期刊文献+
共找到1,499篇文章
< 1 2 75 >
每页显示 20 50 100
Effect of Long Chain Branches of High Melt Strength Polypropylene on Its Supercritical CO_(2)Foaming Behavior
1
作者 Ruiheng He Zilong Lv +3 位作者 Jichun Jiang Fangfei Xing Tao Liu Shicheng Zhao 《Carbon and Hydrogen》 2025年第2期214-225,共12页
Polypropylene(PP)has a relatively low melt strength due to its linear structure,which seriously limits its supercritical CO_(2)foaming performance.Introducing long-chain branches(LCBs)via grafting can significantly en... Polypropylene(PP)has a relatively low melt strength due to its linear structure,which seriously limits its supercritical CO_(2)foaming performance.Introducing long-chain branches(LCBs)via grafting can significantly enhance its melt strength.However,the relationship between the LCB level of high melt strength polypropylene(HMSPP)and its foaming behavior remains unclear.In this study,a series of HMSPP with different LCB levels was prepared using vinyl polydimethylsiloxane(VS)of varying viscosities as grafting monomers to investigate this relationship.Rheological analysis showed that the increase in viscosity of VS led to higher LCB levels in HMSPP.The melt strength of HMSPP increases with the increase of LCB levels,reaching up to 0.62 N,which is 13 times higher than that of the raw material.Supercritical CO_(2)foaming results revealed that the expansion ratio of HMSPP first increased and then decreased with the increase of melt strength,reaching a maximum of 39.4 times.Combining experiments with simulations,the influence of LCB levels on the dissolution and diffusion behavior of CO_(2)in HMSPP was clarified.This study deepens the understanding of the relationship between LCB and the foaming behavior of HMSPP,providing valuable insights for designing HMSPP with optimized foaming properties. 展开更多
关键词 high melt strength polypropylene long-chain branches supercritica CO_(2)foaming
在线阅读 下载PDF
Analysis on the Composition and Structure of Branches of Two Kinds of Tree Shapes in Korla Fragrant Pear 被引量:2
2
作者 成小龙 廖康 +4 位作者 李楠 赵世荣 孙慧瑛 曼苏尔.那斯尔 刘娟 《Agricultural Science & Technology》 CAS 2013年第7期954-958,共5页
ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distr... ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that: The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different. 展开更多
关键词 Korla fragrant pear Tree shape Composition and structure of branch
在线阅读 下载PDF
Study on the Cutting Rooting of Syriga Microphylla with Tender Branches 被引量:1
3
作者 武术杰 周秀华 《Agricultural Science & Technology》 CAS 2010年第11期37-38,81,共3页
[Objective] The study was carried out in order to find out the best method of rapid cutting rooting of Syriga microphylla with tender branches.[Method] Effect of rooting reagent with different concentrations on the ra... [Objective] The study was carried out in order to find out the best method of rapid cutting rooting of Syriga microphylla with tender branches.[Method] Effect of rooting reagent with different concentrations on the rapid cutting rooting of Syriga microphylla with tender branches was studied in our paper.[Result] There was great difference between cuttings with auxin and without auxin.[Conclusion] Tender branches treated by 90 mg/L indole butyric acid(IBA)had the best cutting rooting. 展开更多
关键词 Syriga microphylla Tender branches Cutting rooting Rooting reagent
在线阅读 下载PDF
Processability and Structure of Dynamically Modified Linear Low-density Polyethylene with Different Branching Contents Using a High Peroxide Content
4
作者 Jun-Jin Duan Yan-Qin Huang +3 位作者 Fu-Qing Wei Yan Gao Fu-Shan Wang Jia-Chun Feng 《Chinese Journal of Polymer Science》 2026年第1期87-99,I0011,共14页
Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLD... Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing. 展开更多
关键词 POLYETHYLENE PEROXIDE Short-chain branching Dynamical modification PROCESSABILITY
原文传递
Global Optimization Algorithm for Minimizing Linear Fractional Programming
5
作者 ZHAO Peng SHEN Pei-ping ZHONG Zhe-wei 《Chinese Quarterly Journal of Mathematics》 2026年第1期50-59,共10页
