonhydrolyzable. The role of Maillard reaction in the formation of nonhydrolyzable nitrogen in soil organic matter is discussed.展开更多
基金the Key Programming Research Project of Education Science During the 11~(th) Five-Year Plan Period of Guangdong Province, No. 06TJZ014the Programming Project of Education Science During the 11~(th) Five-Year Plan Period of Guangzhou City, No. 07B290
文摘BACKGROUND: The role of the left midfusiform gyrus as a target for visual word processing has been a topic of discussion. Numerous studies have utilized alphabetic writing for subject matter. However, few have addressed visual processing of Chinese characters in the left midfusiform gyrus. OBJECTIVE: To verify visual processing of Chinese characters and images in the left midfusiform gyrus using functional magnetic resonance imaging. DESIGN, TIME AND SETTING: A blocked design paradigm study. Experiments were performed at the Room of Magnetic Resonance, Guangdong Provincial Second People's Hospital, China from May to June 2009. PARTICIPANTS: A total of eight undergraduate students were recruited from Guangzhou University of China, comprising two females and six males, aged 20-23 years. The subjects were right-handed which was determined by a Chinese standard questionnaire. None of the subjects had a history of psychoneurosis, familial disease, color blindness, or color weakness. METHODS: A total of eight undergraduates were enrolled as subjects. Picture-naming and verb generation tasks were employed through the use of functional magnetic resonance imaging. Analysis of Functional Neurolmages software was used to process the data. MAIN OUTCOME MEASURES: Visual processing of Chinese characters and images in the left midfusiform gyrus was measured. RESULTS: Picture-naming and verb generation tasks were shown to significantly activate the bilateral midfusiform gyrus. Activation occurred in the visual word form area of the left midfusiform gyrus. CONCLUSION: The left midfusiform gyrus plays a general role in visual processing of Chinese characters and images.
文摘Distribution of different forms of sulphur(S)and carbon-nitrogen-sulphur relationships were studied in surface and subsurface soils of some tea growing areas of Northeastern India.The soils were strongly acidic in reaction(pH-4.0 to 5.5),low to very high in organic carbon(4 to 54 g kg^-1),with cation exchange capacity(8.8 to 19.2 cmol(p+)kg^-1)and base saturation(50 to 77%).Organic S mostly contributed to the total-sulphur(62 to 77%)followed by Non sulphate S(28.8 to 37.2%)and sulphate S(0.7 to 1.4%).Except sulphate S,other forms of sulphur showed significant positive correlation among themselves as well as with organic carbon and total nitrogen.The C:N,C:S,N:S and C:N:S ratio varied from 8.2 to 10.0,6.18 to 71.57,0.62 to 7.26 and 100:10.1:1.4 to 100:12.2:16.2 respectively.Wider C:N:S ratios in all the surface and sub-surface soils indicated that the major portion of nitrogen and sulphur in tea growing soils of Northeastern India is locked up in organic combination which might pose as a potential threat towards tea plantation if application of sulphur is continuously ignored.
文摘Three-word Primer is one of Chinese classics of enlightenment. It has the distinctive senses of beauty in form, meaning and rhymes. This paper focuses on the Relevance Theory which plays an important role in guiding to translate Three-word Primer. After analyzing some examples from two translated versions, it's then suggested that it be necessary and important to translate poems in one language into poems in another language.
文摘This paper,after introducing the definition and forms of cultural image,focuses on the detailed comparison and analysis of cultural image of animal words both in English and in Chinese from four aspects,that is,same animal word,same cultural image;same animal word,different cultural images;different animal words,same cultural image;different animal words,different cultural images.
基金Project supported by the National Key Basic Research Support Foundation (No. G1999011707)the National Natural Science Foundation of China (Nos. 39970429, 49890330, 30070429 and 40201028).
文摘Experiments were carried out on a vegetable field with Peking cabbage(Brassica pekinensis (Lour.) Rupr.), cabbage (Brassica, chinensis var. oleifcra Makino and nemoto),green cabbage (Brassica chinensis L.), spinach (Spinacia oleracea L.) and rape(Brassica campestrisL.) to study the effects of N forms and N rates on their growth and nitrate accumulation. Theresults indicated that application of ammonium chloride, ammonium nitrate, sodium nitrate and ureasignificantly increased the yields and nitrate concentrations of Peking cabbage and spinach.Although no significant difference was found in the yields after application of the 4 N forms,nitrate N increased nitrate accumulation in vegetables much more than ammonium N. The vegetableyields were not increased continuously with N rate increase, and oversupply of N reduced the plantgrowth, leading to a yield decline. This trend was also true for nitrate concentrations in somevegetables and at some sampling times. However, as a whole, the nitrate concentrations in vegetableswere positively correlated with N rates. Thus, addition of N fertilizer to soil was the major causefor increases in nitrate concentrations in vegetables. Nitrate concentrations were much higher inroots, stems and petioles than in blades at any N rate.
