Experimental study on failure characteristics of single-sided unloading rock under different intermediate principal stress conditions

Investigation of unloading rock failure under differentσ_(2)facilitates the control mechanism of excavation surrounding rock.This study focused on single-sided unloading tests of granite specimens under true triaxial conditions.The strength and failure characteristics were studied with micro-camera and acoustic emission(AE)monitoring.Furthermore,the choice of test path and the effect ofσ_(2)on fracture of unloading rock were discussed.Results show that the increasedσ_(2)can strengthen the stability of single-sided unloading rock.After unloading,the rock’s free surface underwent five phases,namely,inoculation,particle ejection,buckling rupture,stable failure,and unstable rockburst phases.Moreover,atσ_(2)≤30 MPa,the b value shows the following variation tendency:rising,dropping,significant fluctuation,and dropping,with dispersed damages signal.Atσ_(2)≥40 MPa,the tendency shows:a rise,a decrease,a slight fluctuation,and final drop,with concentrated damages signal.After unloading,AE energy is mainly concentrated in the micro-energy range.With the increasedσ_(2),the micro-energy ratio rises.In contrast,low,medium and large energy ratios drop gradually.The increased tensile fractures and decreased shear fractures indicate that the failure mode of the unloading rock gradually changes from tensile-shear mode to tensile-split one.The fractional dimension of the rock fragments first increases and then decreases with an inflection point at 20 MPa.The distribution of SIF on the planes changes asσ_(2)increases,resulting in strengthening and then weakening of the rock bearing capacity.

Metastatic colon cancer treated using traditional Chinese medicine combined with chemotherapy:A case report

BACKGROUND Colon cancer(CC)is one of the leading causes of cancer-related morbidity and mortality worldwide.Traditional Chinese medicine(TCM)is widely used in the treatment of various chronic diseases.CC easily metastasizes and results in high morbidity and mortality rates.CASE SUMMARY A 71-year-old man with a 12-year history of old myocardial infarction and a 7-year history of type 2 diabetes mellitus was diagnosed with CC and underwent right hemicolectomy 1 year ago.Tumor biopsy revealed moderately poorly differentiated adenocarcinoma.Subsequently,chemotherapy with oxaliplatin and paclitaxel was administered.Anastomosis recurrence and pelvic metastasis were noted 37 d later.The patient received eight 21-d cycles of adjuvant chemotherapy with oxaliplatin and capecitabine after recurrence.However,the tumor persisted,and chemotherapy-related liver damage developed gradually.Thus,he was advised to take TCM for the recurrence and pelvic metastasis.The patient’s metastatic CC was cured after receiving TCM combined with long-term chemotherapy.CONCLUSION TCM may be an effective adjunct therapy in the treatment of patients with metastatic CC.

人卵巢癌顺铂耐药细胞裸鼠腹腔转移模型的建立(英文)

目的 探讨建立人卵巢癌顺铂耐药细胞裸鼠腹腔转移模型的方法。方法 人卵巢癌细胞株 3AO和顺铂耐药细胞株 3AO/cDDP细胞体外培养。 4× 10 6个 3AO、3AO/cDDP分别接种于裸鼠腹腔 96h后 ,各随机分为 2组 ,分别腹腔内注射生理盐水和顺铂 (cDDP) ,观察各组裸鼠的致瘤率、生存期和生存延长率。采用流式细胞技术观察转移瘤LRP、MRP基因的表达情况。转移瘤瘤体行病理学检查。结果 3AO、3AO/cDDP细胞的裸鼠致瘤率差异无显著性 ,P >0 .0 5 ;cDDP能提高 3AO荷瘤鼠的生存期及生存延长率 ,与 3AO/cDDP荷鼠相比 ,差异有显著性 ,P <0 .0 5 ;3AO/cDDP转移瘤的LRP、MRP基因的表达水平显著高于 3AO转移瘤 ,P <0 .0 5 ;病理学检查提示裸鼠腹腔转移瘤细胞具人恶性特征。结论 该方法建立裸鼠卵巢癌腹腔转移模型具有成瘤率高的特点 ,并能保持顺铂耐药特征。

Improvement of thermal performance of envelopes for traditional wooden vernacular dwellings of Tujia Minority in Western Hunan,China

Thermal performance of envelopes and indoor thermal environment were technologically improved for traditional wooden vernacular dwellings of Tujia Minority in Western Hunan, China, on the premise of protecting their conventional styles. Thermal insulation boards and wooden boards were added to the interior side of external walls of vernacular dwellings to form two layers of air cavities, so as to gain excellent thermal performance. The indoor temperature of such dwellings after reconstruction was apparently improved compared with the data before reconstruction both in winter and summer, which verified the feasibility and the effectiveness of the reconstruction technologies proposed.

