Drilling-based measuring method for the c-φ parameter of rock and its field application

The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.

Using deep neural networks coupled with principal component analysis for ore production forecasting at open-pit mines

Ore production is usually affected by multiple influencing inputs at open-pit mines.Nevertheless,the complex nonlinear relationships between these inputs and ore production remain unclear.This becomes even more challenging when training data(e.g.truck haulage information and weather conditions)are massive.In machine learning(ML)algorithms,deep neural network(DNN)is a superior method for processing nonlinear and massive data by adjusting the amount of neurons and hidden layers.This study adopted DNN to forecast ore production using truck haulage information and weather conditions at open-pit mines as training data.Before the prediction models were built,principal component analysis(PCA)was employed to reduce the data dimensionality and eliminate the multicollinearity among highly correlated input variables.To verify the superiority of DNN,three ANNs containing only one hidden layer and six traditional ML models were established as benchmark models.The DNN model with multiple hidden layers performed better than the ANN models with a single hidden layer.The DNN model outperformed the extensively applied benchmark models in predicting ore production.This can provide engineers and researchers with an accurate method to forecast ore production,which helps make sound budgetary decisions and mine planning at open-pit mines.

Testing method of rock structural plane using digital drilling

The rock mass consists of rock blocks and structural planes,which can reduce its integrity and strength.Therefore,accurately obtaining the characteristics of the rock mass structural plane is a prerequisite for evaluating stability and designing supports in underground engineering.Currently,there are no effective testing methods for the characteristic parameters of the rock mass structural plane in underground engineering.The paper presents the digital drilling technology as a new testing method of rock mass structural planes.Flawed rock specimens with cracks of varying widths and angles were used to simulate the rock mass structural planes,and the multifunctional rock mass digital drilling test system was employed to carry out the digital drilling tests.The analysis focuses on the variation laws of drilling parameters,such as drilling pressure and drilling torque,affected by the characteristics of prefabricated cracks,and clarifies the degradation mechanism of rock equivalent compressive strength.Additionally,an identification model for the characteristic parameters of rock mass structural planes during drilling is established.The test results indicate that the average difference of the characteristics of prefabricated cracks identified by the equivalent compressive strength is 2.45°and 0.82 mm,respectively.The identification model while drilling is verified to be correct due to the high identification accuracy.Based on this,a method for testing the characteristic parameters of the surrounding rock structural plane while drilling is proposed.The research offers a theoretical and methodological foundation for precise in situ identification of structural planes of the surrounding rock in underground engineering.

Development of multi-functional anchorage support dynamic-static coupling performance test system and its application

In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses and strong disturbances and construction conditions such as the application of high prestress.It is essential to study the support components performance under dynamic-static coupling conditions.Based on this,a multi-functional anchorage support dynamic-static coupling performance test system(MAC system)is developed,which can achieve 7 types of testing functions,including single component performance,anchored net performance,anchored rock performance and so on.The bolt and cable mechanical tests are conducted by MAC system under different prestress levels.The results showed that compared to the non-prestress condition,the impact resistance performance of prestressed bolts(cables)is significantly reduced.In the prestress range of 50–160 k N,the maximum reduction rate of impact energy resisted by different types of bolts is 53.9%–61.5%compared to non-prestress condition.In the prestress range of 150–300 k N,the impact energy resisted by high-strength cable is reduced by76.8%–84.6%compared to non-prestress condition.The MAC system achieves dynamic-static coupling performance test,which provide an effective means for the design of anchorage support system.

