构思新模式,进一步搞好高三生物学教学

陶行知先生指导的'教学做合一'是其教育理论中关于'实践环节'的一个极为精采的构作,是他在当年的实践和创新中淬取的理论华章。努力领会并实践陶行知教育思想,对我们二十一世纪的教育工作仍有现实和深远的意义。本人就此结合自己在生物'3+1'高考教学实践中谈谈如何将'说做'学习法,运用于高三复习课中。 1 '说做'学习法的定义学生在教师指导下,在解决问题的学习活动过程中,引发出以个体生活和学习经验为基础的。

Temperature effects on the failure of deep circular tunnel under true-triaxial compression

The failure characteristics of thermal treated surrounding rocks should be studied to evaluate the stability and safety of deep ground engineering under high-ground-temperature and high-ground-stress conditions.The failure process of the inner walls of fine-grained granite specimens at different temperatures(25–600℃)was analyzed using a true-triaxial test system.The failure process,peak intensity,overall morphology(characteristics after failure),rock fragment characteristics,and acoustic emission(AE)characteristics were analyzed.The results showed that for the aforementioned type of granite specimens,the trend of the failure stress conditions changed with respect to the critical temperature(200℃).When the temperature was less than 200℃,the initial failure stress increased,final failure stress increased,and failure severity decreased.When the temperature exceeded 200℃,the initial failure stress decreased,final failure stress decreased,and failure severity increased.When the temperature was 600℃,the initial and final failure stresses of the specimens decreased by 60.93%and 19.77%compared with those at 200℃,respectively.The numerical results obtained with the software RFPA3D-Thermal were used to analyze the effect of temperature on the specimen and reveal the mechanism of the failure process in the deep tunnel surrounding rock.

Trigonometric Regularization and Continuation Method Based Time-Optimal Control of Hypersonic Vehicles

Aiming at the time-optimal control problem of hypersonic vehicles(HSV)in ascending stage,a trigonometric regularization method(TRM)is introduced based on the indirect method of optimal control.This method avoids analyzing the switching function and distinguishing between singular control and bang-bang control,where the singular control problem is more complicated.While in bang-bang control,the costate variables are unsmooth due to the control jumping,resulting in difficulty in solving the two-point boundary value problem(TPBVP)induced by the indirect method.Aiming at the easy divergence when solving the TPBVP,the continuation method is introduced.This method uses the solution of the simplified problem as the initial value of the iteration.Then through solving a series of TPBVP,it approximates to the solution of the original complex problem.The calculation results show that through the above two methods,the time-optimal control problem of HSV in ascending stage under the complex model can be solved conveniently.

Non-isothermal thermal decomposition kinetics of high iron gibbsite ore based on Popescu method

The thermal decomposition kinetics of high iron gibbsite ore was investigated under non-isothermal conditions.Popescu method was applied to analyzing the thermal decomposition mechanism.The results show that the most probable thermal decomposition mechanism is the three-dimensional diffusion model of Jander equation,and the mechanism code is D3.The activation energy and pre-exponential factor for thermal decomposition of high iron gibbsite ore calculated by the Popescu method are 75.36 kJ/mol and 1.51×10-5 s-（-1）,respectively.The correctness of the obtained mechanism function is validated by the activation energy acquired by the iso-conversional method.Popescu method is a rational and reliable method for the analysis of the thermal decomposition mechanism of high iron gibbsite ore.

Thermodynamic assessment of Co-Cr-W ternary system

The Co-Cr-W ternary system was critically assessed using the CALPHAD technique.The solution phases including the liquid,γ-Co,ε-Co and α-Cr were described by a substitutional solution model.The σ,μ and R phases were described by three-sublattice models of（Co,W）8（Cr,W）4（Co,Cr,W）18,（Co,Cr,W）7W2（Co,Cr,W）4 and（Co,W）27（Cr,W）14（Co,Cr,W）12,respectively,in order to reproduce their homogeneity ranges.A self-consistent set of thermodynamic parameters for each phase was derived.The calculated isothermal sections at 1 000,1 200 and 1 350 ℃ are in good agreement with the experimental data.A eutectoid reaction of R μ＋γ-Co＋σ in this ternary system was predicted to occur at 1 022 ℃.

