Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogic...Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus, and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability.展开更多
Improving processor frequency to strengthen massive data processing capability will lead to incremen-tal server marginal costs and bring about a series of problems such as power consumption,managementcomplexity,etc.Ba...Improving processor frequency to strengthen massive data processing capability will lead to incremen-tal server marginal costs and bring about a series of problems such as power consumption,managementcomplexity,etc.Based on the field programmable gate array(FPGA),TCP offload engine(TOE),zero-copy and other key technologies,this paper describes the design and realization of a reconfigurable accel-erator board.In this board,TCP/IP protocol will be moved to high-speed reconfigurable acceleratorboard.The packets will be labeled according to the protocol and submitted to the upper data processingsoftware after IP-quintuple filtering in hardware.Reconfigurable accelerator board obtains higher perfor-mance speed-up compared with ordinary NIC card.展开更多
A new filament winding method developed in this study named MFW (multiple-supply FW) method. It performed a high productivity. In the MFW method, a large number of bobbins are used. Carbon fibers are arranged equian...A new filament winding method developed in this study named MFW (multiple-supply FW) method. It performed a high productivity. In the MFW method, a large number of bobbins are used. Carbon fibers are arranged equiangularly above a mandrel, and they are wound and stacked on the mandrel simultaneously. Furthermore, CFRP pipes with non-crimp structure were made by MFW, and the torsional tests were performed in order to investigate mechanical properties comparing with braided CFRP pipes. These results made clear that the non-crimp structure by MFW was capable to improve torsional properties. The MFW machine produce non-crimp tubular preform with carbon fiber automatically. It is expected to produce non-crimp preforms for automotive parts which required high productivity.展开更多
The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 hor...The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.展开更多
Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the...Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the status of organic matter and nutrients in the soil but also affected the environmental quality. This article investigates the contents of organic carbon and the nutrients, and the change over the last 20 years in highly productive paddy soils and their environmental application. Field soils were sampled and the analytical results were compared with the corresponding values in the Second Soil Survey in Yujiang County of Jiangxi Province, China. The results showed that surface soils at a depth of 0-10 cm in highly productive paddy fields in Yujiang County of Jiangxi Province had contents of organic carbon (20.2 ±3.88) g kg^-1, total nitrogen (2.09±0.55) g kg^-1, and available phosphorus (42.7 ±32.7) mg kg^-1, respectively, which were all at very rich levels. Over the last 20 years, the organic carbon pool of the highly productive paddy soils reached a steady state. Total N and available P significantly increased, whereas available K changed a little. The amount and percentage of P immobilization in the surface soil (0-10 cm) of highly productive paddy fields were (142.7 ~ 41.1) mg kg-~ and (36.2~ 10.4)% of added P, and CEC (7.93 ~ 1.32) cmol kg-~. These two parameters were not higher than the mean values of paddy soils and upland red soils in the areas. Results also showed that fertilizer P in highly productive paddy soils had a high mobility and was prone to move toward a water body, which is the main source of nutrients causing eutrophication. Because of a weak K-fixing capacity, the available K content was not high in highly productive paddy soils. This suggests that attention should be paid to the K balance and the increase of soil K pool.展开更多
Marine shale gas resources have great potential in the south of the Sichuan Basin in China.At present,the high-quality shale gas resources at depth of 2000–3500 m are under effective development,and strategic breakth...Marine shale gas resources have great potential in the south of the Sichuan Basin in China.At present,the high-quality shale gas resources at depth of 2000–3500 m are under effective development,and strategic breakthroughs have been made in deeper shale gas resources at depth of 3500–4500 m.To promote the effective production of shale gas in this area,this study examines key factors controlling high shale gas production and presents the next exploration direction in the southern Sichuan Basin based on summarizing the geological understandings from the Lower Silurian Longmaxi Formation shale gas exploration combined with the latest results of geological evaluation.The results show that:(1)The relative sea depth in marine shelf sedimentary environment controls the development and distribution of reservoirs.In the relatively deep water area in deep-water shelf,grade-I reservoirs with a larger continuous thickness develop.The relative depth of sea in marine shelf sedimentary environment can be determined by redox conditions.The research shows that the uranium to thorium mass ratio greater than 1.25 indicates relatively deep water in anoxic reduction environment,and the uranium to thorium mass ratio of 0.75–1.25 indicates semi-deep water in weak reduction and weak oxidation environment,and the uranium to thorium mass ratio less than 0.75 indicates relatively shallow water in strong oxidation environment.