[en] Time correlation coincidence (TCC) is an effective method to measure characteristics of fission materials. In this paper, MCNP code is used to simulate n/γ time-of-flight spectra (TOF) of a "2"5"2Cf spontaneous fission source detected by a BC-501A liquid scintillator. The results are in good agreement with the measured spectra. Therefore, n/γ TCC spectra of the "2"5"2Cf source are simulated. The results indicate that the n/γ TCC spectra are composed of the n-n, γ-γ, n-γ and γ-n coincidence. (authors)

[en] Time correlation coincidence spectra measurement between of fission neutrons and gamma rays is a useful technique in searching and identifying fissionable materials. Some characteristics of the spectrum are correlative to the mass and isotope abundance of measured fissionable materials. This work simulates ²⁵²Cf spontaneous fission n/γ time-of-flight spectra measured with liquid scintillator detector, and obtains the time correlation coincidence spectra, the work laid a sound foundation of measuring uranium and plutonium materials. (authors)

[en] Objective: It is an evaluation of plain film, CT and MRI in the diagnosis of osteosarcoma. Method: The plain film, CT and MRI were retrospectively studied in 11 cases of osteosarcoma, and all the cases were confirmed with pathology. Result: In all cases the basic appearance of osteosarcoma was well revealed in plain film. Accurate preoperative diagnosis was made in 9 cases out of 11, while misdiagnosis was found in the rest two. In 4 cases, bone destruction and tumor bone were better demonstrated in CT than in plain film. In 5 cases, early stage bone destruction, adjacent soft tissue involvement and edema were best showed in MRI. Conclusion: Plain film is the basic modality and first choice of examination for osteosarcoma. CT and MRI are very helpful in staging and further investigations

[en] This paper introduced a method on remote control of DART spectrometer and data Acquisition and dynamic send of the results through Internet by using the JOB function of MEASTRO 32 software and a software programmed with VB. This gave an idea to realize the special networked measurement of spectrometer without the developed tool kit

[en] Background: Nuclear materials especially highly enriched uranium materials attract more and more attentions, and increasing methods and technical means are used to detect its information of mass and enrichment. Purpose: In order to solve the key technique problem of measuring the mass and enrichment of highly enriched uranium materials in the heavy shielded containers, a novel trial method was proposed in the paper: Methods: Time correlation coincidence method was implemented by using 14-MeV neutrons and continuous spectrum neutrons obtained by moderating 14-MeV neutrons to interrogate uranium materials inside of lead container with different mass and enrichment. Results: Within the certain range of low enrichment, the relation of different uranium samples mass of same enrichment was linear, and so was the relation of different uranium samples enrichment of same mass. Conclusion: Time correlation coincidence method might be an effective solution to measure the mass and enrichment of uranium materials in the heavy shielded container in the future. (authors)

[en] Since the establishment of IAEA in 1957, after more than half a century of development, the international nuclear safeguards system has gradually established a relatively perfect verification and safeguards regulation. Under the supervision and mediation of IAEA, the nuclear safeguards system has played an important role in resolving international issues such as denuclearization in Ukraine, nuclear crisis in Libya, Iran and North Korea. However, a series of radical actions such as the recent unilateral withdrawal of the U. S. from the Iran Nuclear Deal and the Intermediate-Range Nuclear Forces Treaty have had a serious impact on the current international nuclear safeguards system. This article analyzed and discussed the impact of the U. S. actions on the current international nuclear safeguard system and the possible impact in the future. (authors)

[en] Objective: To assess the clinical and MR features of vertebrobasilar dolichoectasia (VBD). Methods: The clinical records of 28 patients with diagnosis of VBD from March 2006 through March 2012 in our hospital were analyzed retrospectively. All of the patients underwent MRI and magnetic resonance angiography (MRA). Results: The patients suffered from cerebral infarction (13), brainstem compression (7), cranial nerve compression (5), cerebral hemorrhage (5), or hydrocephalus (2). There were 2 types of VBD: simple (n = 23) and saddle (n = 5). In all patients, the maximum diameters of the basilar and/or vertebral arteries were greater than 4.5 mm with the greatest diameter of 8.3 mm. of 28 patients, the tortuous basilar arteries coursed from left to right in 19 and from right to left in 9. Conclusions: The clinical manifestations of VBD are variable.MRI and MRA are valuable for diagnosing VBD. (authors)

[en] A prototype equipment composed of a NaI(Tl) detector and a small digit gamma-ray spectrometer for on-line monitoring of ⁸⁵Kr was designed and set up, and a set of corresponding software was developed. The equipment has remote control and alarm functions, and it can remotely acquire, analyze and transfer data, work at the continuous or intermittent mode. The equipment working at the intermittent mode is more sensitive than working at the continuous mode. In laboratory, when the measurement time is 1200 s, the detection limit of the equipment for ⁸⁵Kr is 3.4 x 10⁴ Bq/m³, and the judging limit is 1.7 x 10⁴ Bq/m³. When the measurement time is 1200 s, the gas pressure in the measurement container is more than 417 kPa, and the threshold value of alarm is set to be the detection limit, the equipment can work well, and the rates of both misinformation and failure are less than 0.1% for ⁸⁵Kr concentration of more than 8.1 x 10⁴ Bq/m³. (authors)

[en] The age of uranium samples are measured through the radioactivity ratio of ²¹⁴Bi/²³⁴U by gamma spectrometry. The principle of measurement for radioactivity ratio of ²³⁴U/²³⁵U, ²³⁵U/²³⁸U and ²¹⁴Bi/²³⁸U using intrinsic efficiency calibration is discussed. The measurement is a nondestructive assay method for uranium age-dating by gamma spectrometry which is applicable to materials in any physical form and geometrical shape. Two different physical form and geometrical shape samples are measured and investigated,one is U₃O₈ powder,the other is uranyl nitrate.The measurement results are 27.25 and 18.00 a respectively. For the uranyl nitrate sample, the relative standard deviation of highly enriched uranium (HEU) age determination is less than 5% between the measured and declared age. (authors)

[en] Objective: To investigate the spiral CT manifestations of malignant ovarian tumor's. Methods: Spiral CT findings in 100 cases of ovarian malignant tumor's proved by operation and pathology were analyzed retrospectively and compared with surgical and pathological fingdings. Results: (1) Ovarian epithelial tumors were seen in 88 cases (88%), presenting with a cystic mass with solid components (79.5%), and ascites, peritoneal or omental dissemination and metastatic lymphadenopathy were commonly revealed as well. (2) Ovarian sex cord stromal tumors were found in 5 cases (5%) > And in 80% of cases the tumors were unilateral and manifested a mass with cystic and parenchymal components. (3) Ovarian germ cell tumors were diagnosed in 7 cases (7%). The tumor's were all unilateral and solid mass in most cases (71.4%). Conclusion: Spiral CT is a valuable imaging modality in the diagnosis of primary malignant ovarian tumors. (authors)