[Objectives] To determine the content of total flavonoids in Tetracera asiatica from different production areas in Guangxi and provide a basis for improving the quality standards of crude drug. [Methods] Using 50% eth...[Objectives] To determine the content of total flavonoids in Tetracera asiatica from different production areas in Guangxi and provide a basis for improving the quality standards of crude drug. [Methods] Using 50% ethanol as extractor,NaNO_2-Al(NO_3)_3-NaOH as chromogenic system and rutin as the reference substance,the content of total flavonoids from the crude drug was determined. [Results] A method for determining the content of total flavonoids was established,the content of total flavonoids was 11.35-21.35 mg·g^(-1),and the average content was 17.64 mg·g^(-1). [Conclusions] The method had high repeatability and stability,and the method was simple,rapid and sensitive and suitable for quantitative analysis.展开更多
The change and control of nitrogen content in molten steel was investigated through the production process of "LDBAr-LF-RH-CC". Results show that nitrogen content reduces gradually in converter-steelmaking s...The change and control of nitrogen content in molten steel was investigated through the production process of "LDBAr-LF-RH-CC". Results show that nitrogen content reduces gradually in converter-steelmaking stage, rises rapidly from the end of converter process to the end of argon station process, continues to increase in ladle furnace process, and decreases slightly in RH refining stage. Since nitrogen is removed mainly by BOF steelmaking and vacuum refining operations, nitrogen in molten steel should be removed as much as possible in these two operations. However, nitrogen uptake should be minimized in other operations of molten steel production process.展开更多
P2P systems are categorized into tree-based and mesh-based systems according to their topologies. Mesh-based systems are considered more suitable for large-scale lnternet applications, but require optimization on late...P2P systems are categorized into tree-based and mesh-based systems according to their topologies. Mesh-based systems are considered more suitable for large-scale lnternet applications, but require optimization on latency issue. This paper proposes a content subscribing mechanism (CSM) to eliminate unnecessary time delays during data relaying. A node can send content data to its neighbors as soon as it receives the data segment. No additional time is taken during the interactive stages prior to data segment transmission of streaming content. CSM consists of three steps. First, every node records its historical segments latency, and adopts gamma distribution, which possesses powerful expression ability, to express latency statistics. Second, a node predicts subscribing success ratio of every neighbor by comparing the gamma distribution parameters of the node and its neighbors before selecting a neighbor node to subscribe a data segment. The above steps would not increase latency as they are executed before the data segments are ready at the neighbor nodes. Finally, the node, which was subscribed to, sends the subscribed data segment to the subscriber immediately when it has the data segment. Experiments show that CSM significantly reduces the content data transmission latency.展开更多
With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main b...With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main biological role of selenium is to resist oxidation and inflammatory response, mainly focusing on resisting aging, preventing cardiovascular disease, protecting eyesight, counteracting or destroying the toxic properties, preventing cancer and thyroid disease. In most areas of China, there is a widespread shortage of selenium, thus producing selenium-rich agricultural products to provide natural selenium-rich health food to the areas in need of selenium, has gradually become a new hot spot of China's health food industry, but high content of selenium in food is detrimental to human body, even leads to selenium intoxication, and artificially adding inorganic selenium is difficult to guarantee that the selenium content of agricultural products is not exceeded. According to human body's daily demand for selenium in dietetics and the content of selenium in agricultural products in the Chinese food composition table, we put forward the recommendations on the standard of selenium in agricultural products, in order to provide the basis for China to formulate the health standard of selenium content in selenium-rich agricultural products.展开更多
[Objectives] This study was conducted to explore the effect of machine harvesting on ratooning ability of Guitang 47, and to provide basis for mechanized production of Guitang 47. [Methods] On the basis of mechanized ...[Objectives] This study was conducted to explore the effect of machine harvesting on ratooning ability of Guitang 47, and to provide basis for mechanized production of Guitang 47. [Methods] On the basis of mechanized planting and management of newly planted sugarcane Guitang 47, a comparative test of machine harvesting and manual harvesting was conducted, during which the plant generation rate, sugarcane yield, sucrose content and related agronomic traits of ratoon cane were continuously investigated in two years after machine harvesting of the newly planted sugarcane. [Results] There were no significant differences in the plant generation rate, plant height, stalk diameter, millable cane, sugarcane yield and sucrose content from manual harvesting of Guitang 47 in the first and second years after machine harvesting. In the second year after machine harvesting, the yields of ratoon cane and the sugar content reached 101.70 and 15.32 t/hm^2, respectively, which were equivalent to those of manual harvesting. [Conclusions] Guitang 47 has strong ratooning ability and lodging resistance and strong resistance to rolling and crushing, and is adaptive to full mechanized production. It should be promoted and accelerated in sugarcane areas lacking labor to reduce costs and increase benefits.展开更多
Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa (NERICA) on poor oxisol. In this study, two NERICA varieties (NERICA 3 and NERICA 8) w...Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa (NERICA) on poor oxisol. In this study, two NERICA varieties (NERICA 3 and NERICA 8) were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing (control), unplowed soil with dead vegetation cover (DVC), unplowed soil with live vegetation cover (LVC) and unplowed soil with mixed vegetation cover (MVC). DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive (2.16–3.05 t/hm2) compared with NERICA 8 (0.71–1.21 t/hm2). Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.展开更多
This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.