In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,w... In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,we convert the problem(LFP)to the equivalent problem(EP2).Secondly,by applying the linear relaxation technique to the problem(EP2),the linear relaxation programming problem(LRP2Y)was obtained.Then,the overall framework of the algorithm is given,and the convergence and complexity of the algorithm are analyzed.Finally,experimental results are listed to illustrate the effectiveness of the algorithm. 展开更多
关键词 Global optimization Linear Fractional Programming Branch and bound algorithm Linear relaxation
在线阅读 下载PDF
Improvement of Traveling Wave-based Fault Location Method for Overhead Distribution Lines
6
作者 Xinyi Zhang Bingyin Xu +1 位作者 Zhaoru Han Fang Shi 《Protection and Control of Modern Power Systems》 2026年第1期157-172,共16页
Traveling wave(TW)fault location technology has been widely used in transmission systems due to its high accuracy and simplicity.Recently,there has been growing interest in applying this technology to medium voltage(M... Traveling wave(TW)fault location technology has been widely used in transmission systems due to its high accuracy and simplicity.Recently,there has been growing interest in applying this technology to medium voltage(MV)distribution lines.However,current practices in its deployment,signal measurement,and threshold setting are usually from the application experiences in transmission lines,despite significant differences in fault-induced wave characteristics between transmission and distribution systems.To address these issues,this paper investigates the feasibility and applicability of TW fault technology in MV overhead distribution lines through characteristic analysis of fault-induced TWs.The propagation characteristics of aerial mode and zero mode TWs on overhead distribution lines are studied.Furthermore,it evaluates the influence of critical distri-bution network components including distribution transformers,multi-branch configurations,and busbar structures on wave propagation characteristics.Deployment strategies for traveling wave fault location(TWFL)devices is proposed to address the unique challenges of distribution networks,while the fault location method is also improved.Field test results demonstrate the effectiveness of the proposed methodology,showing improved fault detection accuracy and system reliability in distri-bution network applications.This research provides practical implementation suggestions for TWFL technology in distribution networks. 展开更多
关键词 Branch lines distribution network overhead lines propagation characteristics traveling wave based fault location
在线阅读 下载PDF
Instructions for Authors
7
《International Journal of Ophthalmology(English edition)》 2026年第1期202-204,共3页
GENERAL INFORMATION International Journal of Ophthalmology—IJO,published continuously since 2008,a global ophthalmological scientific publication and a peer-reviewed,open access periodical published in print and onli... GENERAL INFORMATION International Journal of Ophthalmology—IJO,published continuously since 2008,a global ophthalmological scientific publication and a peer-reviewed,open access periodical published in print and online monthly(ISSN:2222-3959 print,ISSN:2227-4898 online).IJO is sponsored by the Chinese Medical Association Xi’an Branch,China and obtains guidance.It is indexed in SCI,PubMed,PubMed Central,Chemical Abstract,Scopus,EMBASE etc.The latest JCR IF is 1.8,Five-year Impact Factor is 1.8,CiteScore in 2024 is 2.8. 展开更多
关键词 Peer Reviewed Open Access SCI PUBMED Print Online Chinese Medical Association Xian Branch PubMed Central Global Ophthalmological Publication
原文传递
Hainan’s“Clean Energy Island”Vision
8
作者 WEI HONGCHEN 《China Today》 2026年第3期40-43,共4页
Siemens and Yangpu Economic Development Zone in Hainan have forged a close partnership in a journey towards green energy transition.SIEMENS Energy,one of the world’s leading energy technology companies,became the fir... Siemens and Yangpu Economic Development Zone in Hainan have forged a close partnership in a journey towards green energy transition.SIEMENS Energy,one of the world’s leading energy technology companies,became the first foreign-funded manufacturer to establish a branch and began construction of a gas turbine assembly base and service center in Hainan on December 18,2025. 展开更多
