诗以奇趣为宗——论苏诗的艺术个性

宋、金时人评论苏诗,多以“新”或“奇”目之。《后山诗话》说:“诗欲其好,则不能好矣。王介甫以工,苏子瞻以新,黄鲁直以奇。”元好问《论诗三十首》之二二云:“奇外无奇更出奇,一波才动万波随。只知诗到苏黄尽,沧海横流却是谁?”其二六又云:“金入洪炉不厌频,精真那计受纤尘。苏门果有忠臣在,肯放坡诗百态新?”细味其意,似乎对苏诗之“新”隐含不满。对此,清人曾予反驳,赵翼说:“新岂易言.意未经人说过则新,书未经人用过则新。

Effect of nitrogen ion implantation dose on torsional fretting wear behavior of titanium and its alloy

Various doses of nitrogen ions were implanted into the surface of pure titanium, Ti6Al7Nb and Ti6Al4V, by plasma immersion ion implantation. Torsional fretting wear tests involving flat specimens of no-treated and treated titanium, as well as its alloys, against a ZrO2 ball contact were performed on a torsional fretting wear test rig using a simulated physiological medium of serum solution. The treated surfaces were characterized, and the effect of implantation dose on torsional fretting behavior was discussed in detail. The results showed that the torsional fretting running and damage behavior of titanium and its alloys were strongly dependent on the dose of the implanted nitrogen ions and the angular displacement amplitude. The torsional fretting running boundary moved to smaller angular displacement amplitude, and the central light damage zone decreased, as the ion dose increased. The wear mechanisms of titanium and its alloys were oxidative wear, abrasive wear and delamination, with abrasive wear as the most common mechanism of the ion implantation layers.

Two Steps B Ion-Implantation of Diamond Film Grown on an n-Type Si Substrate and Its p-n Junction Effects

Polycrystalline diamond thin films are deposited on an n-type Si substrates by hot filament chemical vapor deposition,and then are implanted with boron ions in a 200keV ion implanter.In order to achieve a better distribution of the implanted element,boron ions are implanted by two steps:implanting boron ions with the energy of 70keV first,and then with the energy of 100keV.The homogeneous distribution of the B ion is gained.The current-voltage characteristics of the samples are studied.It is found that the p-n heterojunction effect is achieved in these samples.

Empirical Analysis on Rural Financial Development and Farmers' Income Increase in China

The growth of farmer＇s incomes is cIoseIy reIated to rural finance. The research analyzed the dynamic reIationship of rural financial deveIopment, efficiency and farmer＇s incomes based on VAR modeI, and the resuIts indicated that the ex-pansion of rural finance wouId stimuIate farmer＇s incomes in a Iong term, and the growth of rural financial efficiency significantIy improves farmer＇s incomes in a short term, instead of a Iong term. Hence, it is necessary to introduce more credit funds and social funds to rural areas, deepen rural financial system reform and acceIerate use rate of Ioan capital and enhance guidance for farmers and township enterprises in use of Ioan capitals.

An algorithm supporting fast scheduling and viewing of remote sensing images in embedded devices

In order to resolve the conflict between the limited resources of embedded devices and the growing amount of massive image data to be shown, a solution for fast images rendering in embedded devices is proposed and implemented. First, an improved algorithm of a multi-resolution file-pyramid construction which is used for the organization of massive image data is presented. Then, a strategy, adopting technologies such as view-dependent levels of detail, target-tiles quick search and tiles seamless connection, is presented for fast scheduling and viewing of images. The results show that compared with the solution of multi-scale image representations based on wavelet, the proposed solution can improve the rendering speed, and the rendering speed does not depend on the image size, though it increases some data storage space. And the proposed solution is suitable for embedded devices and friendly experience.

