Dynamic interacting relationships among international oil prices, macroeconomic variables and precious metal prices

From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and macroeconomic variables on Chinese gold, silver and platinum prices, but also the feedback effects of Chinese precious metal prices under this impact. The results show that international oil prices play an important role in precious metal price variation both in long-term and short-term, and exchange rate only has an effect in short-term, while interest rate is ineffective in predicting precious metal prices. In addition, precious metal prices have some feedback effects on international oil prices and interest rate in short-term.

给散文“把‘脉’”

解读散文要注意"把‘脉’",如何"把‘脉’",可从以下三个方面着手:由表而里,由点而线,由断而续。"由表而里"是指通过品味语言和分析写作对象来体味作者的情思;"由点而线"是指从整体上把握文本;"由断而续"是指为貌似孤立、矛盾的言说对象建立内在的联系,发现文本思维、思想、情感的路径及其合理性。

Characteristics of Bronchial Arterial Reconstruction of Lung Cancer and the Clinical Significance

Objective: To study vascular characteristics of bronchial arterial reconstruction for lung cancer in relation to patient’s prognosis.Methods: According to the International Staging System for Lung Cancer, bronchial arteriography was performed in 16 patients with stage III a , 42 patients with stage III b lung cancer before bronchial arterial infusion (BAI) of chemotherapy. Angiograms was read by radiologists and analyzed by real-multicolour picture system. All patients were followed up and the data were collected.Results: The common findings of angiographic vessels were variable distending, hypervascularity with shunting as net, and extravasation of contrast, light or dense staining in the regions of the tumors for all patients. Radial growth vessels in pericancer were found in 30 patients, including 20 cases (66.7%) of small cell lung cancer (SCLC), 7 cases (23.3%) of adenocarcinoma, 3 cases (10%) of squamous carcinoma; a thick circular vessels in pericancer in 16 patients: both characteristics above were seen in 5 cases. Hematogenous dissemination was found in 19 of 30 patients (63.3%) with radial growth vessels in pericancer; lymphatic spread (supraclavicular nodes) in 3 of 30 (10%); local recurrences in 2 of 30 (6.7%) 6 and 30 months respectively after curable resection. Hematogenous dissemination was found in 2 of 28 patients (7.1%) without radial growth vessels in pericancer during the period of follow-up. There was significant difference in the rate of hematogenous dissemination in two groups (P<0.01).Conclusion: Radial growth vessels at pericancer for bronchial arteriography of lung cancer was an important sign of high rate of hematogenous dissemination and lymphatic spread. Key words lung cancer - angiography - metastasis

Aortic stenosis： insights on pathogenesis and clinical implications

Aortic stenosis （AS） is a common valvular heart disease in the Western populations, with an estimated overall prevalence of 3% in adults over 75 years. To understand its patho-biological processes represents a priority. In elderly patients, AS usually involves trileaflet valves and is referred to as degenerative calcific processes. Scientific evidence suggests the involvement of an active ＂atherosclerosis-like＂ pathogenesis in the initiation phase of degenerative AS. To the contrary, the progression could be driven by different forces （such as mechanical stress, genetic factors and interaction between inflammation and calcification）. The improved understanding presents potentially new therapeutic targets for preventing and inhibiting the development and progression of the disease. Furthermore, in clinical practice the management of AS patients implies the evaluation of generalized atherosclerotic manifestations （i.e., in the coronary and carotid arteries） even for prognostic reasons. In counselling elderly patients, the risk stratification should address individual frailty beyond the generic risk scores. In these regard, the co-morbidities, and in particular those linked to the global atherosclerotic burden, should be carefully investigated in order to define the risk/benefit ratio for invasive treatment strategies. We present a detailed overview of insights in pathogenesis of AS with possible practical implications.