By the end of 1990,Daqing,Oilfields had been produ-cing for 30 years with water flooding.The composite water cut was as high as 79%.In the general regularity of developing large scale sandstone reservoirs,the oilfield...By the end of 1990,Daqing,Oilfields had been produ-cing for 30 years with water flooding.The composite water cut was as high as 79%.In the general regularity of developing large scale sandstone reservoirs,the oilfields had been in their later stage of production,char-acterized by rapid decline of oil.output.It is very difficult to keep a steady oil production without any breakthrough in oilfield development techno-logies.展开更多
Objective: The paper aims to analyze the dynamic characteristics of litter production and nutrient return of the forest ecosystems in subtropical areas, and provide a theoretical basis for the nutrient cycling study i...Objective: The paper aims to analyze the dynamic characteristics of litter production and nutrient return of the forest ecosystems in subtropical areas, and provide a theoretical basis for the nutrient cycling study in southwest Hubei Province and carbon sink function of the whole forest ecosystem. Methods: Three typical forest stands (Chinese fir plantation, Cryptomeria fortunei plantation and evergreen and deciduous broad-leaved mixed forest) in Golden Mountain Forest Farm in southwest Hubei Province were investigated and monitored continuously for the litter types and productivity and nutrient return. Results: The annual litter productivity of the three forest stands ranged from 161.77 to 396.26 kg·hm<sup>-2</sup>;Litters of branches, leaves and reproductive organs accounted for 14.14% - 20.85%, 33.26% - 78.33%, 7.52% - 42.18% of the total, respectively;The litter productivity and total litter productivity of each composition in the three forest stands show unimodal or bimodal changes over months, and the total litter productivity reached the highest value in January, April and October respectively. For different nutrient contents of the three forest stands, the common feature is C > N. The order of nutrient return amount from greatest to least is evergreen and deciduous broad-leaved mixed forest, Cryptomeria fortunei plantation and Chinese fir plantation. For different nutrient return amounts, the common feature is C > N, and the nutrient return amounts are 76.51-180.69 kg·hm<sup>-2</sup> and 2.3 - 5.71 kg·hm<sup>-2</sup> respectively. Conclusion: The annual litter productivity and nutrient return amount of the evergreen and deciduous broad-leaved mixed forest are the highest among the three forest stands. Therefore, protecting the evergreen and deciduous broad-leaved mixed forest and studying the litter changes of Chinese fir plantation and Cryptomeria fortunei plantation are of far-reaching significance for the development of sustainable forest management in this region and the further improvement of the carbon sequestration function of the whole forest ecosystem.展开更多
Objective] This study was conducted to evaluate the product quality and safety of Peristrophe roxburghiana_ col ected from different places in Hechi City, northwest of Gunagxi, so as to provide basic data for further ...Objective] This study was conducted to evaluate the product quality and safety of Peristrophe roxburghiana_ col ected from different places in Hechi City, northwest of Gunagxi, so as to provide basic data for further development and uti-lization of the characteristic plant resource P. roxburghiana. [Method] Contents of 9 kinds of heavy metals including Cd, Mn, Pb, Zn and Cu in the herb were deter-mined by the method of wet digestion-flame atomic absorption spectrophotometry and atomic fluorescence spectrometry, respectively. [Results] Heavy metal contents of Cd, Mn, Pb, Fe, Cu, Zn, As, Hg and Se were 1.62-17.25, 8.93-142.53, 4.37-18.43, 103.7-242.81, 2.55-5.35, 85.40-146.30, 0.07-0.54, 0.00-0.08 and 0.00-0.47 mg/kg, respectively. According to the national food safety standards and Green Trade Standards of lmporting &amp; Exporting Medicinal plants &amp; Preparations, the heavy metal contents of the P. roxburghiana_samples col ected from different coun-ties in Hechi City exceeded standards or at the critical values. Among which, Cd, Pb and Zn contents of the samples are seriously higher than the standards. [Con-clusion] Therefore, the impact of soil heavy metal pol ution on the safety of edible plants in the northwest of Guangxi should be highly concerned.展开更多
The reduction behaviors and characteristics of products of the Fe-Cr-O system (FeCr2O4 and Fe2O3+Cr2O3) and Fe-Cr-Ni-O system (Fe2O3+Cr2O3+NiO) under various conditions were studied. The results show that more ...The reduction behaviors and characteristics of products of the Fe-Cr-O system (FeCr2O4 and Fe2O3+Cr2O3) and Fe-Cr-Ni-O system (Fe2O3+Cr2O3+NiO) under various conditions were studied. The results show that more Fe-Cr or Fe-Cr-Ni solution and less residual carbon content were obtained at higher temperatures and lower initial molar ratio of C to O (nC:nO). The degree of reduction was highly dependent on both time and temperature, and the residual carbon content greatly increased with increasing nC:nO at each temperature. The products generated during the carbothermic reduction of the Fe-Cr-O system were examined using X-ray diffraction (XRD). A scanning electron microscope (SEM) coupled with energy dispersive spectrometer was used to observe the microstructure and the distribution of elements in the various phases of the final reduction products of the Fe-Cr-O and Fe-Cr-Ni-O.展开更多
