Effects of Different Seasons on Cutting Propagation of Five Citrus Rootstocks

[Objectives]To explore the cutting propagation mode of citrus rootstock,improve the survival rooting rate of citrus rootstock,and provide theoretical guidance and technical reference for the rooting research of difficult-to-root plants such as citrus.[Methods]Five citrus rootstocks Citrus tangerina Tanaka‘Hongju’,Citrus haniana Hort‘Suanju’,Citrus limonia Osbeck‘Hongningmeng’,Citrus sinensis×Poncirus trifoliata‘Zhicheng’and Poncirus trifoliate(L)Raf.‘Zhike’were used as experimental materials to select the suitable cutting substrate for citrus rootstocks by measuring the physical properties of the substrate.Cutting was carried out in spring,summer,autumn and winter respectively.After cutting,the morphological changes of cuttings were observed regularly,and the callus rate,germination rate and rooting rate of cuttings were recorded.[Results]The best substrate for citrus rootstock cutting was peat soil,vermiculite and fine river sand(2:1:1).The callus of citrus rootstock in different cutting seasons began to appear in 10-22 d,and the callus rate reached 55%-100%.In terms of budding,the budding time was the earliest in summer and autumn,and slightly later in spring and winter;the germination rate of C.limonia Osbeck‘Hongningmeng’was the highest,and the germination rate of C.sinensis×P.trifoliata‘Zhicheng’and P.trifoliate(L)Raf.‘Zhike’was lower;in terms of rooting,C.limonia Osbeck‘Hongningmeng’had the earliest rooting time and the highest rooting rate and could reach 100%in all seasons;the rooting rate of C.tangerina Tanaka‘Hongju’was 50%-80%;the rooting rate of C.haniana Hort‘Suanju’was 60%-80%;C.sinensis×P.trifoliata‘Zhicheng’and P.trifoliate(L)Raf.‘Zhike’showed the earliest rooting time and the highest rooting rate in summer,and the latest rooting time and the lowest rooting rate in winter,which were only 14.5%.Therefore,different citrus rootstock varieties should choose the appropriate cutting time according to their own characteristics.[Conclusions]The results of this study can provide a scientific basis for a large number of cutting propagation of different citrus rootstocks,and have practical guiding significance for large-scale planting.

Additional far-red light promotes adventitious rooting of doubleroot-cutting grafted watermelon seedlings

Root regeneration is an important factor influencing the healing rate of graft union and the survival of double-root-cutting grafting.To date,little information is available on how to enhance root regeneration of rootstock in grafted watermelon(Citrullus lanatus)seedlings.In this study,the effects of different light treatments on root regeneration were determined.This revealed that addition of far-red light(Fr)could significantly expedite root formation in the rootstock.Moreover,the results of transcriptome analysis revealed that plant hormone pathway and auxinrelated genes were greatly induced by Fr,especially for auxin-response proteins(including CmIAA11,CmIAA17,and CmAUX28),Small auxinup RNA genes(including CmSAUR20 and CmSAUR50)and the auxin efflux transporter(CmPIN3).In addition,the expression of Phytochrome Interacting Factor(PIFs),such as CmPIF1,CmPIF3 and CmPIF7,was remarkably increased by Fr.These genes may act together to activate auxinrelated pathways under Fr treatment.Based on the results of HPLC-MS/MS analysis,the concentrations of different auxin-types in adventitious root were significantly influenced by Fr.Furthermore,the better growth of rootstock root displayed superior vasculature transport activity of the graft union with Fr treatment,which was determined by the acid magenta dyeing experiment.Therefore,all the results suggested that Fr could induce AR formation in rootstocks,which may be associated with the auxin accumulation by regulating the transcriptional level of auxinrelated and PIF genes.The findings of this study demonstrated a practicable way to shorten the healing period of graftings and improve the quality of grafted watermelon seedlings,which will provide a theoretical basis for the speeding development of industrialized seedlings production.