(2)The propped fractures in shale reservoirs subject to fracturing treatment are generally 10–12 m high,if grade-I reservoirs are more than 10 m in continuous thickness,then all the propped section would be high-quality reserves;in this case,the longer the continuous thickness of penetrated grade-I reservoirs,the higher the production will be.(3)The shale gas reservoirs at 3500–4500 m depth in southern Sichuan are characterized by high formation pressure,high pressure coefficient,well preserved pores,good pore structure and high proportion of free gas,making them the most favorable new field for shale gas exploration;and the pressure coefficient greater than 1.2 is a necessary condition for shale gas wells to obtain high production.(4)High production wells in the deep shale gas reservoirs are those in areas where Long11-Long13 sub-beds are more than 10 m thick,with 1500 m long horizontal section,grade-I reservoirs penetration rate of over 90%,and fractured by dense cutting+high intensity sand injection+large displacement+large liquid volume.(5)The relatively deep-water area in the deep-water shelf and the area at depth of 3500–4500 m well overlap in the southern Sichuan,and the overlapping area is the most favorable shale gas exploration and development zones in the southern Sichuan in the future.With advancement in theory and technology,annual shale gas production in the southern Sichuan is expected to reach 450×108 m3.展开更多
Development strategy for heavy-oil reservoirs is one of the important research interests in China National Offshore Oil Corp. (CNOOC) that plans a highly effective development for heavy oil fields in multilayered fl...Development strategy for heavy-oil reservoirs is one of the important research interests in China National Offshore Oil Corp. (CNOOC) that plans a highly effective development for heavy oil fields in multilayered fluvial reservoirs because of their significant influence on marine oil and even on China's petroleum production. The characteristics analysis of multilayered fluvial reservoirs in the heavy oil fields in Bohai Bay indicates that large amounts ofoil were trapped in the channel, point bar and channel bar sands. The reserves distribution of 8 oilfields illustrates that the reserves trapped in the main sands, which is 20%-40% of all of the sand bodies, account for 70%-90% of total reserves of the heavy oil fields. The cumulative production from high productivity wells (50% of the total wells) was 75%-90% of the production of the overall oilfield, while only 3%-10% of the total production was from the low productivity wells (30% of the total wells). And the high productivity wells were drilled in the sands with high reserves abundance. Based on the above information the development strategy was proposed, which includes reserves production planning, selection of well configuration, productivity design, and development modification at different stages.展开更多
This paper firstly introduces the general situation of cotton planting areas in China and cotton industry in Xinjiang,and the current situation of intellectual property protection of Xinjiang's cotton industry.The...This paper firstly introduces the general situation of cotton planting areas in China and cotton industry in Xinjiang,and the current situation of intellectual property protection of Xinjiang's cotton industry.Then,it analyzes the main problems in its intellectual property protection and high-quality development.On this basis,it comes up with the recommendations for high-quality development of cotton industry in Xinjiang under the strategy of strengthening the country with intellectual property.The recommendations include improving the level of creation of creative intellectual property rights,building an intellectual property rule system in the entire cotton industry chain in Xinjiang,building protected zones for production of major high quality agricultural product cotton,establishing a demonstration zone to undertake the transfer of the domestic cotton textile and garment industry,undertaking education on the sense of community for the Chinese nation in response to the Xinjiang cotton incident,and developing the"Belt and Road"blue market for Xinjiang cotton and its products.展开更多
As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect a...As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect and the theory of multiphase flow. With this model, the transient flow of gas well can be simulated by segmenting the curved part of tubing and calculating numerical solution with the method of characteristic curve. The results show that the higher the opening coefficient of the valve when closed, the larger the peak value of the wellhead pressure, the more gentle the pressure fluctuation, and the less obvious the pressure mutation area will be. On the premise of not exceeding the maximum shut-in pressure of the tubing, adopting large opening coefficient can reduce the impact of the pressure wave. The higher the cross-section liquid holdup, the greater the pressure wave speed, and the shorter the propagation period will be. The larger the liquid holdup, the larger the variation range of pressure, and the greater the pressure will be. In actual production, the production parameters can be adjusted to get the appropriate liquid holdup, control the magnitude and range of fluctuation pressure, and reduce the impact of water hammer effect. When the valve closing time increases, the maximum fluctuating pressure value of the wellhead decreases, the time of pressure peak delays, and the pressure mutation area gradually disappears. The shorter the valve closing time, the faster the pressure wave propagates. Case simulation proves that the transient flow model of gas well can optimize the reasonable valve opening coefficient and valve closing time, reduce the harm of water hammer impact on the wellhead device and tubing, and ensure the integrity of the wellbore.展开更多
