Technique In China Research Articles

Development Progress of Surfactants for Chemical Combination Flooding

Chemical combination flooding is one of the main enhanced oil recovery (EOR) techniques in China. The key factor of a successful chemical combination flooding application is the development of oil displacement surfactants with good performance. In this paper, the basic requirements of surfactant for chemical combination flooding were introduced, and the development progress of surfactants for chemical combination flooding was reviewed and their application results were shown. With the expanding application of chemical combination flooding in different types of reservoir, the challenge and development direction of oil displacement surfactants were indicated.

A Brief Analysis of Domestic Construction and Demolition Waste Recycling Techniques

In this paper, the construction and demolition waste (C&D waste) recycling techniques in China is summarized, and proposed the C&D waste recycling suggestions in this foundation. The C&D waste can be divided into construction waste, decorating waste, demolition waste and natural disaster ruin waste. In addition to be buried, domestic C&D waste can be made into landscape material, roadbed material, recycled aggregate, recycled brick, recycled concrete, recycled admixture and so on. The state should establish positive promoting policies, improve the recycling industrial chain, and promote the healthy development of the C&D waste recycling.

3DSurs – An Example of the Development of Mobile Mapping Systems in China

Since the early 1990s mobile mapping techniques have been developed for the rapid acquisition of data along highways and streets. A number of systems have been successfully tested and applied to numerous projects. China started research and development of mobile mapping in the mid-1990s and several systems reached their application stage in the 2000s. This paper reviews developments in mobile mapping techniques in China and overseas. In particular, our focus is on the 3DSurs system developed by the authors of this paper. First, the system is described in detail, including sensors, coordinate systems, and data processing. Then theoretical error analysis of the system is discussed, followed by field experimental studies.

The Present Situation and Development Trend of Airborne Geophysical Technique in China

The Present Situation and Development Trend of Airborne Geophysical Technique in China

Current status of researches and clinical application of invisible aligner technique in China

口腔正畸学的发展离不开矫治技术的进步与革新.纵观固定矫治技术发展的100多年历史,托槽、弓丝等关键矫治部件的不断创新和改良推动着正畸矫治技术的发展,而具有美观性及隐蔽性的无托槽隐形矫治技术在20世纪90年代出现,该方法无需粘接固定矫治器托槽.从技术角度而言,无托槽隐形矫治技术是基于计算机、三维重建、激光快速成形等相关技术的快速发展而得以实现。

Applications of synchrotron-based X-ray techniques in environmental science

Synchrotron-based X-ray techniques have been widely applied to the fields of environmental science due to their element-specific and nondestructive properties and unique spectral and spatial resolution advantages. The techniques are capable of in situ investigating chemical speciation, microstructure and mapping of elements in question at the molecular or nanometer scale, and thus provide direct evidence for reaction mechanisms for various environmental processes. In this contribution, the applications of three types of the techniques commonly used in the fields of environmental research are reviewed, namely X-ray absorption spectroscopy (XAS), X-ray fluorescence (XRF) spectroscopy and scanning transmission X-ray microscopy (STXM). In particular, the recent advances of the techniques in China are elaborated, and a selection of the applied examples are provided in the field of environmental science. Finally, the perspectives of synchrotron-based X-ray techniques are discussed. With their great progress and wide application, the techniques have revolutionized our understanding of significant geo- and bio-chemical processes. It is anticipatable that synchrotron-based X-ray techniques will continue to play a significant role in the fields and significant advances will be obtained in decades ahead.

