The evolution of territorial space is intrinsically linked to economic growth, societal welfare, and ecological preservation. In the context of escalating spatial conflicts and stringent resource limitations, resource...The evolution of territorial space is intrinsically linked to economic growth, societal welfare, and ecological preservation. In the context of escalating spatial conflicts and stringent resource limitations, resource efficiency has emerged as a fundamental pillar for the scientific optimization of territorial space layout. Drawing upon resource efficiency metrics from cities nationwide, this study constructs scenarios for territorial space development and conservation, assesses developmental capacity under varying preferences, and subsequently delineates strategic blueprints using an integrated “point-axis-area” approach. The findings reveal the following:(1) Resource efficiency in China has witnessed a consistent uptick, yet remains modest overall, with marked regional disparities.(2) Throughout the investigation period, developmental capacity has seen progressive enhancement, with a pronounced capacity in scenarios favoring development, radiating axially from urban conglomerates.(3) The layout of pivotal points and developmental axes has transitioned from a “tri-pillar” to a diamond configuration, with the coastal corridor, Harbin-Beijing-Guangzhou corridor, and the corridor along the Yangtze River standing out.(4) Strategic points progressively converge along key axes, whereas dominant regions exhibit clear differentiation on either side of the Hu Huanyong Line. By integrating elements of the territorial spatial structure,this paper proposes blueprints for “five horizontal and three vertical zones with eight cores and three areas,” “four horizontal and three vertical zones with six cores and three areas,”and “three horizontal and four vertical zones with five cores and three areas,” corresponding to scenarios of prioritizing development, status quo maintenance, and prioritizing conservation, respectively. The outcomes of this research offer a technical foundation and theoretical guidance for the pursuit of high-quality territorial space development and a vision of picturesque landscapes.展开更多
Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dorman...Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （GA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （GA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MGT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.展开更多
To enhance link capacity of a wireless link one or more repeater is used between the sender and the receiver. Recent literature deals with multiple parallel links to enhance throughput instead of conventional single p...To enhance link capacity of a wireless link one or more repeater is used between the sender and the receiver. Recent literature deals with multiple parallel links to enhance throughput instead of conventional single path. In case of a multidirectional and multi-hop wireless network, the selection of link of maximum signal to noise ratio (SNR) does not guarantee the maximum throughput. In this paper, we use augmenting path of Ford-Fulkerson algorithm in detection of maximum flow from sender to receiver. To reduce the process time at the sending node, minimum-cut theorem is used to determine maximum flow like power flow of previous work. Using the maximum flow algorithm, we obtain the capacity of multi-hop wireless link higher than the conventional theorem. The concept of the paper is applicable in MANET (Mobile Ad-hoc Network), WSN (Wireless Sensor Network) and CRN (Cognitive Radio Network).展开更多
Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conse...Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on.展开更多
Vegetables are vital for human health and are consumed five days a week in Cambodia.However,the production cannot meet domestic demands due to labor-intensive farming and production costs related to soil tillage.Mecha...Vegetables are vital for human health and are consumed five days a week in Cambodia.However,the production cannot meet domestic demands due to labor-intensive farming and production costs related to soil tillage.Mechanization is needed along with soil quality and sustainability improvements by the adoption of CA(Conservation Agriculture).The research aimed to compare the performance of the no-till vegetable transplanter with punch-planter in CA and hand transplanting in CT(Conventional Tillage).The study was conducted at the Royal University of Agriculture,Cambodia,starting from January to September 2020,by firstly growing sunn hemp as a cover crop and then transplanting Thai round eggplant.A randomized complete block design was used with three treatments,replicated three times.Each plot was 2 m by 15 m,with 0.2-m row spacing.The results showed that the transplanter speed was 0.54 kmh^-1,almost two times the speed of punch planter and 9 times the speed of hand transplanting.The highest working capacity was also achieved with the transplanter.However,different transplanting did not affect plant spacing,or plant density.Plant spacing was 1 m,and plant density varied from 10,300 to 11,500 plantsha-1.Plant growth and yield were also not influenced by the transplanter in CA,or hand transplanting in CT.Average fruit diameter,fruit weight,fruit number,and yield were 38 mm,31.4 gfruit-1,15.7 fruitsplant-1 and 3.9 tha-1,respectively.The maximum working area of the transplanter and its break-even area were 25.2 ha·y^-1 and 18.3 ha·y^-1,respectively.Using the no-till transplanter may save both time and labor,but its use in combination with CA was unlikely to affect plant growth and yield in the short term.展开更多
基金National Natural Science Foundation of China,No.71974070,No.72221002。
文摘The evolution of territorial space is intrinsically linked to economic growth, societal welfare, and ecological preservation. In the context of escalating spatial conflicts and stringent resource limitations, resource efficiency has emerged as a fundamental pillar for the scientific optimization of territorial space layout. Drawing upon resource efficiency metrics from cities nationwide, this study constructs scenarios for territorial space development and conservation, assesses developmental capacity under varying preferences, and subsequently delineates strategic blueprints using an integrated “point-axis-area” approach. The findings reveal the following:(1) Resource efficiency in China has witnessed a consistent uptick, yet remains modest overall, with marked regional disparities.(2) Throughout the investigation period, developmental capacity has seen progressive enhancement, with a pronounced capacity in scenarios favoring development, radiating axially from urban conglomerates.(3) The layout of pivotal points and developmental axes has transitioned from a “tri-pillar” to a diamond configuration, with the coastal corridor, Harbin-Beijing-Guangzhou corridor, and the corridor along the Yangtze River standing out.(4) Strategic points progressively converge along key axes, whereas dominant regions exhibit clear differentiation on either side of the Hu Huanyong Line. By integrating elements of the territorial spatial structure,this paper proposes blueprints for “five horizontal and three vertical zones with eight cores and three areas,” “four horizontal and three vertical zones with six cores and three areas,”and “three horizontal and four vertical zones with five cores and three areas,” corresponding to scenarios of prioritizing development, status quo maintenance, and prioritizing conservation, respectively. The outcomes of this research offer a technical foundation and theoretical guidance for the pursuit of high-quality territorial space development and a vision of picturesque landscapes.