The RR soybean was quantitatively detected by ABI Prism 7300 sequence detector with PCR primers and fluorescence probes were designed according to the sequences of endogenous Lectin gene and exogenous CP4-EPSPS gene, ...The RR soybean was quantitatively detected by ABI Prism 7300 sequence detector with PCR primers and fluorescence probes were designed according to the sequences of endogenous Lectin gene and exogenous CP4-EPSPS gene, and the PCR systems were based on SYBR Green I and TaqMan. The standard curve of ACt between CP4-EPSPS gene and Lectin gene of the RR soybean in standard materials was generated and a linear regression equation was obtained. Quantification methods were optimized through two different real-time PCR chemistries, i.e. SYBR Green I and TaqMan, and the RR soybean contents were quantified in five standard samples and seven highly processed products by the two assays. Both methods are proved to be specific, highly sensitive and reliable for both identification and quantification of soybean DNA. The results indicate that the two optimized PCR system can be used for the practical quantitative detection of RR soybean in highly processed products.展开更多
The process of the epoxy-bonded Sm_2TM_(17) magnets includes:(1)after melting,the ingots are treated by solid soluiion,and then aged and pulverized;(2)the obtained alloy powder is mixed with epoxy resin bind- er;(3)th...The process of the epoxy-bonded Sm_2TM_(17) magnets includes:(1)after melting,the ingots are treated by solid soluiion,and then aged and pulverized;(2)the obtained alloy powder is mixed with epoxy resin bind- er;(3)the mixture is pressed in a magnetic field;(4)the compacts are cured.When the SmCo_(4.9)Fe_(2.7)Cu_(0.54)Zr_(0.13) alloy is heat treated and pressed with optimum pressing parameters,the high quality bonded magnets with B_r=8250 G,_iH_c=13000 Oe,and(BH)_(max)=16MGOe can be obtained.The stability of the magnets is studied also.The irreversible loss of O.C.(open circuit)remanence B_r in the temperature range between 25 and 150℃,is less than 4%.The average temperature coefficient at temperatures between 25 and 70℃ is-0.03%/℃.The magnets obtained have heat resistance up to 130℃ even in long-term service, and have good corrosion resistance in acid,alkali and salt solutions.展开更多
For cultivation of new common wheat cultivars having valuable morphological traits new resource-saving ridge technology was applied. Our collection of dwarf lines, obtained in the result of cyclical diallel crossings ...For cultivation of new common wheat cultivars having valuable morphological traits new resource-saving ridge technology was applied. Our collection of dwarf lines, obtained in the result of cyclical diallel crossings of genotrophs, induced by pyridine carbonic acids, zoned common wheat cultivars and short stem common wheat samples from the World Wide Collection of the Russian Institute of Plant Industry, was applied for creation of new common wheat lines having valuable morphological traits. It was observed that open blooming dwarfs were good for cross-pollination, and without insulation they demonstrated a great issue of natural hybrids. It was marked that cross-pollination promoted appearance of great number of hybrid plants with high productive tillering capacity. After individual selection among those hybrid plants and their propagation we got fertile constant lines of common winter wheat having 17-20 productive stems per one plant and a productive ear. These lines are firm and resistant to lodging. At the present time these constant lines are cultivated in conditions of resource-saving ridge technology.展开更多
Plastic waste is generally resistant to natural degradation and has become a major environmental pollution problem globally. The pollution of ecosystems seriously affects the health and survival of organisms,including...Plastic waste is generally resistant to natural degradation and has become a major environmental pollution problem globally. The pollution of ecosystems seriously affects the health and survival of organisms,including humans. Much attention has been paid to finding suitable ways to convert plastic waste into high-value-added carbon materials. To this end, we report the high production yield(60%–85%) of carbon dots(CDs) for solid-state fluorescence(SSF) obtained by a one-step solvothermal method using waste expanded polystyrene as the precursor. The SSF mechanism of the CDs was also explored. Their emission wavelength, with a large full width at half maximum of 150–200 nm, exhibited tunable photoluminescence from white to yellow and orange. CDs powder was used to fabricate single-component white and multi-colour light-emitting diodes on UV chips. Overall, plastic waste was converted into tunable solid-state fluorescent CDs powder, which has promising applications in carbon-based lighting, by a simple solvothermal method that provides a viable method for recycling plastic waste.展开更多
