Global stability coefficient of large underground caverns under static loading and earthquake wave condition

Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An evaluation method of the global stability coefficient of underground caverns based on static overload and dynamic overload was proposed.Firstly,the global failure criterion for caverns was defined based on its band connection of plastic-strain between multi-caverns.Then,overloading calculation of the boundary geostress and seismic intensity on the caverns model was carried out,and the critical unstable state of multi-caverns can be identified,if the plastic-strain band appeared between caverns during these overloading processes.Thus,the global stability coefficient for the multi-caverns under static loading and earthquake was obtained based on the corresponding overloading coefficient.Practical analysis for the Yingliangbao(YLB)hydraulic caverns indicated that this method can not only effectively obtain the global stability coefficient of caverns under static and dynamic earthquake conditions,but also identify the caverns’high-risk zone of local instability through localized plastic strain of surrounding rock.This study can provide some reference for the layout design and seismic optimization of underground cavern group.

胺碘酮联合比索洛尔治疗冠心病室性心律失常患者疗效及可行性研究

目的探讨胺碘酮联合比索洛尔在冠心病室性心律失常患者中的应用效果。方法选取该院2015年11月至2017年12月收治的冠心病室性心律失常患者73例,按照随机数字表法分为对照组(36例,采用胺碘酮治疗)和观察组(37例,给予胺碘酮+比索洛尔治疗)。观察比较2组临床治疗效果及治疗前后心电图指标(室性前期收缩数、短阵室速数)变化情况,并统计2组不良反应发生情况。结果观察组治疗总有效率高于对照组,差异有统计学意义(P<0.05)。治疗前2组室性前期收缩数、短阵室速数比较,差异均无统计学意义(P>0.05);治疗1个月后,观察组室性前期收缩数、短阵室速数较对照组小,差异均有统计学意义(P<0.05);观察组不良反应发生率与对照组比较,差异无统计学意义(P>0.05)。结论比索洛尔联合胺碘酮可改善冠心病室性心律失常患者症状,提高疗效,且联合用药安全可靠。

稳心颗粒联合维拉帕米治疗阵发性室上性心动过速的疗效观察

目的探讨稳心颗粒联合盐酸维拉帕米注射液治疗阵发性室上性心动过速的临床疗效。方法选取2021年7月—2023年6月在首都医科大学附属北京康复医院就诊的116例阵发性室上性心动过速患者,按随机数字表法分为对照组和治疗组,每组各58例。对照组静脉推注盐酸维拉帕米注射液,将5 mg盐酸维拉帕米注射液加入10 mL生理盐水,3 min内静脉推注,观察20 min,若病情未好转,重复注射直至转复后停止,每日剂量不超过50 mg。治疗组在对照组治疗基础上开水冲服稳心颗粒,1袋/次,3次/d。两组疗程均为4周。比较两组的临床疗效、发作和治疗情况、超声心电图检查和心功能指标。结果治疗组的总有效率为93.10%,明显高于对照组的总有效率79.31%,差异有统计学意义(P<0.05)。治疗后,治疗组的发作频次、平均转复时间低于治疗前,30 min内转复率高于治疗前(P<0.05);治疗组的发作频次、平均转复时间低于对照组,30 min内转复率高于对照组(P<0.05)。治疗后,治疗组患者的短阵室速数、室性期前收缩数比治疗前小(P<0.05),且比对照组的短阵室速数、室性期前收缩数更小(P<0.05)。治疗后,治疗组的左心室射血分数(LVEF)比治疗前大,左心室收缩末期容积(LVESV)比治疗前小(P<0.05);治疗组患者的LVEF比对照组大,LVESV比对照组小(P<0.05)。结论稳心颗粒联合盐酸维拉帕米注射液可提高阵发性室上性心动过速的临床疗效,减轻发作频率,改善心功能。

Studies on the Inheritance of Locule Formation in Tomatoes (Lycopersicon esculentum Mill.)

