Multiparameter Numerical Investigation of Two Types of Moving Interactions Between the Deep-Sea Mining Vehicle Track Plate and Seabed Soil:Digging and Rotating Motions

To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track plate.The rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed soil.In this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging condition.First,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ sampling.Subsequently,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil heterogeneity.The results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed soil.Therefore,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.

Simulation Analysis of a New Type of Bionic Digging Shovel Based on DEM

The performance of a digging shovel mainly depends on the style of the shovel, while the conventional experiment methods always suffer from the problems of high lost and long period. Aiming at these problems and the characteristic that soil is composed of countless small particles, dynamic simulation analysis was performed on the resistance to a bionic digging shovel and crushing rate of the soil during the normal working process of the bionic digging shovel by EDEM through numerical simulation, calculation and comparison. The results showed that compared with the ordinary shovel, the average drag-reducing rate in the X direction was 10.41%, and the average drag-reducing rate in the Y direction was 16.28%, and the soil crushing rate was improved by 2.67%. Therefore, the bionic digging shovel has certain superiority and extension value in structure and performance. Moreover, this analysis case fully demonstrates the unique advantage of DEM method and its generalizability, and provides certain reference for similar studies.

Specific Power Consumption as Factor Disintegration Process Control of Digging-Wheel Excavators

The determination of digging resistance is of decisive importance when evaluating the mining process of digging-wheel excavators. Methodic of measuring and determinant relations （formulae） are different in various countries and by the comparison of them, underlying data for complex and objective evaluation using the knowledge from the field of rock disintegration can be obtained. In virtue of analysis of many measurements in situ, rather high specific power consumption with a wheel of excavator has been proved. What was the criterion for evaluation was the power consumption related to the volume of a rock disintegrated per unit time. From theoretical analyses, possibilities of eliminating a negative influence of the human factor upon the mining process and thus possibilities of optimum utilizing the power input of a wheel drive follow.

The cluster digging behavior of larvae confers trophic benefits to fitness in insects

Collective behaviors efficiently impart benefits to a diversity of species ranging from bacteria to humans.Fly larvae tend to cluster and form coordinated digging groups under crowded conditions,yet understanding the rules governing this behavior is in its infancy.We primarily took advantage of the Drosophila model to investigate cooperative foraging behavior.Here,we report that Drosophila-related species and the black soldier fly have evolved a conserved strategy of cluster digging in food foraging.Subsequently,we investigated relative factors,including larval stage,population density,and food stiffness and quality,that affect the cluster digging behavior.Remarkably,oxygen supply through the posterior breathing spiracles is necessary for the organization of digging clusters.More importantly,we theoretically devise a mathematical model to accurately calculate how the cluster digging behavior expands food resources by diving depth,cross-section area,and food volume.We found that cluster digging behavior approximately increases 2.2 fold depth,1.7-fold cross-section area,and 1.9 fold volume than control groups,respectively.Amplification of food sources significantly facilitates survival,larval development,and reproductive success of Drosophila challenged with competition for limited food resources,thereby conferring trophic benefits to fitness in insects.Overall,our findings highlight that the cluster digging behavior is a pivotal behavior for their adaptation to food scarcity,advancing a better understanding of how this cooperative behavior confers fitness benefits in the animal kingdom.

Effect of gland extracts on digging and residing preferences of red imported fire ant workers （Hymenoptera＂ Formicidae）