A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of "inverse problem" and the concept "non-inverse p...A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of "inverse problem" and the concept "non-inverse problem", the monitoring program for blast furnace wall with copper staves has been realized, which can be used to calculate online the accretion thickness and temperature of hot surface of copper staves after obtaining the values of thermocouples of copper staves. The accretion state obtained in the actual investigation has proved that the result of the program is correct. The monitoring program shows that the accretion would easily fluctuate when the accretion layer is extremely thick or thin, thereby the stable and smooth operation of the blast furnace is hindered. By maintaining appropriate accretion thickness, both long campaigns and high productivity of the blast furnace can be achieved; furthermore, it can also optimize the operation of blast furnace and maximize its production. Approximately 30--50 mm in thickness of accretion layer is maintained on the wall of Shougang blast furnace 2, which can meet the requirement for obtaining both long campaign and high productivity.展开更多
As the main factors affecting stable and high production and the production regularity of lacustrine shale oil are unclear,the theoretical understandings,key exploration and development technologies,development effect...As the main factors affecting stable and high production and the production regularity of lacustrine shale oil are unclear,the theoretical understandings,key exploration and development technologies,development effect and production regularity of lacustrine shale oil have been analyzed and summarized based on 700 m cores taken systematically from Paleogene Kong 2 Member of 4 wells in Cangdong sag,over 100000 analysis data and formation testing data.Three theoretical understandings on shale oil enrichment and high production have been reached:(1)High-quality shale with“three highs and one low”is the material base for shale oil enrichment.(2)Medium-slightly high thermal evolution degree is the favorable condition for shale oil enrichment.(3)Laminar felsic shale is the optimal shale layer for oil enrichment in semi-deep lake facies.Key exploration and development technologies such as shale oil enrichment layer and area evaluation and prediction,horizontal well pattern layout,shale oil reservoir fracturing,optimization of shale oil production regime have been established to support high and stable shale oil production.Under the guidance of these theoretical understandings and technologies,shale oil in Cangdong sag has achieved high and stable production,and 4 of them had the highest production of over 100 tons a day during formation testing.In particular,Well GY5-1-1 L had a daily oil production of 208 m^(3).By April,2022,the 28 wells combined have a stable oil production of 300–350 tons a day,and have produced 17.8×10^(4) t of oil cumulatively.It is found that the shale oil production of horizontal well declines exponentially in natural flow stage,and declines in step pattern and then tends stable in the artificial lift stage.Proportion of light hydrocarbons in produced shale oil is in positive correlation with daily oil production and decreases regularly during production test.展开更多
A novel method of extracting valuable metals from Ti-bearing blast furnace slag(TBBF slag)via pressure pyrolysis of recyclable ammonium sulfate(AS)−acid leaching process was proposed.The results show that when pressur...A novel method of extracting valuable metals from Ti-bearing blast furnace slag(TBBF slag)via pressure pyrolysis of recyclable ammonium sulfate(AS)−acid leaching process was proposed.The results show that when pressurized roasting at an AS-to-slag mass ratio 3:1 and 370℃for 90 min,the extraction rates of titanium,aluminum and magnesium reached 94.5%,91.9%and 97.4%,respectively.The acid leaching solution was subjected to re-crystallization in a boiling state to obtain a titanium product having a TiO2 content of 94.1%.The above crystallization mother liquor was adjusted to pH=6 and pH≥12.2,respectively,and then qualified Al2O3 and MgO products were obtained.The analysis through XRD and SEM−EDS proves that the main phases in roasted samples were NH4AlSO4,CaSO4 and TiOSO4.The thermodynamic analysis presents that the main minerals of perovskite,spinel and diopside in raw ore could spontaneously react with the intermediate produced by AS under optimal conditions.展开更多
Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be ...Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be controlled to trace levels of below 10 ppm by in situ reduction of the COconcentration to less than 100 ppm via the aforementioned process. The COadsorption capacity of potassiumpromoted hydrotalcite at elevated temperatures under different adsorption(mole fraction, working pressure) and desorption(flow rate, desorption time, steam effects) conditions was systematically investigated using a fixed bed reactor. It was found that the COresidual concentration before the breakthrough of COmainly depended on the total amount of purge gas and the COmole fraction in the inlet syngas.The residual COconcentration and uptake achieved for the inlet gas comprising CO(9.7 mL/min) and He(277.6 mL/min) at a working pressure of 3 MPa after 1 h of Ar purging at 300 mL/min were 12.3 ppm and0.341 mmol/g, respectively. Steam purge could greatly improve the cyclic adsorption working capacity, but had no obvious benefit for the recovery of the residual COconcentration compared to purging with an inert gas. The residual COconcentration obtained with the adsorbent could be reduced to 3.2 ppm after 12 h of temperature swing at 450 °C. A new concept based on an adsorption/desorption process, comprising adsorption, steam rinse, depressurization, steam purge, pressurization, and high-temperature steam purge, was proposed for reducing the steam consumption during CO/COpurification.展开更多
基金supported by the National Natural Science Foundation of China (31401308, 31371555 and 31671445)
文摘Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus, and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability.