Transcriptome profiling of indole-3-butyric acid-induced adventitious root formation in softwood cuttings of walnut

Inducing adventitious root(AR)formation in mature walnut species(Juglans L.)is challenging.However,the AR formation of mature trees can be improved by rejuvenation.In rejuvenated cuttings,exogenous indole-3-butyric acid(IBA)is essential for AR formation,and the underlying mechanism is still not well understood.Therefore,we utilized transcriptome sequencing to investigate the mechanism of IBA-induced AR formation.Our results revealed that,in comparison to the control group,IBA treatment(9 mmol·L^(-1))significantly increased the endogenous indole-3-acetic acid(IAA)content,leading to an enhanced rooting rate.We performed RNA sequencing to identify differentially expressed genes(DEGs)between the IBA-treated and control(CK)groups at 1,2,3,and 5 days after cutting(DAC).The results showed that,compared to the control cuttings,there were 1539,889,785,and 984 up-regulated genes and 2791,2936,3017,and 1752 down-regulated genes,at 1,2,3,and 5 DAC,respectively.Analysis of RNA-seq data revealed that G-type ATP-binding cassette 36/37(ABCG36/37)and ATP-binding cassette subfamily D 1(ABCD1),associated with IBA transport,were down-regulated in the rejuvenation cuttings.In contrast,PIN-FORMED(PIN)and PINOID(PID),associated with auxin efflux,were up-regulated.We identified 49 auxin/indole-3-acetic acid(AUX/IAA)-encoding genes,including IAA1,IAA3,IAA5,IAA6,IAA8,IAA11,IAA12,IAA19,and IAA20,which were up-regulated at 1-5 DAC in the rejuvenated cuttings.This study highlights that the overexpression of JrWOX5/11 in poplar significantly enhance AR growth,as evidenced by increased root length,surface area,volume,and quantity.Moreover,the co-expression network analysis involving JrWOX11 and JrWOX5 in walnut cuttings elucidates complex genetic interactions,underscoring their pivotal role in the formation of AR.Our data supported the following molecular mechanism of IBA-induced adventitious root formation.Firstly,IBA is converted to free IAA in peroxisomes.Then,the highly concentrated IAA in the procambium and parenchyma cells induces WUSCHEL-related homeobox 11(WOX11)expression at two days.Finally,WOX11 acts redundantly to up-regulate WOX5,initiating the development of root primordia cells.

Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables

The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway.

Hole cleaning evaluation and installation spacing optimization of cuttings bed remover in extended-reach drilling

In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the annulus.Once cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,and pipe stuck probably occur,which results in a lot of non-productive time and remedial operations.Cuttings bed remover can efficiently destroy deposited cuttings in time through hydraulic and mechanical stirring effects.This paper aims to build a method for hole cleaning evaluation and installation spacing optimization of cuttings bed remover to improve the wellbore cleaning effect.Firstly,a Computational Fluid Dynamics approach with Eulerian—Eulerian multiphase model was utilized to investigate the mechanism of cuttings transportation,and a new type of cuttings bed remover was designed.Next,an evaluation method of hole cleaning effect of remover was established.After that,the effects of several drilling parameters on hole cleaning including flow rate of drilling fluid,rotational speed of drillpipe,rate of penetration,wellbore size,rheological property of drilling fluid,and remover eccentricity on the performance of cuttings bed remover were investigated.The results demonstrate that the new type of remover with streamline blade performs better than conventional removers.The efficiency of hole cleaning is greatly improved by increasing the rotational speed of drillpipe,flow rate of drilling fluid,remover eccentricity,and 6 rpm Fann dial reading for drilling fluid.While higher rate of penetration and large wellbore size result in worse hole cleaning.These findings can serve as an important guide for the structure optimization design of cuttings bed remover and installation spacing of removers.

Effects of Root Cutting on Morphological Characteristics and Endogenous Hormone Levels of Quercus variabilis Seedlings

The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiological role of endogenous hormones in regulating root-crown interactions in the short term.The morphological characteristics and endogenous hormone contents of normal roots(no root cutting,CK)and cut roots(cut by 1/3 of the length of the main root,RP)were determined by liquid chromatography,which was combined with mass spectrometry at different levels of different developmental stages.The results showed that the root growth indexes and root endogenous hormones in the RP group were superior to those in the CK group.Through comprehensive analysis of endogenous hormones,it was found that the crosstalk of IAA,JA,ABA and SA could activate the root growth defense.After the root cutting treatment,the root growth of Quercus variabilis seedlings could compensate for the inhibition of taproot growth by promoting lateral root growth.The growth and development of compensatory lateral roots contribute to the increase the total root length of plants,thus promoting the absorption of water and nutrients.It is speculated that plant hormones may be the key factors affecting their development,but this is not only related to the content of a single hormone,but more importantly,it is the interaction between various hormones.