Surface doping manipulation of the insulating ground states in Ta_(2)Pd_(3)Te_(5) and Ta_(2)Ni_(3)Te_(5)

Manipulating emergent quantum phenomena is a key issue for understanding the underlying physics and contributing to possible applications.Here we study the evolution of insulating ground states of Ta_(2)Pu_(3)Te_(5) and Ta_(2)Ni_(3)Te_(5) under in-situ surface potassium deposition via angle-resolved photoemission spectroscopy.Our results confirm the excitonic insulator character of Ta_(2)d_(3)Te_(5).Upon surface doping,the size of its global gap decreases obviously.After a deposition time of more than 7 min,the potassium atoms induce a metal-insulator phase transition and make the system recover to a normal state.In contrast,our results show that the isostructural compound Ta_(2)Ni_(3)Te_(5) is a conventional insulator.The size of its global gap decreases upon surface doping,but persists positive throughout the doping process.Our results not only confirm the excitonic origin of the band gap in Ta_(2)Pd_(3)Te_(5),but also offer an effective method for designing functional quantum devices in the future.

Mechanical properties and influence mechanism of confined concrete arches in high-stress tunnels

Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,which makes it difficult to meet the requirements of ground control under complex conditions. As a new support form with high strength and rigidity, the confined concrete arch plays an important role in controlling the rock deformation under complex conditions. The section shape of the tunnel has an important impact on the mechanical properties and design of the support system. However, studies on the mechanical properties and influence mechanism of the new confined concrete arch are rarely reported. To this end, the mechanical properties of traditional U-shaped steel and new confined concrete arches are compared and comparative tests on arches of circular and straight-leg semicircular shapes in deep tunnels are conducted. A large mechanical testing system for underground engineering support structure is developed. The mechanical properties and influence mechanism of confined concrete arches with different section shapes under different loading modes and cross-section parameters are systematically studied. Test results show that the bearing capacity of the confined concrete arch is 2.10 times that of the U-shaped steel arch, and the bearing capacity of the circular confined concrete arch is 2.27 times that of the straight-leg semicircular arch. Among the various influencing factors and their engineering parameters,the lateral stress coefficient has the greatest impact on the bearing capacity of the confined concrete arch,followed by the steel pipe wall thickness, steel strength, and core concrete strength. Subsequently, the economic index of bearing capacity and cost is established, and the optimization design method for the confined concrete arch is proposed. Finally, this design method is applied to a high-stress tunnel under complex conditions, and the deformation of the surrounding rock is effectively controlled.

Plastid phylogenomics and species discrimination in the“Chinese”clade of Roscoea(Zingiberaceae)

Roscoea is an alpine or subalpine genus from the pan-tropical family Zingiberaceae,which consists of two disjunct groups in geography,namely the"Chinese"clade and the"Himalayan"clade.Despite extensive research on the genus,Roscoea species remain poorly defined and relationships between these species are not well resolved.In this study,we used plastid genomes of nine species and one variety to resolve phylogenetic relationships within the"Chinese"clade of Roscoea and as DNA super barcodes for species discrimination.We found that Roscoea plastid genomes ranged in length from 163,063 to 163,796 bp,and encoded 113 genes,including 79 protein-coding genes,30 tRNA genes,four rRNA genes.In addition,expansion and contraction of the IR regions showed obvious infraspecifc conservatism and interspecific differentiation.Plastid phylogenomics revealed that species belonging to the"Chinese"clade of Roscoea can be divided into four distinct subclades.Furthermore,our analysis supported the independence of R.cautleoides var.pubescens,the recovery of Roscoea pubescens Z.Y.Zhu,and a close relationship between R.humeana and R.cautloides.When we used the plastid genome as a super barcode,we found that it possessed strong discriminatory power(90%)with high support values.Intergenic regions provided similar resolution,which was much better than that of protein-coding regions,hypervariable regions,and DNA universal barcodes.However,plastid genomes could not completely resolve Roscoea phylogeny or definitively discriminate species.These limitations are likely related to the complex history of Roscoea speciation,poorly defined species within the genus,and the maternal inheritance of plastid genomes.