There is evidence that ant-derived chemical stimuli are involved in regulat- ing the digging behavior in Solenopsis invicta Buren. However, the source gland（s） and chemistry of such stimuli have never been revealed. In this study, extracts of mandibular, Dufour＇s, postpharyngeal, and poison glands were evaluated for their effect on ant digging and residing preferences of S. invicta workers from three colonies. In the intracolonial bioassays, workers showed significant digging preferences to mandibular gland extracts in 2 of 3 colonies and significant residing preferences in 1 of 3 colonies; significant digging preferences to Dufour＇s gland extracts in 1 of 3 colonies and significant residing preferences in 2 of 3 colonies. No digging and residing preferences were found for postpharyngeal and poison gland extracts. In intercolonial bioassays, significant digging and residing prefer- ences were found for mandibular gland extracts in 3 of 6 colony combinations. Significant digging preferences to Dufour＇s gland extracts were found in 4 of 6 colony combinations and significant residing preferences in all 6 colony combinations. For postpharyngeal gland extracts, significant digging preferences were found only in 1 of 6 colonial combinations and no significant residing preferences were found. For poison gland extracts, no signif- icant digging preferences were found; significant residing preferences were found in 1 of 6 colony combinations. However, a significant residing deterrence （negative residing preference index） was found for 2 of 6 colony combinations. Statistical analyses using data pooled from all colonies showed that mandibular and Dufour＇s gland extracts caused sig- nificant digging and residing preferences in both intracolonial and intercolonial bioassays but not postpharyngeal and poison gland extracts. By analyzing the data pooled from the same three colonies used for gland extract bioassays, it was found that, in no cases, workers showed significant digging and residing preferences to 2-ethyl-3,6-dimethylpyrazine, an alarm pheromone component from mandibular gland.

Quantitative measures for assessment of the hydraulic excavator digging efficiency

In this paper,quantitative measures for the assessment of the hydraulic excavator digging efficiency are proposed and developed.The following factors are considered:(a) boundary digging forces allowed for by the stability of an excavator,(b) boundary digging forces enabled by the driving mechanisms of the excavator,(c) factors taking into consideration the digging position in the working range of an excavator,and(d) sign and direction of potential digging resistive force.A corrected digging force is defined and a mathematical model of kinematic chain and drive mechanisms of a five-member excavator configuration was developed comprising:an undercarriage,a rotational platform and an attachment with boom,stick,and bucket.On the basis of the mathematical model of the excavator,software was developed for computation and detailed analysis of the digging forces in the entire workspace of the excavator.By using the developed software,the analysis of boundary digging forces is conducted and the corrected digging force is determined for two models of hydraulic excavators of the same mass(around 17 000 kg) with identical kinematic chain parameters but with different parameters of manipulator driving mechanisms.The results of the analysis show that the proposed set of quantitative measures can be used for assessment of the digging efficiency of existing excavator models and to serve as an optimization criterion in the synthesis of manipulator driving mechanisms of new excavator models.

DEM-based parameter optimization and tests of digging green onions

In view of the problems of easy damage and high digging resistance in the process of green onion harvesting,a mechanical model of digging green onions was established by taking the moment of digging and drawing green onions as the research object,and the main factors affecting the digging and harvesting effect were determined as the angle of digging,the dip angle of clamping carrier and the length of shovel.Thus,a complex simulation model of soil-green onion-digging mechanism system reflecting the state of harvesting was established,and the model was verified by testing soil compactness.The simulation tests were carried out by means of the complex simulation model of soil-green onion-digging mechanism system,making it clear that digging angle and the length of shovel have a extremely significant impact on the digging resistance,and the dip angle of the clamping carrier had a significant impact on the digging resistance.Through target optimization,the optimal combination of digging parameters was obtained,namely,the digging angle of 20°,the dip angle of clamping carrier of 25°and the shovel length of 70 mm,with the digging resistance of 1394 N at this moment.The field digging resistance test has showed that the average digging resistance is 1543 N with the average clamping damage rate of 1.27%and the average clamping loss rate of 0.44%,which can meet the requirements of green onion harvesting.

Digging in

The situation on the Korean Peninsula remains tense for now, but reconciliation is possible down the

Digging Up Controversy

A new archaeological discovery about a legendary politician from 1,800 years ago triggers heated debate No other archaeological finding in China has attracted more interest from the public than the discovery of the tomb of Cao Cao (155-220) at the end of 2009. Cao was an important politician at the end of the Eastern Han Dynasty (25-220)