To fully understand the tomato ovary locule formation of inheritance, two varieties, ovary multi-locule （MLK1） and few-locule （FL1）, were used in these studies. Using reciprocal cross, self-cross, and backcross, we have constructed various groups to seek the genetic law and mechanisms of tomato locule formation, for modifying the tomato breeding theory. The parental and the resulting FI and F2 generations have been used to examine the heredity of the locule number. The results showed that few-locule was incompletely dominant. The data from backcross demonstrated a significant effect on the locule number, whereas, the reciprocal cross showed an insignificant effect. Not surprisingly, the locule number was controlled by nuclear genomes, not by exogenous substances. The model that inherited the locule number belonged to the additive-dominant model： additive effects played a very important role and were partially dominant. In addition, the results revealed that the locule number in tomato was mainly controlled by a single gene, whereas, it was modulated by a number of other genes. Finally, the general inheritability and narrow inheritability of the locule number were 69.44% and 52.98%, respectively.

教而不“瘦”

香港的教授,全然不像大陆越教越“瘦”的教授。他们既不用卖馅饼,也不用上街挂牌推销自己的专著,更不用“下海”经商,而是过着一种比较纯粹的学院生活。 所在的学校不同,香港教授的薪水也不同。但包括住房等补贴,他们的月收入都在5万港元以上。在寸土千金,一室数万的香港,教授的住房是最令人羡慕的。有一次。

NUMERICAL SIMULATION AND EXPERIMENTS OF THE VECTOR-FLOW CLEANROOM

Based on K ε two equation turbulence model,the air distribution and contamination field under different conditions was numerically simulated in a vector flow cleanroom.Special mesh system was introduced to deal with the quarter circle shaped inlets.Model experiments were also made.By analysis of numerical as well as experimental results,we made some predictions about flow characteristics,contaminant control effect and ventilation performance of this energy saving cleanroom.It has been proved that the vector flow can meet class 100 of Fed. St.with 13 to 12 conventional air change per hour,and reduce layer height and simplify air clean system.

Local anesthesia with ropivacaine for patients undergoing laparoscopic cholecystectomy

AIM:To investigate the effect of pain relief after infu-sion of ropivacaine at port sites at the end of surgery.METHODS:From October 2006 to September 2007,72 patients undergoing laparoscopic cholecystectomy(LC) were randomized into two groups of 36 patients.One group received ropivacaine infusion at the port sites at the end of LC and the other received normal saline.A visual analog scale was used to assess postoperative pain when the patient awakened in the operating room,6 and 24 h after surgery,and before discharge.The amount of analgesics use was also recorded.The demographics,laboratory data,hospital stay,and perioperative complications were compared between the two groups.RESULTS:There was no difference between the two groups preoperatively in terms of demographic and lab-oratory data.After surgery,similar operation time,blood loss,and no postoperative morbidity and mortality were observed in the two groups.However,a significantly lower pain score was observed in the patients undergo-ing LC with local anesthesia infusion at 1 h after LC and at discharge.Regarding analgesic use,the amount of meperidine used 1 h after LC and the total used during admission were lower in patients undergoing LC with local anesthesia infusion.This group also had a shorter hospital stay.CONCLUSION:Local anesthesia with ropivacaine at the port site in LC patients signif icantly decreased post-operative pain immediately.This explains the lower meperidine use and earlier discharge for these patients.

Chronic acalculous cholecystitis:correlation of clinical assessment,laboratory data and final histopathology

Objective:To summarize and analyze the clinical and histopathological features of chronic acalculous cholecystitis (CAC) and to investigate the diagnosis and surgical treatment of chronic acalculous cholecystit.Methods:The study subjects were 39 patients with chronic biliary symptoms but no evidence of stones in the gallbladder by B ultrasonography and magnetic resonance cholopancreatography (MRCP) (CAC group).The CCC group consisted of 66 patients taken randomly from concurrent all patients of chronic calculous cholecystitis (CCC).All patients accepted fibergastroscopy,B ultrasonography,MRCP,laboratory examination preoperatively.We retrospectively analyzed the clinical features,B ultrasonography and MRCP findings,histopathological results and clinical outcomes between the two groups.Results:All the 39 patients were diagnosed by clinical symptoms,B ultrasonography,fatty meal gallbladder contractability studies under ultrasound,fibergastroscopy and magnetic resonance cholangiopancreatography (MRCP),what's more,they were pathologically verified postoperatively.In all patients,there was a complete absence of gallbladder wall contractability.Mucosa epithelial defect was found in 21 patients in CAC group (53.8%) and 16 patients in CCC group (24.2%) respectively (P<0.005).Thickened arteriole wall was found in 29 patients in CAC group (74.4%) and none patient in CCC group (P<0.0001).Thickened gallbladder wall (4 mm or more in thickness) was found in 33 patients in CAC group (84.6%) and 28 patients in CCC group (42.4%) respectively (P<0.005).Bile stasis was found in 23 patients in CAC group (59.0%) and 14 patients in CCC group (21.2%) respectively by ultrasonography preoperatively and confirmed in operation (P<0.005).The outcomes of cholecystectomy,expressed as total or near total relief,was similar in the two groups.No statistically significant differences were observed between patients with CAC (90%) and CCC (80%),the P-value >0.05.Conclusion:Chronic acalculous cholecystitis could be diagnosed by symptoms,ultrasound,fatty meal gallbladder contractability studies under untrasoundand MRCP.The optimal treatment of chronic acalculous cholecystitis characterized by thickened arteriole wall and mucosa epithelial defect is cholecystectomy.