基金the National High Technology Research and Development Programme of China(No2007AA01Z115)
文摘Improving processor frequency to strengthen massive data processing capability will lead to incremen-tal server marginal costs and bring about a series of problems such as power consumption,managementcomplexity,etc.Based on the field programmable gate array(FPGA),TCP offload engine(TOE),zero-copy and other key technologies,this paper describes the design and realization of a reconfigurable accel-erator board.In this board,TCP/IP protocol will be moved to high-speed reconfigurable acceleratorboard.The packets will be labeled according to the protocol and submitted to the upper data processingsoftware after IP-quintuple filtering in hardware.Reconfigurable accelerator board obtains higher perfor-mance speed-up compared with ordinary NIC card.
文摘A new filament winding method developed in this study named MFW (multiple-supply FW) method. It performed a high productivity. In the MFW method, a large number of bobbins are used. Carbon fibers are arranged equiangularly above a mandrel, and they are wound and stacked on the mandrel simultaneously. Furthermore, CFRP pipes with non-crimp structure were made by MFW, and the torsional tests were performed in order to investigate mechanical properties comparing with braided CFRP pipes. These results made clear that the non-crimp structure by MFW was capable to improve torsional properties. The MFW machine produce non-crimp tubular preform with carbon fiber automatically. It is expected to produce non-crimp preforms for automotive parts which required high productivity.
基金Supported by Sinopec Key Science and Technology Research Project(P21060)。
文摘The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.
基金supported by the National Natural Science Foundation of China(40471066)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX1-SW-01-05).
文摘Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the status of organic matter and nutrients in the soil but also affected the environmental quality. This article investigates the contents of organic carbon and the nutrients, and the change over the last 20 years in highly productive paddy soils and their environmental application. Field soils were sampled and the analytical results were compared with the corresponding values in the Second Soil Survey in Yujiang County of Jiangxi Province, China. The results showed that surface soils at a depth of 0-10 cm in highly productive paddy fields in Yujiang County of Jiangxi Province had contents of organic carbon (20.2 ±3.88) g kg^-1, total nitrogen (2.09±0.55) g kg^-1, and available phosphorus (42.7 ±32.7) mg kg^-1, respectively, which were all at very rich levels. Over the last 20 years, the organic carbon pool of the highly productive paddy soils reached a steady state. Total N and available P significantly increased, whereas available K changed a little. The amount and percentage of P immobilization in the surface soil (0-10 cm) of highly productive paddy fields were (142.7 ~ 41.1) mg kg-~ and (36.2~ 10.4)% of added P, and CEC (7.93 ~ 1.32) cmol kg-~. These two parameters were not higher than the mean values of paddy soils and upland red soils in the areas. Results also showed that fertilizer P in highly productive paddy soils had a high mobility and was prone to move toward a water body, which is the main source of nutrients causing eutrophication. Because of a weak K-fixing capacity, the available K content was not high in highly productive paddy soils. This suggests that attention should be paid to the K balance and the increase of soil K pool.