关键词 gas turbine establish branch clean energy island Siemens Energy service center Yangpu Economic Development Zone green energy green energy transition
在线阅读 下载PDF
Cliffs of Contentment:From roads to Internet access, a remote mountainous village in Sichuan Province has transformed itself into a model of sustainable rural development and well-being
9
作者 MA LI 《ChinAfrica》 2026年第4期32-34,共3页
Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and ... Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and secretary of the CPC Gulu Village Branch,better known as Cliff Village,in Hanyuan County,Ya’an City,Sichuan Province,was still dressed in his Yi ethnic waistcoat. 展开更多
关键词 remote mountainous village sustainable rural development internet access Beijing Spring yi ethnic waistcoat cliffs contentment CPC Gulu village branch Chinas annual two sessions
原文传递
Sustained release of branched-chain amino acids from slow-digesting whey enhances endurance running performance and improves skeletal muscle protein synthesis in mice
10
作者 Juncai Leng Tingyi Zhou +5 位作者 Yiming Jiang Beibei Wang Shuoming Liu Shiqi Zhang Li Li Wei Zhao 《Food Science and Human Wellness》 2026年第1期191-201,共11页
Post-exercise whey protein isolate(WPI)supplement is beneficial for skeletal muscle recovery due to the stimulation of branched chain amino acids(BCAAs).This implies us that intake slow digestion rate of protein to su... Post-exercise whey protein isolate(WPI)supplement is beneficial for skeletal muscle recovery due to the stimulation of branched chain amino acids(BCAAs).This implies us that intake slow digestion rate of protein to sustain BCAAs releasing rate may facilitate muscle protein synthesis.To examine this hypothesis,we conducted a series of protein supplements including modified slow-digesting whey(SDW),whey,hydrolyzed whey and casein,orally to mice undergoing endurance running.Our results showed that the SDW gavage constant supplied BCAAs in the serum of mice within 6 h and significantly enhanced(P<0.01)endurance exercise capacity,compared to other groups.In addition,the SDW supplementation increased the crosssectional area of mice gastrocnemius fibers,as well as their muscle and liver glycogen content.It also increased the testosterone/cortisol ratio in serum and interleukin-6(IL-6)levels in muscle,while it decreased the tumor necrosis factor-alpha(TNF-α)levels and oxidative stress in muscle.Moreover,it may activate mechanistic target of rapamycin signaling by upregulating mRNA(bcat-1 and pgc-1α)expression.Thus,our findings illustrate that prolonged BCAAs supply duration promotes mice endurance running capacity and skeletal muscle growth,contributing to the advancement of sports nutrition practices. 展开更多
关键词 Whey protein isolate(WPI) Branched chain amino acids(BCAAs) Endurance running Muscle protein synthesis
在线阅读 下载PDF
Anchorage properties at the interface between soil and roots with branches 被引量:8
11
作者 Xiaodong Ji Lihua Chen Ao Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期83-93,共11页
Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the labo... Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve (F-S curve). The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures: breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches: the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage. 展开更多
关键词 Root-soil interface mechanics Pullout test method Root branches Branch angle
在线阅读 下载PDF
Large borehole with multi-lateral branches: A novel solution for exploitation of clayey silt hydrate 被引量:12
12
作者 Yan-long Li Yi-zhao Wan +5 位作者 Qiang Chen Jia-xin Sun Neng-you Wu Gao-wei Hu Fu-long Ning Pei-xiao Mao 《China Geology》 2019年第3期333-341,共9页