文摘Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （GA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （GA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MGT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.
文摘To enhance link capacity of a wireless link one or more repeater is used between the sender and the receiver. Recent literature deals with multiple parallel links to enhance throughput instead of conventional single path. In case of a multidirectional and multi-hop wireless network, the selection of link of maximum signal to noise ratio (SNR) does not guarantee the maximum throughput. In this paper, we use augmenting path of Ford-Fulkerson algorithm in detection of maximum flow from sender to receiver. To reduce the process time at the sending node, minimum-cut theorem is used to determine maximum flow like power flow of previous work. Using the maximum flow algorithm, we obtain the capacity of multi-hop wireless link higher than the conventional theorem. The concept of the paper is applicable in MANET (Mobile Ad-hoc Network), WSN (Wireless Sensor Network) and CRN (Cognitive Radio Network).
基金China Postdoctoral Science Foundation (No.2017M620758)Special Funds of the National Natural Science Foundation of China(Grant No.L1522032)the Consulting Project of Chinese Academy of Engineering(No.2015-ZCQ-06).
文摘Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on.
基金the generous support of the American People provided to the CE SAIN(Center of Excellence on Sustainable Agricultural Intensification and Nutrition)of the Royal University of Agriculture through the Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification at Kansas State University funded by the USAID(United States Agency for International Development)under Cooperative Agreement No.AID-OAA-L-14-00006the USDA,Agricultural Research Service,National Soil Dynamics Laboratory(NSDL)through mentorship by Dr.Ted Kornecki on the testing of the machine,and the donation of the no-till vegetable transplanter prototype fabricated at NSDL by Mr.Corey Kichler to the Royal University of Agricultureand the IFDC(International Fertilizer Development Center).The contents are the sole responsibility of the authors and do not necessarily reflect the views of USAID,USDA,IFDC or the United States Government.
文摘Vegetables are vital for human health and are consumed five days a week in Cambodia.However,the production cannot meet domestic demands due to labor-intensive farming and production costs related to soil tillage.Mechanization is needed along with soil quality and sustainability improvements by the adoption of CA(Conservation Agriculture).The research aimed to compare the performance of the no-till vegetable transplanter with punch-planter in CA and hand transplanting in CT(Conventional Tillage).The study was conducted at the Royal University of Agriculture,Cambodia,starting from January to September 2020,by firstly growing sunn hemp as a cover crop and then transplanting Thai round eggplant.A randomized complete block design was used with three treatments,replicated three times.Each plot was 2 m by 15 m,with 0.2-m row spacing.The results showed that the transplanter speed was 0.54 kmh^-1,almost two times the speed of punch planter and 9 times the speed of hand transplanting.The highest working capacity was also achieved with the transplanter.However,different transplanting did not affect plant spacing,or plant density.Plant spacing was 1 m,and plant density varied from 10,300 to 11,500 plantsha-1.Plant growth and yield were also not influenced by the transplanter in CA,or hand transplanting in CT.Average fruit diameter,fruit weight,fruit number,and yield were 38 mm,31.4 gfruit-1,15.7 fruitsplant-1 and 3.9 tha-1,respectively.The maximum working area of the transplanter and its break-even area were 25.2 ha·y^-1 and 18.3 ha·y^-1,respectively.Using the no-till transplanter may save both time and labor,but its use in combination with CA was unlikely to affect plant growth and yield in the short term.
