Experimental study on the flow behaviour of water-sand mixtures in fractured rock specimens

The study of flow behaviour of water-sand mixtures in fractured rocks is of great necessity to understand the producing mechanism and prevention of water inrush and sand gushing accidents.A self-developed seepage test system is used in this paper to conduct laboratory experiments in order to study the influence of the particle size distribution,the void ratio,and the initial mass of Aeolian sand on the flow behavior.It is concluded that the water flow velocity is insensitive to the initial mass of the Aeolian sand but increases with the power exponent in the Talbot formula and the specimen height.The outflow of the Aeolian sand increases with the power exponent in the Talbot formula,the specimen height,and the initial mass of the Aeolian sand.Besides,the outflow of the Aeolian sand changes exponentially with the water flow velocity.Finally,it is found that the fractured specimen has a maximum sand filtration capacity beyond which the outflow of the Aeolian sand significantly increases with the initial mass of the Aeolian sand.

Using p53-immunostained large specimens to determine the distal intramural spread margin of rectal cancer

AIM： To determine the distal intramural spread （DIS） margin of rectal cancer.METHODS： Sixty-one p53-positive specimens of rectal cancer were used. After conventional hematoxylin and eosin （H＆E） staining, the DIS margin of rectal cancer in large specimens was examined by immunohistochemistry. The patients were divided into A, B, C, and D groups. After a long-term follow-up, the survival curves of the four groups were estimated using the life table. RESULTS： Fifty-one of the sixty-one cases （83.6%） had DIS. The extent of DIS ranged 0.11-3.5 cm; meanwhile the.mean of DIS measured by H＆E staining was 0.13 cm. The significant difference was found between the means （t=5.622, P〈0.0001）. Only 1 of 51 patients had DIS greater than 3 cm. The DIS was less than 1.0 cm in most rectal cancer patients. The long-term results indicated that the survival rate of the patients whose DIS was greater than 1.0 cm was lower than that of the patients whose DIS was less than 0.5 cm. CONCLUSION： Rectal cancer patients with DIS greater than 1.0 cm have poor prognosis.

Development of a reverse-transcription loop-mediated isothermal amplification assay to detect avian influenza viruses in clinical specimens

In recent years,the avian influenza has brought not only serious economic loss to the poultry industry in China but also a serious threat to human health because of the avian influenza virus(AIV) gene recombination and reassortment.Until now,traditional RT-PCR,fluorescence RT-PCR and virus isolation identification have been developed and utilized to detect AIV,but these methods require high-level instruments and experimental conditions,not suitable for the rapid detection in field and farms.In order to develop a rapid,sensitive and practical method to detect and identify AIV subtypes,4 specific primers to the conserved region of AIV M gene were designed and a loop-mediated isothermal amplification(RT-LAMP) method was established.Using this method,the M gene of H1–H16 subtypes of AIV were amplified in 30 min with a water bath and all 16 H subtypes of AIV were able to be visually identified in presence of fluorescein,without cross reaction with other susceptible avian viruses.In addition,the detection limit of the common H1,H5,H7,and H9 AIV subtypes with the RT-LAMP method was 0.1 PFU(plaque-forming unit),which was 10 times more sensitive than that using the routine RT-PCR.Further comparative tests found that the positivity rate of RT-LAMP on detecting clinical samples was 4.18%(14/335) comparing with 3.58%(12/335) from real-time RT-PCR.All these results suggested that the RT-LAMP method can specifically detect and identify AIV with high sensitivity and can be considered as a fast,convenient and practical method for the clinic test and epidemiological investigation of AIV.