基金Supported by the China National Science and Technology Major Project(2016ZX05062)the PetroChina Science and Technology Major Project(2016E-0611)
文摘Marine shale gas resources have great potential in the south of the Sichuan Basin in China.At present,the high-quality shale gas resources at depth of 2000–3500 m are under effective development,and strategic breakthroughs have been made in deeper shale gas resources at depth of 3500–4500 m.To promote the effective production of shale gas in this area,this study examines key factors controlling high shale gas production and presents the next exploration direction in the southern Sichuan Basin based on summarizing the geological understandings from the Lower Silurian Longmaxi Formation shale gas exploration combined with the latest results of geological evaluation.The results show that:(1)The relative sea depth in marine shelf sedimentary environment controls the development and distribution of reservoirs.In the relatively deep water area in deep-water shelf,grade-I reservoirs with a larger continuous thickness develop.The relative depth of sea in marine shelf sedimentary environment can be determined by redox conditions.The research shows that the uranium to thorium mass ratio greater than 1.25 indicates relatively deep water in anoxic reduction environment,and the uranium to thorium mass ratio of 0.75–1.25 indicates semi-deep water in weak reduction and weak oxidation environment,and the uranium to thorium mass ratio less than 0.75 indicates relatively shallow water in strong oxidation environment.(2)The propped fractures in shale reservoirs subject to fracturing treatment are generally 10–12 m high,if grade-I reservoirs are more than 10 m in continuous thickness,then all the propped section would be high-quality reserves;in this case,the longer the continuous thickness of penetrated grade-I reservoirs,the higher the production will be.(3)The shale gas reservoirs at 3500–4500 m depth in southern Sichuan are characterized by high formation pressure,high pressure coefficient,well preserved pores,good pore structure and high proportion of free gas,making them the most favorable new field for shale gas exploration;and the pressure coefficient greater than 1.2 is a necessary condition for shale gas wells to obtain high production.(4)High production wells in the deep shale gas reservoirs are those in areas where Long11-Long13 sub-beds are more than 10 m thick,with 1500 m long horizontal section,grade-I reservoirs penetration rate of over 90%,and fractured by dense cutting+high intensity sand injection+large displacement+large liquid volume.(5)The relatively deep-water area in the deep-water shelf and the area at depth of 3500–4500 m well overlap in the southern Sichuan,and the overlapping area is the most favorable shale gas exploration and development zones in the southern Sichuan in the future.With advancement in theory and technology,annual shale gas production in the southern Sichuan is expected to reach 450×108 m3.
文摘Development strategy for heavy-oil reservoirs is one of the important research interests in China National Offshore Oil Corp. (CNOOC) that plans a highly effective development for heavy oil fields in multilayered fluvial reservoirs because of their significant influence on marine oil and even on China's petroleum production. The characteristics analysis of multilayered fluvial reservoirs in the heavy oil fields in Bohai Bay indicates that large amounts ofoil were trapped in the channel, point bar and channel bar sands. The reserves distribution of 8 oilfields illustrates that the reserves trapped in the main sands, which is 20%-40% of all of the sand bodies, account for 70%-90% of total reserves of the heavy oil fields. The cumulative production from high productivity wells (50% of the total wells) was 75%-90% of the production of the overall oilfield, while only 3%-10% of the total production was from the low productivity wells (30% of the total wells). And the high productivity wells were drilled in the sands with high reserves abundance. Based on the above information the development strategy was proposed, which includes reserves production planning, selection of well configuration, productivity design, and development modification at different stages.
基金Supported by Foundation for Key Program of Hubei Province (LX201827)
文摘This paper firstly introduces the general situation of cotton planting areas in China and cotton industry in Xinjiang,and the current situation of intellectual property protection of Xinjiang's cotton industry.Then,it analyzes the main problems in its intellectual property protection and high-quality development.On this basis,it comes up with the recommendations for high-quality development of cotton industry in Xinjiang under the strategy of strengthening the country with intellectual property.The recommendations include improving the level of creation of creative intellectual property rights,building an intellectual property rule system in the entire cotton industry chain in Xinjiang,building protected zones for production of major high quality agricultural product cotton,establishing a demonstration zone to undertake the transfer of the domestic cotton textile and garment industry,undertaking education on the sense of community for the Chinese nation in response to the Xinjiang cotton incident,and developing the"Belt and Road"blue market for Xinjiang cotton and its products.
基金Supported by National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05026-002,2016ZX05028-001,2016ZX05024-005)
文摘As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect and the theory of multiphase flow. With this model, the transient flow of gas well can be simulated by segmenting the curved part of tubing and calculating numerical solution with the method of characteristic curve. The results show that the higher the opening coefficient of the valve when closed, the larger the peak value of the wellhead pressure, the more gentle the pressure fluctuation, and the less obvious the pressure mutation area will be. On the premise of not exceeding the maximum shut-in pressure of the tubing, adopting large opening coefficient can reduce the impact of the pressure wave. The higher the cross-section liquid holdup, the greater the pressure wave speed, and the shorter the propagation period will be. The larger the liquid holdup, the larger the variation range of pressure, and the greater the pressure will be. In actual production, the production parameters can be adjusted to get the appropriate liquid holdup, control the magnitude and range of fluctuation pressure, and reduce the impact of water hammer effect. When the valve closing time increases, the maximum fluctuating pressure value of the wellhead decreases, the time of pressure peak delays, and the pressure mutation area gradually disappears. The shorter the valve closing time, the faster the pressure wave propagates. Case simulation proves that the transient flow model of gas well can optimize the reasonable valve opening coefficient and valve closing time, reduce the harm of water hammer impact on the wellhead device and tubing, and ensure the integrity of the wellbore.