Full robot-assisted gastrectomy with intracorporeal robot-sewn anastomosis produces satisfying outcomes

AIM:To evaluate the feasibility and safety of full robotassisted gastrectomy with intracorporeal robot handsewn anastomosis in the treatment of gastric cancer.METHODS:From September 2011 to March 2013,110consecutive patients with gastric cancer at the authors’institution were enrolled for robotic gastrectomies.According to tumor location,total gastrectomy,distal or proximal subtotal gastrectomy with D2 lymphadenectomy was fully performed by the da Vinci Robotic Surgical System.All construction,including Roux-en-Y jejunal limb,esophagojejunal,gastroduodenal and gastrojejunal anastomoses were fully carried out by the intracorporeal robot-sewn method.At the end of surgery,the specimen was removed through a 3-4 cm incision at the umbilicus trocar point.The details of the surgical technique are well illustrated.The benefits in terms of surgical and oncologic outcomes are well documented,as well as the failure rate and postoperative complications.RESULTS:From a total of 110 enrolled patients,radical gastrectomy could not be performed in 2 patients due to late stage disease;1 patient was converted to laparotomy because of uncontrollable hemorrhage,and1 obese patient was converted due to difficult exposure;2 patients underwent extra-corporeal anastomosis by minilaparotomy to ensure adequate tumor margin.Robot-sewn anastomoses were successfully performed for 12 proximal,38 distal and 54 total gastrectomies.The average surgical time was 272.52±53.91 min and the average amount of bleeding was 80.78±32.37 mL.The average number of harvested lymph nodes was 23.1±5.3.All specimens showed adequate surgical margin.With regard to tumor staging,26,32 and 46 patients were staged asⅠ,ⅡandⅢ,respectively.The average hospitalization time after surgery was 6.2 d.One patient experienced a duodenal stump anastomotic leak,which was mild and treated conservatively.One patient was readmitted for intra-abdominal infection and was treated conservatively.Jejunal afferent loop obstruction occurred in 1 patient,who underwent re-operation and recovered quickly.CONCLUSION:This technique is feasible and can produce satisfying postoperative outcomes.It is also convenience and reliable for anastomoses in gastrectomy.Full robotic hand-sewn anastomosis may be a minimally invasive technique for gastrectomy surgery.

Population parameters and dynamic pool models of commercial fishes in the Beibu Gulf, northern South China Sea

Length-frequency data of eight commercial fish species in the Beibu Gulf (Golf of Tonkin), northern South China Sea, were collected during 2006-2007. Length-weight relationships and growth and mortality parameters were analyzed using FiSAT II software. Five species had isometric growth, two species had negative allometric growth, and one species had positive allometric growth. Overall, the exploitation rates of the eight species were lower in 2006-2007 than in 1997-1999: for four species (Saurida tumbil, Saurida undosquamis, Argyrosomus macrocephalus, and Nemipterus virgatus) it was lower in 2006-2007 than in 1997-1999, for two species (Parargyrops edita and Trichiurus haumela) it remained the same, and for the other two species (Trachurus japonicus and Decapterus maruadsi) it was higher in 2006-2007 than in 1997-1999. The exploitation rates might have declined because of the decline in fishing intensity caused by high crude oil prices. The optimum exploitation rate, estimated using Beverton-Holt dynamic pool models, indicated that although fishes in the Beibu Gulf could sustain high exploitation rates, the under-size fishes at first capture resulted in low yields. To increase the yield per recruitment, it is more effective to increase the size at first capture than to control fishing effort.