Study on preparation of In_2O_3 superfine powder via polymer-network process

Nanocrystalline,single-phase undoped In 2O 3 was prepared by a polymer-network synthesis technique with indium nitrate as the starting material;several methods such as X-ray diffractometry (XRD) and transmission electron microscopy (TEM) were employed to obtain detailed information on the crystallography and microstructual appearance of In 2O 3 superfine powders. The influence of the concentration of starting solution,calcination temperature and time on the particle size was also that investigated by means of the XRD patterns. Results indicate that the obtained powders are mostly crystalline single phase with uniform size and also that the size of the products can be controlled under proper condition.

Effects of Ratio of Row Spacing to Intrarow Spacing on Yield and Top Three Leaves of Super High-yielding Early and Late Rice

Using a split plot design, super high-yielding early rice ＆quot;Zhongjiazao 17＆quot;and ＆quot;Ganxin 203＆quot; and super high-yielding late rice ＆quot;Ganxin 688＆quot; and ＆quot;Wufengy-ouT025＆quot; were taken as materials with planting density the same at 312 000 hil s/hm2, to explore the effects of RS/IS （Ratio of row spacing to intrarow row spacing） on yield, top three leaves morphological features and its relationship of them in 2011 and 2012. The results showed that, whether early or late rice, biomass, accumula-tion and apparent utilizing rate of nitrogen were lower in RS/IS5.0 （40.0 cm ＆#215;8.0 cm） treatment, but yield of rice was higher in RS/IS2.0 （25.0 cm ＆#215;12.8 cm） treatment;grain numbers per spike of rice was more in RS/IS2.8 （30.0 cm＆#215;10.7 cm） treatment, and thousand-grain weight of rice was higher in RS/IS1.3 （20.0 cm＆#215;16.0 cm） treat-ment. For 4 varieties of early or late rice aforementioned, basal angle, opening an-gle and leaf area of 2nd leaf from top were larger in RS/IS5.0 treatment, and basal angle and opening angle were smal er in RS/IS2.0 treatment and leaf area smal er in RS/IS1.3 treatment.

Chinese Economy in the “New Normal”: Realities and Prospects

Great achievements were made in the 12th Five-Year Plan period （2011-2015） in such areas as economic growth, living standards, industrial restructuring, innovation- driven growth, new-type urbanization and ecological civilization, trade and investment, and reform. These achievements have paved the way for China to enhance the quality and efficiency of growth in the new normal. China＇s future growth prospects are highly correlated with the 13th Five-Year Plan （2016-2020）. For the 13th Five-Year Plan period, China is committed to maintaining an annual growth rate of no less than 6.5%, which is both necessary for China to build an all-round, well-off society before 2020 and consistent with the characteristics of China＇s current economic development stage. Meanwhile, efforts must be made to give prominence to consumption, investment, and export as drivers of growth while continuing to improve labor and capital input and efficiency which is vital to mid- and long- term economic development.

Homoharringtonine induces apoptosis of endothelium and down－regulates VEGF expression of K562 cells

Homoharringtonine (HHT) has currently been used successfully in the treatment of acute and chronic myeloid leukemias and has been shown to induce apoptosis of different types of leukemic cells in vitro. Emerging evidence suggests that angiogenesis may play an important role in hematological malignancies, such as leukemia. However, whether HHT can relieve leukemia by anti-angiogenesis is still unknown. We investigated the anti-angiogenesis potential of HHT with the human umbilical vein endothelial cell line (ECV304) and leukemic cell line (K562) in vitro. Cellular proliferation was determined by MTT assay and apoptosis was analyzed by flow cytometry, The mRNA expression of vascular endothelial growth factor (VEGF) was assessed by RT-PCR and VEGF protein production was detected by Western blot. Inhibition of cell proliferation and induction of apoptosis by HHT were discovered in ECV304 cells, and appeared in a dose- and time-dependent manner, Also, treatment with HHT caused down-regulation of VEGF mRNA expression in K562 cells in similar dose- and time-dependent manner and inhibition of VEGF protein production in K562 cells in response to the enhancing concentration of HHT. The results demonstrated that HHT could also induce apoptosis in endothelium and down-regulate VEGF expression in K562 cells. In conclusion, we believe HHT has anti-angiogenesis potential and speculate that HHT might exert its anti-leukemia effects via reduction of angiogenesis.