To our knowledge,no single study has systemically compared cryopreservation efficiencies of bovine blastocysts derived from in vitro fertilization (IVF),intracytoplasmic sperm injection (ICSI) and somatic cell nuc...To our knowledge,no single study has systemically compared cryopreservation efficiencies of bovine blastocysts derived from in vitro fertilization (IVF),intracytoplasmic sperm injection (ICSI) and somatic cell nuclear transfer (SCNT) by controlled freezing and vitrification.This experiment,therefore,was designed to compare the cryopreservation of these blastocysts with controlled freezing and OPS vitrification.Adenosine-5’-triphosphate (ATP) content and reactive oxygen species (ROS) level in blastocysts were also analyzed.Firstly,for each type of blastocyst (IVF,ICSI or SCNT),significant differences were observed between the survival rates of the controlled freezing ((81.56±2.33),(68.18±4.72) or (47.89±5.83)%) and OPS vitrification groups ((92.24±4.54),(82.40±3.76) or (78.71±5.91)%;P〈0.05).Secondly,for each type of blastocyst (IVF,ICSI or SCNT),ATP content was significantly decreased after controlled freezing or vitrification,and the ATP content in the controlled freezing group (0.43±0.06),(0.35±0.05) or (0.21±0.02) pmol) was significantly lower than that found in the OPS vitrification group (0.62±0.04),(0.46±0.03) or (0.30±0.01) pmol;P〈0.05).Thirdly,ROS level in fresh IVF ((47.33±3.56) c.p.s (counted photons per second),ICSI ((36.51±2.58) c.p.s) or SCNT blastocysts ((26.44±1.49) c.p.s) was significantly lower than that found in the OPS vitrification group ((72.14±4.31),(58.89±3.89) or (40.11±5.73) c.p.s;P〈0.05),but higher than that of the controlled freezing group (34.41±3.32),(23.13±1.26) or (15.46±2.45) c.p.s;P〈0.05).The present study indicated that vitrification is more efficient in the cryopreservation of bovine blastocysts derived from IVF,ICSI or SCNT than controlled freezing.Furthermore,both vitrification and controlled freezing significantly altered the ATP content and ROS level in those blastocysts.展开更多
Deficit irrigation is critical to global food production,particularly in arid and semi-arid regions with low precipitation.Given water shortage has threatened agricultural sustainability under the dry-land farming sys...Deficit irrigation is critical to global food production,particularly in arid and semi-arid regions with low precipitation.Given water shortage has threatened agricultural sustainability under the dry-land farming system in China,there is an urgent need to develop effective water-saving technologies.We carried out a field study under two cultivation techniques:(1) the ridge and furrow cultivation model(R);and(2) the conventional flat farming model(F),and three simulated precipitation levels(1,275 mm;2,200 mm;3,125 mm) with two deficit irrigation levels(150 and 75 mm).We demonstrated that under the ridge furrow(R) model,rainfall harvesting planting under 150 mm deficit irrigation combined with 200 mm simulated precipitation can considerably increase net photosynthesis rate(P_(n)),quantum yield of PSII(ΦPSⅡ),electron transport rate(ETR),performance index of photosynthetic PSII(F_(v)/F_(m)′),and transformation energy potential of PSII(F_(v)/F_(o)).In addition,during the jointing,anthesis and grain-filling stages,the grain and biomass yield in the R model are 18.9 and 11.1% higher than those in the flat cultivation model,respectively,primarily due to improved soil water contents.The winter wheat fluorescence parameters were significantly positively associated with the photosynthesis,biomass and wheat production.The result suggests that the R cultivation model with irrigation of 150 mm and simulated precipitation of 200 mm is an effective planting method for enhancing P_(n),biomass,wheat production,and chlorophyll fluorescence parameters in dry-land farming areas.展开更多
In recent years, the understanding of human health has progressed considerably, through the study and understanding of the symbiotic role played by the myriad microorganisms that populate the gut and do the digesting,...In recent years, the understanding of human health has progressed considerably, through the study and understanding of the symbiotic role played by the myriad microorganisms that populate the gut and do the digesting, and populate the skin and keep it healthy, and even populate the lining of the lungs and do the same. In plant life, it is the microorganisms in the soil—which “are” the soil’s fertility—which fulfil a similar symbiotic role in a healthy plant’s life, but as yet this is a subject most visible by its absence from all scientific discussion of good farming practice. The science underlying this understanding is summarised in this paper. Understanding this and nurturing the fertility of impoverished soil by “seeding it” with the appropriate mix of microorganisms is transformational for plant health and productivity. Significant results are indicated from early trial examples of doing this in rice, oil palm and tobacco cultivation in Malaysia.展开更多