Numerical investigations on effects of bluff body in flat plate micro thermo photovoltaic combustor with sudden expansion

In order to reveal combustion characteristics of H_2/air mixture in a micro-combustor with and without bluff body, the effects of inlet velocities, equivalence ratios and bluff body's blockage ratios on the temperature field, pressure of the combustor wall, combustion efficiency and blow-off limit were investigated. The numerical results indicate that the sudden expansion plate micro combustor with bluff body could enhance the turbulent disturbance of the mixed gas in the combustion chamber and the combustion condition is improved. Moreover, a low-speed and high temperature recirculation region was formed between the sudden expansion step and the bluff body so that the high and uniform wall temperature(>1000 K) could be gotten. As a result, it could strengthen the mixing process, prolong the residence time of gas, control the flame position effectively and widen the operation range by the synergistic effect of the bluff body and steps. When the blockage ratio ranged from 0.3 to 0.6, it could be found that the bluff body could play a stabilizing effect and expand combustion blow burning limit, and combustion efficiency firstly was increased with the inlet velocity and equivalence ratio, and then was decreased.

Modeling Methane Emission from Rice Paddy Soils:Ⅰ.Model Development

With an understanding of the processes of methane production, oxidation and emission, a semi-empirical model, focused on the contributions of rice plants to the processes and also the influence of environmental factors, was developed to predict methane emission from rice paddy soils. In the present model, the amount of methane transported from the soil to the atmosphere was determined by the rates of CH4 production and an emitted fraction. The rates of CH4 production in irrigated rice soils were computed from the availability of methanogenic substrates that are primarily derived from rice plaaes and added organic matter and the influence of soil texture, soil redox potential and temperature. The fraction of methane emitted was assumed to be modulated by the rice plants and declines with rice growth and development. TO make it applicable to a wider area with limited data sets, a simplified version of the model was also derived to predict methane emission in a more practical manner.

Mechanical properties and reinforcement effect of jointed rock mass with pre-stressed bolt

Pre-stressed bolt anchorage is the key technology for jointed rock masses in rock tunnelling,slope treatment and mining engineering.To investigate the mechanical properties and reinforcement effect of jointed rock masses with pre-stressed bolts,in this study,uniaxial compression tests were conducted on specimens with different anchoring types and flaw inclination angles.ABAQUS software was used to verify and supplement the laboratory tests.The laws of the uniaxial compressive strength(UCS)obtained from the numerical simulations and laboratory tests were consistent.The results showed that under the same flaw angle,both the UCS and elastic modulus of the bolted specimens were improved compared with those of the specimens without bolts and the improvements increased with an increase in the bolt pre-stress.Under the same anchoring type,the UCS and elastic modulus of the jointed specimens increased with an increase in the flaw angle.The pre-stressed bolt could not only restrain the slip of the specimens along the flaw surface but also change the propagation mode of the secondary cracks and limit the initiation of cracks.In addition,the plot contours of the maximum principal strain and the Tresca stress of the numerical models were influenced by the anchoring type,flaw angle,anchoring angle and bolt position.