Yield and Nutritive Values of Semi- and Non-Fall Dormant Alfalfa Cultivars under Late-Cutting Schedule in California’s Central Valley

California is one of the major alfalfa (Medicago sativa L) forage-producing states in the U.S, but its production area has decreased significantly in the last couple of decades. Selection of cultivars with high yield and nutritive value under late-cutting schedule strategy may help identify cultivars that growers can use to maximize yield while maintaining area for sustainable alfalfa production, but there is little information on this strategy. A field study was conducted to determine cumulative dry matter (DM) and nutritive values of 20 semi- and non-fall dormant (FD) ratings (FD 7 and FD 8 - 10, respectively) cultivars under 35-day cut in California’s Central Valley in 2020-2022. Seasonal cumulative DM yields ranged from 6.8 in 2020 to 37.0 Mg·ha−1 in 2021. Four FD 8 - 9 cultivars were the highest yielding with 3-yrs avg. DM greater than the lowest yielding lines by 46%. FD 7 cultivar “715RR” produced the highest crude protein (CP: 240 g·Kg−1) while FD 8 cultivar “HVX840RR” resulted in the highest neutral detergent fiber digestibility (NDFD: 484 g·Kg−1, 7% greater than the top yielding cultivars) but with DM yield intermediate. Yields and NDFD correlated positively but weakly indicating some semi- and non-FD cultivars performing similarly. These results suggest that selecting high yielding cultivars under 35-day cutting schedule strategy can be used as a tool to help growers to maximize yield while achieving good quality forages for sustainable alfalfa production in California’s Central Valley.

Unraveling engineering disturbance effects on deformation in red-bed mudstone railway cuttings:incorporating crack-facilitated moisture diffusion

Red-bed mudstone, prevalent in southwest China, poses a formidable challenge due to its hydrophilic clay minerals, resulting in expansion, deformation, and cracking upon exposure to moisture. This study addresses uplift deformation disasters in high-speed railways by employing a moisture diffusion-deformation-fracture coupling model based on the finite-discrete element method(FDEM). The model integrates the influence of cracks on moisture diffusion. The investigation into various excavation depths reveals a direct correlation between depth and the formation of tensile cracks at the bottom of the railway cutting. These cracks expedite moisture migration, significantly impacting the temporal and spatial evolution of the moisture field. Additionally, crack expansion dominates hygroscopic deformation, with the lateral coordinate of the crack zone determining peak vertical displacement. Furthermore, key factors influencing deformation in railway cuttings, including the swelling factor and initial moisture content at the bottom of the cutting, are explored. The number of tensile and shear cracks increases with greater excavation depth, particularly concerning shear cracks. Higher swelling factors and initial moisture contents result in an increased total number of cracks, predominantly shear cracks. Numerical calculations provide valuable insights, offering a scientific foundation and directional guidance for the precise prevention, control, prediction, and comprehensive treatment of mudstone-related issues in high-speed railways.

Assessing cutter-rock interaction during TBM tunnelling in granite:Large-scale standing rotary cutting tests and 3D DEM simulations

The widespread utilisation of tunnel boring machines(TBMs)in underground construction engineering requires a detailed investigation of the cutter-rock interaction.In this paper,we conduct a series of largescale standing rotary cutting tests on granite in conjunction with high-fidelity numerical simulations based on a particle-type discrete element method(DEM)to explore the effects of key cutting parameters on the TBM cutter performance and the distribution of cutter-rock contact stresses.The assessment results of cutter performance obtained from the cutting tests and numerical simulations reveal similar dependencies on the key cutting parameters.More specifically,the normal and rolling forces exhibit a positive correlation with penetration but are slightly influenced by the cutting radius.In contrast,the side force decreases as the cutting radius increases.Additionally,the side force shows a positive relationship with the penetration for smaller cutting radii but tends to become negative as the cutting radius increases.The cutter's relative effectiveness in rock breaking is significantly impacted by the penetration but shows little dependency on the cutting radius.Consequently,an optimal penetration is identified,leading to a low boreability index and specific energy.A combined Hertz-Weibull function is developed to fit the cutter-rock contact stress distribution obtained in DEM simulations,whereby an improved CSM(Colorado School of Mines)model is proposed by replacing the original monotonic cutting force distribution with this combined Hertz-Weibull model.The proposed model outperforms the original CSM model as demonstrated by a comparison of the estimated cutting forces with those from the tests/simulations.The findings from this work that advance our understanding of TBM cutter performance have important implications for improving the efficiency and reliability of TBM tunnelling in granite.