Venous thromboembolism prophylaxis of a patient with MYH-9 related disease and COVID-19 infection:A case report

BACKGROUND The May-Hegglin anomaly is among a group of genetic disorders known as MYH9-related disease.Patients with inherited platelet disorders such as May-Hegglin anomaly are at a variably increased risk for bleeding due to a combination of platelet dysfunction and thrombocytopenia.Patients admitted to the hospital with coronavirus disease 2019(COVID-19)infection are at an increased risk for a venous thromboembolism event(VTE).The National Institutes of Health COVID-19 treatment guidelines recommend using a prophylactic dose of heparin as VTE prophylaxis for adults who are receiving high-flow oxygen.We describe a patient admitted for COVID-19 infection with pneumonia and a history of May-Hegglin anomaly.The patient presented a challenge to determine prophylactic anticoagulation as there are no clear guidelines for this patient population.CASE SUMMARY Herein,we describe the case of a 39-year-old woman admitted with acute hypoxic respiratory failure secondary to COVID-19 pneumonia.She had a history of May-Hegglin anomaly and demonstrated risk for bleeding since childhood,including a life-threatening bleeding event at the age of 9 years requiring blood and platelet transfusions.Her baseline platelet count was 40-50×109/L throughout her adult life.Her family history was also notable for May-Hegglin disorder in her mother,maternal uncle,maternal grandfather and her son.Computed tomography/pulmonary angiography revealed bilateral consolidative opacities consistent with multifocal pneumonia.Complete blood count was notable for platelet count of 54×109/L.She was admitted for inpatient respiratory support with high-flow oxygen per nasal cannula and was managed with guideline-directed therapy for COVID-19,including baricitinib and dexamethasone.The Hematology/Oncology consultation team was requested to assist with management of VTE prophylaxis in the setting of active COVID-19 infection and an inherited bleeding disorder.After review of the literature and careful consideration of risks and benefits,it was decided to treat the patient with prophylactic enoxaparin.She was closely monitored in the hospital for bleeding and worsening thrombocytopenia.She had no bleeding or signs of VTE.Her respiratory status improved,and she was discharged home after 5 d of hospitalization with supplemental oxygen by nasal cannula and dexamethasone.At the 6-month follow-up,the patient successfully discontinued her home oxygen use after only a few weeks following discharge.CONCLUSION The patient presented a challenge to determine prophylactic anticoagulation as anticoagulation guidelines exist for patients with COVID-19,but there are no clear guidelines for management of patients with COVID-19 and inherited bleeding disorders,particularly those with MYH9-related disease.She was discharged after recovery from the COVID-19 infection without bleeding or thrombosis.As there are no published guidelines for this situation,we present a pragmatic,informed approach to a patient with MYH9-related disease who had an indication for anticoagulation.

The Spectrum of Kidney Disease in Type Two Diabetic Patients: A Single-Center Study

Background: Diabetic nephropathy (DN) is the dominant reason for end-stage kidney disease linked with a rise in cardiovascular mortality rate. However, besides DN, type 2 diabetic patients may also suffer from various non-diabetic renal diseases (NDRD). Aim: The objective of the current research was to assess the occurrence and type of NDRD diagnosed by kidney biopsy in type 2 diabetic subjects, evaluate the association of various clinical and laboratory characteristics with histopathology findings, and identify essential predictors of NDRD. Methods: Retrospective analysis has been performed through medical record revision of 101 patients with type 2 diabetes undergoing percutaneous renal biopsy at Qilu Hospital of Shandong University (Jinan, China) between January 2015 and December 2020. Results: Renal biopsy results showed that NDRD was found in 59 patients (58.42%), while DN existed in 32 patients (31.68%) and 10 patients (9.90%) showed DN complicated with NDRD. Membranous nephropathy was prevailing NDRD (42%), followed by focal segmental glomerulosclerosis (11.6%) and IgA nephropathy (10.1%). In univariate analysis, patients with NDRD had older age (p Conclusions: Clinical parameters such as short duration of diabetes, older age, higher hemoglobin level, and lower proteinuria might be associated with NDRD in type 2 diabetic patients. An early diagnosis of NDRD poses a favorable renal prognosis because it requires a different approach than DN, further larger multicenter randomized prospective investigations focused on identifying possible risk markers of NDRD are still in priority.