汉简所见“致籍”与“出入名籍”考辨——以肩水金关简为中心

"致籍"和"出入名籍"同属于出入关文书系统,学界之前对二者格式分类界定模糊。随着肩水金关汉简(壹)、(贰)简文的公布,有利于推进对此问题的研究。"致籍"多由传发放机构提前转送至关口,以供关吏核查持传、符者是否本人。它包含原文通知性文书以及出行人员名单附件。学界对出行人员名单附件格式归类尚不统一,以金关简出土名籍简为基础可大致将其分为四种类型。"出入名籍"与"致籍"格式有类似之处,但不属于同一种文书,它们关键性区别在于"出入名籍"上会有明确的出入关记录文字。"出入名籍"分为单人出入关记录和多人同时出入关记录。后者应只有一件致籍通知文书和传文书,关吏可能会将多人名籍编连在一起,只在其中一枚简之上附记出入时间。

Indentation of sandwich beams with metal foam core

The quasi-static indentation behavior of sandwich beams with a metal foam core was investigated. An analytical model was developed to predict the large deflections of indention of the sandwich beams with a metal foam core subjected to a concentrated loading. The interaction of plastic bending and stretching in the local deformation regions of the face sheet was considered in the analytical model. Moreover, the effects of the shear strength of the foam core on the indentation behavior were discussed in detail. The finite element simulations were preformed to validate the theoretical model. Comparisons between the analytical predictions and finite element results were conducted and good agreement was achieved. The results show that the membrane force dominates indentation behavior of the sandwich beams when the maximum deflection exceeds the thickness of the face sheet.

Microstructure, mechanical and bio-corrosion properties of as-extruded Mg-Sn-Ca alloys

The as-extruded Mg？Sn？Ca alloys were prepared and investigated for orthopedic applications via using optical microscopy, scanning electron microscopy, X-ray diffraction, as well as tensile, immersion and electrochemical tests. The results showed that, with the addition of 1% Sn and the Ca content of 0.2%？0.5%, the microstructure of the as-extruded Mg？Sn？Ca alloys became homogenous, which led to increased mechanical properties and improved corrosion resistance. Further increase of Ca content up to 1.5% improved the strength, but deteriorated the ductility and corrosion resistance. For the alloy containing 0.5% Ca, when the Sn content increased from 1% to 3%, the ultimate tensile strength increased with a decreased corrosion resistance, and the lowest yield strength and ductility appeared with the Sn content of 2%. These behaviors were determined by Sn/Ca mass ratio. The analyses showed that as-extruded Mg？1Sn？0.5Ca alloy was promising as a biodegradable orthopedic implant.

The Cost-effectiveness Analysis of Percutaneous Transhepatic Metal Versus Plastic Biliary Stent Implantation for Treating Malignant Biliary Obstruction (Multiple Center Investigation)

Objective: To compare metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction in cost-effectiveness ratio (CER). Methods: Percutaneous transhepatic self-expandable metal stent (MS, n=61) or 10F plastic stent (PS, n=34) implantation was performed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival and stent patency rates of the patients in the two groups. CERs of two groups were calculated. The main indexes were CERsurvival period (total cost/median survival period), CERpatency period (total cost/median patency period). Results: The total costs of treatment were 53177±3139 yuan (RMB) in MS group and 42564±4950 yuan (RMB) in PS group respectively (P>0.05). CER in MS group was superior to that in PS group (CERsurvival period was 237.4 yuan /d vs 452.6 yuan /d, respectively; CERpatency period was 231.2 yuan /d vs 472.9 yuan /d, respectively). Conclusion: The metal stent implantation is superior to the plastic stent in the CER for treatment of malignant biliary obstruction.

Effect of N-ion implantation and diamond-like carbon coating on fretting wear behaviors of Ti6Al7Nb in artificial saliva

The tribology behaviors of Ti6Al7Nb,its alloy with N-ion implantation,and its alloy with diamond-like carbon(DLC)coating were investigated in artificial saliva.Fretting wear tests of untreated,N-ion implanted and DLC coated Ti6Al7Nb alloys plate against a Si3N4ball were carried out on a reciprocating sliding fretting wear test rig.Based on the analysis of X-ray diffraction,Raman spectroscopy,3-D profiler,SEM morphologies and frictional kinetics behavior analysis,the damage behavior of surface modification layer was discussed in detail.The results indicated that the fretting wear behavior of Ti6Al7Nb alloy with N-ion implantation was increased with the dose increase of the implanted nitrogen ions.Moreover,the DLC-coated Ti6Al7Nb alloy with low ion implantation could improve the fretting wear behavior greatly.In addition,the Ti6Al7Nb with DLC coating had better ncorrosion resistance due to the special compact structure.All results suggested that the Ti6Al7Nb with DLC coating had better wear resistance than that with N-ion implantation in artificial saliva.