Precipitates Generation Mechanism and Surface Quality Improvement for Aluminum Alloy 6061 in Diamond Cutting

To improve the surface quality for aluminum alloy 6061(Al6061) in ultra-precision machining, we investigated the factors affecting the surface finish in single point diamond turning(SPDT)by studying influence of the precipitates generation of Al6061 on surface integrity and surface roughness.Based on the Johnson-Mehl-Avrami solid phase transformation kinetics equation, theoretical and experimental studies were conducted to build the relationship between the aging condition and the type, size and number of the precipitates for Al6061. Diamond cutting experiments were conducted to machine Al6061 samples under different aging conditions. The experimental results show that, the protruding on the chip surface is mainly Mg_(2)Si and the scratches on the machined surface mostly come from the iron-containing phase(α-, β-AlFeSi).Moreover, the generated Mg_(2)Si and α-, β-AlFeSi affect the surface integrity and the diamond turned surface roughness. Especially, the achieved surface roughness in SPDT is consistent with the variation of the number of AlFeSi and Mg_(2)Si with the medium size(more than 1 μm and less than 2 μm) in Al6061.

Failure mechanism of directional roof cutting and design method optimization

Directional roof cutting(DRC)is one of the key techniques in non-pillar coal mining with self-formed entries(NCMSE)mining method.Due to the inability to accurately measure the expansion coefficient of the goaf rock mass,the implementation of this technology often encounters design challenges,leading to suboptimal results and increased costs.This paper establishes a structural analysis model of the goaf working face roof,revealing the failure mechanism of DRC,and clarifies the positive role of DRC in improving the stress of the roadway surrounding rock and reducing the subsidence of the roof through numerical simulation experiments.On this basis,the paper further analyses the roadway pressure and roof settlement under different DRC design heights,and ultimately proposes an optimized design method for the DRC height.The results indicate that the implementation of DRC can significantly optimize the stress environment of the working face roadway surrounding rock.At the same time,during the application of DRC,three scenarios may arise:insufficient,reasonable,and excessive DRC height.Insufficient height will significantly reduce the effectiveness of the technology,while excessive height has little impact on the implementation effect but will greatly increase construction costs and difficulty.Engineering verification shows that the optimized DRC design method proposed in this paper reduces the peak stress of the protective coal pillar in the roadway by 27.2%and the central subsidence of the roof by 41.8%,demonstrating excellent application results.This method provides technical support for the further promotion of NCMSE mining method.

Ground response and failure mechanism of gob-side entry by roof cutting with hard main roof

This study is the result of long-term efforts of the authors’team to assess ground response of gob-side entry by roof cutting(GSERC)with hard main roof,aiming at scientific control for GSERC deformation.A comprehensive field measurement program was conducted to determine entry deformation,roof fracture zone,and anchor bolt(cable)loading.The results indicate that GSERC deformation presents asymmetric characteristics.The maximum convergence near roof cutting side is 458 mm during the primary use process and 1120 mm during the secondary reuse process.The entry deformation is closely associated with the primary development stage,primary use stage,and secondary reuse stage.The key block movement of roof cutting structure,a complex stress environment,and a mismatch in the supporting design scheme are the failure mechanism of GSERC.A controlling ideology for mining states,including regional and stage divisions,was proposed.Both dynamic and permanent support schemes have been implemented in the field.Engineering practice results indicate that the new support scheme can efficiently ensure long-term entry safety and could be a reliable approach for other engineering practices.

Cutting Propagation Technique of Pennisetum purpureum Schum

[Objectives]The paper was to study the cutting propagation technique of Pennisetum purpureum Schum and to provide a technical reference for establishing an efficient cutting propagation method.[Methods]Six treatments were set up using P.purpureum cv.Guiminyin and P.purpureum cv.Guimu-1 as test materials,including 1-node oblique insertion,1-node oblique insertion+rooting powder,1-node transverse burial,2-node oblique insertion,2-node oblique insertion+rooting powder and 2-node transverse burial.The following indices were observed and determined for P.purpureum cuttings:emergence rate,rooting rate,root number,longest root length,fresh root weight,plant height,number of tillers,number of leaves,and fresh stem and leaf weight.[Results]In the 2-node cutting+rooting powder treatment,Guiminyin and Guimu-1 exhibited the highest survival rate,root growth indices,and stem and leaf growth indices,with the emergence rates of 94.29%and 90.26%,respectively.The 2-node cutting treatment followed closely behind,while the 1-node cutting treatment had the lowest indices.Under the same treatment,Guimuyin exhibited higher mean values for plant height,number of leaves,fresh stem and leaf weight,longest root length,and fresh root weight compared to Guimu-1.However,it had lower mean number of tillers,and emergence rate and rooting rate of the 1-node cutting treatment compared to Guimu-1.[Conclusions]The P.purpureum cuttings thrived in the 2-node cutting+rooting powder treatment,and the overall cutting effect of Guiminyin was superior to that of Guimu-1.