Development and verification of Chinese dietary exposure evaluation model software

To develop the dietary exposure evaluation model software accredited of Chinese intellectual property rights and to verify the rationality and accuracy of the results from the probabilistic model in Chinese dietary exposure evaluation model software according to international standards. The software of SAS was used to build various evaluation model based on the data from Chinese dietary survey and the chemical compound in food surveillance and to design an operation interface. The results from probabilistic dietary exposure model for children 2 - 7 years old were compared with that from duplicate portion study of 2-7 years children dietary exposure in Jinhu, Jiangsu province in order to analyze the rationality of model. The results from probabilistic model of dietary exposure were compared with the results from @Risk software to verify the correction of the probabilistic model by using the same data of randomly selected 10 000 study subjects from national dietary survey. While, the mean drift was used as an internal index to illustrate the accuracy of the computation. Chinese dietary exposure evaluation software was developed successfully. On the rationality, the results from probabilistic model were lower than that from the point estimation (e.g., cucumber: the result of point estimation of acephate was 4.78 microg x kg(-1) x d(-1), while the results of probabilistic model which was 0.39 microg x kg(-1) x d(-1)). Meanwhile the results from probabilistic model were higher than the results of duplicate portion study (on the P95, the result of probabilistic model of Pb exposure in children was 11.08 microg x kg(-1) x d(-1), while the results of duplicate portion study was 5.75 microg x kg(-1) x d(-1)). On accuracy, the results from @Risk and the probabilistic model were highly consistent (on the P95, the result of probabilistic assessment of acephate diet exposure was 4.27 microg x kg(-1) x d(-1), while the results of duplicate portion study was 4.24 microg x kg(-1) x d(-1)), and the mean drift was of random distribution, the drift region varied from 0.05% to 11.9%. The results computed by the software of Chinese dietary exposure evaluation model are reliable and reasonable, which is a meaningful step to improve the dietary exposure evaluation technique in China.

The present situation and prospect of liver resection technique in China

肝切除术是肝胆外科临床实践中最重要的一种手术方法.从我国人民疾病的发病谱和疾病危险性来看,肝切除术是目前肝癌治疗最有效的一线根治性手段,也是众多肝脏良性疾病、胆道疾病的有效治疗手段.就肝切除技术而言,随着现代生物医学科学的发展,其内涵也有新的拓展。

Study of methanol-to-gasoline process for production of gasoline from coal

The methanol-to-gasoline (MTG) process is an efficient way to produce liquid fuel. The academic basis of the coal-to-liquid process is described and two different synthesis processes are focused on: Fixed MTG process and Fluid Bed MTG process. Then, the superiority of the Fluid Bed MTG Process is pointed out relative to the Fixed MTG Process. In addition, the development of the coal-to-liquid technique in China is briefly summarized.

Earnings management in China: an exploratory study

PurposeIn recent years, China has been making progress in internationalizing its financial reporting system. However, it is believed that earnings management from legitimate accounting choices to fraud that violates generally accepted accounting principles, is common in the mainland. The purpose of this study is to identify the most frequently used earnings management techniques in China and the underlying factors that motivate firms to engage in earnings management.Design/methodology/approachData were gained through a questionnaire sent to managers and accountants in mainland Chinese companies.FindingsThe results show that the size and form of ownership of companies materially influence earnings management incentives and techniques in China. Public ownership companies have stronger incentives to manage earnings for management compensation, while private ownership companies pay more attention to tax expense savings. Also, several popular techniques employed in China are revealed.Originality/valueThis study presents a general picture of earnings management in China by surveying the opinions of accountants and financial managers in Chinese companies.