Effect of admission hypertriglyceridemia on the episodes of severe acute pancreatitis

AIM： To investigate the effect of admission hypertriglyceridemia （HTG） on the episodes of severe acute pancreatitis （SAP）. METHODS： One hundred and seventy-six patients with SAP were divided into HTG group （n = 45） and control group （n = 131） according to admission triglyceride （TG） ≥ 5.65 mmol/L and 〈 5.65 retool/L, respectively. Demographics, etiology, underlying diseases, biochemical parameters, Ranson＇ s score, acute physiology and chronic heath evaluation Ⅱ （APACHE Ⅱ） score, Balthazar＇s computed tomography （CT） score, complications and mortality were compared. Correlation between admission TG and 24-h APACHE Ⅱ score was analyzed. RESULTS： SAP patients with HTG were younger （40.8 ± 9.3 years vs 52.6 ± 13.4 years, P 〈 0.05） with higher etiology rate of overeating, high-fat diet （40.0% vs 14.5%, P 〈 0.05） and alcohol abuse （46.7% vs 23.7%, P 〈 0.01）, incidence rate of hypocalcemia （86.7% vs 63.4%, P 〈 0.01） and hypoalbuminemia （84.4% vs 60.3%, P 〈 0.01）, 24-h APACHE Ⅱ score （13.6 ± 5.7 vs 10.7 ± 4.6, P 〈 0.01） and admission serum glucose （17.7 ± 7.7 vs 13.4 ± 6.1, P 〈 0.01）, complication rate of renal failure （51.1% vs 16.8%, P 〈 0.01）, shock （37.9% vs 14.5%, P 〈 0.01） and infection （37.4% vs 18.3%, P 〈 0.01） and mortality （13.1% vs 9.1%, P 〈 0.01）. Logistic regression analysis showed a positive correlation between admission TG and 24-h APACHE Ⅱ score （r = 0.509, P = 0.004）.CONCLUSION： The clinical features of SAP patients with HTG are largely consistent with previous studies, HTG aggravates the episodes of SAP.

Diagnostic evaluation of acute pancreatitis in two patients with hypertriglyceridemia

We present two diagnostically challenging cases of acute pancreatitis with hypertriglyceridemia accompanied with chylomicronemia caused with a deficiency of lipoprotein lipase and with the presence of type Ⅴ hyperlipidemia. Both cases suffered from acute abdomen following the ingestion of fatty food and revealed the increase in parameters of inflammation without significant elevation of serum amylase levels.The imaging examination of ultrasonography could not detect significant findings of acute pancreatitis and a computer tomography scan eventually confirmed the findings of acute pancreatitis.Both cases responded to a low fat diet and administration of a cholecystokinin receptor antagonist,exhibiting a relief of abdominal symptoms.As in the present cases with acute abdomen following the ingestion of fatty food,the identification of serum hypertriglyceridemia and an abdominal computer tomography scan might be useful in establishing the diagnosis of acute pancreatitis and in developing the therapeutic regimen,when hypertriglyceridemia interferes with the evaluation of pancreatic enzyme activities and ultrasound examination provides poor pancreatic visualization.