Effects of laser phase transformation hardening parameters on heat input and hardened-bead profile quality of unalloyed titanium

Laser transformation hardening(LTH)of unalloyed titanium of 1.6 mm-thick sheet,nearer to ASTM Grade 3 of chemical composition was investigated using 2 kW CW Nd:YAG laser.The effects of laser power(750-1 250 W),scanning speed(1 000-3 000 mm/min)and focal point position(from-10 to-30 mm)on the heat input,and hardened-bead geometry(i.e.hardened bead width(HBW),hardened depth(HD)and angle of entry of hardened bead profile with the surface(AEHB))were investigated using response surface methodology(RSM).The experimental plan is based on Box-Behnken design matrix method.Linear and quadratic polynomial equations for predicting the heat input and the hardened bead geometry were developed.The results indicate that the proposed models predict the responses adequately within the limits of hardening parameters being used.It is suggested that regression equations can be used to find optimum hardening conditions for desired criteria.

Load Dependence of Nanohardness in Nitrogen Ion Implanted Ti6Al4V Alloy and Fractal Characterization

Three different nitrogen ion doses were implanted into a Ti6A14V alloy to improve its mechanical surface properties for the application of artificial joints. The titanium nitride phase and nitrogen element distribution profile were characterized with X-ray photoelectron spectroscopy （XPS）. Nano-indentation tests were carried out on the surface of the Ti6A14V alloy and implanted samples on a large scale of applied loads. The XPS analysis results indicate that nitrogen diffuses into the titanium alloy and forms a hard TiN layer on the Ti6A14V alloy. The nanohardness results reveal that nitrogen ion implantation effectively enhances the surface hardness of Ti6A14V. In addition, the nanohardness clearly reveals load dependence over a large segment of the applied loads. Thus a concept of nanohardness fractal dimension is first proposed and the dual fractal model can effectively describe nonlinear deformation in indentation areas on the Ti6A14V surface. The fractal dimension shows a decreased trend in two regions of applied loads, indicating a decrease of the self-similarity complexity in surface indentation owing to an increase in nanohardness after nitrogen ion implantation.

Effect of welding heat input and post-weld aging time on microstructure and mechanical properties in dissimilar friction stir welded AA7075-AA5086

The effects of welding heat input and post-weld heat treatment on the mechanical and microstructural aspects of dissimilarfriction stir welds of age-hardened AA7075-T6and strain hardenable AA5086-H32aluminium alloys were investigated.X-raydiffraction(XRD)residual stress analysis and tensile testing together with optical metallography and transmission electronmicroscopy(TEM)were performed to assess the effects of process parameters on welded joints.It was discovered that jointsproduced without heat sink exhibited more homogeneous stir zones than other joints.Of the natural aging time studied,higheramount of solid solution during rapid cooling of welds produced higher driving force for increase in hardness in the AA7075sideduring natural aging.Natural aging within stirring zone and thermo-mechanical affected zone of AA7075side resulted in a10to25MPa reduction in the residual stress in these zones;its effect decreased considerably in the welds performed without heat sink.Inaddition,natural aging had no noticeable effect on the joint strength.