The?convergence of the Internet, sensor networks, and Radio Frequency Identification (RFID) systems has ushered to the concept of Internet of Things (IoT) which is capable of connecting daily things, making them smart...The?convergence of the Internet, sensor networks, and Radio Frequency Identification (RFID) systems has ushered to the concept of Internet of Things (IoT) which is capable of connecting daily things, making them smart through sensing, reasoning, and cooperating with other things. Further, RFID technology enables tracking of an object and assigning it a unique ID. IoT has the potential for a wide range of applications relating to healthcare, environment, transportation, cities… Moreover, the middleware is a basic component in the IoT architecture. It handles heterogeneity issues among IoT devices and provides a common framework for communication. More recently, the interest has focusing on developing publish/subscribe middleware systems for the IoT to allow asynchronous communication between the IoT devices. The scope of our paper is to study routing protocols for publish/subscribe schemes that include content and context-based routing. We propose an Energy-Efficient Content-Based Routing (EECBR) protocol for the IoT that minimizes the energy consumption. The proposed algorithm makes use of a virtual topology that is constructed in a centralized manner and then routes the events from the publishers to the intended interested subscribers in a distributed manner. EECBR has been simulated using Omnet++. The simulation results show that EECBR has a significant performance in term of the energy variance compared to the other schemes.展开更多
Under the global value chain, a country extensively employs foreign intermediate inputs in manufacturing its export products, which may not employ entirely local technology. Science-based measurement of technology con...Under the global value chain, a country extensively employs foreign intermediate inputs in manufacturing its export products, which may not employ entirely local technology. Science-based measurement of technology content in and structure of exports should be conducted using production process data. Using world input-output tables(WIOTs) of 1995-2011, this paper developed a new method for measuring the export technology content of China and other major countries. Our research findings suggest that, since 1995, there has been some technology upgrade of Chinese exports. China's overall and sector-specific technology contents, and domestic technology contents and indexes all increased and demonstrated a weak convergence towards the average level of developed countries. Judging by the relative rankings of sector-specific technology levels, China is almost locked at the lowest level in the world, and cannot challenge the technological superiority of developed countries like the U.S. and Japan.展开更多
Peanut or groundnut ( Arachis hypogaea L. ) is an important source of vegetable oil in the world. Genetic enhancement for high yield and high oil content has greatly contributed to enhanced pro-ductivit...Peanut or groundnut ( Arachis hypogaea L. ) is an important source of vegetable oil in the world. Genetic enhancement for high yield and high oil content has greatly contributed to enhanced pro-ductivity of peanut and increased supply of peanut oil. Further improving oil content and quality of peanut is still crucial for increasing productivity of arable land and market competitiveness of peanut oil. Based on investigation among the peanut germplasm accessions including wild Arachis species, the oil content could be as high as 65%. Heterosis has been observed for oil content in hybrids derived from diverse crossing parents. Segregates with enhanced oil content have been obtained by pyramiding different genes or alleles with major and minor additive effects. Improved testing techniques for oil content in breeding lines with reduced cost have accelerated breeding progress for high oil content. SSR markers associated with oil content have been identified by association and linkage analysis. The stability of oil content in peanut across seasons and locations is highly associated with cold tolerance, high nutrition efficiency and drought tolerance. Recent progress on improving fatty acids in particular marker assisted backcrossing breeding has contributed to higher quality peanut oil and other products. High oil peanut lines with im-proved resistance to aflatoxin production have been developed. The wild Arachis species would be of great value for peanut breeding in increasing oil content.展开更多
基金Supported by Youth Fund Project of Guangxi Natural Science Foundation(2016GXNSFBA380014)Key Laboratory Project of Guangxi Zhuang and Yao Medicine(GuiKeJiZi201432)+5 种基金Collaborative Innovation Center Project of Zhuang and Yao Medicine(GuiJiaoKeYan201320)Guangxi Key Discipline(Zhuang Medicine Study)Project(GuiJiaoKeYan201316)Bagui Scholar Program"Innovation Theory and Efficacy Studies of Traditional Chinese Medicine"Special Traditional Chinese Medicine Science and Technology Project of Health Department of Guangxi Zhuang Autonomous Region(GZPT1204)Scientific Research Project of Guangxi’s Colleges and Universities(KY2015-YB160)Scientific Research Project of Guangxi University of Chinese Medicine in 2015(2015LX005)
文摘[Objectives] To determine the content of total flavonoids in Tetracera asiatica from different production areas in Guangxi and provide a basis for improving the quality standards of crude drug. [Methods] Using 50% ethanol as extractor,NaNO_2-Al(NO_3)_3-NaOH as chromogenic system and rutin as the reference substance,the content of total flavonoids from the crude drug was determined. [Results] A method for determining the content of total flavonoids was established,the content of total flavonoids was 11.35-21.35 mg·g^(-1),and the average content was 17.64 mg·g^(-1). [Conclusions] The method had high repeatability and stability,and the method was simple,rapid and sensitive and suitable for quantitative analysis.