Digging A Hole4

詹姆斯：杰克，你干吗挖洞啊？ 杰克：我的鱼死了。 詹姆斯：这洞是不是太大了？ 杰克：不是，那是因为我的鱼在你的猫的胃里啊。

词汇类型学视域下“爬”“挠”“刨”“挖”等动词的语义演变及共时语义关联

“爬”“挠”“刨”“挖”等汉语动词的历时语义演变路径,以及现代汉语方言中有关的同词化多义现象,表现出{挖掘}(DIG)、{搔挠}(SCRATCH)、{攀爬}(CLIMB)三个概念之间较强的关联性。汉语历时语料呈现的语义演变方向为SCRATCH→DIG或SCRATCH→CLIMB,具有单向性。这种语义关联模式符合一定的语言共性,可以得到词汇类型学跨语言考察的支持,同时,可以根据汉语实际为词汇类型学增补SCRATCH→CLIMB型语义关联。

Distribution Characteristics Comparison of Salix Psammophila Roots under Different Landforms in Mu Us Desert

[Objective] In order to study plant adaptation mechanism under different landforms in drought regions.[Method] Observe soil moisture dynamic of Salix psammophila sample areas on the dune and depression with neutron moisture gauge and research the roots distribution of Salix psammophila sample areas on the dune and depression respectively by digging method.[Result] The quantity of Salix psammophila roots on the dune exponentially decreases while that on the depression decreases by power function in horizontal direction.In vertical direction,Salix psammophila roots on the dune are mainly distributed in 0-30 and 80-120 cm layers as 72% of all,while Salix psammophila roots on the depression are mainly distributed in 0-40 cm layers as 54% of all.[Conclusion] Salix psammophila roots on the dune not only use surface soil water but also use middle-layer groundwater.Salix psammophila roots on the depression primarily use surface soil water.

基于DIG-化学发光法的Southern blot方法优化

目前,基于DIG-化学发光法的Southern blot技术已在生物实验室广泛应用,但在试验过程中经常会遇到背景黑、目的信号弱等问题,以致不能获得理想结果。在棉花线粒体基因组RFLP分析过程中结合前人经验对基于DIG-化学发光法的Southern blot技术在探针标记、探针浓度、探针剥离等方面进行了优化。优化后的方法重复性好,一张转好的尼龙膜最多可以反复使用11次;一份杂交液在两年内至少可以反复使用5次且不会明显降低杂交效果。

核酸探针检测鸡传染性支气管炎病毒方法的建立及应用

以地高辛(DIG)标记鸡传染性支气管炎病毒(IBV)pol基因的保守片段制成核酸探针,与IBV参考株、新城疫病毒、传染性法氏囊病病毒、禽流感病毒、正常鸡胚尿囊液及正常鸡肾组织等的RT-PCR产物进行斑点杂交,以检测探针的特异性,结果该探针仅与IBV毒株的RT-PCR产物杂交呈阳性,与对照病毒和组织的RT-PCR产物杂交呈阴性。敏感性试验显示,探针最低能检出约3.4pg的IBVRT-PCR产物。用该方法检测了38份疑似IBV临床病料,31份阳性;而用RT-PCR法扩增IBVS2基因确诊为阳性的只有29份。对人工接种IBV H52弱毒苗鸡咽喉和肛门拭子32份进行检测,检出15份阳性。结果表明,利用DIG探针检测IBV的RT-PCR产物,特异性和敏感性强,可重复,能克服RT-PCR非特异性反应和探针Northern杂交的不稳定性。

Dig标记探针原位杂交检测MSG-肝再生-大鼠下丘脑弓状核TGF-β_1mRNA

目的 通过建立MSG 肝再生 大鼠模型 ,检测MSG 肝再生 大鼠下丘脑弓状核 (ARN)TGF β1mRNA的表达与神经内分泌免疫网络的关系。方法 用肝大部分切除MSG 大鼠的方法建立MSG 肝再生 大鼠模型 ,原位杂交技术检测MSG 肝再生 大鼠下丘脑弓状核 (ARN)TGF β1mRNA的表达。结果 发现MSG -肝再生 -大鼠ARNTGF - β1mRNA的表达显著上调 ,切除 11天达 2 0 9± 1 6 ,与生理盐水组 (11 1± 1 2 )和MSG -大鼠假手术组 (15 2± 1 1)比较 ,差异显著 (P <0 0 1)。结论 MSG -肝再生 -大鼠神经 -内分泌 -免疫网络功能紊乱与其ARNTGF - β1mRNA表达失调密切相关。