Raising the in situ decomposition rate of natural gas hydrate and increasing the decomposition contact area are two main ways to raise the productivity of hydrate. An exploitation technique based on large borehole wit... Raising the in situ decomposition rate of natural gas hydrate and increasing the decomposition contact area are two main ways to raise the productivity of hydrate. An exploitation technique based on large borehole with multi-lateral branches (LB & MB) was proposed in this paper. This technique is mainly intended for the clayey silt hydrate reservoir in the South China Sea, and its main purpose is to alleviate the sand output from formation for maintaining the stability of the reservoir and to greatly increase the gas productivity of the reservoir. In this paper, the following aspects were mainly expounded: definition of the basic geometric parameters for layout of multi-lateral branches in clayey silt hydrate reservoir, simulation of the stimulation effect of a typical well profile with two branches, and prediction and simulation of the reservoir failure risk in a well profile with eight branches. The results show that the LB & MB effectively improves the flow field in the formation, raises the productivity of the reservoir and may also help to decrease the produced water-gas ratio (WGR). When the lateral branches spacing is too small, the failure zones around adjacent lateral branches overlap each other, possibly causing reservoir failure in a larger range. Therefore, the geometric parameters of multi-lateral branches depend on the dual control of the productivity and geotechnical risk factor of reservoir. Further study is being carried out, so as to obtain the optimal combination of parameters of multi-lateral branches. 展开更多
关键词 Natural gas HYDRATE Clayey SILT Multi-lateral branches Stimulation Numerical simulation HYDRATE exploration engineering SOUTH China Sea China
在线阅读 下载PDF
Sleeve bridging of the rhesus monkey ulnar nerve with muscular branches of the pronator teres: multiple amplification of axonal regeneration 被引量:3
13
作者 Yu-hui Kou Pei-xun Zhang +6 位作者 Yan-hua Wang Bo Chen Na Han Feng Xue Hong-bo Zhang Xiao-feng Yin Bao-guo Jiang 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第1期53-59,共7页
Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previo... Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previous studies have verified the limit and validity of multiple ampli- fication of peripheral nerve regeneration using small gap sleeve bridging of small donor nerves to repair large receptor nerves in rodents. The present study sought to observe multiple ampli- fication of myelinated nerve fiber regeneration in the primate peripheral nerve. Rhesus monkey models of distal ulnar nerve defects were established and repaired using muscular branches of the right forearm pronator teres. Proximal muscular branches of the pronator teres were su- tured into the distal ulnar nerve using the small gap sleeve bridging method. At 6 months after suture, two-finger flexion and mild wrist flexion were restored in the ulnar-sided injured limbs of rhesus monkey. Neurophysiological examination showed that motor nerve conduction veloc- ity reached 22.63 _+ 6.34 m/s on the affected side of rhesus monkey. Osmium tetroxide staining demonstrated that the number of myelinated nerve fibers was 1,657 + 652 in the branches of pronator teres of donor, and 2,661 ~ 843 in the repaired ulnar nerve. The rate of multiple amplification of regenerating myelinated nerve fibers was 1.61. These data showed that when muscular branches of the pronator teres were used to repair ulnar nerve in primates, effective regeneration was observed in regenerating nerve fibers, and functions of the injured ulnar nerve were restored to a certain extent. Moreover, multiple amplification was subsequently detected in ulnar nerve axons. 展开更多
关键词 nerve regeneration peripheral nerve rhesus monkey muscular branches of pronator teres ulnar nerve multiple amplification small gap sleeve bridging NSFC grants neural regeneration
暂未订购
Study on the Metallogenetism of Sub-mantle Plume and Mantle Branches in the Gold Mineralization Concentration Area of Northwest Jiaodong Peninsula 被引量:4
14
作者 NIU Shuyin CHENG Guangsuo +8 位作者 ZHANG Jianzhen SUN Aiqun MA Baojun ZHANG Fuxiang WANG Baode XU Meng WU Jichun ZHAO Rongxin WANG Shanfei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第5期1409-1420,共12页