Feasibility and safety of vaginal myomectomy: analysis of 90 cases

Vaginal myomectomy was firstly reported in 1994, however, it is a relatively new technique in China. The feasibility and safety of the procedure is still controversial in this country. The aim of this study was to analyze the outcomes of vaginal myomectomy in 90 patients and to investigate the feasibility and safety of the surgery. From June 2001 to June 2004, 90 patients with uterine leiomyoma were treated with vaginal myomectomy in our hospital (vaginal group). The indications, operative performance, postoperative complications, and recovery of the patients were analyzed and compared with those of 93 patients with uterine leiomyoma treated by laparotomic myomectomy from January 2000 to January 2001 (laparotomy group). The Student's t test was used to compare the continuous variables between the two groups, and the chi-square test was used to compare the categorical variables. The vaginal and laparotomy groups were followed up for 10 - 34 months (median, 21) and 15 - 24 months (median, 30), respectively. Vaginal myomectomy was performed successfully in 87 of the 90 patients (96.7%). In the other 3 patients, the procedure failed and laparotomy was carried out. In both groups, the uterus was enlarged to 8 - 16 weeks gestational size (median, 10 gestational weeks). The number of resected tumors was 1 - 12 (median, 2) in the vaginal group and 1 - 15 (median, 4) in the laparotomy group, respectively (P > 0.05). The mean operating time, intraoperative blood loss, and postoperative hospital stay were (52 +/- 21) minutes, (230 +/- 44) ml, and (7.0 +/- 1.2) days in the vaginal group, and (65 +/- 32) minutes, (200 +/- 56) ml, and (7.0 +/- 1.5) days in the laparotomy group (P > 0.05). The mean top postoperative temperature was (38.4 +/- 1.1) degrees C and (37.8 +/- 0.6) degrees C in the two groups respectively (P < 0.05). Both groups had one recurrent case during the follow-up (P > 0.05). Vaginal myomectomy is feasible and safe in treating uterine leiomyoma. To some extent, it is superior to laparotomic myomectomy by avoiding severe trauma during the surgery.

Radiotherapy for carcinoma of the Esophagus: Progress of treatment and research in China

Carcinoma of the esophagus is a common malignancy in China. Radiotherapy is one of the most important modalities of treatment. This article provides a review of the natural history of this disease, the results of radiotherapy for esophageal cancer and the recent advances in radiation techniques in China. Significant progress has been made in this area of research and treatment. Combined treatment modalities and new therapies are being evaluated and may be expected to contribute to improved patient outcomes and better palliation of symptoms in the future.

The technical development of crystals and oscillators in China and their market situation

In recent years the manufacture of and demand for crystals and oscillators in China have been increasing quickly because of the development of industries, communications, science, transportation, and electronic techniques. This paper introduces the manufacture, research, and characteristics of the technical development of crystals and oscillators in the last ten years in China. To meet the demand from industry, science, and other markets, the number of companies that produce and research crystals and oscillators has increased from several to more than 300 in the last 20 years. Manufacturing technology and equipment have also improved. For marketing and technical reasons, more than 75% of the companies manufacture mainly 49 micro, 49 micros, and microm crystals. Now more and more companies plan to build production lines to make cold-weld crystals and other precision crystals, and at least two companies have already built their production lines. Most of the precision crystals are AT-cut but some are SC-cut. Integrated TCXOs and DTCXOs have been made by different companies, and the frequency-temperature stability of them is from +/- 2 ppm to +/- 0.5 ppm in a wide temperature range. Specifications of some OCXOs are almost the same as those of foreign OCXOs. The main design techniques in China are experimental. However, in recent years, specially designed software has been developed for oscillator design, and advanced instrumentation and equipment are used. The market situation for crystals and oscillators has increased.

Acuality and progress of pathologic techniques in China

Acuality and progress of pathologic techniques in China

Study of Dongting Lake area variation and its influence on water level using MODIS data / Etude de la variation de la surface du Lac Dongting et de son influence sur le niveau d’eau, grâce à des données MODIS

MODerate-resolution Imaging Spectroradiometer (MODIS) is a new generation remote sensing (RS) sensor and its applications in hydrology and water resources have attracted much attention. To overcome the problems of slow response in flood disaster monitoring based on traditional RS techniques in China, the Flood Disaster Monitoring and Assessing System (FDMAS), based on MODIS and a Geographic Information System (GIS), was designed and applied to Dongting Lake, Hunan Province, China. The storage curve of Dongting Lake for 1995 was obtained using 1:10 000 topographic map data and then a relationship between water level at the Chenglingji hydrological station and lake area was derived. A new relationship between water level and lake area was obtained by processing MODIS images of Dongting Lake from April 2002 to April 2003 and the influence of lake area variation on water level was analysed with the 1996 flood data. It was found that the water level reduction reached 0.64 m for the 1996 flood if the original lake area curve was replaced with the area curve of 2002. This illustrates that the flood water level has been considerably reduced as a result of the increased area of Dongting Lake since the Chinese Central Government’s ȁreturn land to lakeȁ policy took effect in 1998.