用人肝细胞cDNA文库制备Dig-Fas探针

为探索SLE发生、发展与Fas表达的关系 ,本文采用降落PCR技术、分子克隆技术和Fas特异性引物 ,将从人肝细胞cDNA文库中扩增的FascDNA插入T -easyvector中 ,转染JM10 9,经耐药性和lacZ插入失活筛选 ,快速细胞裂解法、限制性内切酶酶切片段和PCR扩增试验分析鉴定 ,确证获阳性转化子。然后采用地高辛化学连接标记和查见方法 ,标记扩增、分离和纯化的FascDNA ,经斑点免疫实验证实获高滴度Dig

光敏生物素和DIG标记Orf病毒DNA探针的研究

目的 :是用于Orf病毒病的诊断和相应重组菌的检测 ,将HCEDNAHindⅢ A、B片断及重组质粒pGRL - 4A中消化的A片断用光敏生物素和地高辛进行标记 ,对不同病毒分离株DNA进行检测 ,并对不同重组质粒进行了Dot-blotting和Southern -blotting检测。结果 :用光敏生物素标记的探针最低可检出 1 2pg的DNA ,地高辛标记的探针最低可检出 0 1pg的DNA ,且有极强的特异性。

DIG标记罗非鱼DNA指纹图谱研究

运用 Hae / 33.6、Hae / 33.15、Hinf / 33.6、Hinf / 33.154种限制酶 /探针组合对奥利亚罗非鱼、美国尼罗罗非鱼、沙市尼罗罗非鱼三种群体罗非鱼进行非放射性 DNA指纹图谱研究 ,结果表明在三种罗非鱼群体中 4种限制酶 /探针组合都能产生具有种属特异性和个体特异性的 DNA指纹图谱 .Hae / 33.6、Hae / 33.15组合中奥利亚罗非鱼特有的强阳性杂交图带可作为鉴别奥利亚罗非鱼的分子遗传标记 .4种限制酶 /探针组合在奥利亚罗非鱼、沙市尼罗罗非鱼、美国尼罗罗非鱼检出的个体平均图带数分别为 8.72 6、8.0 86和 6 .975.4种限制酶 /探针组合在奥利亚罗非鱼、沙市尼罗罗非鱼、美国尼罗罗非鱼检出的多态性位点比例分别为 6 2 .95%、96 .31%和85.2 6 % .

地高辛配基标记探针在流行性出血热尸检组织中原位分子杂交技术的应用和探讨

将地高辛配基(Dig)标记的探针应用于流行性出血热(EHF)尸检组织的石蜡切片中,进行原位分子杂交四例。方法要点:(1)采用Dig标记的探针及碱性磷酸酶系统、提高其敏感性;(2)为达到被检核酸的暴露彻底、准确,选择合适的消化酶;(3)选择适当的杂交温度和时间,防止了非特异性背景,并避免了组织脱片。结果表明此方法操作简便、安全、快速、敏感。

大鼠脊髓半切损伤后SynDIG1对神经的修复作用

目的探讨Syn DIG1是否在突触重塑过程中对神经具有保护修复作用。方法建立大鼠脊髓半切损伤模型,将其分为治疗组和对照组,治疗组使用微渗透泵鞘内注射Syn DIG1蛋白,对照组注射等量的生理盐水。分别在24 h、7 d、42 d处死,进行HE染色、免疫组织化学染色(AMPAR、Caspase-3、TNF-α)和免疫荧光染色(MOP-FITC、CD45-PE、CD68-PE、GAP-43-PE)。结果 Syn DIG1治疗能够减少囊性空腔的形成,降低神经细胞凋亡相关因子Caspase-3、TNF-α和炎性相关因子MPO、CD45、CD68的表达,表明Syn DIG1能够减少神经元的死亡,减弱组织损伤,减轻机体炎症反应;同时,Syn DIG1能够提高神经修复相关蛋白AMPAR、GAP-43的含量,促进神经系统的修复、突触的形成。每周对大鼠的运动功能评分也显示,自术后2周起Syn DIG1治疗组的运动能力得到显著提高。结论 Syn DIG1蛋白在突触重塑、神经修复中起重要作用。