The northwest of Jiaodong peninsula is characterized by its greatest gold concentration area, enormous gold reserves and limited time interval (115±5Ma) of gold mineralization in China. Studies show that the ea... The northwest of Jiaodong peninsula is characterized by its greatest gold concentration area, enormous gold reserves and limited time interval (115±5Ma) of gold mineralization in China. Studies show that the east area of north China began its mantle plume evolution since the Yanshanian movement, and the Laiyang sub-mantle plume and its surrounding mantle branches such as those in Guojiadian, Aishan and Panshidian were formed in the mineralization concentration area of northwestern Jiaodong peninsula. With the development of mantle plume →sub-mantle plume → mantle branch→ favorable expending structures, the deep-derived hydrothermal fluid moved up to the favorable places, such as brittle-ductile or ductile-brittle shearing zones, the internal and external contact zones of intrusions, dense fracturing zones and the contact zones between dikes and countryrocks, and concentrated into deposits. Then the gold mineralization concentration zones that are centralized on mantle branches were formed. This study takes Guojiadian mantle branch as an example to discuss their metallogenetism and conclude the metallogenetic mode. 展开更多
关键词 sub-mantle plume mantle branch ore-controlling structure metallogenetism metallogenetic mode northwest Jiaodong peninsula
在线阅读 下载PDF
Influence of different portal vein branches on hepatic encephalopathy during intrahepatic portal shunt via jugular vein 被引量:2
15
作者 Xin Yao Sheng He +1 位作者 Meng Wei Jian-Ping Qin 《World Journal of Gastroenterology》 SCIE CAS 2022年第31期4467-4470,共4页
This letter is regarding the study titled‘Targeted puncture of left branch of intrahepatic portal vein in transjugular intrahepatic portosystemic shunt(TIPS)to reduce hepatic encephalopathy’.Prior to the approval of... This letter is regarding the study titled‘Targeted puncture of left branch of intrahepatic portal vein in transjugular intrahepatic portosystemic shunt(TIPS)to reduce hepatic encephalopathy’.Prior to the approval of TIPS dedicated stents(Viatorr stents)in China in October 2015,Fluency covered stents were typically used.As Fluency covered stents have a strong support force and axial elastic tension,a‘cap’may form if the stent is located too low at the end of the hepatic vein or too short at the end of the portal vein during surgery,leading to stent dysfunction.Since the blood shunted by the stent is from the main trunk of the portal vein,the correlation between the incidence of postoperative hepatic encephalopathy and the location of the puncture target(left or right portal vein branch)is worth discussion.Notably,no studies in China or foreign countries have proven the occurrence of left and right blood stratification after the accumulation of splenic vein and mesenteric blood flow in the main trunk of the portal vein in patients with cirrhotic portal hypertension. 展开更多
关键词 Viatorr stent Portosystemic shunt Transjugular intrahepatic Hypertension PORTAL Left and right portal vein branches
暂未订购
Detection of long-chain branches in polyethylene via rheological measurements 被引量:2
16
作者 Yun-Fan Mei Bao-Hua Guo Jun Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2016年第4期588-592,共5页
The detection of long-chain branches(LCB) in polyethylene is of considerable importance as the processing properties of polyethylene are strongly affected by even a small amount of LCB. While the conventional charac... The detection of long-chain branches(LCB) in polyethylene is of considerable importance as the processing properties of polyethylene are strongly affected by even a small amount of LCB. While the conventional characterization techniques such as GPC-MALS and13 C NMR fail or take very long time to detect low content of LCB, we turn to the rheological method, which is more sensitive to LCB. In our study, we performed oscillatory shear test, creep test and stress relaxation test on two series of metallocene linear low density polyethylene(LLDPE), revealing that the resins with LCB show higher zero-shear-rate viscosity, retarded relaxation and higher flow activation energy than those without or with less LCB. The resins with LCB showed shear thinning at very low shear rate and their zero-shear-rate viscosities were obtained via creep test. The content of LCB was quantitatively estimated from the flow activation energy. In addition, the modulus-time curves during stress relaxation of melt of the different resins obeyed the power law. The exponent of the resins with more LCB was 0.7, different from that of the resins with less LCB, around 1.7. 展开更多