Long-term settlement prediction of high-speed railway bridge pile foundation

The process and characteristics of loading on high-speed railway bridge pile foundation were firstly obtained by means of field research and analysis,and the corresponding loading function was presented.One-dimensional consolidation equation of elastic multilayered soils was then established with single drainage or double drainages under multilevel loading.Moreover,the formulas for calculating effective stress and settlement were derived from the Laplace numerical inversion transform.The three-dimensional composite analysis method of bridge pile group was improved,where the actual load conditions of pile foundation could be simulated,and the consolidation characteristics of soil layers beneath pile were also taken into account.Eventually,a corresponding program named LTPGS was developed to improve the calculation efficiency.The comparison between long-term settlement obtained from the proposed method and the in-situ measurements of pile foundation was illustrated,and a close agreement is obtained.The error between computed and measured results is less than 1 mm,and it gradually reduces with time.It is shown that the proposed method can effectively simulate the long-term settlement of pile foundation and program LTPGS can provide a reliable estimation.

Key technologies and engineering practices for soft-rock protective seam mining

Severe gas disasters in deep mining areas are increasing,and traditional protective coal seam mining is facing significant challenges.This paper proposes an innovative technology using soft rock as the protective seam in the absence of an appropriate coal seam.Based on the geological engineering conditions of the new horizontal first mining area of Luling Coal Mine in Huaibei,China,the impacts of different mining parameters of the soft-rock protective seam on the pressure-relief effect of the protected coal seam were analyzed through numerical simulation.The unit stress of the protected coal seam,which was less than half of the primary rock stress,was used as the mining stress pressure-relief index.The optimized interlayer space was found to be 59 m for the first soft-rock working face,with a 2 m mining thickness and 105 m face length.The physicochemical characteristics of the orebody were analyzed,and a device selection framework for the soft-rock protective seam was developed.Optimal equipment for the working face was selected,including the fully-mechanized hydraulic support and coal cutter.A production technology that combined fully-mechanized and blasting-assisted soft-rock mining was developed.Engineering practices demonstrated that normal circulation operation can be achieved on the working face of the soft-rock protective seam,with an average advancement rate of 1.64 m/d.The maximum residual gas pressure and content,which were measured at the cut hole position of the protected coal seams(Nos.8 and 9),decreased to 0.35 MPa and 4.87 m^3/t,respectively.The results suggested that soft-rock protective seam mining can produce a significant gas-control effect.

Spatial-temporal Evolution Characteristics and Decoupling Analysis of Influencing Factors of China’s Aviation Carbon Emissions

The aviation industry has become one of the top ten greenhouse gas emission industries in the world. China’s aviation carbon emissions continue to increase, but the analysis of its influencing factors at the provincial level is still incomplete. This paper firstly uses Stochastic Impacts by Regression on Population, Affluence and Technology model(STIRPAT) model to analyze the time series evolution of China’s aviation carbon emissions from 2000 to 2019. Secondly, it uses the Logarithmic Mean Divisia Index(LDMI) model to analyze the influencing characteristics and degree of four factors on China’s aviation carbon emissions, which are air transportation revenue, aviation route structure, air transportation intensity and aviation energy intensity. Thirdly, it determines the various factors’ influencing direction and evolution trend of 31 provinces’ aviation carbon emissions in China(not including Hong Kong, Macao, Taiwan of China due to incomplete data). Finally, it derives the decoupling effort model and analyzes the decoupling relationship and decoupling effort degree between air carbon emissions and air transportation revenue in different provinces. The study found that from 2000 to2019, China’s total aviation carbon emissions continued to grow, while the growth rate of aviation carbon emissions showed a fluctuating downward trend. Air transportation revenue and aviation route structure promote the growth of total aviation carbon emissions, and air transportation intensity and aviation energy intensity have a restraining effect on the growth of total aviation carbon emissions. The scope of negative driving effect of air transportation revenue and air transportation intensity on total aviation carbon emissions in various provinces has increased. While the scope of positive driving influence of aviation route structure on total aviation carbon emissions of various provinces has increased, aviation energy intensity mainly has negative driving influence on total aviation carbon emissions of each province. Overall, the emission reduction trend in the areas to the west and north of the Qinling-Huaihe River Line is obvious. The decoupling mode between air carbon emissions and air transportation revenue in 31 provinces is mainly expansion negative decoupling.The air transportation intensity effect shows strong decoupling efforts in most provinces, the decoupling effort of aviation route structure effect and aviation energy intensity effect is not prominent.