基金Supported by the Innovative Team Funds of Northeast Agricultural University (CXT004-3-2)Foundation of Heilongjiang Educational Committee(11511030)
文摘The RR soybean was quantitatively detected by ABI Prism 7300 sequence detector with PCR primers and fluorescence probes were designed according to the sequences of endogenous Lectin gene and exogenous CP4-EPSPS gene, and the PCR systems were based on SYBR Green I and TaqMan. The standard curve of ACt between CP4-EPSPS gene and Lectin gene of the RR soybean in standard materials was generated and a linear regression equation was obtained. Quantification methods were optimized through two different real-time PCR chemistries, i.e. SYBR Green I and TaqMan, and the RR soybean contents were quantified in five standard samples and seven highly processed products by the two assays. Both methods are proved to be specific, highly sensitive and reliable for both identification and quantification of soybean DNA. The results indicate that the two optimized PCR system can be used for the practical quantitative detection of RR soybean in highly processed products.
文摘The process of the epoxy-bonded Sm_2TM_(17) magnets includes:(1)after melting,the ingots are treated by solid soluiion,and then aged and pulverized;(2)the obtained alloy powder is mixed with epoxy resin bind- er;(3)the mixture is pressed in a magnetic field;(4)the compacts are cured.When the SmCo_(4.9)Fe_(2.7)Cu_(0.54)Zr_(0.13) alloy is heat treated and pressed with optimum pressing parameters,the high quality bonded magnets with B_r=8250 G,_iH_c=13000 Oe,and(BH)_(max)=16MGOe can be obtained.The stability of the magnets is studied also.The irreversible loss of O.C.(open circuit)remanence B_r in the temperature range between 25 and 150℃,is less than 4%.The average temperature coefficient at temperatures between 25 and 70℃ is-0.03%/℃.The magnets obtained have heat resistance up to 130℃ even in long-term service, and have good corrosion resistance in acid,alkali and salt solutions.
文摘For cultivation of new common wheat cultivars having valuable morphological traits new resource-saving ridge technology was applied. Our collection of dwarf lines, obtained in the result of cyclical diallel crossings of genotrophs, induced by pyridine carbonic acids, zoned common wheat cultivars and short stem common wheat samples from the World Wide Collection of the Russian Institute of Plant Industry, was applied for creation of new common wheat lines having valuable morphological traits. It was observed that open blooming dwarfs were good for cross-pollination, and without insulation they demonstrated a great issue of natural hybrids. It was marked that cross-pollination promoted appearance of great number of hybrid plants with high productive tillering capacity. After individual selection among those hybrid plants and their propagation we got fertile constant lines of common winter wheat having 17-20 productive stems per one plant and a productive ear. These lines are firm and resistant to lodging. At the present time these constant lines are cultivated in conditions of resource-saving ridge technology.
基金financially supported by the National Natural Science Foundation of China (21905253, 51973200)the China Postdoctoral Science Foundation (2018M640681, 2019T120632)
文摘Plastic waste is generally resistant to natural degradation and has become a major environmental pollution problem globally. The pollution of ecosystems seriously affects the health and survival of organisms,including humans. Much attention has been paid to finding suitable ways to convert plastic waste into high-value-added carbon materials. To this end, we report the high production yield(60%–85%) of carbon dots(CDs) for solid-state fluorescence(SSF) obtained by a one-step solvothermal method using waste expanded polystyrene as the precursor. The SSF mechanism of the CDs was also explored. Their emission wavelength, with a large full width at half maximum of 150–200 nm, exhibited tunable photoluminescence from white to yellow and orange. CDs powder was used to fabricate single-component white and multi-colour light-emitting diodes on UV chips. Overall, plastic waste was converted into tunable solid-state fluorescent CDs powder, which has promising applications in carbon-based lighting, by a simple solvothermal method that provides a viable method for recycling plastic waste.
基金Item Sponsored by National Natural Science Foundation of China(60472095)
文摘A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of "inverse problem" and the concept "non-inverse problem", the monitoring program for blast furnace wall with copper staves has been realized, which can be used to calculate online the accretion thickness and temperature of hot surface of copper staves after obtaining the values of thermocouples of copper staves. The accretion state obtained in the actual investigation has proved that the result of the program is correct. The monitoring program shows that the accretion would easily fluctuate when the accretion layer is extremely thick or thin, thereby the stable and smooth operation of the blast furnace is hindered. By maintaining appropriate accretion thickness, both long campaigns and high productivity of the blast furnace can be achieved; furthermore, it can also optimize the operation of blast furnace and maximize its production. Approximately 30--50 mm in thickness of accretion layer is maintained on the wall of Shougang blast furnace 2, which can meet the requirement for obtaining both long campaign and high productivity.