Comparison of different intervention procedures in benign stricture of gastrointestinal tract

AIM:To determine the most effective intervention procedure by evaluation of mid and long-term therapeutic efficacy in patients of stricture of the gastrointestinal tract (GTT). METHODS:Different intervention procedures were used to treat benign stricture of GIT in 180 patients including pneumatic dilation (group A,n=80),permanent (group B, n=25) and temporary (group C,n=75) placement of expandable metallic stents. RESULTS:The diameters of the strictured GIT were significantly greater after the treatment of all procedures employed (P<0.01).For the 80 patients in group A,160 dilations were performed (mean,2.0 times per patient). Complications in group A included chest pain (n=20),reflux (n=16),and bleeding (n=6).Dysphagia relapse occurred in 24(30%) and 48 (60%) patients respectively during 6-and- 12 momth follow-up periods in group A.In group B,25 uncovered or partially covered or antireflux covered expandable metallic stents were placed permantly, complications included chest pain (n=10),reflux (n=15), bleeding (n=3),and stent migration (n=4),and dysphagia relapse occurred in 5 (20%) and 3 patients (25%) during the 6-and-12 month follow-up periods,respectively.In group C,the partially covered expandable metallic stents were temporarily placed in 75 patients and removed after 3 to 7 days via gastroscope,complications including chest pain (n=30),reflux (n=9),and bleeding (n=12),and dysphagia relapse occurred in 9 (12%) and 8 patients (16%) during the 6-and-12 month follow-up periods,respectively.The placement and withdrawal of stents were all successfully performed.The follow-up of all patients lasted for 6 to 96 months (mean 45.3±18.6 months). CONCLUSION:The effective procedures for benign GIT stricture are pneumatic dilation and temporary placement of partially-covered expandable metallic stents.Temporary placement of partially-covered expandable metallic stents is one of the best methods for benign GIT strictures in mid and long-term therapeutic efficacy.

Competitiveness of Egyptian cotton exports in the international market

Cotton plays a vital role in the Egyptian economy by meeting domestic and export demands,contributing significantly to agriculture,industry,export earnings,and providing a cash income to roughly one million small farmers.This paper examines the competitiveness of Egyptian cotton exports(ECE) in the international market during the period 1990-2006.It mainly aims at investigating the trends in cotton exports over the studied period,analyzing the competitive position of Egyptian cotton by employing several economic and trade indices,and identifying the key factors that influence Egypt's cotton exports to the world.The results revealed that the total quantity of ECE has fallen from 196.8 thousand tons in 2003 to 87.2 thousand tons in 2006.It also shows a high degree of geographic concentration of ECE,into India,Italy,the Republic of Korea,and Japan.Together,these markets imported about 50%of ECE during 1990-2006.The competitive advantage of Egyptian cotton would appear dependent on quality not price.Japan,the Republic of Korea and Italy presented the most stable markets for ECE.Linear regression analysis suggests that a one percent increase in the Egypt-to-USA export price ratio leads to a decrease in ECE by about 27.8 thousand tons.Such analysis has also shown a positive and significant effect of the World Trade Organization on ECE.

Effect of Ca addition on microstructure and impression creep behavior of cast AZ61 magnesium alloy

Microstructure and creep properties of AZ61 alloy containing 1 and 3 wt.% Ca were investigated. The creep properties were examined using impression method under different stresses between 200 and 500 MPa at the temperature ranging from 423 to 491 K. The microstructure of AZ61 alloy contains α(Mg) matrix and Mg17 Al12 intermetallic phases. It is shown that adding Ca to AZ61 alloy reduces the amount of Mg17 Al12 phase via forming(Mg,Al)2 Ca phase;furthermore, increasing the Ca content to 3 wt.% leads to the formation of(Mg,Al)2 Ca phase, as well as the elimination of the Mg17 Al12 phase. Creep properties of AZ61 alloy are improved with the Ca addition. The improvement in creep properties is attributed to the reduction in the amount of Mg17 Al12 phase and the formation of(Mg,Al)2 Ca phase with high thermal stability. According to the obtained creep data, it is concluded that the pipe diffusion-climb controlled dislocation creep is the dominant creep mechanism and Ca addition has no influence on this mechanism. The effect of pre-deformation on the creep properties of AZ61+3%Ca alloy reveals that the creep resistance of the alloy depends on the continuity of(Mg,Al)2 Ca phase. It is decreased by reducing the phase continuity.