文摘Effects of different levels of compost application on the amounts and percentage distribution of organic N forms in whole soils and particle size fractions were investigated. Soil samples were collected from three plots: (a) F, only chemical fertilizers;(b) F+LC, chemical fertilizers plus low level of compost;(c) F+HC, chemical fertilizers plus high level of compost. Each soil sample was divided into five fractions: coarse sand-sized aggregate (CSA), medium sand-sized aggregate (MSA), fine sand-sized aggregate (FSA), silt-sized aggregate (SIA) and clay-sized aggregate (CLA) fractions. The sand fractions were subdivided into decayed plants (DP) and mineral particles (MP). The amounts of total N and different organic N forms in the whole soils as well as size fractions generally increased with increasing the amount of compost. In the whole soils, percentage distribution of non-hydrolysable-N and amino sugar-N increased by compost application while the distribution values of the hydrolysable ammonium- N and unidentified-N decreased. The application did not affect the distribution degree of amino acid-N. In the size fractions, the distribution values of most organic N forms increased in the CSA-DP, MSA-DP and FSA-DP fractions by compost application. In the CLA fractions, the amounts and percentage distribution of organic N forms were the highest, although the application caused decreases in their distribution values. These findings indicate that the CLA fraction merit close attention as an important reservoir of various organic N.
基金supported by the National Natural science Foundation of China.(No.39790100)
文摘Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy. Of the detectable 15N-signal intensity in the spectra of soil humic substances 71%-79% may be attributed to amide groups, 10%-18% to aromatic/aliphatic amines and 6%~11% to indole- and pyrrole-like N. Whereas in the spectrum of the fulvic acid from weathered coal 46%, at least, of the total 15N-signal intensity might be assigned to pyrrole-like N, 14% to aromatic/aliphatic ammes, and the remaining intensities could not be assigned with certainty. Data on nonhydrolyzable residue of protein-sugar mixture and a 15N-labelled soil fulvic acid confirm the formation of nonhydrolyzable heterocyclic N during acid hydrolysis. Project (No. 39790100) supported by the National Natural Science Foundation of China.
文摘The growth, chlorophyll composition, photosynthesis, respiration, K uptake and root K+ secretion offlue-cured tobacco as thected by different concentrations of N supplied as urea, NaNO3 and NH4NO3 werestudied under the experimental condition of sand culture. The results showed that the content of K in thefiue-cured tobacco was not merely related with root vitality and uptake but also closely related with root cellmembrane structure and K+ secretion.
文摘Mn18Cr18N, the high-nitrogen steel, is the 2nd generation material for manufacturing the retaining ring of firepower generators. In this paper, the hot deformation behavior of the material was investigated by thermo-mechanical modeling tests. And the flow stress curves of the steel were obtained for various combinations of the temperature and strain rate. Based on the results of the tests, the complex forming process of a retaining ring including punching, expanding and extrusion with an enclosure was put forward and simulated by means of numerical simulation method. The results indicate that the process is a novel and force-saved practical technology for manufacturing heavy retaining rings.
基金supported by the National Natural Science Foundation of China(Nos.31800369,32271686,U1904204)the State Scholarship Fund of Chinathe Innovation Scientists and Technicians Troop Construction Projects of Henan Province(No.182101510005)。
文摘Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and phosphorus(P)in forest plant-soil-microbe systems remains unclear.Methods:We conducted a meta-analysis based on 751 pairs of observations to evaluate the responses of plant,soil and microbial biomass C,N and P nutrients and stoichiometry to N addition in different N intensity(050,50–100,>100 kg·ha^(-1)·year^(-1)of N),duration(0–5,>5 year),method(understory,canopy),and matter(ammonium N,nitrate N,organic N,mixed N).Results:N addition significantly increased plant N:P(leaf:14.98%,root:13.29%),plant C:P(leaf:6.8%,root:25.44%),soil N:P(13.94%),soil C:P(10.86%),microbial biomass N:P(23.58%),microbial biomass C:P(12.62%),but reduced plant C:N(leaf:6.49%,root:9.02%).Furthermore,plant C:N:P stoichiometry changed significantly under short-term N inputs,while soil and microorganisms changed drastically under high N addition.Canopy N addition primarily affected plant C:N:P stoichiometry through altering plant N content,while understory N inputs altered more by influencing soil C and P content.Organic N significantly influenced plant and soil C:N and C:P,while ammonia N changed plant N:P.Plant C:P and soil C:N were strongly correlated with mean annual precipitation(MAT),and the C:N:P stoichiometric flexibility in soil and plant under N addition connected with soil depth.Besides,N addition decoupled the correlations between soil microorganisms and the plant.Conclusions:N addition significantly increased the C:P and N:P in soil,plant,and microbial biomass,reducing plant C:N,and aggravated forest P limitations.Significantly,these impacts were contingent on climate types,soil layers,and N input forms.The findings enhance our comprehension of the plant-soil system nutrient cycling mechanisms in forest ecosystems and plant strategy responses to N deposition.