关键词 Metallocene polyethylene Long-chain branch RHEOLOGY Stress relaxation
原文传递
Activity maintenance of the excised branches and a case study of NO_2 exchange between the atmosphere and P.nigra branches 被引量:1
17
作者 Chun Chen Yuzheng Wang +9 位作者 Yuanyuan Zhang Xiaoxiu Lun Chengtang Liu Yujing Mu Chenglong Zhang Pengfei Liu Chaoyang Xue Min Song Can Ye Junfeng Liu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第6期316-326,共11页
The efficient maintenance of the activity of excised branches is the powerful guarantee to accurately determine gas exchange flux between the detached branches of tall trees and the atmosphere. In this study, the net ... The efficient maintenance of the activity of excised branches is the powerful guarantee to accurately determine gas exchange flux between the detached branches of tall trees and the atmosphere. In this study, the net photosynthetic rate(NPR) of the excised branches and branches in situ were measured simultaneously by using two photosynthetic instruments to characterize the activity of the excised branches of Phyllostachys nigra. The ratio of normalized NPR of excised branches to NPR in situ was used to assess the photosynthetic activity of detached branches. Based on photosynthetic activity, an optimal hydroponics protocol for maintaining activity of excised P. nigra branches was presented:1/8 times the concentration of Gamborg B5 vitamin mixture with p H = 6. Under the best cultivation protocol, photosynthetic activity of excised P. nigra branches could be maintained more than 90% within 6 hr in the light intensity range of 200–2000 μmol/(m2·sec) and temperature range of 13.4–28.7°C. The nitrogen dioxide(NO2) flux differences between in situ and in vitro branches and the atmosphere were compared using double dynamic chambers.Based on the maintenance method of excised branches, the NO2 exchange flux between the excised P. nigra branches and the atmosphere(from-1.01 to-2.72 nmol/(m2·sec) was basically consistent with between the branches in situ and the atmosphere(from-1.12 to-3.16 nmol/(m2 sec)) within 6 hr. Therefore, this study provided a feasible protocol for in vitro measurement of gas exchange between tall trees and the atmosphere for a period of time. 展开更多
关键词 Excised branches ACTIVITY maintenance NO2 EXCHANGE flux HYDROPONICS Dynamic CHAMBER
原文传递
Thermal pretreatment of willow branches impacts yield and pore development of activated carbon in subsequent activation with ZnCl_(2) via modifying cellulose structure 被引量:2
18
作者 Linghui Kong Chao Li +7 位作者 Runxing Sun Shu Zhang Yi Wang Jun Xiang Song Hu Dong Wang Chuanjun Leng Xun Hu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第5期227-237,共11页
Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the feedstock.Thermal pretreatment of biomass could induce d... Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the feedstock.Thermal pretreatment of biomass could induce dehydration and/or aromatization to change the structure of cellulose/hemicellulose.This might interfere with evolution of structures of AC,which was investigated herein via thermal pretreatment of willow branch(WB)from 200 to 360℃and the subsequent activation with ZnCl_(2) at 550℃.The results showed that thermal pretreatment at 360℃(WB-360)could lead to substantial pyrolysis to form biochar,with a yield of 31.9%,accompanying with nearly complete destruction of cellulose crystals and remarkably enhanced aromatic degree.However,cellulose residual in WB-360 could still be activated to form AC-360 with specific surface