Progress and challenges for petroleum geophysical techniques in China

This paper summarizes the technological progress of the Chinese petroleum geophysical industry in recent years and analyzes in detail the trend of development in the petroleum industry as well as the main challenges to geophysical techniques on the mainland. Proposals to improve the situation have also been put forward.

Progress in treatment of intra-articular injury and arthroscopic techniques in China

关节内损伤指涉及关节结构的骨、软骨和关节内软组织包括韧带、软骨盘、滑膜等的急性或慢性损伤.传统的诊断和治疗方法由于其局限性常导致关节失稳和创伤性关节病变.关节镜作为一种微创技术,自上世纪80年代以来国内开始用于诊治急慢性关节损伤,随着关节镜手术理论和技术的提高和普及,关节镜设备和器械的改进,关节镜更广泛地应用于诊断和治疗急性关节创伤、关节内骨与软骨骨折、关节内韧带损伤、半月板损伤,肩关节损伤等方面.本文对此进行综述。

Simultaneous observations of optical and electrical signals in altitude‐triggered negative lightning flashes

This paper presents an analysis of the experimental data on five negative lightning flashes initiated using the altitude‐triggering technique in China. The data include highly time‐resolved optical images and electric fields measured 60 m and 1300 m from the lightning channel. The triggering technique involves the launching upward of a small rocket trailing a wire electrically floating. The data show that these 5 flashes have a similar chronological sequence of events, including a bidirectional leader system followed by a mini‐return stroke and a bidirectional discharge process. The bidirectional leader system consists of an upward positive leader initiated from the top of the wire and a downward negative stepped leader from the bottom, with the onset of the former prior to the latter by 3 to 8.3 ms. The downward negative stepped leader, having a step interval of 12–30 μs, appears to pause and resume several times while the upward positive leader extends forward continuously. With the downward negative stepped leader close to ground, a mini‐return stroke occurs between the ground and the bottom of the wire. The mini‐return stroke propagates upward with a speed of 1–2 × 108 m/s and emits intense light signals similar to a normal return stroke below the bottom of the wire. It becomes invisible after entering the bottom of the wire and appears again as a bright upward discharge from the top of the wire several microseconds later. This upper bright discharge ceases after propagating forward several hundred meters at a speed of 1.5–5.4 × 107 m/s. The cessation of the upper bright discharge is obviously associated with the disintegration of the wire at that moment. Right after the cessation of the upper bright discharge, a bidirectional discharge process starts from the bottom of the wire with its positively charged part having an upward speed of 3–10 × 105 m/s and its negatively charged part a downward speed of 2–2.6 × 105 m/s. Reflection of current waves at the bottom of the wire due to the explosion of the wire at that moment may be a major reason for the occurrence of this lower bidirectional discharge.

Potential of gas turbine co-generation in China

With the fast economic development in China, the situation of environmental protection becomes more and more serious. Most of the pollutants are produced by burning coal, especially in heating period. To achieve the aim of environmental protection, some clean energy resources and clean techniques should be wildly promoted. This paper explores the policy, environmental and economic aspects of co-generation of heat and power using natural gas in China. Also, the arresting factors in developing the GT co-generation system and proposals of the countermeasures are discussed. All the discussions show that natural gas-fired GT co-generation system can be a quite suitable technique in China.

State-of-Practice Review of Deep Soil Mixing Techniques in China

Deep soil mixing techniques have been widely adopted in China since the late 1970s and mainly used for ground improvement for structural support and earth-retaining structures for excavations. A comprehensive state-of-practice review on development, applications, soil-cement properties, mechanistic studies, design methods, and quality control of deep soil mixing techniques in China is presented. These research results will serve as a reference for advancing deep soil mixing techniques in the United States and other countries.