Dynamic characteristics of coal specimens with varying static preloading levels under low-frequency disturbance load

The mechanical properties of residual coal pillars under the influence of upward mining disturbances significantly affect the safety of residual mining activities on working faces.This study conducted low-frequency disturbance dynamic uniaxial compression tests on coal specimens using a self-developed dynamic-static load coupling electro-hydraulic servo system,and studied the strength evolutions,surface deformations,acoustic emission(AE)characteristic parameters,and the failure modes of coal specimens with different static preloading levels were studied.The disturbance damage is positively correlated with the coal specimen static preload level.Specifically,the cumulative AE count rates of the initial accelerated damage stage for the coal specimens with static preloading level of 60%and 70%of the uniaxial compressive strength(UCS)were 2.66 and 3.19 times that of the 50%UCS specimens,respectively.Macroscopically,this behaviour manifested as a decrease in the compressive strength,and the mean strengths of the disturbance-damaged coal specimens with 60%and 70%of UCS static preloading decreased by 8.53%and 9.32%,respectively,compared to those of the specimens under pure static loading.The crack sources,such as the primary fissures,strongly control the dynamic response of the coal specimen.The difference between the dynamic responses of the coal specimens and that of dense rocks is significant.

Catalog of insect type specimens preserved at the Kunming Institute of Zoology,Chinese Academy of Science with corrections of some specimens

This article presents a list of insect types preserved in Kunming Natural History Museum of Zoology （KNHMZ）. As of March, 2015, 3412 type specimens belonging to 266 species/subspecies of 37 families in 9 orders （Odonata, Isoptera, Mantodea, Orthoptera, Hemiptera, Coleoptera, Diptera, Hymenoptera and Lepidoptera） are included. Information corrections of some specimens are provided in this article.

Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China

Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.

A CATASTROPHE ANALYSIS ON THE STABILITY OF THE CRACK GROWTH IN THREE-POINT BENDING SPECIMENS

This paper presents an attempt at the application of catastrophe theory to the stability analysis of J-controlled crack growth in three-point bending specimens. By introducing the solutions of J-integral in the completely yielding state for the ideal plastic material, the critical condition of losing stability for the crack propagation in the specimen is obtained, based on the cusp catastrophe theory. The process of the crack growth from geometrical sense is described.

Catalogue of the Type Specimens of Amphibians and Reptiles in the Herpetological Museum of Chengdu Institute of Biology, Chinese Academy of Sciences: I. Rhacophoridae(Anura, Amphibia)

In order to facilitate herpetological research for all the herpetologists both in and outside of China, we will report all the type specimens of amphibia and reptilia deposited in the Herpetological Museum of Chengdu Institute of Biology(CIB), Chinese Academy of Sciences in series. This report focuses on the family Rhacophoridae of Anura in Amphibia, including 13 species. The contents of the report include synonym lists and generic transfer of type species, measurements of type specimens, particularly for those with no previously published measurement data, and chromosomal data for each species.

Catalogue of the Type Specimens of Amphibians and Reptiles in the Herpetological Museum of the Chengdu Institute of Biology,Chinese Academy of Sciences:Ⅱ.Hynobiidae (Amphibia,Urodela)

In order to facilitate herpetological research for herpetologists in and outside of China,we will report all the type specimens of Amphibia and Reptilia deposited in the Herpetological Museum of the Chengdu Institute of Biology(CIB),Chinese Academy of Sciences(CAS) in series. This report focuses on the type specimens of the family Hynobiidae of Urodela in Amphibia,which comprises seven species. Each entry provides the genus name,species name,information of the original description,the catalog number of holotype,sex,type locality,information of allotype(if any) and paratype,number and distribution of deposited specimens,and comments where they are appropriate.

Catalogue of the Type Specimens of Amphibians and Reptiles in the Herpetological Museum of the Chengdu Institute of Biology,Chinese Academy of Sciences:Ⅲ.Snakes Excluding Viperids (Reptilia,Serpentes)

In China,there are over 180 species of snakes in 57 genera and eight families(excluding the family Viperidae). In the Herpetological Museum of the Chengdu Institute of Biology(CIB),Chinese Academy of Sciences,the snake type specimens represent 11 species in 10 genera and three families(Xenopeltidae,Xenodermatidae and Colubridae). As a series of reports on the type specimens of Amphibia and Reptilia deposited in the Herpetological Museum of CIB,this paper focuses on the serpent families excluding Viperidae in the collections at this Museum.