Community structure and carbon and nitrogen storage of sagebrush desert under grazing exclusion in Northwest China

Overgrazing is regarded as one of the key factors of vegetation and soil degradation in the arid and semi-arid regions of Northwest China.Grazing exclusion(GE)is one of the most common pathways used to restore degraded grasslands and to improve their ecosystem services.Nevertheless,there are still significant controversies concerning GE’s effects on grassland diversity as well as carbon(C)and nitrogen(N)storage.It remains poorly understood in the arid desert regions,whilst being essential for the sustainable use of grassland resources.To assess the effects of GE on community characteristics and C and N storage of desert plant community in the arid desert regions,we investigated the community structure and plant biomass,as well as C and N storage of plants and soil(0-100 cm depth)in short-term GE(three years)plots and adjacent long-term freely grazing(FG)plots in the areas of sagebrush desert in Northwest China,which are important both for spring-autumn seasonal pasture and for ecological conservation.Our findings indicated that GE was beneficial to the average height,coverage and aboveground biomass(including stems,leaves and inflorescences,and litter)of desert plant community,to the species richness and importance values of subshrubs and perennial herbs,and to the biomass C and N storage of aboveground parts(P<0.05).However,GE was not beneficial to the importance values of annual herbs,root/shoot ratio and total N concentration in the 0-5 and 5-10 cm soil layers(P<0.05).Additionally,the plant density,belowground biomass,and soil organic C concentration and C storage in the 0-100 cm soil layer could not be significantly changed by short-term GE(three years).The results suggest that,although GE was not beneficial for C sequestration in the sagebrush desert ecosystem,it is an effective strategy for improving productivity,diversity,and C and N storage of plants.As a result,GE can be used to rehabilitate degraded grasslands in the arid desert regions of Northwest China.

Adaptive Antenna-Activation Based Beamforming for Large-Scale MIMO Communication Systems of High Speed Railway

Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambiguity(IBA) increases as the directional difference between beams becomes smaller.An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA.In the district near the base station(BS),all antenna elements(AEs) were activated to generate two beams.As the distance from the train to the BS increased,only the minimum number of AEs satisfying the resolution criterion would be activated.At the cell edge,one beam was switched off due to intolerable IBA.The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival(DOA) estimation error.

Restrictive vs liberal transfusion for upper gastrointestinal bleeding:A meta-analysis of randomized controlled trials

AIM:To compare the outcome of upper gastrointestinal bleeding(UGIB) between patients receiving restrictive and liberal transfusion.METHODS:PubMed,EMBASE,and Cochrane Library databases were employed to identify all relevant randomized controlled trials regarding the outcome of UGIB after restrictive or liberal transfusion. Primary outcomes were death and rebleeding. Secondary outcomes were length of hospitalization,amount of blood transfused,and hematocrit and hemoglobin at discharge or after expansion.RESULTS:Overall,4 papers were included in this meta-analysis. The incidence of death was significantly lower in patients receiving restrictive transfusion than those receiving liberal transfusion(OR:0.52,95%CI:0.31-0.87,P = 0.01). The incidence of rebleeding was lower in patients receiving restrictive transfusion than those receiving liberal transfusion,but this difference did not reach any statistical significance(OR:0.26,95%CI:0.03-2.10,P = 0.21). Compared with those receiving liberal transfusion,patients receiving restrictive transfusion had a significantly shorter length of hospitalization(standard mean difference:-0.17,95%CI:-0.30--0.04,P = 0.009) and a significantly smaller amount of blood transfused(standard mean difference:-0.74,95%CI:-1.15--0.32,P = 0.0005) with a lower hematocrit and hemoglobin level at discharge or after expansion.CONCLUSION:Restrictive transfusion should be employed in patients with UGIB.