文摘The change and control of nitrogen content in molten steel was investigated through the production process of "LDBAr-LF-RH-CC". Results show that nitrogen content reduces gradually in converter-steelmaking stage, rises rapidly from the end of converter process to the end of argon station process, continues to increase in ladle furnace process, and decreases slightly in RH refining stage. Since nitrogen is removed mainly by BOF steelmaking and vacuum refining operations, nitrogen in molten steel should be removed as much as possible in these two operations. However, nitrogen uptake should be minimized in other operations of molten steel production process.
基金the National Natural Science Foundation of China (Nos. 60533090 and 60525108)the National Basic research Program (973) of China (No. 2002CB312101)+2 种基金the China-US Million Book Digital Library Project (www.cadal.zju.edu.cn)the Science and Technology Project of Zhejiang Province (Nos. 2005C13032 and 2005C11001-05)the Research Project of Education Department of Zhejiang Province (No. 20061352), China
文摘P2P systems are categorized into tree-based and mesh-based systems according to their topologies. Mesh-based systems are considered more suitable for large-scale lnternet applications, but require optimization on latency issue. This paper proposes a content subscribing mechanism (CSM) to eliminate unnecessary time delays during data relaying. A node can send content data to its neighbors as soon as it receives the data segment. No additional time is taken during the interactive stages prior to data segment transmission of streaming content. CSM consists of three steps. First, every node records its historical segments latency, and adopts gamma distribution, which possesses powerful expression ability, to express latency statistics. Second, a node predicts subscribing success ratio of every neighbor by comparing the gamma distribution parameters of the node and its neighbors before selecting a neighbor node to subscribe a data segment. The above steps would not increase latency as they are executed before the data segments are ready at the neighbor nodes. Finally, the node, which was subscribed to, sends the subscribed data segment to the subscriber immediately when it has the data segment. Experiments show that CSM significantly reduces the content data transmission latency.
基金Supported by Hunan University Innovation Team FoundationHunan Science and Technology Plan Project (2011NK3093)
文摘With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main biological role of selenium is to resist oxidation and inflammatory response, mainly focusing on resisting aging, preventing cardiovascular disease, protecting eyesight, counteracting or destroying the toxic properties, preventing cancer and thyroid disease. In most areas of China, there is a widespread shortage of selenium, thus producing selenium-rich agricultural products to provide natural selenium-rich health food to the areas in need of selenium, has gradually become a new hot spot of China's health food industry, but high content of selenium in food is detrimental to human body, even leads to selenium intoxication, and artificially adding inorganic selenium is difficult to guarantee that the selenium content of agricultural products is not exceeded. According to human body's daily demand for selenium in dietetics and the content of selenium in agricultural products in the Chinese food composition table, we put forward the recommendations on the standard of selenium in agricultural products, in order to provide the basis for China to formulate the health standard of selenium content in selenium-rich agricultural products.