Review and Discussion on Seismic Subsidence of Loess

The research and achievements made on seismic subsidence of loess,obtained over the past30 years,were reviewed.Seismic Subsidence of Loess(SSL)has been verified by microstructure characteristics,dynamic triaxial experiments,and in-situ explosion tests,and has become an important subject in the field of seismic loess engineering research.While,the research is still in the stage of theoretical study of saturated soil,and there are no representative cases of seismic subsidence of loess in historical earthquakes.It is difficult to express structure characteristics using microstructure morphology.While,soil mechanics are available methods for this.Seismic subsidence judgment is absolute in some certain value ranges for several parameters.Therefore,probabilistic judgment should be developed.The seismic subsidence ratio is estimated mostly by empirical formulas or semiempirical and semi-theoretical formulas,which are based on laboratory data.These formulas are not established on the basis of physical process and mechanics of seismic subsidence,and this leads to more variables,complicated computation,and poor practicability.To solve these problems,we need to distinguish the main factors and corresponding variables,to establish a mechanics model for seismic subsidence estimation,and to characterize its physio-mechanical process.The key of anti-seismic subsidence treatment is to reduce the seismic subsidence property of soils,and to lower the interaction between the soil body and underground structures.

Digoxin intoxication： An old enemy in modern era

Objectives Although development of new treatment modalities limited digoxin usage, digoxin intoxication is still an important issue which could be easily overlooked. In this report, we analyzed a case series definitively diagnosed as digoxin intoxication in the modern era. Methods We analyzed 71 patients hospitalized with digoxin intoxication confirmed by history, complaints, clinical and electrocardiograph （ECG） findings, and serum digoxin levels 〉 2.0 ng/mL, during a five year period. The demographic and clinical data, indications for digoxin use, digoxin dosage, concurrent medications, laboratory data, hospital monitoring, and ECG findings were obtained from all patients. Results Thirty-eight of 71 patients （53.5%） had symptoms of heart failure during admission or later. Sixty-four percent of patients were older than 75 years. The percentage of females was 67%. Atrial fibrillation, hypertension and gastrointestinal complaints were more frequent in the females （64% in females, 30% in males, P = 0.007; 81% in female, 52% in males, P = 0.01; 50% in female, 17.3% in males, P = 0.008, respectively）. The mortality rate during the hospital course was 7%. Conclusions This report demonstrated the reduced mortality rates in patients with digoxin intoxication over the study period. Gastrointestinal complaints are the most common symptoms in this population.

Small cell carcinoma of the gastric remnant：a case report

Objective Small cell carcinoma(SCC) is mostly found in the lungs. It is extremely rare in the gastric remnant. Here, we report a case and review the literature in order to improve the diagnosis and treatment of SCC of the gastric remnant.Methods We report a case of SCC of the gastric remnant in a 71-year-old male Chinese patient who presented with epigastric pain, acid regurgitation, and belching and who underwent Billroth II gastrectomy more than 38 years ago.Results Physical examination showed no obvious abnormalities. Laboratory data were within normal limits, except for anemia. Pathology of the mass showed a protruded tumor measuring 5.0 × 5.0 × 2.5 cm at the anastomotic edge of the gastric remnant that infiltrated through the full wall of the stomach; this was confirmed by immunohistochemical staining for cytokeratin [CK(-)], leukocyte common antigen(LCA)(+), synaptophysin(+), CD56(+), and Ki-67(+ > 50%).Conclusion SCC of the gastric remnant is extremely rare, although the pathology, symptoms, diagnosis, treatment, and prognosis of SCC are similar to those of gastric SCC. Although the standard treatment of SCC of the gastric remnant remains unclear, effective surgical resection and subsequent multiagent chemotherapy should be performed for long-term survival. Our case shows the efficacy of tegafurgimeracil-oteracil-potassium capsule chemotherapy. Examination of a large series is required to determine the optimal treatment strategy for SCC of the gastric remnant.

Serum magnesium concentration in children with functional constipation treated with magnesium oxide

AIM:To determine whether hypermagnesemia recently reported in adult patients possibly develops in children with functional constipation taking daily magnesium oxide.METHODS:We enrolled 120 patients (57 male and 63 female) aged 1-14 years old (median:4.7 years) with functional constipation from 13 hospitals and two private clinics.All patients fulfilled the Rome Ⅲ criteria for functional constipation and were treated with daily oral magnesium oxide for at least 1 mo.The median treatment dose was 600 (500-800) mg/d.Patients were assessed by an interview and laboratory examination to determine possible hypermagnesemia.Serum magnesium concentration was also measured in sex-and agematched control subjects (n=38).RESULTS:In the constipation group,serum magnesium concentration [2.4 (2.3-2.5) mg/dL,median and interquartile range] was significantly greater than that of the control group [2.2 (2.0-2.2) mg/dL] (P < 0.001).The highest value was 3.2 mg/dL.Renal magnesium clearance was significantly increased in the constipation group.Serum magnesium concentration in the constipation group decreased significantly with age (P < 0.01).There was no significant correlation between the serum level of magnesium and the duration of treatment with magnesium oxide or the daily dose.None of the patients had side effects associated with hypermagnesemia.CONCLUSION:Serum magnesium concentration increased significantly,but not critically,after daily treatment with magnesium oxide in constipated children with normal renal function.