Effect of temperature on soil respiration in a Chinese fir forest

在 88 岁的中国冷杉木(Cunninghamia lanceolata ) 从表土(0 10 厘米) 收集的土壤样品在 Nanping 的森林，福建，中国在实验室在 15 ° C， 25 ° C 和 35 ° C 的温度被孵化 90 天。土壤公司 2 进化率在 2， 5， 10， 15， 20， 25， 30， 35， 40， 50， 60， 70， 80 和 90 天的孵化时间被测量。结果证明土壤样品的公司 2 进化率在孵化期期间与孵化时间和温度显著地变化了。吝啬的公司 2 进化率和从土壤的公司 2 进化的累积数量在 35 ° C 是最高的，在 25 ° C，和 15 ° C 由那些列在后面。在进化率在 Q 10 价值被发现的公司 2 的实质的差别为第二 and 计算了第 90 天孵化。为平均公司 2 进化率的 Q 10 价值在 15 25 ° C 的温度范围是 2.0，但是它在 25 35 ° C 减少了到 1.2。土壤公司 2 进化率与孵化时间减少了。在孵化期的结束的累积使矿物化的 C (在第 90 天) 是在孵化以前的不到 10% 起始的 C 数量。

Synthesis of flowerlike nickel particles and their microwave absorbing properties

Two kinds of nickel particles with flower-like structures assembled with a number of nano-flakes were synthesized and the relationship of their morphology and microwave absorbing properties was studied.The electromagnetic parameters of these flower-like Ni were measured with vector network analyzer at 2-18 GHz frequency and the reflection losses(RL) with different sample thicknesses were calculated.The results indicate that the flower-like nickel-wax composites with the sample thickness less than 2 mm show excellent absorbing ability.This result is expected to play a guiding role in the preparation of the highly efficient absorber.

Pollutant emissions,energy consumption and economic development in China:Evidence from dynamic panel data

This study investigates the relationship among pollutant emissions,energy consumption and economic development in China during the period 1982-2007 by using a one-step GMM-system model under a multivariable panel VAR framework,controlling for capital stock and labor force.Regarding the data for all 28 provinces as a whole,we find that there is a unidirectional positive relationship running from pollutant emission to economic development and a unidirectional negative relationship between pollutant emission and energy consumption.Based on traditional economic planning,the panel data of28 provinces are divided into two cross-province groups.It is discovered that in the eastern coastal region of China,there is only a unidirectional positive causal relationship leading from economic development to pollutant emission;while in the central and western regions,there are the unidirectional Granger causal relationships between pollutant emission and energy consumption,as well as between pollutant emission and economic development.There is also a unique unidirectional causal relationship running from economic development to energy consumption,which does not appear in the eastem coastal region or in China as a whole.

Influences of sand cover on erosion processes of loess slopes based on rainfall simulation experiments

Aeolian-fluvial interplay erosion regions are subject to intense soil erosion and are of particular concern in loess areas of northwestern China. Understanding the composition, distribution, and transport processes of eroded sediments in these regions is of considerable scientific significance for controlling soil erosion. In this study, based on laboratory rainfall simulation experiments, we analyzed rainfall-induced erosion processes on sand-covered loess slopes （SS） with different sand cover patterns （including length and thickness） and uncovered loess slopes （LS） to investigate the influences of sand cover on erosion processes of loess slopes in case regions of aeolian-fluvial erosion. The grain-size curves of eroded sediments were fitted using the Weibull function. Compositions of eroded sediments under different sand cover patterns and rainfall intensities were analyzed to explore sediment transport modes of SS. The influences of sand cover amount and pattern on erosion processes of loess slopes were also discussed. The results show that sand cover on loess slopes influences the proportion of loess erosion and that the compositions of eroded sediments vary between SS and LS. Sand cover on loess slopes transforms silt erosion into sand erosion by reducing splash erosion and changing the rainfall-induced erosion processes. The percentage of eroded sand from SS in the early stage of runoff and sediment generation is always higher than that in the late stage. Sand cover on loess slopes aggravates loess erosion, not only by adding sand as additional eroded sediments but also by increasing the amount of eroded loess, compared with the loess slopes without sand cover. The influence of sand cover pattern on runoff yield and the amount of eroded sediments is larger than that of sand cover amount. Furthermore, given the same sand cover pattern, a thicker sand cover could increase sand erosion while a thinner sand cover could aggravate loess erosion. This difference explains the existence of intense erosion on slopes that are thinly covered with sand in regions where aeolian erosion and fluvial erosion interact.