基金Supported by Guangxi Scientific Research and Technology Development Program(GK AB 16380177)Project of Province and Ministry Co-sponsored Collaborative Innovation Center of Sugarcane IndustryGuangxi Special Finance Project
文摘[Objectives] This study was conducted to explore the effect of machine harvesting on ratooning ability of Guitang 47, and to provide basis for mechanized production of Guitang 47. [Methods] On the basis of mechanized planting and management of newly planted sugarcane Guitang 47, a comparative test of machine harvesting and manual harvesting was conducted, during which the plant generation rate, sugarcane yield, sucrose content and related agronomic traits of ratoon cane were continuously investigated in two years after machine harvesting of the newly planted sugarcane. [Results] There were no significant differences in the plant generation rate, plant height, stalk diameter, millable cane, sugarcane yield and sucrose content from manual harvesting of Guitang 47 in the first and second years after machine harvesting. In the second year after machine harvesting, the yields of ratoon cane and the sugar content reached 101.70 and 15.32 t/hm^2, respectively, which were equivalent to those of manual harvesting. [Conclusions] Guitang 47 has strong ratooning ability and lodging resistance and strong resistance to rolling and crushing, and is adaptive to full mechanized production. It should be promoted and accelerated in sugarcane areas lacking labor to reduce costs and increase benefits.
基金the Laboratory of Biotechnology and Environment as well as the Food and Nutrition Research Center(CRAN)of Institute for Medical Research and Study of Medicinal Plants in Cameroon for their support
文摘Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa (NERICA) on poor oxisol. In this study, two NERICA varieties (NERICA 3 and NERICA 8) were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing (control), unplowed soil with dead vegetation cover (DVC), unplowed soil with live vegetation cover (LVC) and unplowed soil with mixed vegetation cover (MVC). DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive (2.16–3.05 t/hm2) compared with NERICA 8 (0.71–1.21 t/hm2). Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.
文摘This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.
文摘By the end of 1990,Daqing,Oilfields had been produ-cing for 30 years with water flooding.The composite water cut was as high as 79%.In the general regularity of developing large scale sandstone reservoirs,the oilfields had been in their later stage of production,char-acterized by rapid decline of oil.output.It is very difficult to keep a steady oil production without any breakthrough in oilfield development techno-logies.
文摘Objective: The paper aims to analyze the dynamic characteristics of litter production and nutrient return of the forest ecosystems in subtropical areas, and provide a theoretical basis for the nutrient cycling study in southwest Hubei Province and carbon sink function of the whole forest ecosystem. Methods: Three typical forest stands (Chinese fir plantation, Cryptomeria fortunei plantation and evergreen and deciduous broad-leaved mixed forest) in Golden Mountain Forest Farm in southwest Hubei Province were investigated and monitored continuously for the litter types and productivity and nutrient return. Results: The annual litter productivity of the three forest stands ranged from 161.77 to 396.26 kg·hm<sup>-2</sup>;Litters of branches, leaves and reproductive organs accounted for 14.14% - 20.85%, 33.26% - 78.33%, 7.52% - 42.18% of the total, respectively;The litter productivity and total litter productivity of each composition in the three forest stands show unimodal or bimodal changes over months, and the total litter productivity reached the highest value in January, April and October respectively. For different nutrient contents of the three forest stands, the common feature is C > N. The order of nutrient return amount from greatest to least is evergreen and deciduous broad-leaved mixed forest, Cryptomeria fortunei plantation and Chinese fir plantation. For different nutrient return amounts, the common feature is C > N, and the nutrient return amounts are 76.51-180.69 kg·hm<sup>-2</sup> and 2.3 - 5.71 kg·hm<sup>-2</sup> respectively. Conclusion: The annual litter productivity and nutrient return amount of the evergreen and deciduous broad-leaved mixed forest are the highest among the three forest stands. Therefore, protecting the evergreen and deciduous broad-leaved mixed forest and studying the litter changes of Chinese fir plantation and Cryptomeria fortunei plantation are of far-reaching significance for the development of sustainable forest management in this region and the further improvement of the carbon sequestration function of the whole forest ecosystem.
基金Supported by Fund for Key Laboratories in Guangxi Universities-Featured Resource Research and Development Laboratory of Northwest of Guangxi(GJKY 2010[6])Fund for Platform Built by University and Local Government or University and EnterpriseLocal Resource Protection and Utilization Engineering Center of Northwest of Guangxi(GJKY 2010[9])~~
文摘Objective] This study was conducted to evaluate the product quality and safety of Peristrophe roxburghiana_ col ected from different places in Hechi City, northwest of Gunagxi, so as to provide basic data for further development and uti-lization of the characteristic plant resource P. roxburghiana. [Method] Contents of 9 kinds of heavy metals including Cd, Mn, Pb, Zn and Cu in the herb were deter-mined by the method of wet digestion-flame atomic absorption spectrophotometry and atomic fluorescence spectrometry, respectively. [Results] Heavy metal contents of Cd, Mn, Pb, Fe, Cu, Zn, As, Hg and Se were 1.62-17.25, 8.93-142.53, 4.37-18.43, 103.7-242.81, 2.55-5.35, 85.40-146.30, 0.07-0.54, 0.00-0.08 and 0.00-0.47 mg/kg, respectively. According to the national food safety standards and Green Trade Standards of lmporting &amp; Exporting Medicinal plants &amp; Preparations, the heavy metal contents of the P. roxburghiana_samples col ected from different coun-ties in Hechi City exceeded standards or at the critical values. Among which, Cd, Pb and Zn contents of the samples are seriously higher than the standards. [Con-clusion] Therefore, the impact of soil heavy metal pol ution on the safety of edible plants in the northwest of Guangxi should be highly concerned.