Hypertriglyceridemia is positively correlated with the development of colorectal tubular adenoma in Japanese men

AIM： To determine the real association between serum lipid levels and colonic polyp formation. METHODS： We performed a large scale retrospective study to analyze the correlation between the incidence of colorectal adenoma or carcinoma and the fasting serum levels of total cholesterol （TC） and triglycerides （TG） in patients who underwent total colonoscopy for screening for colon cancer. RESULTS： Both levels were significantly elevated in patients with adenomas as compared with patients without any neoplastic lesion （TC 207.6 ± 29.5 vs 199.5 ±34.3, n= 4883, p〈 0.001; TG 135.0 ± 82.2 vs 108.7± 71.5, n= 4874, p〈 0.001）. The difference was significant in patients with tubular adenoma but not in those with villous or serrated adenoma. Multiple logistic regression analysis including age and sex revealed that TG was an independent correlation factor in male （p〈0.01）, but not in female patients. The level of TG in patients with invasive carcinoma did not show a significant elevation from that in patients with adenoma. These findings suggest that hypertriglyceridemia is an independent risk factor for colonic adenoma in men. CONCLUSION： Although a high level of serum triglyceride does not appear to be mechanically involved in the development of carcinoma, reduction of serum TG and intensive surveillance with total colonoscopy may have benefit in men with hypertriglyceridemia.

Simultaneous determination of five nucleosides and nucleobases in Panax notoginseng using high-performance liquid chromatography

Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-Aq column using a gradient elution with mobile phase of 8 mmol^L-1 ammonium acetate aqueous solution （A） and methanol （B）. The assay was carried out at a flow rate of 1 mL·min^-1 at 25 ℃ with the diode-array detection at 260 nm. Results Cytidine, uridine, guanosine, adenosine and uracil had good linearity in the ranges of 1.79 - 57.40 μg·mL^-1 （r^2 = 1.0000）, 3.30 - 105.60 μg·mL^-1 （r^2 = 1.0000）, 3.09 - 98.80 μg·mL^ -1（r^2 = 0.9999）, 2.77 - 88.60 μg·mL^-1 （r^2 = 1.0000） and 0.38 - 12.30 μg·mL ^-1 （r^2 = 1.0000） with average recoveries of 93.9%, 96.5%, 92.7%, 93.2% and 98.8%, respectively. The content of cytidine, uridine, guanosine, adenosine and uracil in different parts of P. notogingeng were significantly different. Conclusion This is the first report on quantitative determination of nucleosides and nucleobases in P notoginseng.

Study of a high-temperature and high-pressure FBG sensor with Al_2O_3 thin-wall tube substrate

A fiber Bragg grating(FBG) high-temperature and high pressure sensor has been designed and fabricated by using the Al2O3 thin-wall tube as a substrate.The test results show that the sensor can withstand a pressure range of 0-45 MPa and a temperature range of -10-300 ℃,and has a pressure sensitivity of 0.0426 nm/MPa and a temperature sensitivity of 0.0112 nm /

Gender and metabolic differences of gallstone diseases

AIM： To investigate the risk factors for gallstone disease in the general population of Chengdu, China. METHODS： This study was conducted at the West China Hospital. Subjects who received a physical examination at this hospital between January and December 2007 were included. Body mass index, blood pressure, fasting plasma glucose, serum lipid and lipoproteins concentrations were analyzed. Gallstone disease was diagnosed by ultrasound or on the basis of a history of cholecystectomy because of gallstone disease. Unconditional logistic regression analysis was used to investigate the risk factors for gallstone disease, and the Chi-square test was used to analyze differences in the incidence of metabolic disorders between subjects with and without gallstone disease. RESULTS： A total of 3573 people were included, 10.7% （384/3573） of whom had gallstone diseases. Multiple logistic regression analysis indicated that the incidence of gallstone disease in subjects aged 40-64 or ≥65 years was significantly different from that in those aged 18-39 years （P 〈 0.05）; the incidence was higher in women than in men （P 〈 0.05）. In men,a high level of fasting plasma glucose was obvious in gallstone disease （P 〈 0.05）, and in women, hypertriglyceridemia or obesity were significant in gallstone disease （P 〈 0.05）. CONCLUSION： We assume that age and sex are profoundly associated with the incidence of gallstone disease; the metabolic risk factors for gallstone disease were different between men and women.