Cutting-edge Technological Innovation Outcome Displayed at 2024 Beijing Science and Technology Week

The 2024 National Science and Technology Week and Beijing Science and Technology Week opened in Shougang Park in Shijingshan District from May 25 to June 1.Under the theme of“Carrying forward the spirit of scientists and inspiring societal innovation,”this event focused on the new-generation IT technology,medical health,energy and technology,modern agriculture and intelligent manufacturing industries.

Endoscopic radial incision and cutting method for adult congenital duodenal webs:A case report

BACKGROUND Congenital duodenal webs are rare in adults and can lead to various symptoms such as nausea,vomiting,and postprandial fullness.The treatment for this disease is mostly surgical.Endoscopic treatment techniques have been developed and attempted for this disease.Endoscopic radial incision and cutting(RIC)techniques are reportedly very effective in benign anastomotic stricture.This case report highlights the effectiveness and safety of endoscopic RIC as a minimally invasive treatment for adult congenital duodenal webs.CASE SUMMARY A 23-year-old female patient with indigestion was referred to a tertiary hospital.The patient complained of postprandial fullness in the epigastric region.Previous physical examinations or blood tests indicated no abnormalities.Computed tomography revealed an eccentric broad-based delayed-enhancing mass-like lesion in the second portion of the duodenum.Endoscopy showed an enlarged gastric cavity and a significantly dilated duodenal bulb;a very small hole was observed in the distal part of the second portion,and scope passage was not possible.Gastrografin upper gastrointestinal series was performed,revealing an intraduodenal barium contrast-filled sac with a curvilinear narrow radiolucent rim,a typical"windsock"sign.Endoscopic RIC was performed on the duodenal web.The patient recovered uneventfully.Follow-up endoscopy showed a patent duodenal lumen without any residual stenosis.The patient reported complete resolution of symptoms at the 18-month follow-up.CONCLUSION Endoscopic RIC may be an effective treatment for congenital duodenal webs in adults.

Application of Fuyang Paper Cutting Art in Cultural and Creative Design from the Perspective of Rural Revitalization

The application significance of Fuyang paper cutting art in cultural and creative design from the perspective of rural revitalization was discussed,and the implementation principles and specific practices of applying the elements and techniques of Fuyang traditional paper cutting art in cultural and creative products with local features were analyzed to provide reference for rural revitalization and development of cultural industry.

Design and Numerical Simulation of Dust Removal System for Sutomotive Iongitudinal Beam Plasma Cutting

To improve the poor efficiency of the dust removal system in the plasma cutting station of automotive longitudinal beams,and reduce the cutting surface quality degradation due to dust,a bottom-side suction dust removal system is designed,and the dust removal effect is optimized through the setting of the following dampers and diversion plates.The result of numerical simulation indicates that the particle collection rate can reach 99.44%,and the field test also proves the effectiveness of the dust removal system,which is of guiding significance for the transformation of other similar dust removal systems.

Research on the Resistance of Cutting Mechanism of Mining Longitudinal Roadheader

In order to accurately obtain the dynamic characteristics of the cutting mechanism of the mining longitudinal roadheader,combined with the working principle of the mining longitudinal roadheader,the theoretical analysis and derivation are carried out in detail.By using ADAMS to simulate,the resistance curve and torque curve of the cutting mechanism in different directions are obtained.The results show that ADAMS can effectively predict the excavation resistance and torque of the cutting mechanism of mining longitudinal roadheader,which has certain reference value for future optimization design.

Effects of Remaining Leaf Combining with IBA on Rooting,Physiological and Biochemical Indicators of Leaves from Bougainvillea spectabilis Cuttings

[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects of remaining leaf combining with IBA on rooting,physiological and biochemical indicators of B.spectabilis cuttings were studied under the regulation and control of intelligent seed propagation system,and then set four treatments：remaining leaf combining with soaking in clean water,remaining leaf combining with soaking in IBA,defoliation combining soaking in clean water,and defoliation combining with soaking in IBA.[Result] The soluble sugar content was high,but indoleacetic acid oxidase activity was lower in the initial stage of adventitious root differentiation in treatment of remaining leaf.While the rooting number,root length,the root mass growth and survival rate of cutting were obviously higher than that in treatment of defoliation.Compared to the treatment soaking in clean water,the treatment soaking in 500×10^-6 IBA increased the soluble sugar content in leaves of cuttings and enhanced rooting of cuttings.[Conclusion] The survival rate and rooting of cuttings improved obviously in the treatment of remaining leaf combining with soaking in 500×10^-6 IBA before cutting under the regulation and control of intelligent seed propagation system.

Study on the Cutting Rooting of Syriga Microphylla with Tender Branches

[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.