Analytic model of non-uniform corrosion induced cracking of reinforced concrete structure

In order to perfectly reflect the dynamic corrosion of reinforced concrete (RC) cover in practical engineering,an analytic model of non-uniform corrosion induced cracking was presented based on the elastic-plastic fracture mechanics theory.Comparisons with the published experimental data show that the predictions given by the present model are in good agreement with the results both for natural exposed experiments and short-time indoor tests (the best difference is about 2.7%).Also it obviously provides much better precision than those models under the assumption of uniform corrosion (the maximal improved precision is about 48%).Therefore,it is pointed out that the so-called uniform corrosion models to describe the cover cracking of RC should be adopted cautiously.Finally,the influences of thickness of local rusty layer around the reinforcing steel bar on the critical corrosion-induced crack indexes were investigated.It is found that the thickness of local rusty layer has great effect on the critical mass loss of reinforcing steel,threshold expansion pressure,and time to cover cracking.For local rusty layer thickness with a size of a=0.5 mm,the time to cover cracking will increase by about one times when a/b (a,semi-minor axis;b,semi-major axis) changes from 0.1 to 1 mm.

Secondary hyperparathyroidism associated with multiple brown tumor:a case report

Brown tumour represents a serious complication of hyperparathyroidism.Definitive diagnosis is based on histological examination,clinical,radiological and laboratory data.Here we report a case of multiple brown tumours localised in collarbone,rib and in the distal ulna due to secondary hyperparathyroidism in a 37-year-old women with chronic renal failure.The clinical management of brown tumour aimed primarily to reduce the elevated parathyroid hormone levels by pharmacological treatment.In our experience,clinicians usually consider brown tumor of hyperparathyroidism is caused by giant cell lesions in maintenance hemodialysis recipients,and multiple brown tumours are rarely seen in these patients.

Numerical study of effect of front cavity on hydrogen/air premixed combustion in a micro-combustion chamber

The micro-combustion chamber is the key component for micro-TPV systems. To improve the combustor wall temperature level and its uniformity and efficiency, an improved flat micro-combustor with a front cavity is built, and the combustion performance of the original and improved combustors of premixed H2/air flames under various inlet velocities and equivalence ratios is numerically investigated. The effects of the front cavity height and length on the outer wall temperature and efficiency are also discussed. The front cavity significantly improves the average outer wall temperature, outer wall temperature uniformity, and combustion efficiency of the micro-combustor, increases the area of the high temperature zone, and enhances the heat transfer between the burned blends and inner walls. The micro-combustor with the front cavity length of 2.0 mm and height of 0.5 mm is suitable for micro-TPV system application due to the relatively high outer wall temperature, combustion efficiency, and the most uniform outer wall temperature.

Influence of Fine Sediment on the Fluidity of Debris Flows

Debris flows include a great diversity of grain sizes with inherent features such as inverse grading, particle size segregation, and liquefaction of fine sediment. The liquefaction of fine sediment affects the fluidity of debris flows, although the behavior and influence of fine sediment in debris flows have not been examined sufficiently. This study used flume tests to detect the effect of fine sediment on the fluidity of laboratory debris flows consisting of particles with various diameters. From the experiments, the greatest sediment concentration and flow depth were observed in the debris flows mixed with fine sediment indicating increased flow resistance. The experimental friction coefficient was then compared with the theoretical friction coefficient derived by substituting the experimental values into the constitutive equations for debris flow. The theoretical friction coefficient was obtained from two models with different fine-sediment treatments： assuming that all of the fine sediments were solid particles or that the particles consisted of a fluid phase involving pore water liquefaction. From the comparison of the friction coefficients, a fully liquefaction state was detected for the fine particle mixture. When the mixing ratio and particle size of the fine sediment were different, some other eases were considered to be in a partially liquefied transition state. These results imply that the liquefaction of fine sediment in debris flows was induced not only by the geometric conditions such as particle sizes, but also by the flow conditions.