Insulin and heparin in treatment of hypertriglyceridemia-induced pancreatitis

TO THE EDITOR We read with great interest the case report, “Hypertriglyceridernia -induced pancreatitis： A case-based review” by Gan eta]11 in the November 2006 issue of World Journal of Gastroenterology. We agree that in acute setting, pancreatitis due to hyper- triglyceridemia （HTG） should be ruled out as it is a treat-able and preventable condition. It needs to be treated conservatively along with measures to lower the triglyceride level. The various modalities to treat hypertriglyceridemia are plasmapheresis, insulin and heparin, purified apo C Ⅱ, and fibric acid derivatives^[2-5]. Plasmapheresis and purified apo C Ⅱ infusion are not easily available. There is limited literature about the efficacy of intravenous insulin and heparin, both of which can enhance lipoprotein lipase activity.

GF-3 data real-time processing method based on multi-satellite distributed data processing system

Due to the limited scenes that synthetic aperture radar(SAR)satellites can detect,the full-track utilization rate is not high.Because of the computing and storage limitation of one satellite,it is difficult to process large amounts of data of spaceborne synthetic aperture radars.It is proposed to use a new method of networked satellite data processing for improving the efficiency of data processing.A multi-satellite distributed SAR real-time processing method based on Chirp Scaling(CS)imaging algorithm is studied in this paper,and a distributed data processing system is built with field programmable gate array(FPGA)chips as the kernel.Different from the traditional CS algorithm processing,the system divides data processing into three stages.The computing tasks are reasonably allocated to different data processing units(i.e.,satellites)in each stage.The method effectively saves computing and storage resources of satellites,improves the utilization rate of a single satellite,and shortens the data processing time.Gaofen-3(GF-3)satellite SAR raw data is processed by the system,with the performance of the method verified.

Heat and hazardous contaminant transports in ventilated high-rise industrial halls

Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.

High-Performance Liquid Chromatographical Analysis of Ginsenosides in Panax ginseng,P.quinquef(?)lium and P.notoginseng

The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed on an Alltech Adsorbosphere HS C_(18) column,using 5×10^(-3)M NaH_2PO_4-H_3PO_4 buffer solution(pH 3.0)and acetonitrile-water(50:50)as gradient eluents. The baseline separation of ginsenosides Rb_1,Rb_2,Rb_1,Rc,Rd,Rf,Ro,and Re+Rg_1 was obtained in one analytical run.The ginsenosides are directly detected at 203 nm.The detection limit is 40μg at a signal to noise ratio of 3:1.The improved sample preparation and clean-up prior to injection with SEP-PAK C_(18)cartridge strongly reduced the front peaks caused by the impurities in the methanolic extracts of samples to afford a smooth baseline and clear background.The HPLC patterns of methanolic extracts mainly including the ginsenosides were found capable of serving as chemical fingerprints to differentiate the three species from each other.It was also found that there are no significant diffe- rences of the HPLC patterns between the wild Panax ginseng and the cultivated,the white and the red ginsengs,Chinese and Korean red ginsengs,and the tap roots of Panax ginseng collected in four consecutive months,only certain differences in contents of ginsenosides do exist.The contents of the nine major ginsenosides present in the rhizome,tap root and rootlet as well as the leaf of Panax quinquefolium were also determined and compared.

Mechanism of stibnite volatilization at high temperature

The volatilization of stibnite(Sb2S3) in nitrogen from 700 to 1000 °C was investigated by using thermogravimetric analysis. The results indicate that in inert atmosphere, stibnite can be volatilized most efficiently as Sb2S3(g) at a linear rate below850 °C, with activation energy of 137.18 k J/mol, and the reaction rate constant can be expressed as k=206901exp(-16.5/T). Stibnite can be decomposed into Sb and sulfur at temperature above 850 °C in a nitrogen atmosphere. However, in the presence of oxygen,stibnite is oxidized into Sb and SO2 gas at high temperature. Otherwise, Sb is oxidized quickly into antimony oxides such as Sb2O3 and Sb O2, while Sb2O3 can be volatilized efficiently at high temperature.