基金Supported by the National Key R&D Program of China(2020YFA0710504)Science and Technology Project of China National Petroleum Corporation(2021DQ0508)PetroChina Science and Technology Major Project(2019E-2602)。
文摘As the main factors affecting stable and high production and the production regularity of lacustrine shale oil are unclear,the theoretical understandings,key exploration and development technologies,development effect and production regularity of lacustrine shale oil have been analyzed and summarized based on 700 m cores taken systematically from Paleogene Kong 2 Member of 4 wells in Cangdong sag,over 100000 analysis data and formation testing data.Three theoretical understandings on shale oil enrichment and high production have been reached:(1)High-quality shale with“three highs and one low”is the material base for shale oil enrichment.(2)Medium-slightly high thermal evolution degree is the favorable condition for shale oil enrichment.(3)Laminar felsic shale is the optimal shale layer for oil enrichment in semi-deep lake facies.Key exploration and development technologies such as shale oil enrichment layer and area evaluation and prediction,horizontal well pattern layout,shale oil reservoir fracturing,optimization of shale oil production regime have been established to support high and stable shale oil production.Under the guidance of these theoretical understandings and technologies,shale oil in Cangdong sag has achieved high and stable production,and 4 of them had the highest production of over 100 tons a day during formation testing.In particular,Well GY5-1-1 L had a daily oil production of 208 m^(3).By April,2022,the 28 wells combined have a stable oil production of 300–350 tons a day,and have produced 17.8×10^(4) t of oil cumulatively.It is found that the shale oil production of horizontal well declines exponentially in natural flow stage,and declines in step pattern and then tends stable in the artificial lift stage.Proportion of light hydrocarbons in produced shale oil is in positive correlation with daily oil production and decreases regularly during production test.
基金Project(DY135-B2-15)supported by China Ocean Mineral Resources R&D AssociationProject(2015ZX07205-003)supported by Major Science and Technology Program for Water Pollution Control and Treatment,ChinaProjects(21176242,21176026)supported by the National Natural Science Foundation of China。
文摘A novel method of extracting valuable metals from Ti-bearing blast furnace slag(TBBF slag)via pressure pyrolysis of recyclable ammonium sulfate(AS)−acid leaching process was proposed.The results show that when pressurized roasting at an AS-to-slag mass ratio 3:1 and 370℃for 90 min,the extraction rates of titanium,aluminum and magnesium reached 94.5%,91.9%and 97.4%,respectively.The acid leaching solution was subjected to re-crystallization in a boiling state to obtain a titanium product having a TiO2 content of 94.1%.The above crystallization mother liquor was adjusted to pH=6 and pH≥12.2,respectively,and then qualified Al2O3 and MgO products were obtained.The analysis through XRD and SEM−EDS proves that the main phases in roasted samples were NH4AlSO4,CaSO4 and TiOSO4.The thermodynamic analysis presents that the main minerals of perovskite,spinel and diopside in raw ore could spontaneously react with the intermediate produced by AS under optimal conditions.
基金financed by Shanxi Province Science and Technology Major Projects of MH2015-06
文摘Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be controlled to trace levels of below 10 ppm by in situ reduction of the COconcentration to less than 100 ppm via the aforementioned process. The COadsorption capacity of potassiumpromoted hydrotalcite at elevated temperatures under different adsorption(mole fraction, working pressure) and desorption(flow rate, desorption time, steam effects) conditions was systematically investigated using a fixed bed reactor. It was found that the COresidual concentration before the breakthrough of COmainly depended on the total amount of purge gas and the COmole fraction in the inlet syngas.The residual COconcentration and uptake achieved for the inlet gas comprising CO(9.7 mL/min) and He(277.6 mL/min) at a working pressure of 3 MPa after 1 h of Ar purging at 300 mL/min were 12.3 ppm and0.341 mmol/g, respectively. Steam purge could greatly improve the cyclic adsorption working capacity, but had no obvious benefit for the recovery of the residual COconcentration compared to purging with an inert gas. The residual COconcentration obtained with the adsorbent could be reduced to 3.2 ppm after 12 h of temperature swing at 450 °C. A new concept based on an adsorption/desorption process, comprising adsorption, steam rinse, depressurization, steam purge, pressurization, and high-temperature steam purge, was proposed for reducing the steam consumption during CO/COpurification.