Teflon-pad shaping process of circular metal blanks into quasi-cup specimens by theoretical and experimental methods

Teflon-pad shaping process of circular metal blanks into quasi-cup specimens is investigated by theoretical and experimental methods in the quasi-static condition. In the experiments, circular metal sheets are formed into the quasi-cup samples by compressing them between a Teflon-filled die and a rigid punch with desirable shape. To investigate influences of different parameters on the forming progress, 12 rigid punches with different dimensions, two blank material types of aluminum and galvanized iron, three blank thicknesses of 0.6, 1.1 and 1.5 mm, and two Teflon-fillers of PVC and polyurethane are used in several experimental tests. In the analytical part, theoretical deformation models of metal blank and Teflon-filler are introduced and based on energy method, energy absorptions by the blank and Teflon-filler are calculated to derive a theoretical formula for predicting total required energy of the forming process. For this purpose, several energy absorption mechanisms are considered in the blank and filler. Furthermore, predictions by theoretical equation are compared with the corresponding experimental tests to study the verity of the calculated formulas. Theoretical and experimental results illustrate change trend of forming energy with respect to blank thickness. Also, the performed forming tests show that when external cone angle of rigid punch with respect to the horizontal direction increases, forming energy increases nonlinearly; and when the depth of spherical part of rigid punch increases, the probability of rupture increases. Additionally, the experiments demonstrate that there is a direct relationship between the forming energy and flow stress of the blanks. Furthermore, experimental observations illustrate that forming energy of a certain blank with PVC Teflon-filler is higher than that of a similar specimen with polyurethane Teflon-filler; but, the probability of wrinkling decreases when PVC Teflon-pad is used as the filler; and it is advantage of PVC Teflon-filler with respect to polyurethane Teflon.

THE ANALYSES OF THE THREE-DIMENSIONAL STRESS STRUCTURE NEAR THE CRACK TIP OF MODE I CT SPECIMENS IN ELASTICPLASTIC STATE(Ⅰ)--THE ANALYSES OF CONSTRAINT PARAMETERS AND FRACTURE PARAMETERS

In the present paper,three dimensional analyses of some general constraint parameters and fracture parameters near the crack tip of Mode I CT specimens in two different thicknesses are carried out by employing ADINA program.The results reveal that the constraints along the thickness direction are obviously separated into two parts:the keeping similar high constraint field(Z_(1))and rapid reducing constraints one(Z_(2)).The two fields are experimentally confiremed to correspond to the smooth region and the shear lip on the fracture face respectively.So the three dimensional stress structure of Mode I specimens can be derived through discussing the two fields respectively.The distribution of the Crack Tip Opening Displacement(CTOD)along the thickness direction and the three dimensional distribution of the void growth ratio(V_(g))near the crack tip are also obtained.The two fracture parameters are in similar trends along the thickness direction,and both of them can reflect the effect of thickness and that of the loading level to a certain degree.

Catalogue of the Type Specimens of Amphibians and Reptiles in the Herpetological Museum of the Chengdu Institute of Biology, Chinese Academy of Sciences: Ⅳ. Lizards(Reptilia, Sauria)

In the present study, we report the six type specimens and two paratypes of eight lizard species in the Herpetological Museum of the Chengdu Institute of Biology（CIB）, Chinese Academy of Sciences（CAS）. Each entry provides the information of the original description, the catalog number of the holotype, sex, type locality, and information of allotype and paratype（if any）, number and distribution of deposited specimens, and comments. Additionally, two invalid species and one invalid subspecies are discussed.

Catalogue of the Type Specimens of Amphibians and Reptiles in the Herpetological Museum of the Chengdu Institute of Biology,Chinese Academy of Sciences:V.Viperidae(Reptilia,Serpentes)

In China, there are about 37 species of vipers belonging to 12 genera in the family Viperidae. In the Herpetological Museum of the Chengdu Institute of Biology（CIB）, Chinese Academy of Sciences, the type specimens of snakes represent seven species in four genera. As a series of reports on the type specimens of Amphibians and Reptilies deposited in the Herpetological Museum of CIB, this paper focuses on the venomous snake family Viperidae in the collections at this Museum.