Treatment of portal hypertension

Portal hypertension is the main complication of cirrhosis and is defined as an hepatic venous pressure gradient （HVPG） of more than 5 mmHg. Clinically significant portal hypertension is defined as HVPG of 10 mmHg or more. Development of gastroesophageal varices and variceal hemorrhage are the most direct consequence of portal hypertension. Over the last decades significant advancements in the field have led to standard treatment options. These clinical recommendations have evolved mostly as a result of rando.mized controlled trials and consensus conferences among experts where existing evidence has been reviewed and future goals for research and practice guidelines have been pro- posed. Management of varices/variceal hemorrhage is based on the clinical stage of portal hypertension. No specific treatment has shown to prevent the formation of varices. Prevention of first variceal hemorrhage depends on the size/characteristics of varices. In patients with small varices and high risk of bleeding, nonselective β-blockers are recommended, while patients with medium/large varices can be treated with either β-blockers or esophageal band ligation. Standard ofcare for acute variceal hemorrhage consists of vasoacrive drugs, endoscopic band ligation and antibiotics prophylaxis. Transjugular intrahepatic portosystemic shunt （TIPS） is reserved for those who fail standard of care or for patients who are likely to fail （＂early TIPS＂）. Prevention of recurrent variceal hemorrhage consists of the combination of β-blockers and endoscopic band ligation.

Chemical Characteristics and Environmental Significance of Fresh Snow Deposition on Urumqi Glacier No.1 of Tianshan Mountains, China

Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ > SO42-> NH4+ > NO3-> Cl-> Na+ > Mg2+ > K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains.

Vasospastic angina with J waves formation in patients with sudden loss of consciousness

Vasospastic angina is caused by sudden occlusive vasoconstriction of a segment of an epicardial artery, which can present with a wide spectrum of clinical scenario. We report the cases of two patients diagnosed with vasospastic angina, with one of which presenting with sudden cardiac arrest, while the other presenting with a relatively benign syncope. But both of them have J waves formation on ECG during active ischemia. The diagnosis and management of vasospastic angina, as well as the proposed clinical significance of J waves during coro- nary soasm are discussed.

Aliasing-free high resolution imaging of fast rotating targets with narrowband radar

Narrowband radar has been successfully used for high resolution imaging of fast rotating targets by exploiting their micro-motion features.In some practical situations,however,the target image may suffer from aliasing due to the fixed pulse repetition interval(PRI)of traditional radar scheme.In this work,the random PRI signal associated with compressed sensing(CS)theory was introduced for aliasing reduction to obtain high resolution images of fast rotating targets.To circumvent the large-scale dictionary and high computational complexity problem arising from direct application of CS theory,the low resolution image was firstly generated by applying a modified generalized Radon transform on the time-frequency domain,and then the dictionary was scaled down by random undersampling as well as the atoms extraction according to those strong scattering areas of the low resolution image.The scale-down-dictionary CS(SDD-CS)processing scheme was detailed and simulation results show that the SDD-CS scheme for narrowband radar can achieve preferable images with no aliasing as well as acceptable computational cost.

语篇语义的研究路径——一个范式、两个脉络、三种功能、四种语义、五个视角

本文首先重新认识语篇是什么、语篇有什么、语篇语义是什么、语篇语义主要包括什么,然后提出语篇语义研究的一个路径,回答用什么理论范式研究及为什么,研究什么对象及为什么,研究语篇的什么功能及为什么,研究语篇的哪些语义及为什么,以及如何研究这些语义。