石墨烯晶圆的制备:从高品质到规模化

石墨烯晶圆是引领未来的战略材料,在集成电路、微机电系统和传感器等领域具有广阔的应用前景。实现石墨烯晶圆广泛应用的前提是高品质材料的规模化制备。可控性高、工艺兼容性强、成本低的化学气相沉积(chemical vapor deposition,CVD)法,是高品质石墨烯晶圆规模化制备的首选方法。本文将综述石墨烯晶圆的CVD制备进展:首先探讨石墨烯晶圆的制备需求,从实用牵引和应用场景出发,提出石墨烯晶圆的制备品质等级;随后重点介绍石墨烯的晶圆级制备方法和石墨烯晶圆材料的规模化制备技术;最后,对石墨烯晶圆可行的制备路线进行总结,并展望未来可能的发展方向。

Comparative study of model tests on automatically formed roadway and gob-side entry driving in deep coal mines

Automatically formed roadway(AFR)by roof cutting with bolt grouting(RCBG)is a new deep coal mining technology.By using this technology,the broken roadway roof is strengthened,and roof cutting is applied to cut off stress transfer between the roadway and gob to ensure the collapse of the overlying strata.The roadway is automatically formed owing to the broken expansion characteristics of the collapsed strata and mining pressure.Taking the Suncun Coal Mine as the engineering background,the control effect of this new technology on roadways was studied.To compare the law of stress evolution and the surrounding rock control mechanisms between AFR and traditional gob-side entry driving,a comparative study of geomechanical model tests on the above methods was carried out.The results showed that the new technology of AFR by RCBG effectively reduced the stress concentration of the roadway compared with gob-side entry driving.The side abutment pressure peak of the solid coal side was reduced by 24.3%,which showed an obvious pressure-releasing effect.Moreover,the position of the side abutment pressure peak was far from the solid coal side,making it more beneficial for roadway stability.The deformation of AFR surrounding rock was also smaller than the deformation of the gob-side entry driving by the overload test.The former was more beneficial for roadway stability than the latter under higher stress conditions.Field application tests showed that the new technology can effectively control roadway deformation.Moreover,the technology reduced roadway excavation and avoided resource waste caused by reserved coal pillars.

Dynamic mechanical characteristics and application of constant resistance energy-absorbing supporting material

In deep underground engineering,rock burst and other dynamic disasters are prone to occur due to stress concentration and energy accumulation in surrounding rock.The control of dynamic disasters requires bolts and cables with high strength,high elongation,and high energy-absorbing capacity.Therefore,a constant resistance energy-absorbing(CREA)material is developed.In this study,the dynamic characteristics of the new material are obtained via the drop hammer tests and the Split Hopkinson Pressure Bar(SHPB)tests of the new material and two common bolt(CB)materials widely used in the field.The test results of drop hammer test and SHPB test show that the percentage elongation of CREA material is more than 2.64 and 3.22 times those of the CB material,and the total impact energy acting on CREA material is more than 18.50 and 21.84 times,respectively,indicating that the new material has high elongation and high energy-absorbing capacity.Subsequently,the CREA bolts and cables using the new material are developed,which are applied in roadways with high stress and strong dynamic disturbance.The field monitoring results show that CREA bolts and cables can effectively control the surrounding rock deformation and ensure engineering safety.

Relationship between rock uniaxial compressive strength and digital core drilling parameters and its forecast method

The rock uniaxial compressive strength(UCS)is the basic parameter for support designs in underground engineering.In particular,the rock UCS should be obtained rapidly for underground engineering with complex geological conditions,such as soft rock,fracture areas,and high stress,to adjust the excavation and support plan and ensure construction safety.To solve the problem of obtaining real-time rock UCS at engineering sites,a rock UCS forecast idea is proposed using digital core drilling.The digital core drilling tests and uniaxial compression tests are performed based on the developed rock mass digital drilling system.The results indicate that the drilling parameters are highly responsive to the rock UCS.Based on the cutting and fracture characteristics of the rock digital core drilling,the mechanical analysis of rock cutting provides the digital core drilling strength,and a quantitative relationship model(CDP-UCS model)for the digital core drilling parameters and rock UCS is established.Thus,the digital core drilling-based rock UCS forecast method is proposed to provide a theoretical basis for continuous and quick testing of the surrounding rock UCS.