Energy-dispersive X-ray Spectroscopy for the Quantitative Analysis of Pyrite Thin Specimens

To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.

Characterizations and Analysis of the Mold from Animal Specimens in Shenzhen Museum

Biological specimens play an important role in cultural exchange, science popularization, scientific research and economic window, but the preparation and preservation technology system of biological specimens is relatively unsafe and inefficient. Mold grows seriously on animal specimens, which is not only harmful to human beings’ health and environment, but also is one of the factors that restricts the development of the natural history museums where these specimens are kept. This paper identified the mold species of animal specimens by PCR with ITS primers, bio-micro-scopic observation, sequencing and phylogenetic tree analysis. The results showed the mold of animal specimens mainly belonged to Aspergillus and Neurospora. This study established the foundations of controlling and restoring the mold that infected animal specimens and guided a new methodology of preparation and environmental friendly exhibition for animal specimens.

Buildings and civil engineering works-Sealants-Determination of changes in cohesion and appearance of elastic weatherproofing sealants after exposure of statically cured specimens to artificial weathering and mechanical cycling

Foreword ISO(the International Organization for Standardization)is a worldwide federation of national standards bodies(ISO member bodies).The work of preparing International Standards is normally carried out through ISO technical committees.Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee.

The Role of Anatomical Specimens in the Teaching of Anatomy

characteristics,complex content,and it is difficult to understand.In view of the nature of the subject,many different models and specimens are required during teaching,increasing the difficulty of its teaching.Although the mode of medical teaching is constantly updating,anatomical specimens are still important in the teaching of anatomy,as they help students to understand the organs,their positions,and structural forms as well as to better grasp the theoretical aspect.In addition,anatomical specimens and medical students contact condition can affect the teaching effect.Therefore,it is imperative to give full play to the role of anatomical specimens in anatomy teaching to improve the teaching effect.This paper summarizes the research on the use of anatomical specimens in the teaching of anatomy.

Complete laparoscopic resection of the rectum using natural orifice specimen extraction

AIM: To investigate how complete laparoscopic anterior resection with natural orifice specimen extraction (NOSE), as a novel minimally invasive surgery, compares to conventional laparoscopic surgery.

Stability of SARS Coronavirus in Human Specimens and Environment and Its Sensitivity to Heating and UV Irradiation

Objective The causal agent for SARS is considered as a novel coronavirus that has never been described both in human and animals previously. The stability of SARS coronavirus in human specimens and in environments was studied. Methods Using a SARS coronavirus strain CoV-P9, which was isolated from pharyngeal swab of a probable SARS case in Beijing, its stability in mimic human specimens and in mimic environment including surfaces of commonly used materials or in household conditions, as well as its resistances to temperature and UV irradiation were analyzed. A total of 106 TCID50 viruses were placed in each tested condition, and changes of the viral infectivity in samples after treatments were measured by evaluating cytopathic effect (CPE) in cell line Vero-E6 at 48 h after infectionn. Results The results showed that SARS coronavirus in the testing condition could survive in serum, 1:20 diluted sputum and feces for at least 96 h, whereas it could remain alive in urine for at least 72 h with a low level of infectivity. The survival abilities on the surfaces of eight different materials and in water were quite comparable, revealing reduction of infectivity after 72 to 96 h exposure. Viruses stayed stable at 4℃, at room temperature (20℃) and at 37℃ for at least 2 h without remarkable change in the infectious ability in cells, but were converted to be non-infectious after 90-, 60- and 30-min exposure at 56℃, at 67℃ and at 75℃, respectively. Irradiation of UV for 60 min on the virus in culture medium resulted in the destruction of viral infectivity at an undetectable level. Conclusion The survival ability of SARS coronavirus in human specimens and in environments seems to be relatively strong. Heating and UV irradiation can efficiently eliminate the viral infectivity.