Gravitational wave astronomy: the current status

In the centenary year of Einstein's General Theory of Relativity, this paper reviews the current status of gravitational wave astronomy across a spectrum which stretches from attohertz to kilohertz frequencies. Sect. 1 of this paper reviews the historical development of gravitational wave astronomy from Einstein's first prediction to our current understanding the spectrum. It is shown that detection of signals in the audio frequency spectrum can be expected very soon, and that a north-south pair of next generation detectors would provide large scientific benefits. Sect. 2 reviews the theory of gravitational waves and the principles of detection using laser interferometry. The state of the art Advanced LIGO detectors are then described. These detectors have a high chance of detecting the first events in the near future. Sect. 3 reviews the KAGRA detector currently under development in Japan,which will be the first laser interferometer detector to use cryogenic test masses. Sect. 4 of this paper reviews gravitational wave detection in the nanohertz frequency band using the technique of pulsar timing. Sect. 5 reviews the status of gravitational wave detection in the attohertz frequency band, detectable in the polarisation of the cosmic microwave background, and discusses the prospects for detection of primordial waves from the big bang. The techniques described in sects. 1–5 have already placed significant limits on the strength of gravitational wave sources. Sects. 6 and 7 review ambitious plans for future space based gravitational wave detectors in the millihertz frequency band. Sect. 6 presents a roadmap for development of space based gravitational wave detectors by China while sect. 7 discusses a key enabling technology for space interferometry known as time delay interferometry.

THE EFFECTS OF TIMING OF PULSE SPRAYING AND RELEASING PERIODS ON DYNAMICS OF GENERALIZED PREDATOR-PREY MODEL

Based on the facts of releasing natural enemies and spraying pesticides at different time points, we propose a generalized predator-prey model with impulsive interventions. The threshold values for the existence and stability of pest eradication periodic solution are provided under the assumptions of releasing natural enemies either more or less frequent than spray. In order to address how the different pulse time points, control tactics affect the pest control （i.e. the threshold value）, the Holling Type II Lotka-Volterra predator- prey system, as an example, with impulsive intervention at different time points axe investigated carefully. The numerical results show how the threshold values are affected by the factors including instantaneous killing rates of pesticides on pests and natural enemies, the release rate of natural enemies and release constant, timing of pesticide application and timing of release period. Furthermore, it is confirmed that the system has the coexistences of pests and natural enemies for a wide range of parameters and with quite different pest amplitudes.

Nerve pulse propagation in biological membranes： Solitons and other invariant solutions

We investigate a generalized form of the Boussinesq equation, relevant for nerve pulse propagation in biological membranes. The generalized conditional symmetry （GCS） method is applied in order to obtain the conditions that enable the equation to admit a special class of second-order GCSs. For the case of quadratic nonlinearities, we outline a new class of invariant solutions.

Origin and geological significance of the 1.81 Ga hyalophane-rich pegmatite veins from the high-pressure granulite terrain in the Central Zone of North China Craton

Hyalophane-rich pegmatites are identified from the Manjinggou high-pressure granulite terrain in the Central Zone of North China Craton. Based on field investigation, mineral assemblage and mineral geochemistry, two types of pegmatites can be defined, i.e., hyalophane pegmatite and hyalophane-rich pegmatite. The hyalophane pegmatite is composed of pure hyalophane with 18.7 mol%-19.4 mol% celsian, whereas the hyalophane-rich pegmatite consists of clinopyroxene + titanite + epidote + hyalophane with 11.9 mol%-12.5 mol% celsian. Hyalophane-rich pegmatite has typical magmatic zircons with oscillatory zoning and high Th/U ratios, implying that this type of pegmatite crystallized from special melt similar to magma. SIMS (Cameca 1280) zircon U-Pb dating shows that the crystallization age of the hyalophane-rich pegmatite is 1812±5 Ma, younger than the regional metamorphic age (peak of ca. 1.85 Ga). Zircon δ18O (8.0 ‰-9.3 ‰) and ?Hf (-7.0 to-2.7) values measured by SIMS suggest that the high-pressure granulite terrain was the source of these veins. Therefore, the hyalophane-rich pegmatite veins were likely to be generated by melting of the high-pressure granulite terrain during post collisional uplift. A quick tectonic uplifting process with a velocity of 0.4 to 0.6 mm/a has been estimated for the high-pressure granulite terrane from the Central Zone of North China Craton.