Determination of Eight Organophosphorus Pesticide Residues in Pepper by QuEChERS-Gas Chromatography

[ Objectives] This study was conducted to establish a QuEChERS-gas chromatography method for determination of eight kinds of organophosphorus pesticide residues in pepper. [Methods] The samples were extracted by acetonitrile, and anhydrous magnesium sulfate was used for salting out. The extracts were then purified by dispersive solid phase extraction combining with GCB, C18 and PSA. Samples were analyzed by FPD detector. External standard was used as quantitive method. [ Results] The detection limits were in the range of 0. 001 -0. 008 mg/kg, the average recoveries ranged from 83.5% to 101.2% , and the relative standard deviation （RSD） of the eight organophosphorus pesticide residues were below 5%. [ Conclusions] The method is simple, quick, easy and effective for the determination of pepper.

Analysis of impacting factors on polarimetric SAR oil spill detection

Polarimetric synthetic aperture radar （SAR） oil spill detection parameters conformity coefficient （μ）, Muller matrix parameters （｜C｜,B0 ）, the eigenvalues of simplified coherency matrix （λnos） and the influence of SAR observing parameters, ocean environment and noise level are investigated. Radarsat-2 data are used to make systematic analysis of polarimetric parameters for different incidences, wind speeds, noise levels and the ocean phenomena （oil slick and look likes）. The influence of the SAR observing parameters, the ocean environment and the noise level on the typical polarimetric SAR parameter conformity coefficient has been analyzed. The results indicate that conformity coefficient cannot be simply used for oil spill detection, which represents the image signal to the noise level to some extent. When the signals are below the noise level for the oil slick and the look likes, the conformity coefficients are negative; while the signals above the noise level corresponds to positive conformity coefficients. For dark patches （low wind and biogenic slick） with the signal below the noise, polarization features such as conformity coefficient cannot separate them with oil slick. For the signal above the noise, the oil slick, the look likes （low wind and biogenic slick） and clean sea all have positive conformity coefficients, among which, the oil slick has the smallest conformity coefficient, the look likes the second, and the clean sea the largest value. For polarimetric SAR data oil spill detection, the noise plays a significant role. So the polafimetric SAR data oil spill detection should be carried out on the basis of noise consideration.

Synthesis, Bioactivity and Crystal Structure Analysis of 2-(Benzo[d]isothiazol-3-yloxy)-N-(3-cyano-1-(4-fluorophenyl)-1H-pyrazol-5-yl) Acetamide

A novel benzisothiazolin-3-one derivative, 2-（benzo[d]isothiazol-3-yloxy）-N-（3- cyano-l-（4-fluorophenyl）-lH-pyrazol-5-yl） acetamide （8）, was synthesized from the initial compound benzo[d]isothiazol-3（2H）-one （BIT） 1 and 4-fluoroaniline 3. The structure of the target compound 8 was determined by elemental analyses, IR and 1H NMR. The single crystals of intermediate compound 6 and the target compound 8 were obtained and determined by X-ray diffraction analysis. The preliminary biological activity was also evaluated and the results showed tile target compound exhibited a good anti-microbial activity.

Research on Strategy Marine Noise Map Based on i4Ocean Platform： Constructing Flow and Key Approach

Noise level in a marine environment has raised extensive concern in the scientific community.The research is carried out on i4 Ocean platform following the process of ocean noise model integrating,noise data extracting,processing,visualizing,and interpreting,ocean noise map constructing and publishing.For the convenience of numerical computation,based on the characteristics of ocean noise field,a hybrid model related to spatial locations is suggested in the propagation model.The normal mode method K/I model is used for far field and ray method CANARY model is used for near field.Visualizing marine ambient noise data is critical to understanding and predicting marine noise for relevant decision making.Marine noise map can be constructed on virtual ocean scene.The systematic marine noise visualization framework includes preprocessing,coordinate transformation interpolation,and rendering.The simulation of ocean noise depends on realistic surface.Then the dynamic water simulation gird was improved with GPU fusion to achieve seamless combination with the visualization result of ocean noise.At the same time,the profile and spherical visualization include space,and time dimensionality were also provided for the vertical field characteristics of ocean ambient noise.Finally,marine noise map can be published with grid pre-processing and multistage cache technology to better serve the public.