基金Project (51074025) supported by the National Natural Science Foundation of ChinaProject (FRF-SD-12-009A) supported by the Fundamental Research Funds for the Central Universities,China
文摘The reduction behaviors and characteristics of products of the Fe-Cr-O system (FeCr2O4 and Fe2O3+Cr2O3) and Fe-Cr-Ni-O system (Fe2O3+Cr2O3+NiO) under various conditions were studied. The results show that more Fe-Cr or Fe-Cr-Ni solution and less residual carbon content were obtained at higher temperatures and lower initial molar ratio of C to O (nC:nO). The degree of reduction was highly dependent on both time and temperature, and the residual carbon content greatly increased with increasing nC:nO at each temperature. The products generated during the carbothermic reduction of the Fe-Cr-O system were examined using X-ray diffraction (XRD). A scanning electron microscope (SEM) coupled with energy dispersive spectrometer was used to observe the microstructure and the distribution of elements in the various phases of the final reduction products of the Fe-Cr-O and Fe-Cr-Ni-O.
基金supported by the Fund of China Agriculture Research System(CARS-37)the Genetically Modified Organisms Breeding Major Projects of China(2009ZX08011-031B)+1 种基金the Basic Research Fund of IAS,CAAS(2010jc-3-1)the National Natural Science Foundation of China(31001011)
文摘To our knowledge,no single study has systemically compared cryopreservation efficiencies of bovine blastocysts derived from in vitro fertilization (IVF),intracytoplasmic sperm injection (ICSI) and somatic cell nuclear transfer (SCNT) by controlled freezing and vitrification.This experiment,therefore,was designed to compare the cryopreservation of these blastocysts with controlled freezing and OPS vitrification.Adenosine-5’-triphosphate (ATP) content and reactive oxygen species (ROS) level in blastocysts were also analyzed.Firstly,for each type of blastocyst (IVF,ICSI or SCNT),significant differences were observed between the survival rates of the controlled freezing ((81.56±2.33),(68.18±4.72) or (47.89±5.83)%) and OPS vitrification groups ((92.24±4.54),(82.40±3.76) or (78.71±5.91)%;P〈0.05).Secondly,for each type of blastocyst (IVF,ICSI or SCNT),ATP content was significantly decreased after controlled freezing or vitrification,and the ATP content in the controlled freezing group (0.43±0.06),(0.35±0.05) or (0.21±0.02) pmol) was significantly lower than that found in the OPS vitrification group (0.62±0.04),(0.46±0.03) or (0.30±0.01) pmol;P〈0.05).Thirdly,ROS level in fresh IVF ((47.33±3.56) c.p.s (counted photons per second),ICSI ((36.51±2.58) c.p.s) or SCNT blastocysts ((26.44±1.49) c.p.s) was significantly lower than that found in the OPS vitrification group ((72.14±4.31),(58.89±3.89) or (40.11±5.73) c.p.s;P〈0.05),but higher than that of the controlled freezing group (34.41±3.32),(23.13±1.26) or (15.46±2.45) c.p.s;P〈0.05).The present study indicated that vitrification is more efficient in the cryopreservation of bovine blastocysts derived from IVF,ICSI or SCNT than controlled freezing.Furthermore,both vitrification and controlled freezing significantly altered the ATP content and ROS level in those blastocysts.