Comparative study on bearing mechanism and design parameters of confined concrete arch joints in deep soft rock roadway

Square confined concrete arch is increasingly used in deep soft rock roadway support because of its advantages of high strength and construction convenience.However,the design of confined concrete arch in underground engineering still remains in experience-based method and lacks quantitative analysis.As a connecting component between arch sections,the connection joints have an important influence on the internal force distribution and failure mechanism of support arch.Therefore,a reasonable design of arch joints is the premise of rational support design.Taking Liangjia Coal Mine,a typical deep soft rock mine in China,as research background,this paper fully compared the most widely used joint types of confined concrete arch as analytical objects:flange joints and casing joints.The main failure modes of these two kinds of joints under bending moment are defined.Laboratory and numerical tests are carried out to study the mechanical characteristics of joints.Based on the M-θ curve,the influence law of different design parameters is analyzed,and the design principles of joints are proposed.The research results could provide a theoretical basis for the design and application of confined concrete arch in related projects.

Two New Iridoid Glucosides from Clerodendrum serratum

Two new iridoid glucosides, serratoside A and serratoside B, were isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Their structures were elucidated by spectral and chemical methods.

A New Phenolic Compound from Thamnolia vermicularis

A new phenolic compound, thamnolin (1), was isolated from the extract of Thamnolia vermicularis. Its structure was determined as 6-tricosyl-2,4-dimethoxy-phenol by spectral methods.

A New Antimalarial Noreudesmane Sesquiterpenoid from Dobinea delavayi

One previously undescribed angeloylated noreudesmane sesquiterpenoid,dobinin O(1),along with four known eudesmane sesquiterpenoids(2-5)were isolated from the peeled roots of Dobinea delavayi.Their structures were elucidated by extensive spectroscopic data analyses.In addition,compound 1 exhibited moderate antimalarial activity against Plasmodium yoelii BY265RFP with the inhibition ratio of 17.8±13.3%at the dose of 30 mg/kg/day.

应用网络药理学预测白芍抗血吸虫病及肝纤维化的作用机制

运用网络药理学方法预测白芍抗血吸虫病及肝纤维化的作用机制。通过TCMSP数据库对白芍主要活性成分及靶点进行筛选,通过GeneCards数据库检索血吸虫病及肝纤维化相关靶点,利用Cytoscape 3.8.2软件构建药物-成分-靶点-疾病网络图,利用STRING数据库构建蛋白质相互作用网络,采用R语言对药物-疾病共同靶点进行GO和KEGG富集分析。筛选得到白芍中的活性成分有13个,白芍抗血吸虫病及肝纤维化的靶点有16个,PPI网络包含15个蛋白质,涉及JUN、PTGS2和CAT等。白芍抗血吸虫病及肝纤维化的通路主要有脂质和动脉粥样硬化,糖尿病并发症中的AGE-RAGE信号通路,肿瘤坏死因子信号通路和NF-kappa B信号通路等。初步预测白芍抗血吸虫病及肝纤维化的作用机制,为其深入研究提供新思路及理论依据。

Two New ent-Kaurane Diterpenoids from Isodon xerophilus

Two new ent-kaurane diterpenoids, xerophilusin E (1) and xerophilusin F (2), were isolated from the leaves of Isodon xerophilus. Their structures were determined as 3, 20: 7, 20-diepoxy-ent-kaur-16-en-15-one and 7 beta, 14 beta, 20 (R)-trihydroxy-11 beta-acetoxy-7,20-cyclo-ent-kaur-16-en-6, 15-dione, respectively, by spectral methods and X-ray crystallographic analysis.

Two New C_(29) Sterols from Clerodendrum colebrookianum

From the aerial parts of Clerodendrum colebrookianum Walp., two new C_29 sterols colebrin A and colebrin B, were isolated, along with a known compound, clerosterol. The structures of the new compounds were elucidated on the basis of spectral evidence.