area of 1837.9 m~2·g^(-1),which was lower than that in AC from activation of untreated WB(AC-blank,2077.8 m~2·g^(-1)).Nonetheless,the AC-200 from activation of WB-200 had more developed pores(2113.9 m~2·g^(-1))and superior capability for adsorption of phenol,due to increased permeability of ZnCl_(2) to the largely intact cellulose structure in WB-200.The thermal pretreatment did increase diameters of micropores of AC but reduced the overall yield of AC(26.8%for AC-blank versus 18.0%for AC-360),resulting from accelerated cracking but reduced intensity of condensation.In-situ infrared characterization of the activation showed that ZnCl_(2) mainly catalyzed dehydration,dehydrogenation,condensation,and aromatization but not cracking,suppressing the formation of derivatives of cellulose and lignin in bio-oil.The thermal pretreatment formed phenolic-OH and C=O with higher chemical innerness,which changed the reaction network in activation,shifting morphology of fibrous structures in AC-blank to“melting surface”in AC-200 or AC-280. 展开更多
关键词 Thermal pretreatment Activation with ZnCl_(2) Willow branch Activated carbon Biochar
在线阅读 下载PDF
Dual Branches of MHD Three-Dimensional Rotating Flow of Hybrid Nanofluid on Nonlinear Shrinking Sheet 被引量:1
19
作者 Liaquat Ali Lund Zurni Omar +1 位作者 Ilyas Khan El-Sayed MSherif 《Computers, Materials & Continua》 SCIE EI 2021年第1期127-139,共13页
In this study,magnetohydrodynamic(MHD)three-dimensional(3D)flow of alumina(Al2O3)and copper(Cu)nanoparticles of an electrically conducting incompressible fluid in a rotating frame has been investigated.The shrinking s... In this study,magnetohydrodynamic(MHD)three-dimensional(3D)flow of alumina(Al2O3)and copper(Cu)nanoparticles of an electrically conducting incompressible fluid in a rotating frame has been investigated.The shrinking surface generates the flow that also has been examined.The single-phase(i.e.,Tiwari and Das)model is implemented for the hybrid nanofluid transport phenomena.Results for alumina and copper nanomaterials in the water base fluid are achieved.Boundary layer approximations are used to reduce governing partial differential(PDEs)system into the system of the ordinary differential equations(ODEs).The three-stage Lobatto IIIa method in bvp4c solver is applied for solutions of the governing model.Graphical results have been shown to examine how velocity and temperature fields are influenced by various applied parameters.It has been found that there are two branches for certain values of the suction/injection parameter b:The rise in copper volumetric concentration improved the velocity of hybrid nanofluid in the upper branch.The heat transfer rate improved for the case of hybrid nanofluid as compared to the viscous fluid and simple nanofluid. 展开更多
关键词 Nonlinear surface viscous dissipation MHD Hybrid nanofluid two branches
在线阅读 下载PDF
Average bit error rate performance analysis of subcarrier intensity modulated MRC and EGC FSO systems with dual branches over M distribution turbulence channels 被引量:3
20
作者 王冉冉 王平 +2 位作者 曹天 郭立新 杨银堂 《Optoelectronics Letters》 EI 2015年第4期281-285,共5页
Based on the space diversity reception,the binary phase-shift keying(BPSK) modulated free space optical(FSO) system over Málaga(M) fading channels is investigated in detail.Under independently and identically dis... Based on the space diversity reception,the binary phase-shift keying(BPSK) modulated free space optical(FSO) system over Málaga(M) fading channels is investigated in detail.Under independently and identically distributed and independently and non-identically distributed dual branches,the analytical average bit error rate(ABER) expressions in terms of H-Fox function for maximal ratio combining(MRC) and equal gain combining(EGC) diversity techniques are derived,respectively,by transforming the modified Bessel function of the second kind into the integral form of Meijer Gfunction.Monte Carlo(MC) simulation is also provided to verify the accuracy of the presented models. 展开更多
关键词 turbulence branches modulated identically fading verify Bessel keying maximal independently
原文传递
上一页 1 2 75 下一页 到第
使用帮助 返回顶部