基金supported by the National Key Technologies R&D Program of China (2012BAD09B03)the China Postdoctoral Science Foundation Project Funding (2018M642614)+2 种基金the Special Fund for Agro-scientific Research, China (201303104)the Natural Science Foundation of Shandong Province, China (ZR2017ZB0422)the “Taishan Scholar” Project of Shandong Province, China。
文摘Deficit irrigation is critical to global food production,particularly in arid and semi-arid regions with low precipitation.Given water shortage has threatened agricultural sustainability under the dry-land farming system in China,there is an urgent need to develop effective water-saving technologies.We carried out a field study under two cultivation techniques:(1) the ridge and furrow cultivation model(R);and(2) the conventional flat farming model(F),and three simulated precipitation levels(1,275 mm;2,200 mm;3,125 mm) with two deficit irrigation levels(150 and 75 mm).We demonstrated that under the ridge furrow(R) model,rainfall harvesting planting under 150 mm deficit irrigation combined with 200 mm simulated precipitation can considerably increase net photosynthesis rate(P_(n)),quantum yield of PSII(ΦPSⅡ),electron transport rate(ETR),performance index of photosynthetic PSII(F_(v)/F_(m)′),and transformation energy potential of PSII(F_(v)/F_(o)).In addition,during the jointing,anthesis and grain-filling stages,the grain and biomass yield in the R model are 18.9 and 11.1% higher than those in the flat cultivation model,respectively,primarily due to improved soil water contents.The winter wheat fluorescence parameters were significantly positively associated with the photosynthesis,biomass and wheat production.The result suggests that the R cultivation model with irrigation of 150 mm and simulated precipitation of 200 mm is an effective planting method for enhancing P_(n),biomass,wheat production,and chlorophyll fluorescence parameters in dry-land farming areas.
文摘In recent years, the understanding of human health has progressed considerably, through the study and understanding of the symbiotic role played by the myriad microorganisms that populate the gut and do the digesting, and populate the skin and keep it healthy, and even populate the lining of the lungs and do the same. In plant life, it is the microorganisms in the soil—which “are” the soil’s fertility—which fulfil a similar symbiotic role in a healthy plant’s life, but as yet this is a subject most visible by its absence from all scientific discussion of good farming practice. The science underlying this understanding is summarised in this paper. Understanding this and nurturing the fertility of impoverished soil by “seeding it” with the appropriate mix of microorganisms is transformational for plant health and productivity. Significant results are indicated from early trial examples of doing this in rice, oil palm and tobacco cultivation in Malaysia.
文摘The?convergence of the Internet, sensor networks, and Radio Frequency Identification (RFID) systems has ushered to the concept of Internet of Things (IoT) which is capable of connecting daily things, making them smart through sensing, reasoning, and cooperating with other things. Further, RFID technology enables tracking of an object and assigning it a unique ID. IoT has the potential for a wide range of applications relating to healthcare, environment, transportation, cities… Moreover, the middleware is a basic component in the IoT architecture. It handles heterogeneity issues among IoT devices and provides a common framework for communication. More recently, the interest has focusing on developing publish/subscribe middleware systems for the IoT to allow asynchronous communication between the IoT devices. The scope of our paper is to study routing protocols for publish/subscribe schemes that include content and context-based routing. We propose an Energy-Efficient Content-Based Routing (EECBR) protocol for the IoT that minimizes the energy consumption. The proposed algorithm makes use of a virtual topology that is constructed in a centralized manner and then routes the events from the publishers to the intended interested subscribers in a distributed manner. EECBR has been simulated using Omnet++. The simulation results show that EECBR has a significant performance in term of the energy variance compared to the other schemes.
文摘Under the global value chain, a country extensively employs foreign intermediate inputs in manufacturing its export products, which may not employ entirely local technology. Science-based measurement of technology content in and structure of exports should be conducted using production process data. Using world input-output tables(WIOTs) of 1995-2011, this paper developed a new method for measuring the export technology content of China and other major countries. Our research findings suggest that, since 1995, there has been some technology upgrade of Chinese exports. China's overall and sector-specific technology contents, and domestic technology contents and indexes all increased and demonstrated a weak convergence towards the average level of developed countries. Judging by the relative rankings of sector-specific technology levels, China is almost locked at the lowest level in the world, and cannot challenge the technological superiority of developed countries like the U.S. and Japan.
文摘Peanut or groundnut ( Arachis hypogaea L. ) is an important source of vegetable oil in the world. Genetic enhancement for high yield and high oil content has greatly contributed to enhanced pro-ductivity of peanut and increased supply of peanut oil. Further improving oil content and quality of peanut is still crucial for increasing productivity of arable land and market competitiveness of peanut oil. Based on investigation among the peanut germplasm accessions including wild Arachis species, the oil content could be as high as 65%. Heterosis has been observed for oil content in hybrids derived from diverse crossing parents. Segregates with enhanced oil content have been obtained by pyramiding different genes or alleles with major and minor additive effects. Improved testing techniques for oil content in breeding lines with reduced cost have accelerated breeding progress for high oil content. SSR markers associated with oil content have been identified by association and linkage analysis. The stability of oil content in peanut across seasons and locations is highly associated with cold tolerance, high nutrition efficiency and drought tolerance. Recent progress on improving fatty acids in particular marker assisted backcrossing breeding has contributed to higher quality peanut oil and other products. High oil peanut lines with im-proved resistance to aflatoxin production have been developed. The wild Arachis species would be of great value for peanut breeding in increasing oil content.