文摘The syntheses of 5 new 17-membered macrocycles containing naphthalene ring are reported. The macrocycle ring in each of these new ligands contains an O2N3-donor set. Structures of these new compounds were characterized by IR,1H NMR, MS and elemental analysis.
文摘We use a lot of devices in our daily life to communicate with others. In this modern world, people use email, Facebook, Twitter, and many other social network sites for exchanging information. People lose their valuable time misspelling and retyping, and some people are not happy to type large sentences because they face unnecessary words or grammatical issues. So, for this reason, word predictive systems help to exchange textual information more quickly, easier, and comfortably for all people. These systems predict the next most probable words and give users to choose of the needed word from these suggested words. Word prediction can help the writer by predicting the next word and helping complete the sentence correctly. This research aims to forecast the most suitable next word to complete a sentence for any given context. In this research, we have worked on the Bangla language. We have presented a process that can expect the next maximum probable and proper words and suggest a complete sentence using predicted words. In this research, GRU-based RNN has been used on the N-gram dataset to develop the proposed model. We collected a large dataset using multiple sources in the Bangla language and also compared it to the other approaches that have been used such as LSTM, and Naive Bayes. But this suggested approach provides excellent exactness than others. Here, the Unigram model provides 88.22%, Bi-gram model is 99.24%, Tri-gram model is 97.69%, and 4-gram and 5-gram models provide 99.43% and 99.78% on average accurateness. We think that our proposed method profound impression on Bangla search engines.
基金Project supported by the National Natural Science Foundation of China.
文摘Results of a 10-year decomposition experiment indicated that the annual mineralization rate of organic N in newly-formed humus varied with the type of original plant materials and the water regimes for decomposition, ranging from 0.028 to 0.074. The mineralization rate under waterlogged conditions was higher than that under upland conditions. The proportion of α-amino acid N in humus newly-formed under waterlogged conditions was slightly higher than that under upland conditions. It decreased gradually with time, while the proportion of nonhydrolyzable N showed no consistent trend, irrespective of the water regimes for decomposition. The distribution of amino acids in humus newly- formed from different plant materials under various water regimes was quite similar with that in original plant materials, and only minor differences could be found among them. For example, in comparison to original plant materials, the newly-formed humus contained higher proportions of isoleucine, cystine, γ-amino-butync acid and ornithine, and lower proportions of phenylalanine and proline. Moreover the proportion of phenylalanine was higher in the humus newly-formed under waterlogged conditions than that under upland conditions.
文摘In the hot forming of Mn18Cr18N steel, such problems as easy cracking, difficult controlling of forming paramenters often occur. In this paper,the variation rule of the plasticity of the steel, the starting mechanism of micro-crack and its generating characteristics were studied with the combination of thermodynamic simulation test, micro-simulation and FEM, the related data of microstructure change and hot forming parameters were produced. The hot forming process of 600MW generator retaining ring was analyzed as an example.
基金the National Natural Science Foundation of China(Grant No.11871116)the Fundamental Research Funds for the Central Universities of China(Grant No.2019XD-A11)the BUPT Innovation and Entrepreneurship Support Program,Beijing University of Posts and Telecommunications,and the National Scholarship for Doctoral Students of China.
文摘The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-de Vriesmodified Korteweg-de Vries equation for the atmosphere,oceanic fluids and plasmas.With symbolic computation,beginning with a presumption,we work out certain scaling transformations,bilinear forms through the binary Bell polynomials and our scaling transformations,N solitons(with N being a positive integer)via the aforementioned bilinear forms and bilinear auto-Bäcklund transformations through the Hirota method with some solitons.In addition,Painlevé-type auto-Bäcklund transformations with some solitons are symbolically computed out.Respective dependences and constraints on the variable/constant coefficients are discussed,while those coefficients correspond to the quadratic-nonlinear,cubic-nonlinear,dispersive,dissipative and line-damping effects in the atmosphere,oceanic fluids and plasmas.
文摘English words in pairs are a special form of English idioms, which have different kinds and are used widely. For English learners, words in pairs are one of the difficult points. This paper discusses their form patterns, semantic relations, grammatical functions, rhetoric features and their application in translation. Its purpose is to help learners understand and use them accurately and correctly so as to improve language expressing ability.
文摘Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days and partitioned into acid-insoluble (MHA) and acid-soluble (MFA) fractions. The nitrogen forms in these polymers were studied by using the 15N cross polarization-magic angle spinning nuclear magnetic resonance (CPMAS NMR) technique in combination with chemical methods. The 15N nuclear magnetic resonance (NMR) data showed that while the yield, especially the MHA/MFA ratio, varied considerably with the concentrations of the reactants, the nitrogen distribution patterns of these polymers were quite similar.From 65% to 70% of nitrogen in them was in the secondary amide and/or indole form with 24%~25% present as aliphatic and/or aromatic ammes and 5% to 11% as pyrrole and/or pyrrole-like nitrogen. More than half (50%~77%) of the N in these polymers were nonhydrolyzable. The role of Maillard reaction in the formation of nonhydrolyzable nitrogen in soil organic matter is discussed.