Effect of heat input on microstructure and mechanical properties of butt-welded dissimilar magnesium alloys joint

The effects of heat input on the microstructures and mechanical properties of tungsten inert gas （TIG） butt-welded AZ31/MB3 dissimilar Mg alloys joint were investigated by microstructural observations, microhardness testing and tensile testing. The results reveal that with the increase of heat input, the width of welding seam increases obviously and the grains both in the fusion zone and the heat affected zone coarsen during TIG welding process. The tensile strength of butt-welded joint increases with the increase of heat input and the maximum joining strength of 242 MPa is obtained with wedding current of 90 A. However, lots of welding pores occur with the further increase of heat input, which results in the decrease of joining strength. It is experimentally demonstrated that robust joint can be obtained by TIG welding process.

Improvements onthe Earnings Forecast Model——Based on Correlation between Financial Ratio, Auditor Opinion and Future Earnings

This paper aims to find evidence for the improvements on the present earnings forecast models through analyzing the correlation among financial ratios, auditor opinion of listed companies and their future earnings. This paper uses two statistical regression methods including Logistic model and Linear model to examine the inner interaction between financial ratios and future earnings from qualitative and quantitative perspectives respectively. Empirical tests find that financial ratios, especially ROE, can help to predict future earnings. Then we add auditor opinion variable into Logistic model to test whether going concern opinion in the auditor reports can be helpful for earnings forecast. Result shows the degree of optimistic statement of going concern opinion is significantly correlated with future earnings but with the disturbance of earnings management.

Effects of heat input in friction stir welding on microstructure and mechanical properties of AA3003-H18 plates

The non-heat-treatable AA3003-H18 plates were joined by friction stir welding（FSW） to achieve a proper joint by optimizing the welding parameters.For this purpose,the effects of heat input on microstructure and mechanical properties of the welded samples were investigated by changing the ratios of rotational speed（800-1200 r/min） to travel speed（40-100 mm/min）（w/v）.It was revealed that the grain growth rate was strongly increased with the increase of the heat input by rotational speed at constant travel speed,while the grain growth rate was slightly increased with the increase of the heat input by travel speed at constant rotational speed.Subsequently,hardness reduction was observed in the stir zone at higher rotational speed compared with that at lower one.An interesting observation was that various welding parameters do not have noticeable effect on the tensile strength of the FSW joints.Also,it has been observed that the fracture location of tensile test specimens was placed in the heat-affected zone（HAZ）on the advancing side at lower travel speed,while at higher travel speed,it was placed at the HAZ/thermomechanical affected zone（TMAZ） interface on the retreating side.

Prediction Ability of Cash Flows, Net Income （NI）, and Auditors

The accounting information should help investors and creditors evaluate the amounts, timing, and uncertainty of firms＇ future cash receipts and disbursements. The Financial Accounting Standards Board （FASB） contends that accrual-based historical earnings are superior to cash flows in predicting future cash flows. But, Bowen, Burgstahler, and Daley （1986） showed that traditional measures of cash flows （net income （NI） plus depreciation and working capital from operations） appear to be better predictors of future cash flows than accrual accounting earnings. Since then, many researchers have articulated the importance of accounting data, especially cash flows and NI, in the predictive and forecasting processes. In this study, we empirically re-examined the ability of cash flows from operating activities （CFO） and accrual-based NI in predicting firms＇ bankruptcy. In the past, the results of this type of research were mixed. Differently from previous research, we focus on the timing of predictive ability, i.e., which indicator, cash flows or NI, is faster in predicting a firm＇s bankruptcy. We also investigate the timing of auditors＇ issuance of a going-concern opinion. The preliminary results show that the accrual-based NI is more accurate and faster than either CFO or audit opinion in predicting firms＇ failures. On average, NI signals a firm＇s bankruptcy 2.41 years before the bankruptcy filing, while CFO signals 1.48 years before filing. Auditors issued a going-concern opinion, another signal for firms＇ failure, to only 16 out of 41 bankrupt firms one year before bankruptcy, and no auditor issued the going-concern opinion two years before bankruptcy.